1190 lines
63 KiB
ReStructuredText
1190 lines
63 KiB
ReStructuredText
================
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Deployment Guide
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================
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-----------------------
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Hardware Considerations
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-----------------------
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Swift is designed to run on commodity hardware. At Rackspace, our storage
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servers are currently running fairly generic 4U servers with 24 2T SATA
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drives and 8 cores of processing power. RAID on the storage drives is not
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required and not recommended. Swift's disk usage pattern is the worst
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case possible for RAID, and performance degrades very quickly using RAID 5
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or 6.
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------------------
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Deployment Options
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------------------
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The swift services run completely autonomously, which provides for a lot of
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flexibility when architecting the hardware deployment for swift. The 4 main
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services are:
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#. Proxy Services
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#. Object Services
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#. Container Services
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#. Account Services
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The Proxy Services are more CPU and network I/O intensive. If you are using
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10g networking to the proxy, or are terminating SSL traffic at the proxy,
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greater CPU power will be required.
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The Object, Container, and Account Services (Storage Services) are more disk
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and network I/O intensive.
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The easiest deployment is to install all services on each server. There is
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nothing wrong with doing this, as it scales each service out horizontally.
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At Rackspace, we put the Proxy Services on their own servers and all of the
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Storage Services on the same server. This allows us to send 10g networking to
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the proxy and 1g to the storage servers, and keep load balancing to the
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proxies more manageable. Storage Services scale out horizontally as storage
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servers are added, and we can scale overall API throughput by adding more
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Proxies.
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If you need more throughput to either Account or Container Services, they may
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each be deployed to their own servers. For example you might use faster (but
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more expensive) SAS or even SSD drives to get faster disk I/O to the databases.
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Load balancing and network design is left as an exercise to the reader,
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but this is a very important part of the cluster, so time should be spent
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designing the network for a Swift cluster.
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---------------------
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Web Front End Options
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---------------------
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Swift comes with an integral web front end. However, it can also be deployed
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as a request processor of an Apache2 using mod_wsgi as described in
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:doc:`Apache Deployment Guide <apache_deployment_guide>`.
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.. _ring-preparing:
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------------------
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Preparing the Ring
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------------------
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The first step is to determine the number of partitions that will be in the
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ring. We recommend that there be a minimum of 100 partitions per drive to
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insure even distribution across the drives. A good starting point might be
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to figure out the maximum number of drives the cluster will contain, and then
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multiply by 100, and then round up to the nearest power of two.
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For example, imagine we are building a cluster that will have no more than
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5,000 drives. That would mean that we would have a total number of 500,000
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partitions, which is pretty close to 2^19, rounded up.
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It is also a good idea to keep the number of partitions small (relatively).
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The more partitions there are, the more work that has to be done by the
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replicators and other backend jobs and the more memory the rings consume in
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process. The goal is to find a good balance between small rings and maximum
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cluster size.
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The next step is to determine the number of replicas to store of the data.
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Currently it is recommended to use 3 (as this is the only value that has
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been tested). The higher the number, the more storage that is used but the
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less likely you are to lose data.
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It is also important to determine how many zones the cluster should have. It is
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recommended to start with a minimum of 5 zones. You can start with fewer, but
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our testing has shown that having at least five zones is optimal when failures
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occur. We also recommend trying to configure the zones at as high a level as
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possible to create as much isolation as possible. Some example things to take
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into consideration can include physical location, power availability, and
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network connectivity. For example, in a small cluster you might decide to
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split the zones up by cabinet, with each cabinet having its own power and
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network connectivity. The zone concept is very abstract, so feel free to use
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it in whatever way best isolates your data from failure. Zones are referenced
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by number, beginning with 1.
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You can now start building the ring with::
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swift-ring-builder <builder_file> create <part_power> <replicas> <min_part_hours>
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This will start the ring build process creating the <builder_file> with
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2^<part_power> partitions. <min_part_hours> is the time in hours before a
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specific partition can be moved in succession (24 is a good value for this).
