Deployment Guide ================ ----------------------- Hardware Considerations ----------------------- Swift is designed to run on commodity hardware. At Rackspace, our storage servers are currently running fairly generic 4U servers with 24 2T SATA drives and 8 cores of processing power. RAID on the storage drives is not required and not recommended. Swift's disk usage pattern is the worst case possible for RAID, and performance degrades very quickly using RAID 5 or 6. ------------------ Deployment Options ------------------ The Swift services run completely autonomously, which provides for a lot of flexibility when architecting the hardware deployment for Swift. The 4 main services are: #. Proxy Services #. Object Services #. Container Services #. Account Services The Proxy Services are more CPU and network I/O intensive. If you are using 10g networking to the proxy, or are terminating SSL traffic at the proxy, greater CPU power will be required. The Object, Container, and Account Services (Storage Services) are more disk and network I/O intensive. The easiest deployment is to install all services on each server. There is nothing wrong with doing this, as it scales each service out horizontally. At Rackspace, we put the Proxy Services on their own servers and all of the Storage Services on the same server. This allows us to send 10g networking to the proxy and 1g to the storage servers, and keep load balancing to the proxies more manageable. Storage Services scale out horizontally as storage servers are added, and we can scale overall API throughput by adding more Proxies. If you need more throughput to either Account or Container Services, they may each be deployed to their own servers. For example you might use faster (but more expensive) SAS or even SSD drives to get faster disk I/O to the databases. A high-availability (HA) deployment of Swift requires that multiple proxy servers are deployed and requests are load-balanced between them. Each proxy server instance is stateless and able to respond to requests for the entire cluster. Load balancing and network design is left as an exercise to the reader, but this is a very important part of the cluster, so time should be spent designing the network for a Swift cluster. --------------------- Web Front End Options --------------------- Swift comes with an integral web front end. However, it can also be deployed as a request processor of an Apache2 using mod_wsgi as described in :doc:`Apache Deployment Guide `. .. _ring-preparing: ------------------ Preparing the Ring ------------------ The first step is to determine the number of partitions that will be in the ring. We recommend that there be a minimum of 100 partitions per drive to insure even distribution across the drives. A good starting point might be to figure out the maximum number of drives the cluster will contain, and then multiply by 100, and then round up to the nearest power of two. For example, imagine we are building a cluster that will have no more than 5,000 drives. That would mean that we would have a total number of 500,000 partitions, which is pretty close to 2^19, rounded up. It is also a good idea to keep the number of partitions small (relatively). The more partitions there are, the more work that has to be done by the replicators and other backend jobs and the more memory the rings consume in process. The goal is to find a good balance between small rings and maximum cluster size. The next step is to determine the number of replicas to store of the data. Currently it is recommended to use 3 (as this is the only value that has been tested). The higher the number, the more storage that is used but the less likely you are to lose data. It is also important to determine how many zones the cluster should have. It is recommended to start with a minimum of 5 zones. You can start with fewer, but our testing has shown that having at least five zones is optimal when failures occur. We also recommend trying to configure the zones at as high a level as possible to create as much isolation as possible. Some example things to take into consideration can include physical location, power availability, and network connectivity. For example, in a small cluster you might decide to split the zones up by cabinet, with each cabinet having its own power and network connectivity. The zone concept is very abstract, so feel free to use it in whatever way best isolates your data from failure. Each zone exists in a region. A region is also an abstract concept that may be used to distinguish between geographically separated areas as well as can be used within same datacenter. Regions and zones are referenced by a positive integer. You can now start building the ring with:: swift-ring-builder create This will start the ring build process creating the with 2^ partitions. is the time in hours before a specific partition can be moved in succession (24 is a good value for this). Devices can be added to the ring with:: swift-ring-builder add rz-:/_ This will add a device to the ring where is the name of the builder file that was created previously, is the number of the region the zone is in, is the number of the zone this device is in, is the ip address of the server the device is in, is the port number that the server is running on, is the name of the device on the server (for example: sdb1), is a string of metadata for the device (optional), and is a float weight that determines how many partitions are put on the device relative to the rest of the devices in the cluster (a good starting point is 100.0 x TB on the drive).Add each device that will be initially in the cluster. Once all of the devices are added to the ring, run:: swift-ring-builder rebalance This will distribute the partitions across the drives in the ring. It is important whenever making changes to the ring to make all the changes required before running rebalance. This will ensure that the ring stays as balanced as possible, and as few partitions are moved as possible. The above process should be done to make a ring for each storage service (Account, Container and Object). The builder files will be needed in future changes to the ring, so it is very important that these be kept and backed up. The resulting .tar.gz ring file should be pushed to all of the servers in the cluster. For more information about building rings, running swift-ring-builder with no options will display help text with available commands and options. More information on how the ring works internally can be found in the :doc:`Ring Overview `. .. _server-per-port-configuration: ------------------------------- Running object-servers Per Disk ------------------------------- The lack of true asynchronous file I/O on Linux leaves the object-server workers vulnerable to misbehaving disks. Because any object-server worker can service a request for any disk, and a slow I/O request blocks the eventlet hub, a single slow disk can impair an entire storage node. This also prevents object servers from fully utilizing all their disks during heavy load. Another way to get full I/O isolation is to give each disk on a storage node a different port in the storage policy rings. Then set the :ref:`servers_per_port ` option in the object-server config. NOTE: while the purpose of this config setting is to run one or more object-server worker processes per *disk*, the implementation just runs object-servers per unique port of local devices in the rings. The deployer must combine this option with appropriately-configured rings to benefit from this feature. Here's an example (abbreviated) old-style ring (2 node cluster with 2 disks each):: Devices: id region zone ip address port replication ip replication port name 0 1 1 1.1.0.1 6200 1.1.0.1 6200 d1 1 1 1 1.1.0.1 6200 1.1.0.1 6200 d2 2 1 2 1.1.0.2 6200 1.1.0.2 6200 d3 3 1 2 1.1.0.2 6200 1.1.0.2 6200 d4 And here's the same ring set up for `servers_per_port`:: Devices: id region zone ip address port replication ip replication port name 0 1 1 1.1.0.1 6200 1.1.0.1 6200 d1 1 1 1 1.1.0.1 6201 1.1.0.1 6201 d2 2 1 2 1.1.0.2 6200 1.1.0.2 6200 d3 3 1 2 1.1.0.2 6201 1.1.0.2 6201 d4 When migrating from normal to `servers_per_port`, perform these steps in order: #. Upgrade Swift code to a version capable of doing `servers_per_port`. #. Enable `servers_per_port` with a > 0 value #. Restart `swift-object-server` processes with a SIGHUP. At this point, you will have the `servers_per_port` number of `swift-object-server` processes serving all requests for all disks on each node. This preserves availability, but you should perform the next step as quickly as possible. #. Push out new rings that actually have different ports per disk on each server. One of the ports in the new ring should be the same as the port used in the old ring ("6200" in the example above). This will cover existing proxy-server processes who haven't loaded the new ring yet. They can still talk to any storage node regardless of whether or not that storage node has loaded the ring and started object-server processes on the new ports. If you do not run a separate object-server for replication, then this setting must be available to the object-replicator and object-reconstructor (i.e. appear in the [DEFAULT] config section). .. _general-service-configuration: ----------------------------- General Service Configuration ----------------------------- Most Swift services fall into two categories. Swift's wsgi servers and background daemons. For more information specific to the configuration of Swift's wsgi servers with paste deploy see :ref:`general-server-configuration`. Configuration for servers and daemons can be expressed together in the same file for each type of server, or separately. If a required section for the service trying to start is missing there will be an error. The sections not used by the service are ignored. Consider the example of an object storage node. By convention, configuration for the object-server, object-updater, object-replicator, object-auditor, and object-reconstructor exist in a single file ``/etc/swift/object-server.conf``:: [DEFAULT] reclaim_age = 604800 [pipeline:main] pipeline = object-server [app:object-server] use = egg:swift#object [object-replicator] [object-updater] [object-auditor] Swift services expect a configuration path as the first argument:: $ swift-object-auditor Usage: swift-object-auditor CONFIG [options] Error: missing config path argument If you omit the object-auditor section this file could not be used as the configuration path when starting the ``swift-object-auditor`` daemon:: $ swift-object-auditor /etc/swift/object-server.conf Unable to find object-auditor config section in /etc/swift/object-server.conf If the configuration path is a directory instead of a file all of the files in the directory with the file extension ".conf" will be combined to generate the configuration object which is delivered to the Swift service. This is referred to generally as "directory based configuration". Directory based configuration leverages ConfigParser's native multi-file support. Files ending in ".conf" in the given directory are parsed in lexicographical order. Filenames starting with '.' are ignored. A mixture of file and directory configuration paths is not supported - if the configuration path is a file only that file will be parsed. The Swift service management tool ``swift-init`` has adopted the convention of looking for ``/etc/swift/{type}-server.conf.d/`` if the file ``/etc/swift/{type}-server.conf`` file does not exist. When using directory based configuration, if the same option under the same section appears more than once in different files, the last value parsed is said to override previous occurrences. You can ensure proper override precedence by prefixing the files in the configuration directory with numerical values.:: /etc/swift/ default.base object-server.conf.d/ 000_default.conf -> ../default.base 001_default-override.conf 010_server.conf 020_replicator.conf 030_updater.conf 040_auditor.conf You can inspect the resulting combined configuration object using the ``swift-config`` command line tool .. _general-server-configuration: ---------------------------- General Server Configuration ---------------------------- Swift uses paste.deploy (http://pythonpaste.org/deploy/) to manage server configurations. Default configuration options are set in the `[DEFAULT]` section, and any options specified there can be overridden in any of the other sections BUT ONLY BY USING THE SYNTAX ``set option_name = value``. This is the unfortunate way paste.deploy works and I'll try to explain it in full. First, here's an example paste.deploy configuration file:: [DEFAULT] name1 = globalvalue name2 = globalvalue name3 = globalvalue set name4 = globalvalue [pipeline:main] pipeline = myapp [app:myapp] use = egg:mypkg#myapp name2 = localvalue set name3 = localvalue set name5 = localvalue name6 = localvalue The resulting configuration that myapp receives is:: global {'__file__': '/etc/mypkg/wsgi.conf', 'here': '/etc/mypkg', 'name1': 'globalvalue', 'name2': 'globalvalue', 'name3': 'localvalue', 'name4': 'globalvalue', 'name5': 'localvalue', 'set name4': 'globalvalue'} local {'name6': 'localvalue'} So, `name1` got the global value which is fine since it's only in the `DEFAULT` section anyway. `name2` got the global value from `DEFAULT` even though it appears to be overridden in the `app:myapp` subsection. This is just the unfortunate way paste.deploy works (at least at the time of this writing.) `name3` got the local value from the `app:myapp` subsection because it is using the special paste.deploy syntax of ``set option_name = value``. So, if you want a default value for most app/filters but want to override it in one subsection, this is how you do it. `name4` got the global value from `DEFAULT` since it's only in that section anyway. But, since we used the ``set`` syntax in the `DEFAULT` section even though we shouldn't, notice we also got a ``set name4`` variable. Weird, but probably not harmful. `name5` got the local value from the `app:myapp` subsection since it's only there anyway, but notice that it is in the global configuration and not the local configuration. This is because we used the ``set`` syntax to set the value. Again, weird, but not harmful since Swift just treats the two sets of configuration values as one set anyway. `name6` got the local value from `app:myapp` subsection since it's only there, and since we didn't use the ``set`` syntax, it's only in the local configuration and not the global one. Though, as indicated above, there is no special distinction with Swift. That's quite an explanation for something that should be so much simpler, but it might be important to know how paste.deploy interprets configuration files. The main rule to remember when working with Swift configuration files is: .. note:: Use the ``set option_name = value`` syntax in subsections if the option is also set in the ``[DEFAULT]`` section. Don't get in the habit of always using the ``set`` syntax or you'll probably mess up your non-paste.deploy configuration files. -------------------- Common configuration -------------------- An example of common configuration file can be found at etc/swift.conf-sample The following configuration options are available: ========================== ========== ============================================= Option Default Description -------------------------- ---------- --------------------------------------------- max_header_size 8192 max_header_size is the max number of bytes in the utf8 encoding of each header. Using 8192 as default because eventlet use 8192 as max size of header line. This value may need to be increased when using identity v3 API tokens including more than 7 catalog entries. See also include_service_catalog in proxy-server.conf-sample (documented in overview_auth.rst). extra_header_count 0 By default the maximum number of allowed headers depends on the number of max allowed metadata settings plus a default value of 32 for regular http headers. If for some reason this is not enough (custom middleware for example) it can be increased with the extra_header_count constraint. auto_create_account_prefix . Prefix used when automatically creating accounts. ========================== ========== ============================================= --------------------------- Object Server Configuration --------------------------- An Example Object Server configuration can be found at etc/object-server.conf-sample in the source code repository. The following configuration sections are available: * :ref:`[DEFAULT] ` * `[object-server]`_ * `[object-replicator]`_ * `[object-reconstructor]`_ * `[object-updater]`_ * `[object-auditor]`_ * `[object-expirer]`_ .. _object-server-default-options: ********* [DEFAULT] ********* ================================ ========== ============================================ Option Default Description -------------------------------- ---------- -------------------------------------------- swift_dir /etc/swift Swift configuration directory devices /srv/node Parent directory of where devices are mounted mount_check true Whether or not check if the devices are mounted to prevent accidentally writing to the root device bind_ip 0.0.0.0 IP Address for server to bind to bind_port 6200 Port for server to bind to keep_idle 600 Value to set for socket TCP_KEEPIDLE bind_timeout 30 Seconds to attempt bind before giving up backlog 4096 Maximum number of allowed pending connections workers auto Override the number of pre-forked workers that will accept connections. If set it should be an integer, zero means no fork. If unset, it will try to default to the number of effective cpu cores and fallback to one. Increasing the number of workers helps slow filesystem operations in one request from negatively impacting other requests, but only the :ref:`servers_per_port ` option provides complete I/O isolation with no measurable overhead. servers_per_port 0 If each disk in each storage policy ring has unique port numbers for its "ip" value, you can use this setting to have each object-server worker only service requests for the single disk matching the port in the ring. The value of this setting determines how many worker processes run for each port (disk) in the ring. If you have 24 disks per server, and this setting is 4, then each storage node will have 1 + (24 * 4) = 97 total object-server processes