openstack/trove-specs
Code Issues Proposed changes
b19c9cf4f3
trove-specs/specs/liberty/redis-configuration-groups.rst
Nikhil Manchanda 4a72d213aa Add unit tests for Trove specs 
Add simple unit tests to the Trove specs repo which ensure that
specifications submitted follow the template correctly and address
all the needed sections.

Update tox to run these unit tests automatically.

At the beginning of each release, test_titles.py will need to be updated
and 'current_release' modified to reflect the new release directory.  At
the same time, the new release directory will be created, the index.rst
file in doc/source ammended to include this directory, and any unmerged
specs moved there.  In this way, changes to the template will only
affect specs going forward and avoids having to modify any specs that
have merged in previous releases.

(It will also have the side effect of signalling the 'opening' of the
release to new specs.)

Change-Id: I8f1175bceed63d36d96b6c6c6b4188ef27d3102e
2015-06-16 21:53:16 +00:00

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..
This work is licensed under a Creative Commons Attribution 3.0 Unported
License.
http://creativecommons.org/licenses/by/3.0/legalcode
Sections of this template were taken directly from the Nova spec
template at:
https://github.com/openstack/nova-specs/blob/master/specs/template.rst
==========================
Redis Configuration Groups
==========================
Launchpad Blueprint:
https://blueprints.launchpad.net/trove/+spec/redis-configuration-groups
Problem Description
===================
The Redis guestagent currently does not support configuration groups.
Proposed Change
===============
The patch set will implement configuration groups for Redis 3.0 or above.
Redis stores its configuration [1]_ in 'redis.conf' file which can optionally
import other files. If there are multiple configuration directives for a single
property the last one is used.
Configuration directives have key-value format:
"keyword argument1 argument2 ... argumentN"
Redis configuration will be reconfigured on the fly without stopping and
restarting the service using the special CONFIG command [1]_.
Note: Not all directives are supported by the CONFIG commands and
that modifying the configuration on the fly has no effects on the 'redis.conf'
file.
The base configuration file for Redis 3.0 [2]_ will be used as the default
configuration template.
Guest agent interfaces exposing the configuration properties will be made
available to other modules such as backup and replication.
Most configuration properties will be available via configuration groups.
Some, however, do not make sense in the Trove context.
These include:
- irrelevant options (like automatic snapshots, since the Trove user cannot
retrieve them)
- guestagent specific (e.g. file paths, passwords)
- items that Trove needs to control (replication/clustering properties)
See `Available Configuration Properties`_ for the full list of supported
options.
The CONFIG directives will be renamed to a name known only to the
guestagent for its internal use. This is to prevent a user from
bypassing Trove configuration groups by changing properties in the client.
Guestagent managed properties such as locations of database files and logs
could be potentially used to hijack the NOVA instance.
Configuration overrides will be implemented using the in-file imports
supported by the Redis configuration file format.
User defined overrides if any, will be saved in 'redis.conf.override'
and will be imported at the end of the default 'redis.conf' file.
Available Configuration Properties
----------------------------------
Keys not included in the lists are kept at their default values and are not
configurable via Trove. See [2]_ for more details and default values.
The properties configurable by the user via the Trove API:
- tcp-backlog
- timeout
- tcp-keepalive
- loglevel
- databases
- save
- stop-writes-on-bgsave-error
- rdbcompression
- rdbchecksum
- slave-serve-stale-data
- slave-read-only
- repl-diskless-sync
- repl-diskless-sync-delay
- repl-ping-slave-period
- repl-timeout
- repl-disable-tcp-nodelay
- repl-backlog-size
- repl-backlog-ttl
- slave-priority
- min-slaves-to-write
- min-slaves-max-lag
- requirepass
- maxclients
- maxmemory
- maxmemory-policy
- maxmemory-samples
- appendonly
- appendfsync
- no-appendfsync-on-rewrite
- auto-aof-rewrite-percentage
- auto-aof-rewrite-min-size
- aof-load-truncated
- lua-time-limit
- cluster-node-timeout
- cluster-slave-validity-factor
- cluster-migration-barrier
- cluster-require-full-coverage
- slowlog-log-slower-than
- slowlog-max-len
- latency-monitor-threshold
- notify-keyspace-events
- hash-max-ziplist-entries
- hash-max-ziplist-value
- list-max-ziplist-entries
- list-max-ziplist-value
- set-max-intset-entries
- zset-max-ziplist-entries
- zset-max-ziplist-value
- hll-sparse-max-bytes
- activerehashing
- client-output-buffer-limit normal
- client-output-buffer-limit slave
- client-output-buffer-limit pubsub
- hz
- aof-rewrite-incremental-fsync
Non-configurable properties with updated default values:
- *daemonize* **yes**
- *pidfile* **(controlled-by guestagent)**
- *logfile* **(controlled-by guestagent)**
- *dir* **(controlled-by guestagent)**
- *slaveof* **(controlled-by replication)**
- *masterauth* **(controlled-by guestagent)**
- *cluster-enabled* **(controlled-by clustering)**
- *cluster-config-file* **(controlled-by guestagent)**
Configuration
-------------
None
Database
--------
None
Public API
----------
None
Public API Security
-------------------
None
Python API
----------
None (empty section added after merging)
CLI (python-troveclient)
------------------------
None (empty section added after merging)
Internal API
------------
CLI (python-troveclient)
------------------------
This work will enable the following client commands:
* configuration-attach
* configuration-create
* configuration-default
* configuration-delete
* configuration-detach
* configuration-instances
* configuration-list
* configuration-parameter-list
* configuration-parameter-show
* configuration-patch
* configuration-show
* configuration-update
Guest Agent
-----------
* Update facilities for handling of Redis config files
in the *operating_system* module.
* Implement *update_overrides* and *apply_overrides* in
the *manager* and *service* modules.
* The current configuration template will be updated to [2]_
with changes noted in `Available Configuration Properties`_.
The following existing files will be updated:
.. code-block:: bash
guestagent/datastore/experimental/redis/manager.py
guestagent/datastore/experimental/redis/service.py
templates/redis/config.template
Alternatives
------------
None
Implementation
==============
Assignee(s)
-----------
Petr Malik <pmalik@tesora.com>
Milestones
----------
Liberty
Work Items
----------
1. Implement functionality to handle (read/write/update) Redis configuration
files.
2. Implement configuration-related manager API calls:
.. code-block:: python
def update_overrides(self, context, overrides, remove=False)
def apply_overrides(self, context, overrides)
Upgrade Implications
====================
None
Dependencies
============
None
Testing
=======
Unit tests will be added to validate implemented functions and non-trivial
codepaths. Relevant integration tests will be added.
Documentation Impact
====================
The datastore documentation should be updated to reflect the enabled features.
References
==========
.. [1] Documentation on Redis configuration: http://redis.io/topics/config
.. [2] Self-documented configuration file for Redis 3.0: https://raw.githubusercontent.com/antirez/redis/3.0/redis.conf
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