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Devices can be added to the ring with::
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swift-ring-builder <builder_file> add z<zone>-<ip>:<port>/<device_name>_<meta> <weight>
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This will add a device to the ring where <builder_file> is the name of the
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builder file that was created previously, <zone> is the number of the zone
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this device is in, <ip> is the ip address of the server the device is in,
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<port> is the port number that the server is running on, <device_name> is
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the name of the device on the server (for example: sdb1), <meta> is a string
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of metadata for the device (optional), and <weight> is a float weight that
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determines how many partitions are put on the device relative to the rest of
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the devices in the cluster (a good starting point is 100.0 x TB on the drive).
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Add each device that will be initially in the cluster.
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Once all of the devices are added to the ring, run::
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swift-ring-builder <builder_file> rebalance
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This will distribute the partitions across the drives in the ring. It is
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important whenever making changes to the ring to make all the changes
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required before running rebalance. This will ensure that the ring stays as
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balanced as possible, and as few partitions are moved as possible.
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The above process should be done to make a ring for each storage service
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(Account, Container and Object). The builder files will be needed in future
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changes to the ring, so it is very important that these be kept and backed up.
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The resulting .tar.gz ring file should be pushed to all of the servers in the
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cluster. For more information about building rings, running
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swift-ring-builder with no options will display help text with available
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commands and options. More information on how the ring works internally
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can be found in the :doc:`Ring Overview <overview_ring>`.
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.. _general-service-configuration:
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-----------------------------
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General Service Configuration
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-----------------------------
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Most Swift services fall into two categories. Swift's wsgi servers and
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background daemons.
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For more information specific to the configuration of Swift's wsgi servers
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with paste deploy see :ref:`general-server-configuration`
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Configuration for servers and daemons can be expressed together in the same
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file for each type of server, or separately. If a required section for the
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service trying to start is missing there will be an error. The sections not
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used by the service are ignored.
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Consider the example of an object storage node. By convention configuration
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for the object-server, object-updater, object-replicator, and object-auditor
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exist in a single file ``/etc/swift/object-server.conf``::
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[DEFAULT]
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[pipeline:main]
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pipeline = object-server
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[app:object-server]
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use = egg:swift#object
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[object-replicator]
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reclaim_age = 259200
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[object-updater]
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[object-auditor]
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Swift services expect a configuration path as the first argument::
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$ swift-object-auditor
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Usage: swift-object-auditor CONFIG [options]
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Error: missing config path argument
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If you omit the object-auditor section this file could not be used as the
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configuration path when starting the ``swift-object-auditor`` daemon::
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$ swift-object-auditor /etc/swift/object-server.conf
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Unable to find object-auditor config section in /etc/swift/object-server.conf
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If the configuration path is a directory instead of a file all of the files in
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the directory with the file extension ".conf" will be combined to generate the
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configuration object which is delivered to the Swift service. This is
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referred to generally as "directory based configuration".
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Directory based configuration leverages ConfigParser's native multi-file
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support. Files ending in ".conf" in the given directory are parsed in
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lexicographical order. Filenames starting with '.' are ignored. A mixture of
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file and directory configuration paths is not supported - if the configuration
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path is a file only that file will be parsed.
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The swift service management tool ``swift-init`` has adopted the convention of
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looking for ``/etc/swift/{type}-server.conf.d/`` if the file
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``/etc/swift/{type}-server.conf`` file does not exist.
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When using directory based configuration, if the same option under the same
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section appears more than once in different files, the last value parsed is
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said to override previous occurrences. You can ensure proper override
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precedence by prefixing the files in the configuration directory with
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numerical values.::
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/etc/swift/
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default.base
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object-server.conf.d/
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000_default.conf -> ../default.base
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001_default-override.conf
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010_server.conf
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020_replicator.conf
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030_updater.conf
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040_auditor.conf
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You can inspect the resulting combined configuration object using the
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``swift-config`` command line tool
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.. _general-server-configuration:
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----------------------------
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General Server Configuration
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----------------------------
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Swift uses paste.deploy (http://pythonpaste.org/deploy/) to manage server
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configurations.
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Default configuration options are set in the `[DEFAULT]` section, and any
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options specified there can be overridden in any of the other sections BUT
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ONLY BY USING THE SYNTAX ``set option_name = value``. This is the unfortunate
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way paste.deploy works and I'll try to explain it in full.