running. This gives complete I/O isolation, drastically reducing the impact of slow disks on storage node performance. The object-replicator and object-reconstructor need to see this setting too, so it must be in the [DEFAULT] section. See :ref:`server-per-port-configuration`. max_clients 1024 Maximum number of clients one worker can process simultaneously (it will actually accept(2) N + 1). Setting this to one (1) will only handle one request at a time, without accepting another request concurrently. disable_fallocate false Disable "fast fail" fallocate checks if the underlying filesystem does not support it. log_name swift Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory log_max_line_length 0 Caps the length of log lines to the value given; no limit if set to 0, the default. log_custom_handlers None Comma-separated list of functions to call to setup custom log handlers. log_udp_host Override log_address log_udp_port 514 UDP log port log_statsd_host None Enables StatsD logging; IPv4/IPv6 address or a hostname. If a hostname resolves to an IPv4 and IPv6 address, the IPv4 address will be used. log_statsd_port 8125 log_statsd_default_sample_rate 1.0 log_statsd_sample_rate_factor 1.0 log_statsd_metric_prefix eventlet_debug false If true, turn on debug logging for eventlet fallocate_reserve 1% You can set fallocate_reserve to the number of bytes or percentage of disk space you'd like fallocate to reserve, whether there is space for the given file size or not. Percentage will be used if the value ends with a '%'. This is useful for systems that behave badly when they completely run out of space; you can make the services pretend they're out of space early. conn_timeout 0.5 Time to wait while attempting to connect to another backend node. node_timeout 3 Time to wait while sending each chunk of data to another backend node. client_timeout 60 Time to wait while receiving each chunk of data from a client or another backend node network_chunk_size 65536 Size of chunks to read/write over the network disk_chunk_size 65536 Size of chunks to read/write to disk container_update_timeout 1 Time to wait while sending a container update on object update. reclaim_age 604800 Time elapsed in seconds before the tombstone file representing a deleted object can be reclaimed. This is the maximum window for your consistency engine. If a node that was disconnected from the cluster because of a fault is reintroduced into the cluster after this window without having its data purged it will result in dark data. This setting should be consistent across all object services. nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. ================================ ========== ============================================ .. _object-server-options: *************** [object-server] *************** ================================== ====================== =============================================== Option Default Description ---------------------------------- ---------------------- ----------------------------------------------- use paste.deploy entry point for the object server. For most cases, this should be `egg:swift#object`. set log_name object-server Label used when logging set log_facility LOG_LOCAL0 Syslog log facility set log_level INFO Logging level set log_requests True Whether or not to log each request set log_address /dev/log Logging directory user swift User to run as max_upload_time 86400 Maximum time allowed to upload an object slow 0 If > 0, Minimum time in seconds for a PUT or DELETE request to complete. This is only useful to simulate slow devices during testing and development. mb_per_sync 512 On PUT requests, sync file every n MB keep_cache_size 5242880 Largest object size to keep in buffer cache keep_cache_private false Allow non-public objects to stay in kernel's buffer cache allowed_headers Content-Disposition, Comma separated list of headers Content-Encoding, that can be set in metadata on an object. X-Delete-At, This list is in addition to X-Object-Manifest, X-Object-Meta-* headers and cannot include X-Static-Large-Object Content-Type, etag, Content-Length, or deleted Cache-Control, Content-Language, Expires, X-Robots-Tag replication_server Configure parameter for creating specific server. To handle all verbs, including replication verbs, do not specify "replication_server" (this is the default). To only handle replication, set to a True value (e.g. "True" or "1"). To handle only non-replication verbs, set to "False". Unless you have a separate replication network, you should not specify any value for "replication_server". replication_concurrency 4 Set to restrict the number of concurrent incoming SSYNC requests; set to 0 for unlimited replication_concurrency_per_device 1 Set to restrict the number of concurrent incoming SSYNC requests per device; set to 0 for unlimited requests per devices. This can help control I/O to each device. This does not override replication_concurrency described above, so you may need to adjust both parameters depending on your hardware or network capacity. replication_lock_timeout 15 Number of seconds to wait for an existing replication device lock before giving up. replication_failure_threshold 100 The number of subrequest failures before the replication_failure_ratio is checked replication_failure_ratio 1.0 If the value of failures / successes of SSYNC subrequests exceeds this ratio, the overall SSYNC request will be aborted splice no Use splice() for zero-copy object GETs. This requires Linux kernel version 3.0 or greater. If you set "splice = yes" but the kernel does not support it, error messages will appear in the object server logs at startup, but your object servers should continue to function. nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. eventlet_tpool_num_threads auto The number of threads in eventlet's thread pool. Most IO will occur in the object server's main thread, but certain "heavy" IO operations will occur in separate IO threads, managed by eventlet. The default value is auto, whose actual value is dependent on the servers_per_port value. If servers_per_port is zero then it uses eventlet's default (currently 20 threads). If the servers_per_port is nonzero then it'll only use 1 thread per process. This value can be overridden with an integer value. ================================== ====================== =============================================== ******************* [object-replicator] ******************* =========================== ======================== ================================ Option Default Description --------------------------- ------------------------ -------------------------------- log_name object-replicator Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory daemonize yes Whether or not to run replication as a daemon interval 30 Time in seconds to wait between replication passes concurrency 1 Number of replication jobs to run per worker process replicator_workers 0 Number of worker processes to use. No matter how big this number is, at most one worker per disk will be used. The default value of 0 means no forking; all work is done in the main process. sync_method rsync The sync method to use; default is rsync but you can use ssync to try the EXPERIMENTAL all-swift-code-no-rsync-callouts method. Once ssync is verified as or better than, rsync, we plan to deprecate rsync so we can move on with more features for replication. rsync_timeout 900 Max duration of a partition rsync rsync_bwlimit 0 Bandwidth limit for rsync in kB/s. 0 means unlimited. rsync_io_timeout 30 Timeout value sent to rsync --timeout and --contimeout options rsync_compress no Allow rsync to compress data which is transmitted to destination node during sync. However, this is applicable only when destination node is in a different region than the local one. NOTE: Objects that are already compressed (for example: .tar.gz, .mp3) might slow down the syncing process. stats_interval 300 Interval in seconds between logging replication statistics handoffs_first false If set to True, partitions that are not supposed to be on the node will be replicated first. The default setting should not be changed, except for extreme situations. handoff_delete auto By default handoff partitions will be removed when it has successfully replicated to all the canonical nodes. If set to an integer n, it will remove the partition if it is successfully replicated to n nodes. The default setting should not be changed, except for extreme situations. node_timeout DEFAULT or 10 Request timeout to external services. This uses what's set here, or what's set in the DEFAULT section, or 10 (though other sections use 3 as the final default). http_timeout 60 Max duration of an http request. This is for REPLICATE finalization calls and so should be longer than node_timeout. lockup_timeout 1800 Attempts to kill all workers if nothing replicates for lockup_timeout seconds rsync_module {replication_ip}::object Format of the rsync module where the replicator will send data. The configuration value can include some variables that will be extracted from the ring. Variables must follow the format {NAME} where NAME is one of: ip, port, replication_ip, replication_port, region, zone, device, meta. See