Track changes for gitlab-ce#30392 support for multiple key value stores

Track changes for gitlab-ce#30392 support for multiple key value stores

Scheduled:

9.3

See: !298 (closed)

• Add support for multiple key-value stores
  • allows different policies for retention, backup, deployment topologies by key namespace
• Abstract key-value store name away from name of underlying technology such as "Redis"
• update Procfile to launch additional key-value stores

partially solves:

• https://gitlab.com/gitlab-org/gitlab-ce/issues/30392

see also:

• https://gitlab.com/gitlab-org/gitlab-ce
• https://gitlab.com/gitlab-org/gitlab-ee
• https://gitlab.com/gitlab-org/omnibus-gitlab
• !298 (closed)

Context -- configuration files added

resque.yml

This file is called resque.yml for historical reasons. We are NOT using Resque at the moment. It is used to specify Redis configuration values instead when a single database instance of Redis is desired.

Advanced Redis configuration files

In more advanced configurations of Redis key-value storage, it is desirable to separate the keys by lifecycle and intended use to ease provisioning and management of scalable Redis clusters.

These settings provide routing and other configuration data (such as sentinel, persistence policies, and other Redis customization) for connections to Redis single instances, Redis sentinel, and Redis clusters.

If desired, the routing URL provided by these settings can be used with:

1. Unix Socket
   1. named socket for each Redis instance desired.
   2. database number desired for each Redis instance desired.
2. TCP Socket
   1. host name or IP for each Redis instance desired
   2. TCP port number for each Redis instance desired
   3. database number for each Redis instance desired

---

redis.cache.yml

If configured, redis.cache.yml overrides the resque.yml settings to configure the Redis database instance used for Rails.cache and other volatile non-persistent data which enhances the performance of gitlab. Settings here can be overridden by the environment variables DEFAULT_REDIS_CACHE_URL which overrides the URL used by the Redis connection manager, and GITLAB_REDIS_CACHE_CONFIG_FILE which provides an alternate location for configuration settings.

The order of precedence for the URL used to connect to the Redis instance used for cache is:

1. URL from environment variable DEFAULT_REDIS_CACHE_URL
2. URL from a configuration file pointed to by the GITLAB_REDIS_CACHE_CONFIG_FILE environment variable
3. URL from redis.cache.yml
4. URL from environment variable DEFAULT_REDIS_URL
5. URL from a configuration file pointed to by the GITLAB_REDIS_CONFIG_FILE environment variable
6. URL from resque.yml

The order of precedence for all other configuration settings for cache are selected from only the first of the following files found (if a setting is not provided in an earlier file, the remainder of the files are not searched):

1. the configuration file pointed to by the GITLAB_REDIS_CACHE_CONFIG_FILE environment variable
2. the configuration file redis.cache.yml
3. the configuration file pointed to by the GITLAB_REDIS_CONFIG_FILE environment variable
4. the configuration file resque.yml

---

redis.queues.yml

If configured, redis.queues.yml overrides the resque.yml settings to configure the Redis database instance used for clients of ::Gitlab::Redis::Queues. These queues are intended to be the foundation of reliable inter-process communication between modules, whether on the same host node, or within a cluster. The primary clients of the queues are SideKiq, Mailroom, CI Runner, Workhorse, and push services. Settings here can be overridden by the environment variables DEFAULT_REDIS_QUEUES_URL which overrides the URL used by the Redis connection manager, and GITLAB_REDIS_QUEUES_CONFIG_FILE which provides an alternate location for configuration settings.

The order of precedence for the URL used to connect to the Redis instance used for queues is:

1. URL from environment variable DEFAULT_REDIS_QUEUES_URL
2. URL from a configuration file pointed to by the GITLAB_REDIS_QUEUES_CONFIG_FILE environment variable
3. URL from redis.queues.yml
4. URL from environment variable DEFAULT_REDIS_URL
5. URL from a configuration file pointed to by the GITLAB_REDIS_CONFIG_FILE environment variable
6. URL from resque.yml

The order of precedence for all other configuration settings for queues are selected from only the first of the following files found (if a setting is not provided in an earlier file, the remainder of the files are not searched):

1. the configuration file pointed to by the GITLAB_REDIS_QUEUES_CONFIG_FILE environment variable
2. the configuration file redis.queues.yml
3. the configuration file pointed to by the GITLAB_REDIS_CONFIG_FILE environment variable
4. the configuration file resque.yml

---

redis.shared_state.yml

If configured, redis.shared_state.yml overrides the resque.yml settings to configure the Redis database instance used for clients of ::Gitlab::Redis::SharedState such as session state, and rate limiting. Settings here can be overridden by the environment variables DEFAULT_REDIS_SHARED_STATE_URL which overrides the URL used by the Redis connection manager, and GITLAB_REDIS_SHARED_STATE_CONFIG_FILE which provides an alternate location for configuration settings.

The order of precedence for the URL used to connect to the Redis instance used for shared_state is:

1. URL from environment variable DEFAULT_REDIS_SHARED_STATE_URL
2. URL from a configuration file pointed to by the GITLAB_REDIS_SHARED_STATE_CONFIG_FILE environment variable
3. URL from redis.shared_state.yml
4. URL from environment variable DEFAULT_REDIS_URL
5. URL from a configuration file pointed to by the GITLAB_REDIS_CONFIG_FILE environment variable
6. URL from resque.yml

The order of precedence for all other configuration settings for shared_state are selected from only the first of the following files found (if a setting is not provided in an earlier file, the remainder of the files are not searched):

1. the configuration file pointed to by the GITLAB_REDIS_SHARED_STATE_CONFIG_FILE environment variable
2. the configuration file redis.shared_state.yml
3. the configuration file pointed to by the GITLAB_REDIS_CONFIG_FILE environment variable
4. the configuration file resque.yml