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First, here's an example paste.deploy configuration file::
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[DEFAULT]
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name1 = globalvalue
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name2 = globalvalue
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name3 = globalvalue
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set name4 = globalvalue
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[pipeline:main]
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pipeline = myapp
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[app:myapp]
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use = egg:mypkg#myapp
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name2 = localvalue
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set name3 = localvalue
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set name5 = localvalue
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name6 = localvalue
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The resulting configuration that myapp receives is::
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global {'__file__': '/etc/mypkg/wsgi.conf', 'here': '/etc/mypkg',
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'name1': 'globalvalue',
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'name2': 'globalvalue',
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'name3': 'localvalue',
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'name4': 'globalvalue',
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'name5': 'localvalue',
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'set name4': 'globalvalue'}
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local {'name6': 'localvalue'}
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So, `name1` got the global value which is fine since it's only in the `DEFAULT`
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section anyway.
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`name2` got the global value from `DEFAULT` even though it appears to be
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overridden in the `app:myapp` subsection. This is just the unfortunate way
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paste.deploy works (at least at the time of this writing.)
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`name3` got the local value from the `app:myapp` subsection because it is using
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the special paste.deploy syntax of ``set option_name = value``. So, if you want
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a default value for most app/filters but want to overridde it in one
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subsection, this is how you do it.
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`name4` got the global value from `DEFAULT` since it's only in that section
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anyway. But, since we used the ``set`` syntax in the `DEFAULT` section even
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though we shouldn't, notice we also got a ``set name4`` variable. Weird, but
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probably not harmful.
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`name5` got the local value from the `app:myapp` subsection since it's only
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there anyway, but notice that it is in the global configuration and not the
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local configuration. This is because we used the ``set`` syntax to set the
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value. Again, weird, but not harmful since Swift just treats the two sets of
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configuration values as one set anyway.
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`name6` got the local value from `app:myapp` subsection since it's only there,
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and since we didn't use the ``set`` syntax, it's only in the local
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configuration and not the global one. Though, as indicated above, there is no
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special distinction with Swift.
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That's quite an explanation for something that should be so much simpler, but
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it might be important to know how paste.deploy interprets configuration files.
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The main rule to remember when working with Swift configuration files is:
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.. note::
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Use the ``set option_name = value`` syntax in subsections if the option is
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also set in the ``[DEFAULT]`` section. Don't get in the habit of always
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using the ``set`` syntax or you'll probably mess up your non-paste.deploy
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configuration files.
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--------------------
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Common configuration
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--------------------
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An example of common configuration file can be found at etc/swift.conf-sample
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The following configuration options are available:
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=================== ========== =============================================
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Option Default Description
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------------------- ---------- ---------------------------------------------
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max_header_size 8192 max_header_size is the max number of bytes in
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the utf8 encoding of each header. Using 8192
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as default because eventlet use 8192 as max
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size of header line. This value may need to
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be increased when using identity v3 API
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tokens including more than 7 catalog entries.
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See also include_service_catalog in
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proxy-server.conf-sample (documented in
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overview_auth.rst)
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=================== ========== =============================================
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---------------------------
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Object Server Configuration
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---------------------------
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An Example Object Server configuration can be found at
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etc/object-server.conf-sample in the source code repository.
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The following configuration options are available:
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[DEFAULT]
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=================== ========== =============================================
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Option Default Description
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------------------- ---------- ---------------------------------------------
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swift_dir /etc/swift Swift configuration directory
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devices /srv/node Parent directory of where devices are mounted
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mount_check true Whether or not check if the devices are
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mounted to prevent accidentally writing
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to the root device
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bind_ip 0.0.0.0 IP Address for server to bind to
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bind_port 6000 Port for server to bind to
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bind_timeout 30 Seconds to attempt bind before giving up
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workers auto Override the number of pre-forked workers
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that will accept connections. If set it
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should be an integer, zero means no fork. If
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unset, it will try to default to the number
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of effective cpu cores and fallback to one.