etc/rsyncd.conf-sample for some examples. rsync_error_log_line_length 0 Limits how long rsync error log lines are ring_check_interval 15 Interval for checking new ring file recon_cache_path /var/cache/swift Path to recon cache nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. =========================== ======================== ================================ ********************** [object-reconstructor] ********************** =========================== ======================== ================================ Option Default Description --------------------------- ------------------------ -------------------------------- log_name object-reconstructor Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory daemonize yes Whether or not to run reconstruction as a daemon interval 30 Time in seconds to wait between reconstruction passes reconstructor_workers 0 Maximum number of worker processes to spawn. Each worker will handle a subset of devices. Devices will be assigned evenly among the workers so that workers cycle at similar intervals (which can lead to fewer workers than requested). You can not have more workers than devices. If you have no devices only a single worker is spawned. concurrency 1 Number of reconstruction threads to spawn per reconstructor process. stats_interval 300 Interval in seconds between logging reconstruction statistics handoffs_only false The handoffs_only mode option is for special case emergency situations during rebalance such as disk full in the cluster. This option SHOULD NOT BE CHANGED, except for extreme situations. When handoffs_only mode is enabled the reconstructor will *only* revert fragments from handoff nodes to primary nodes and will not sync primary nodes with neighboring primary nodes. This will force the reconstructor to sync and delete handoffs' fragments more quickly and minimize the time of the rebalance by limiting the number of rebuilds. The handoffs_only option is only for temporary use and should be disabled as soon as the emergency situation has been resolved. node_timeout DEFAULT or 10 Request timeout to external services. The value used is the value set in this section, or the value set in the DEFAULT section, or 10. http_timeout 60 Max duration of an http request. This is for REPLICATE finalization calls and so should be longer than node_timeout. lockup_timeout 1800 Attempts to kill all threads if no fragment has been reconstructed for lockup_timeout seconds. ring_check_interval 15 Interval for checking new ring file recon_cache_path /var/cache/swift Path to recon cache nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. =========================== ======================== ================================ **************** [object-updater] **************** =================== =================== ========================================== Option Default Description ------------------- ------------------- ------------------------------------------ log_name object-updater Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory interval 300 Minimum time for a pass to take updater_workers 1 Number of worker processes concurrency 8 Number of updates to run concurrently in each worker process node_timeout DEFAULT or 10 Request timeout to external services. This uses what's set here, or what's set in the DEFAULT section, or 10 (though other sections use 3 as the final default). objects_per_second 50 Maximum objects updated per second. Should be tuned according to individual system specs. 0 is unlimited. slowdown 0.01 Time in seconds to wait between objects. Deprecated in favor of objects_per_second. report_interval 300 Interval in seconds between logging statistics about the current update pass. recon_cache_path /var/cache/swift Path to recon cache nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. =================== =================== ========================================== **************** [object-auditor] **************** =========================== =================== ========================================== Option Default Description --------------------------- ------------------- ------------------------------------------ log_name object-auditor Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory log_time 3600 Frequency of status logs in seconds. interval 30 Time in seconds to wait between auditor passes disk_chunk_size 65536 Size of chunks read during auditing files_per_second 20 Maximum files audited per second per auditor process. Should be tuned according to individual system specs. 0 is unlimited. bytes_per_second 10000000 Maximum bytes audited per second per auditor process. Should be tuned according to individual system specs. 0 is unlimited. concurrency 1 The number of parallel processes to use for checksum auditing. zero_byte_files_per_second 50 object_size_stats recon_cache_path /var/cache/swift Path to recon cache rsync_tempfile_timeout auto Time elapsed in seconds before rsync tempfiles will be unlinked. Config value of "auto" try to use object-replicator's rsync_timeout + 900 or fallback to 86400 (1 day). nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. =========================== =================== ========================================== **************** [object-expirer] **************** ============================= =============================== ========================================== Option Default Description ----------------------------- ------------------------------- ------------------------------------------ log_name object-expirer Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory interval 300 Time in seconds to wait between expirer passes report_interval 300 Frequency of status logs in seconds. concurrency 1 Level of concurrency to use to do the work, this value must be set to at least 1 expiring_objects_account_name expiring_objects name for legacy expirer task queue dequeue_from_legacy False This service will look for jobs on the legacy expirer task queue. processes 0 How many parts to divide the legacy work into, one part per process that will be doing the work. When set 0 means that a single legacy process will be doing all the work. This can only be used in conjunction with `dequeue_from_legacy`. process 0 Which of the parts a particular legacy process will work on. It is "zero based", if you want to use 3 processes, you should run processes with process set to 0, 1, and 2. This can only be used in conjunction with `dequeue_from_legacy`. reclaim_age 604800 How long an un-processable expired object marker will be retried before it is abandoned. It is not coupled with the tombstone reclaim age in the consistency engine. request_tries 3 The number of times the expirer's internal client will attempt any given request in the event of failure recon_cache_path /var/cache/swift Path to recon cache nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. ============================= =============================== ========================================== ------------------------------ Container Server Configuration ------------------------------ An example Container Server configuration can be found at etc/container-server.conf-sample in the source code repository. The following configuration sections are available: * :ref:`[DEFAULT] ` * `[container-server]`_ * `[container-replicator]`_ * `[container-updater]`_ * `[container-auditor]`_ .. _container_server_default_options: ********* [DEFAULT] ********* =============================== ========== ============================================ Option Default Description ------------------------------- ---------- -------------------------------------------- swift_dir /etc/swift Swift configuration directory devices /srv/node Parent directory of where devices are mounted mount_check true Whether or not check if the devices are mounted to prevent accidentally writing to the root device bind_ip 0.0.0.0 IP Address for server to bind to bind_port 6201 Port for server to bind to keep_idle 600 Value to set for socket TCP_KEEPIDLE bind_timeout 30 Seconds to attempt bind before giving up backlog 4096 Maximum number of allowed pending connections workers auto Override the number of pre-forked workers that will accept connections. If set it should be an integer, zero means no fork. If unset, it will try to default to the number of effective cpu cores and fallback to one. Increasing the number of workers may reduce the possibility of slow file system operations in one request from negatively impacting other requests. See :ref:`general-service-tuning`. max_clients 1024 Maximum number of clients one worker can process simultaneously (it will actually accept(2) N + 1). Setting this to one (1) will only handle one request at a time, without accepting another request concurrently. user swift User to run as disable_fallocate false Disable "fast fail" fallocate checks if the underlying filesystem does not support it. log_name swift Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory log_max_line_length 0 Caps the length of log lines to the value given; no limit if set to 0, the default. log_custom_handlers None Comma-separated list of functions to call to setup custom log handlers. log_udp_host Override log_address log_udp_port 514 