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Increasing the number of workers may reduce
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the possibility of slow file system
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operations in one request from negatively
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impacting other requests, but may not be as
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efficient as tuning :ref:`threads_per_disk
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<object-server-options>`
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max_clients 1024 Maximum number of clients one worker can
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process simultaneously (it will actually
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accept(2) N + 1). Setting this to one (1)
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will only handle one request at a time,
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without accepting another request
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concurrently.
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disable_fallocate false Disable "fast fail" fallocate checks if the
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underlying filesystem does not support it.
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log_max_line_length 0 Caps the length of log lines to the
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value given; no limit if set to 0, the
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default.
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log_custom_handlers None Comma-separated list of functions to call
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to setup custom log handlers.
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eventlet_debug false If true, turn on debug logging for eventlet
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fallocate_reserve 0 You can set fallocate_reserve to the number of
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bytes you'd like fallocate to reserve, whether
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there is space for the given file size or not.
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This is useful for systems that behave badly
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when they completely run out of space; you can
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make the services pretend they're out of space
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early.
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conn_timeout 0.5 Time to wait while attempting to connect to
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another backend node.
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node_timeout 3 Time to wait while sending each chunk of data
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to another backend node.
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client_timeout 60 Time to wait while receiving each chunk of
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data from a client or another backend node.
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network_chunk_size 65536 Size of chunks to read/write over the network
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disk_chunk_size 65536 Size of chunks to read/write to disk
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=================== ========== =============================================
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.. _object-server-options:
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[object-server]
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============================= ============= =================================
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Option Default Description
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----------------------------- ------------- ---------------------------------
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use paste.deploy entry point for the
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object server. For most cases,
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this should be
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`egg:swift#object`.
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set log_name object-server Label used when logging
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set log_facility LOG_LOCAL0 Syslog log facility
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set log_level INFO Logging level
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set log_requests True Whether or not to log each
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request
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user swift User to run as
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max_upload_time 86400 Maximum time allowed to upload an
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object
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slow 0 If > 0, Minimum time in seconds
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for a PUT or DELETE request to
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complete
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mb_per_sync 512 On PUT requests, sync file every
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n MB
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keep_cache_size 5242880 Largest object size to keep in
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buffer cache
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keep_cache_private false Allow non-public objects to stay
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in kernel's buffer cache
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threads_per_disk 0 Size of the per-disk thread pool
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used for performing disk I/O. The
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default of 0 means to not use a
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per-disk thread pool. It is
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recommended to keep this value
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small, as large values can result
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in high read latencies due to
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large queue depths. A good
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starting point is 4 threads per
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disk.
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replication_concurrency 4 Set to restrict the number of
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concurrent incoming REPLICATION
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requests; set to 0 for unlimited
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replication_one_per_device True Restricts incoming REPLICATION
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requests to one per device,
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replication_currency above
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allowing. This can help control
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I/O to each device, but you may
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wish to set this to False to
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allow multiple REPLICATION
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requests (up to the above
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replication_concurrency setting)
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per device.
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replication_lock_timeout 15 Number of seconds to wait for an
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existing replication device lock
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before giving up.
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replication_failure_threshold 100 The number of subrequest failures
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before the
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replication_failure_ratio is
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checked
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replication_failure_ratio 1.0 If the value of failures /
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successes of REPLICATION
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subrequests exceeds this ratio,
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the overall REPLICATION request
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will be aborted
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============================= ============= =================================
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[object-replicator]
|
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|
|
================== ================= =======================================
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Option Default Description
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------------------ ----------------- ---------------------------------------
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log_name object-replicator Label used when logging
|
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log_facility LOG_LOCAL0 Syslog log facility
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log_level INFO Logging level
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daemonize yes Whether or not to run replication as a
|
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daemon
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run_pause 30 Time in seconds to wait between
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replication passes
|
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concurrency 1 Number of replication workers to spawn
|
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timeout 5 Timeout value sent to rsync --timeout
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and --contimeout options
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stats_interval 3600 Interval in seconds between logging
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replication statistics
|
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reclaim_age 604800 Time elapsed in seconds before an
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object can be reclaimed
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handoffs_first false If set to True, partitions that are
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not supposed to be on the node will be
|
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replicated first. The default setting
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should not be changed, except for
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extreme situations.