UDP log port log_statsd_host None Enables StatsD logging; IPv4/IPv6 address or a hostname. If a hostname resolves to an IPv4 and IPv6 address, the IPv4 address will be used. log_statsd_port 8125 log_statsd_default_sample_rate 1.0 log_statsd_sample_rate_factor 1.0 log_statsd_metric_prefix eventlet_debug false If true, turn on debug logging for eventlet fallocate_reserve 1% You can set fallocate_reserve to the number of bytes or percentage of disk space you'd like fallocate to reserve, whether there is space for the given file size or not. Percentage will be used if the value ends with a '%'. This is useful for systems that behave badly when they completely run out of space; you can make the services pretend they're out of space early. db_preallocation off If you don't mind the extra disk space usage in overhead, you can turn this on to preallocate disk space with SQLite databases to decrease fragmentation. nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. =============================== ========== ============================================ ****************** [container-server] ****************** ============================== ================ ======================================== Option Default Description ------------------------------ ---------------- ---------------------------------------- use paste.deploy entry point for the container server. For most cases, this should be `egg:swift#container`. set log_name container-server Label used when logging set log_facility LOG_LOCAL0 Syslog log facility set log_level INFO Logging level set log_requests True Whether or not to log each request set log_address /dev/log Logging directory node_timeout 3 Request timeout to external services conn_timeout 0.5 Connection timeout to external services allow_versions false Enable/Disable object versioning feature replication_server Configure parameter for creating specific server. To handle all verbs, including replication verbs, do not specify "replication_server" (this is the default). To only handle replication, set to a True value (e.g. "True" or "1"). To handle only non-replication verbs, set to "False". Unless you have a separate replication network, you should not specify any value for "replication_server". nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. ============================== ================ ======================================== ********************** [container-replicator] ********************** ==================== =========================== ============================= Option Default Description -------------------- --------------------------- ----------------------------- log_name container-replicator Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory per_diff 1000 Maximum number of database rows that will be sync'd in a single HTTP replication request. Databases with less than or equal to this number of differing rows will always be sync'd using an HTTP replication request rather than using rsync. max_diffs 100 Maximum number of HTTP replication requests attempted on each replication pass for any one container. This caps how long the replicator will spend trying to sync a given database per pass so the other databases don't get starved. concurrency 8 Number of replication workers to spawn interval 30 Time in seconds to wait between replication passes databases_per_second 50 Maximum databases to process per second. Should be tuned according to individual system specs. 0 is unlimited. node_timeout 10 Request timeout to external services conn_timeout 0.5 Connection timeout to external services reclaim_age 604800 Time elapsed in seconds before a container can be reclaimed rsync_module {replication_ip}::container Format of the rsync module where the replicator will send data. The configuration value can include some variables that will be extracted from the ring. Variables must follow the format {NAME} where NAME is one of: ip, port, replication_ip, replication_port, region, zone, device, meta. See etc/rsyncd.conf-sample for some examples. rsync_compress no Allow rsync to compress data which is transmitted to destination node during sync. However, this is applicable only when destination node is in a different region than the local one. NOTE: Objects that are already compressed (for example: .tar.gz, mp3) might slow down the syncing process. recon_cache_path /var/cache/swift Path to recon cache nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. ==================== =========================== ============================= ******************* [container-updater] ******************* ======================== ================= ================================== Option Default Description ------------------------ ----------------- ---------------------------------- log_name container-updater Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory interval 300 Minimum time for a pass to take concurrency 4 Number of updater workers to spawn node_timeout 3 Request timeout to external services conn_timeout 0.5 Connection timeout to external services containers_per_second 50 Maximum containers updated per second. Should be tuned according to individual system specs. 0 is unlimited. slowdown 0.01 Time in seconds to wait between containers. Deprecated in favor of containers_per_second. account_suppression_time 60 Seconds to suppress updating an account that has generated an error (timeout, not yet found, etc.) recon_cache_path /var/cache/swift Path to recon cache nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. ======================== ================= ================================== ******************* [container-auditor] ******************* ===================== ================= ======================================= Option Default Description --------------------- ----------------- --------------------------------------- log_name container-auditor Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory interval 1800 Minimum time for a pass to take containers_per_second 200 Maximum containers audited per second. Should be tuned according to individual system specs. 0 is unlimited. recon_cache_path /var/cache/swift Path to recon cache nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. ===================== ================= ======================================= ---------------------------- Account Server Configuration ---------------------------- An example Account Server configuration can be found at etc/account-server.conf-sample in the source code repository. The following configuration sections are available: * :ref:`[DEFAULT] ` * `[account-server]`_ * `[account-replicator]`_ * `[account-auditor]`_ * `[account-reaper]`_ .. _account_server_default_options: ********* [DEFAULT] ********* =============================== ========== ============================================= Option Default Description ------------------------------- ---------- --------------------------------------------- swift_dir /etc/swift Swift configuration directory devices /srv/node Parent directory or where devices are mounted mount_check true Whether or not check if the devices are mounted to prevent accidentally writing to the root device bind_ip 0.0.0.0 IP Address for server to bind to bind_port 6202 Port for server to bind to keep_idle 600 Value to set for socket TCP_KEEPIDLE bind_timeout 30 Seconds to attempt bind before giving up backlog 4096 Maximum number of allowed pending connections workers auto Override the number of pre-forked workers that will accept connections. If set it should be an integer, zero means no fork. If unset, it will try to default to the number of effective cpu cores and fallback to one. Increasing the number of workers may reduce the possibility of slow file system operations in one request from negatively impacting other requests. See :ref:`general-service-tuning`. max_clients 1024 Maximum number of clients one worker can process simultaneously (it will actually accept(2) N + 1). Setting this to one (1) will only handle one request at a time, without accepting another request concurrently. user swift User to run as db_preallocation off If you don't mind the extra disk space usage in overhead, you can turn this on to preallocate disk space with SQLite databases to decrease fragmentation. disable_fallocate false Disable "fast fail" fallocate checks if the underlying filesystem does not support it. log_name swift Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory log_max_line_length 0 Caps the length of log lines to the value given; no limit if set to 0, the default. log_custom_handlers None Comma-separated list of functions to call to setup custom log handlers. log_udp_host Override log_address log_udp_port 514 UDP log port log_statsd_host None Enables StatsD logging; IPv4/IPv6 address or a hostname. If a hostname resolves to an IPv4 and IPv6 address, the IPv4 address will be used. log_statsd_port 8125 log_statsd_default_sample_rate 1.0 log_statsd_sample_rate_factor 1.0 log_statsd_metric_prefix eventlet_debug false If true, turn on debug logging for eventlet fallocate_reserve 1% You can set fallocate_reserve to the number of bytes or percentage of disk space you'd like fallocate to reserve, whether there is space for the given file size or not. Percentage will be used if the value ends with a '%'. This is useful for systems that behave badly when they completely run out of space; you can make the services pretend they're out of space early. nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. =============================== ========== ============================================= **************** [account-server] **************** ============================= ============== ========================================== Option Default Description ----------------------------- -------------- ------------------------------------------ use Entry point for paste.deploy for the account server. For most cases, this should be `egg:swift#account`. set log_name account-server Label used when logging set log_facility LOG_LOCAL0 Syslog log facility set log_level INFO Logging level set log_requests True Whether or not to log each request set log_address /dev/log Logging directory replication_server Configure parameter for creating specific server. To handle all verbs, including replication verbs, do not specify "replication_server" (this is the default). To only handle replication, set to a True value (e.g. "True" or "1"). To handle only non-replication verbs, set to "False". Unless you have a separate replication network, you should not specify any value for "replication_server". nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. ============================= ============== ========================================== ******************** [account-replicator] ******************** ==================== ========================= =============================== Option Default Description -------------------- ------------------------- ------------------------------- log_name account-replicator Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory per_diff 1000 Maximum number of database rows that will be sync'd in a single HTTP replication request. Databases with less than or equal to this number of differing rows will always be sync'd using an HTTP replication request rather than using rsync. max_diffs 100 Maximum number of HTTP replication requests attempted on each replication pass for any one container. This caps how long the replicator will spend trying to sync a given database per pass so the other databases don't get starved. concurrency 8 Number of replication workers to spawn interval 30 Time in seconds to wait between replication passes databases_per_second 50 Maximum databases to process per second. Should be tuned according to individual system specs. 0 is unlimited. node_timeout 10 Request timeout to external services conn_timeout 0.5 Connection timeout to external services reclaim_age 604800 Time elapsed in seconds before an account can be reclaimed rsync_module {replication_ip}::account Format of the rsync module where the replicator will send data. The configuration value can include some variables that will be extracted from the ring. Variables must follow the format {NAME} where NAME is one of: ip, port, replication_ip, replication_port, region, zone, device, meta. See etc/rsyncd.conf-sample for some examples. rsync_compress no Allow rsync to compress data which is transmitted to destination node during sync. However, this is applicable only when destination node is in a different region than the local one. NOTE: Objects that are already compressed (for example: .tar.gz, mp3) might slow down the syncing process. recon_cache_path /var/cache/swift Path to recon cache nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. ==================== ========================= =============================== ***************** [account-auditor] ***************** ==================== ================ ======================================= Option Default Description -------------------- ---------------- --------------------------------------- log_name account-auditor Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory interval 1800 Minimum time for a pass to take accounts_per_second 200 Maximum accounts audited per second. Should be tuned according to individual system specs. 0 is unlimited. recon_cache_path /var/cache/swift Path to recon cache nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. ==================== ================ ======================================= **************** [account-reaper] **************** ================== =============== ========================================= Option Default Description ------------------ --------------- ----------------------------------------- log_name account-reaper Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_address /dev/log Logging directory concurrency 25 Number of replication workers to spawn interval 3600 Minimum time for a pass to take node_timeout 10 Request timeout to external services conn_timeout 0.5 Connection timeout to external services delay_reaping 0 Normally, the reaper begins deleting account information for deleted accounts immediately; you can set this to delay its work however. The value is in seconds, 2592000 = 30 days, for example. The sum of this value and the container-updater ``interval`` should be less than the account-replicator ``reclaim_age``. This ensures that once the account-reaper has deleted a container there is sufficient time for the container-updater to report to the account before the account DB is removed. reap_warn_after 2892000 If the account fails to be reaped due to a persistent error, the account reaper will log a message such as: Account has not been reaped since You can search logs for this message if space is not being reclaimed after you delete account(s). This is in addition to any time requested by delay_reaping. nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. ================== =============== ========================================= .. _proxy-server-config: -------------------------- Proxy Server Configuration -------------------------- An example Proxy Server configuration can be found at etc/proxy-server.conf-sample in the source code repository. The following configuration sections are available: * :ref:`[DEFAULT] ` * `[proxy-server]`_ * Individual sections for `Proxy middlewares`_ .. _proxy_server_default_options: ********* [DEFAULT] ********* ==================================== ======================== ======================================== Option Default Description ------------------------------------ ------------------------ ---------------------------------------- bind_ip 0.0.0.0 IP Address for server to bind to bind_port 80 Port for server to bind to keep_idle 600 Value to set for socket TCP_KEEPIDLE bind_timeout 30 Seconds to attempt bind before giving up backlog 4096 Maximum number of allowed pending connections swift_dir /etc/swift Swift configuration directory workers auto Override the number of pre-forked workers that will accept connections. If set it should be an integer, zero means no fork. If unset, it will try to default to the number of effective cpu cores and fallback to one. See :ref:`general-service-tuning`. max_clients 1024 Maximum number of clients one worker can process simultaneously (it will actually accept(2) N + 1). Setting this to one (1) will only handle one request at a time, without accepting another request concurrently. user swift User to run as cert_file Path to the ssl .crt. This should be enabled for testing purposes only. key_file Path to the ssl .key. This should be enabled for testing purposes only. cors_allow_origin List of origin hosts that are allowed for CORS requests in addition to what the container has set. strict_cors_mode True If True (default) then CORS requests are only allowed if their Origin header matches an allowed origin. Otherwise, any Origin is allowed. cors_expose_headers This is a list of headers that are included in the header Access-Control-Expose-Headers in addition to what the container has set. client_timeout 60 trans_id_suffix This optional suffix (default is empty) that would be appended to the swift transaction id allows one to easily figure out from which cluster that X-Trans-Id belongs to. This is very useful when one is managing more than one swift cluster. log_name swift Label used when logging log_facility LOG_LOCAL0 Syslog log facility log_level INFO Logging level log_headers False log_address /dev/log Logging directory log_max_line_length 0 Caps the length of log lines to the value given; no limit if set to 0, the default. log_custom_handlers None Comma separated list of functions to call to setup custom log handlers. log_udp_host Override log_address log_udp_port 514 UDP log port log_statsd_host None Enables StatsD logging; IPv4/IPv6 address or a hostname. If a hostname resolves to an IPv4 and IPv6 address, the IPv4 address will be used. log_statsd_port 8125 log_statsd_default_sample_rate 1.0 log_statsd_sample_rate_factor 1.0 log_statsd_metric_prefix eventlet_debug false If true, turn on debug logging for eventlet expose_info true Enables exposing configuration settings via HTTP GET /info. admin_key Key to use for admin calls that are HMAC signed. Default is empty, which will disable admin calls to /info. disallowed_sections swift.valid_api_versions Allows the ability to withhold sections from showing up in the