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handoff_delete auto By default handoff partitions will be
|
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removed when it has successfully
|
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replicated to all the canonical nodes.
|
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If set to an integer n, it will remove
|
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the partition if it is successfully
|
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replicated to n nodes. The default
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setting should not be changed, except
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for extreme situations.
|
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node_timeout DEFAULT or 10 Request timeout to external services.
|
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This uses what's set here, or what's set
|
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in the DEFAULT section, or 10 (though
|
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other sections use 3 as the final
|
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default).
|
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================== ================= =======================================
|
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[object-updater]
|
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================== ============== ==========================================
|
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Option Default Description
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------------------ -------------- ------------------------------------------
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log_name object-updater Label used when logging
|
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log_facility LOG_LOCAL0 Syslog log facility
|
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log_level INFO Logging level
|
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interval 300 Minimum time for a pass to take
|
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concurrency 1 Number of updater workers to spawn
|
|
node_timeout DEFAULT or 10 Request timeout to external services. This
|
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uses what's set here, or what's set in the
|
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DEFAULT section, or 10 (though other
|
|
sections use 3 as the final default).
|
|
slowdown 0.01 Time in seconds to wait between objects
|
|
================== ============== ==========================================
|
|
|
|
[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_time 3600 Frequency of status logs in seconds.
|
|
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.
|
|
================== ============== ==========================================
|
|
|
|
------------------------------
|
|
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 options are available:
|
|
|
|
[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 6001 Port for server to bind to
|
|
bind_timeout 30 Seconds to attempt bind before giving up
|
|
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_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.
|
|
eventlet_debug false If true, turn on debug logging for eventlet
|
|
fallocate_reserve 0 You can set fallocate_reserve to the number of
|
|
bytes you'd like fallocate to reserve, whether
|
|
there is space for the given file size or not.
|
|
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.
|
|
=================== ========== ============================================
|
|
|
|
[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
|
|
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
|
|
================== ================ ========================================
|
|
|
|
[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
|
|
per_diff 1000
|
|
concurrency 8 Number of replication workers to
|
|
spawn
|
|
run_pause 30 Time in seconds to wait between
|
|
replication passes
|
|
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
|
|
================== ==================== ====================================
|
|
|
|
[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
|
|
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
|
|
slowdown 0.01 Time in seconds to wait between
|
|
containers
|
|
account_suppression_time 60 Seconds to suppress updating an
|
|
account that has generated an
|
|
error (timeout, not yet found,
|
|
etc.)
|
|
======================== ================= ==================================
|
|
|
|
[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
|
|
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.
|
|
===================== ================= =======================================
|
|
|
|
----------------------------
|
|
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 options are available:
|
|
|
|
[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 6002 Port for server to bind to
|
|
bind_timeout 30 Seconds to attempt bind before giving up
|
|
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_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.
|
|
eventlet_debug false If true, turn on debug logging for eventlet
|
|
fallocate_reserve 0 You can set fallocate_reserve to the number of
|
|
bytes you'd like fallocate to reserve, whether
|
|
there is space for the given file size or not.
|
|
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.
|
|
=================== ========== =============================================
|
|
|
|
[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
|
|
================== ============== ==========================================
|
|
|
|
[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
|
|
per_diff 1000
|
|
concurrency 8 Number of replication workers to spawn
|
|
run_pause 30 Time in seconds to wait between
|
|
replication passes
|
|
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
|
|
================== ================== ======================================
|
|
|
|
[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
|
|
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.
|
|
==================== =============== =======================================
|
|
|
|
[account-reaper]
|
|
|
|
================== =============== =========================================
|
|
Option Default Description
|
|
------------------ --------------- -----------------------------------------
|
|
log_name account-auditor Label used when logging
|
|
log_facility LOG_LOCAL0 Syslog log facility
|
|
log_level INFO Logging level
|
|
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.
|
|
================== =============== =========================================
|
|
|
|
.. _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 options are available:
|
|
|
|
[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
|
|
bind_timeout 30 Seconds to attempt bind before
|
|
giving up
|
|
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 This is a list of hosts that
|
|
are included with any CORS
|
|
request by default and
|
|
returned with the
|
|
Access-Control-Allow-Origin
|
|
header in addition to what
|
|
the container has set.