public calls to /info. You can withhold subsections by separating the dict level with a ".". expiring_objects_container_divisor 86400 expiring_objects_account_name expiring_objects nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort) and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. ==================================== ======================== ======================================== ************** [proxy-server] ************** ====================================== =============== ===================================== Option Default Description -------------------------------------- --------------- ------------------------------------- use Entry point for paste.deploy for the proxy server. For most cases, this should be `egg:swift#proxy`. set log_name proxy-server Label used when logging set log_facility LOG_LOCAL0 Syslog log facility set log_level INFO Log level set log_headers True If True, log headers in each request set log_handoffs True If True, the proxy will log whenever it has to failover to a handoff node recheck_account_existence 60 Cache timeout in seconds to send memcached for account existence recheck_container_existence 60 Cache timeout in seconds to send memcached for container existence object_chunk_size 65536 Chunk size to read from object servers client_chunk_size 65536 Chunk size to read from clients memcache_servers 127.0.0.1:11211 Comma separated list of memcached servers ip:port or [ipv6addr]:port memcache_max_connections 2 Max number of connections to each memcached server per worker node_timeout 10 Request timeout to external services recoverable_node_timeout node_timeout Request timeout to external services for requests that, on failure, can be recovered from. For example, object GET. client_timeout 60 Timeout to read one chunk from a client conn_timeout 0.5 Connection timeout to external services error_suppression_interval 60 Time in seconds that must elapse since the last error for a node to be considered no longer error limited error_suppression_limit 10 Error count to consider a node error limited allow_account_management false Whether account PUTs and DELETEs are even callable account_autocreate false If set to 'true' authorized accounts that do not yet exist within the Swift cluster will be automatically created. max_containers_per_account 0 If set to a positive value, trying to create a container when the account already has at least this maximum containers will result in a 403 Forbidden. Note: This is a soft limit, meaning a user might exceed the cap for recheck_account_existence before the 403s kick in. max_containers_whitelist This is a comma separated list of account names that ignore the max_containers_per_account cap. rate_limit_after_segment 10 Rate limit the download of large object segments after this segment is downloaded. rate_limit_segments_per_sec 1 Rate limit large object downloads at this rate. request_node_count 2 * replicas Set to the number of nodes to contact for a normal request. You can use '* replicas' at the end to have it use the number given times the number of replicas for the ring being used for the request. swift_owner_headers up to the auth system in use, but usually indicates administrative responsibilities. sorting_method shuffle Storage nodes can be chosen at random (shuffle), by using timing measurements (timing), or by using an explicit match (affinity). Using timing measurements may allow for lower overall latency, while using affinity allows for finer control. In both the timing and affinity cases, equally-sorting nodes are still randomly chosen to spread load. This option may be overridden in a per-policy configuration section. timing_expiry 300 If the "timing" sorting_method is used, the timings will only be valid for the number of seconds configured by timing_expiry. concurrent_gets off Use replica count number of threads concurrently during a GET/HEAD and return with the first successful response. In the EC case, this parameter only affects an EC HEAD as an EC GET behaves differently. concurrency_timeout conn_timeout This parameter controls how long to wait before firing off the next concurrent_get thread. A value of 0 would we fully concurrent, any other number will stagger the firing of the threads. This number should be between 0 and node_timeout. The default is conn_timeout (0.5). nice_priority None Scheduling priority of server processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). The default does not modify priority. ionice_class None I/O scheduling class of server processes. I/O niceness class values are IOPRIO_CLASS_RT (realtime), IOPRIO_CLASS_BE (best-effort), and IOPRIO_CLASS_IDLE (idle). The default does not modify class and priority. Linux supports io scheduling priorities and classes since 2.6.13 with the CFQ io scheduler. Work only with ionice_priority. ionice_priority None I/O scheduling priority of server processes. I/O niceness priority is a number which goes from 0 to 7. The higher the value, the lower the I/O priority of the process. Work only with ionice_class. Ignored if IOPRIO_CLASS_IDLE is set. read_affinity None Specifies which backend servers to prefer on reads; used in conjunction with the sorting_method option being set to 'affinity'. Format is a comma separated list of affinity descriptors of the form =. The may be r for selecting nodes in region N or rz for selecting nodes in region N, zone M. The value should be a whole number that represents the priority to be given to the selection; lower numbers are higher priority. Default is empty, meaning no preference. This option may be overridden in a per-policy configuration section. write_affinity None Specifies which backend servers to prefer on writes. Format is a comma separated list of affinity descriptors of the form r for region N or rz for region N, zone M. Default is empty, meaning no preference. This option may be overridden in a per-policy configuration section. write_affinity_node_count 2 * replicas The number of local (as governed by the write_affinity setting) nodes to attempt to contact first on writes, before any non-local ones. The value should be an integer number, or use '* replicas' at the end to have it use the number given times the number of replicas for the ring being used for the request. This option may be overridden in a per-policy configuration section. write_affinity_handoff_delete_count auto The number of local (as governed by the write_affinity setting) handoff nodes to attempt to contact on deletion, in addition to primary nodes. Example: in geographically distributed deployment, If replicas=3, sometimes there may be 1 primary node and 2 local handoff nodes in one region holding the object after uploading but before object replicated to the appropriate locations in other regions. In this case, include these handoff nodes to send request when deleting object could help make correct decision for the response. The default value 'auto' means Swift will calculate the number automatically, the default value is (replicas - len(local_primary_nodes)). This option may be overridden in a per-policy configuration section. ====================================== =============== ===================================== .. _proxy_server_per_policy_config: ************************ Per policy configuration ************************ Some proxy-server configuration options may be overridden for individual :doc:`overview_policies` by including per-policy config section(s). These options are: - ``sorting_method`` - ``read_affinity`` - ``write_affinity`` - ``write_affinity_node_count`` - ``write_affinity_handoff_delete_count`` The per-policy config section name must be of the form:: [proxy-server:policy:] .. note:: The per-policy config section name should refer to the policy index, not the policy name. .. note:: The first part of proxy-server config section name must match the name of the proxy-server config section. This is typically ``proxy-server`` as shown above, but if different then the names of any per-policy config sections must be changed accordingly. The value of an option specified in a per-policy section will override any value given in the proxy-server section for that policy only. Otherwise the value of these options will be that specified in the proxy-server section. For example, the following section provides policy-specific options for a policy with index ``3``:: [proxy-server:policy:3] sorting_method = affinity read_affinity = r2=1 write_affinity = r2 write_affinity_node_count = 1 * replicas write_affinity_handoff_delete_count = 2 .. note:: It is recommended that per-policy config options are *not* included in the ``[DEFAULT]`` section. If they are then the following behavior applies. Per-policy config sections will inherit options in the ``[DEFAULT]`` section of the config file, and any such inheritance will take precedence over inheriting options from the proxy-server config section. Per-policy config section options will override options in the ``[DEFAULT]`` section. Unlike the behavior described under `General Server Configuration`_ for paste-deploy ``filter`` and ``app`` sections, the ``set`` keyword is not required for options to override in per-policy config sections. For example, given the following settings in a config file:: [DEFAULT] sorting_method = affinity read_affinity = r0=100 write_affinity = r0 [app:proxy-server] use = egg:swift#proxy # use of set keyword here overrides [DEFAULT] option set read_affinity = r1=100 # without set keyword, [DEFAULT] option overrides in a paste-deploy section write_affinity = r1 [proxy-server:policy:0] sorting_method = affinity # set keyword not required here to override [DEFAULT] option write_affinity = r1 would result in policy with index ``0`` having settings: * ``read_affinity = r0=100`` (inherited from the ``[DEFAULT]`` section) * ``write_affinity = r1`` (specified in the policy 0 section) and any other policy would have the default settings of: * ``read_affinity = r1=100`` (set in the proxy-server section) * ``write_affinity = r0`` (inherited from the ``[DEFAULT]`` section) ***************** Proxy Middlewares ***************** Many features in Swift are implemented as middleware in the proxy-server pipeline. See :doc:`middleware` and the ``proxy-server.conf-sample`` file for more information. In particular, the use of some type of :doc:`authentication and authorization middleware ` is highly recommended. ------------------------ Memcached Considerations ------------------------ Several of the Services rely on Memcached for caching certain types of lookups, such as auth tokens, and container/account existence. Swift does not do any caching of actual object data. Memcached should be able to run on any servers that have available RAM and CPU. At Rackspace, we run Memcached on the proxy servers. The `memcache_servers` config option in the `proxy-server.conf` should contain all memcached servers. ----------- System Time ----------- Time may be relative but it is relatively important for Swift! Swift uses timestamps to determine which is the most recent version of an object. It is very important for the system time on each server in the cluster to by synced as closely as possible (more so for the proxy server, but in general it is a good idea for all the servers). At Rackspace, we use NTP with a local NTP server to ensure that the system times are as close as possible. This should also be monitored to ensure that the times do not vary too much. .. _general-service-tuning: ---------------------- General Service Tuning ---------------------- Most services support either a `worker` or `concurrency` value in the settings. This allows the services to make effective use of the cores available. A good starting point to set the concurrency level for the proxy and storage services to 2 times the number of cores available. If more than one service is sharing a server, then some experimentation may be needed to find the best balance. At Rackspace, our Proxy servers have dual quad core processors, giving us 8 cores. Our testing has shown 16 workers to be a pretty good balance when saturating a 10g network and gives good CPU utilization. Our Storage server processes all run together on the same servers. These servers have dual quad core processors, for 8 cores total. We run the Account, Container, and Object servers with 8 workers each. Most of the background jobs are run at a concurrency of 1, with the exception of the replicators which are run at a concurrency of 2. The `max_clients` parameter can be used to adjust the number of client requests an individual worker accepts for processing. The fewer requests being processed at one time, the less likely a request that consumes the worker's CPU time, or blocks in the OS, will negatively impact other requests. The more requests being processed at one time, the more likely one worker can utilize network and disk capacity. On systems that have more cores, and more memory, where one can afford to run more workers, raising the number of workers and lowering the maximum number of clients serviced per worker can lessen the impact of CPU intensive or stalled requests. The `nice_priority` parameter can be used to set program scheduling priority. The `ionice_class` and `ionice_priority` parameters can be used to set I/O scheduling class and priority on the systems that use an I/O scheduler that supports I/O priorities. As at kernel 2.6.17 the only such scheduler is the Completely Fair Queuing (CFQ) I/O scheduler. If you run your Storage servers all together on the same servers, you can slow down the auditors or prioritize object-server I/O via these parameters (but probably do not need to change it on the proxy). It is a new feature and the best practices are still being developed. On some systems it may be required to run the daemons as root. For more info also see setpriority(2) and ioprio_set(2). The above configuration setting should be taken as suggestions and testing of configuration settings should be done to ensure best utilization of CPU, network connectivity, and disk I/O. ------------------------- Filesystem Considerations ------------------------- Swift is designed to be mostly filesystem agnostic--the only requirement being that the filesystem supports extended attributes (xattrs). After thorough testing with our use cases and hardware configurations, XFS was the best all-around choice. If you decide to use a filesystem other than XFS, we highly recommend thorough testing. For distros with more recent kernels (for example Ubuntu 12.04 Precise), we recommend using the default settings (including the default inode size of 256 bytes) when creating the file system:: mkfs.xfs -L D1 /dev/sda1 In the last couple of years, XFS has made great improvements in how inodes are allocated and used. Using the default inode size no longer has an impact on performance. For distros with older kernels (for example Ubuntu 10.04 Lucid), some settings can dramatically impact performance. We recommend the following when creating the file system:: mkfs.xfs -i size=1024 -L D1 /dev/sda1 Setting the inode size is important, as XFS stores xattr data in the inode. If the metadata is too large to fit in the inode, a new extent is created, which can cause quite a performance problem. Upping the inode size to 1024 bytes provides enough room to write the default metadata, plus a little headroom. The following example mount options are recommended when using XFS:: mount -t xfs -o noatime,nodiratime,logbufs=8 -L D1 /srv/node/d1 We do not recommend running Swift on RAID, but if you are using RAID it is also important to make sure that the proper sunit and swidth settings get set so that XFS can make most efficient use of the RAID array. For a standard Swift install, all data drives are mounted directly under ``/srv/node`` (as can be seen in the above example of mounting label ``D1`` as ``/srv/node/d1``). If you choose to mount the drives in another directory, be sure to set the `devices` config option in all of the server configs to point to the correct directory. The mount points for each drive in ``/srv/node/`` should be owned by the root user almost exclusively (``root:root 755``). This is required to prevent rsync from syncing files into the root drive in the event a drive is unmounted. Swift uses system calls to reserve space for new objects being written into the system. If your filesystem does not support `fallocate()` or `posix_fallocate()`, be sure to set the `disable_fallocate = true` config parameter in account, container, and object server configs. Most current Linux distributions ship with a default installation of updatedb. This tool runs periodically and updates the file name database that is used by the GNU locate tool. However, including Swift object and container database files is most likely not required and the periodic update affects the performance quite a bit. To disable the inclusion of these files add the path where Swift stores its data to the setting PRUNEPATHS in `/etc/updatedb.conf`:: PRUNEPATHS="... /tmp ... /var/spool ... /srv/node" --------------------- General System Tuning --------------------- Rackspace currently runs Swift on Ubuntu Server 10.04, and the following changes have been found to be useful for our use cases. The following settings should be in `/etc/sysctl.conf`:: # disable TIME_WAIT.. wait.. net.ipv4.tcp_tw_recycle=1 net.ipv4.tcp_tw_reuse=1 # disable syn cookies net.ipv4.tcp_syncookies = 0 # double amount of allowed conntrack net.ipv4.netfilter.ip_conntrack_max = 262144 To load the updated sysctl settings, run ``sudo sysctl -p``. A note about changing the TIME_WAIT values. By default the OS will hold a port open for 60 seconds to ensure that any remaining packets can be received. During high usage, and with the number of connections that are created, it is easy to run out of ports. We can change this since we are in control of the network. If you are not in control of the network, or do not expect high loads, then you may not want to adjust those values. ---------------------- Logging Considerations ---------------------- Swift is set up to log directly to syslog. Every service can be configured with the `log_facility` option to set the syslog log facility destination. We recommended using syslog-ng to route the logs to specific log files locally on the server and also to remote log collecting servers. Additionally, custom log handlers can be used via the custom_log_handlers setting.