|
|
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.
|
|
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.
|
|
============================ =============== =============================
|
|
|
|
[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
|
|
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
|
|
object_post_as_copy true Set object_post_as_copy = false
|
|
to turn on fast posts where only
|
|
the metadata changes are stored
|
|
anew and the original data file
|
|
is kept in place. This makes for
|
|
quicker posts; but since the
|
|
container metadata isn't updated
|
|
in this mode, features like
|
|
container sync won't be able to
|
|
sync posts.
|
|
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 <see the sample These are the headers whose
|
|
conf file for values will only be shown to
|
|
the list of swift_owners. The exact
|
|
default definition of a swift_owner is
|
|
headers> up to the auth system in use,
|
|
but usually indicates
|
|
administrative responsibilities.
|
|
============================ =============== =============================
|
|
|
|
[tempauth]
|
|
|
|
===================== =============================== =======================
|
|
Option Default Description
|
|
--------------------- ------------------------------- -----------------------
|
|
use Entry point for
|
|
paste.deploy to use for
|
|
auth. To use tempauth
|
|
set to:
|
|
`egg:swift#tempauth`
|
|
set log_name tempauth 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
|
|
reseller_prefix AUTH The naming scope for the
|
|
auth service. Swift
|
|
storage accounts and
|
|
auth tokens will begin
|
|
with this prefix.
|
|
auth_prefix /auth/ The HTTP request path
|
|
prefix for the auth
|
|
service. Swift itself
|
|
reserves anything
|
|
beginning with the
|
|
letter `v`.
|
|
token_life 86400 The number of seconds a
|
|
token is valid.
|
|
storage_url_scheme default Scheme to return with
|
|
storage urls: http,
|
|
https, or default
|
|
(chooses based on what
|
|
the server is running
|
|
as) This can be useful
|
|
with an SSL load
|
|
balancer in front of a
|
|
non-SSL server.
|
|
===================== =============================== =======================
|
|
|
|
Additionally, you need to list all the accounts/users you want here. The format
|
|
is::
|
|
|
|
user_<account>_<user> = <key> [group] [group] [...] [storage_url]
|
|
|
|
or if you want to be able to include underscores in the ``<account>`` or
|
|
``<user>`` portions, you can base64 encode them (with *no* equal signs) in a
|
|
line like this::
|
|
|
|
user64_<account_b64>_<user_b64> = <key> [group] [group] [...] [storage_url]
|
|
|
|
There are special groups of::
|
|
|
|
.reseller_admin = can do anything to any account for this auth
|
|
.admin = can do anything within the account
|
|
|
|
If neither of these groups are specified, the user can only access containers
|
|
that have been explicitly allowed for them by a .admin or .reseller_admin.
|
|
|
|
The trailing optional storage_url allows you to specify an alternate url to
|
|
hand back to the user upon authentication. If not specified, this defaults to::
|
|
|
|
$HOST/v1/<reseller_prefix>_<account>
|
|
|
|
Where $HOST will do its best to resolve to what the requester would need to use
|
|
to reach this host, <reseller_prefix> is from this section, and <account> is
|
|
from the user_<account>_<user> name. Note that $HOST cannot possibly handle
|
|
when you have a load balancer in front of it that does https while TempAuth
|
|
itself runs with http; in such a case, you'll have to specify the
|
|
storage_url_scheme configuration value as an override.
|
|
|
|
Here are example entries, required for running the tests::
|
|
|
|
user_admin_admin = admin .admin .reseller_admin
|
|
user_test_tester = testing .admin
|
|
user_test2_tester2 = testing2 .admin
|
|
user_test_tester3 = testing3
|
|
|
|
# account "test_y" and user "tester_y" (note the lack of padding = chars)
|
|
user64_dGVzdF95_dGVzdGVyX3k = testing4 .admin
|
|
|
|
------------------------
|
|
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 servers 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 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 /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 /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,nobarrier,logbufs=8 /dev/sda1 /srv/node/sda
|
|
|
|
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 /def/sda1 as
|
|
/srv/node/sda). 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.
|
|
|
|
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.
|
|
|
|
---------------------
|
|
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.
|