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diff --git a/docs/workers.md b/docs/workers.md index 4bd60ba0a0..7512eff43a 100644 --- a/docs/workers.md +++ b/docs/workers.md @@ -1,23 +1,31 @@ # Scaling synapse via workers -Synapse has experimental support for splitting out functionality into -multiple separate python processes, helping greatly with scalability. These +For small instances it recommended to run Synapse in monolith mode (the +default). For larger instances where performance is a concern it can be helpful +to split out functionality into multiple separate python processes. These processes are called 'workers', and are (eventually) intended to scale horizontally independently. -All of the below is highly experimental and subject to change as Synapse evolves, -but documenting it here to help folks needing highly scalable Synapses similar -to the one running matrix.org! +Synapse's worker support is under active development and subject to change as +we attempt to rapidly scale ever larger Synapse instances. However we are +documenting it here to help admins needing a highly scalable Synapse instance +similar to the one running `matrix.org`. -All processes continue to share the same database instance, and as such, workers -only work with postgres based synapse deployments (sharing a single sqlite -across multiple processes is a recipe for disaster, plus you should be using -postgres anyway if you care about scalability). +All processes continue to share the same database instance, and as such, +workers only work with PostgreSQL-based Synapse deployments. SQLite should only +be used for demo purposes and any admin considering workers should already be +running PostgreSQL. -The workers communicate with the master synapse process via a synapse-specific -TCP protocol called 'replication' - analogous to MySQL or Postgres style -database replication; feeding a stream of relevant data to the workers so they -can be kept in sync with the main synapse process and database state. +## Master/worker communication + +The workers communicate with the master process via a Synapse-specific protocol +called 'replication' (analogous to MySQL- or Postgres-style database +replication) which feeds a stream of relevant data from the master to the +workers so they can be kept in sync with the master process and database state. + +Additionally, workers may make HTTP requests to the master, to send information +in the other direction. Typically this is used for operations which need to +wait for a reply - such as sending an event. ## Configuration @@ -27,72 +35,61 @@ the correct worker, or to the main synapse instance. Note that this includes requests made to the federation port. See [reverse_proxy.md](reverse_proxy.md) for information on setting up a reverse proxy. -To enable workers, you need to add two replication listeners to the master -synapse, e.g.: - - listeners: - # The TCP replication port - - port: 9092 - bind_address: '127.0.0.1' - type: replication - # The HTTP replication port - - port: 9093 - bind_address: '127.0.0.1' - type: http - resources: - - names: [replication] - -Under **no circumstances** should these replication API listeners be exposed to -the public internet; it currently implements no authentication whatsoever and is -unencrypted. - -(Roughly, the TCP port is used for streaming data from the master to the -workers, and the HTTP port for the workers to send data to the main -synapse process.) - -You then create a set of configs for the various worker processes. These -should be worker configuration files, and should be stored in a dedicated -subdirectory, to allow synctl to manipulate them. An additional configuration -for the master synapse process will need to be created because the process will -not be started automatically. That configuration should look like this: - - worker_app: synapse.app.homeserver - daemonize: true - -Each worker configuration file inherits the configuration of the main homeserver -configuration file. You can then override configuration specific to that worker, -e.g. the HTTP listener that it provides (if any); logging configuration; etc. -You should minimise the number of overrides though to maintain a usable config. +To enable workers, you need to add *two* replication listeners to the +main Synapse configuration file (`homeserver.yaml`). For example: -You must specify the type of worker application (`worker_app`). The currently -available worker applications are listed below. You must also specify the -replication endpoints that it's talking to on the main synapse process. -`worker_replication_host` should specify the host of the main synapse, -`worker_replication_port` should point to the TCP replication listener port and -`worker_replication_http_port` should point to the HTTP replication port. +```yaml +listeners: + # The TCP replication port + - port: 9092 + bind_address: '127.0.0.1' + type: replication -Currently, the `event_creator` and `federation_reader` workers require specifying -`worker_replication_http_port`. + # The HTTP replication port + - port: 9093 + bind_address: '127.0.0.1' + type: http + resources: + - names: [replication] +``` -For instance: - - worker_app: synapse.app.synchrotron - - # The replication listener on the synapse to talk to. - worker_replication_host: 127.0.0.1 - worker_replication_port: 9092 - worker_replication_http_port: 9093 - - worker_listeners: - - type: http - port: 8083 - resources: - - names: - - client - - worker_daemonize: True - worker_pid_file: /home/matrix/synapse/synchrotron.pid - worker_log_config: /home/matrix/synapse/config/synchrotron_log_config.yaml +Under **no circumstances** should these replication API listeners be exposed to +the public internet; they have no authentication and are unencrypted. + +You should then create a set of configs for the various worker processes. Each +worker configuration file inherits the configuration of the main homeserver +configuration file. You can then override configuration specific to that +worker, e.g. the HTTP listener that it provides (if any); logging +configuration; etc. You should minimise the number of overrides though to +maintain a usable config. + +In the config file for each worker, you must specify the type of worker +application (`worker_app`). The currently available worker applications are +listed below. You must also specify the replication endpoints that it should +talk to on the main synapse process. `worker_replication_host` should specify +the host of the main synapse, `worker_replication_port` should point to the TCP +replication listener port and `worker_replication_http_port` should point to +the HTTP replication port. + +For example: + +```yaml +worker_app: synapse.app.synchrotron + +# The replication listener on the synapse to talk to. +worker_replication_host: 127.0.0.1 +worker_replication_port: 9092 +worker_replication_http_port: 9093 + +worker_listeners: + - type: http + port: 8083 + resources: + - names: + - client + +worker_log_config: /home/matrix/synapse/config/synchrotron_log_config.yaml +``` ...is a full configuration for a synchrotron worker instance, which will expose a plain HTTP `/sync` endpoint on port 8083 separately from the `/sync` endpoint provided @@ -101,7 +98,75 @@ by the main synapse. Obviously you should configure your reverse-proxy to route the relevant endpoints to the worker (`localhost:8083` in the above example). -Finally, to actually run your worker-based synapse, you must pass synctl the -a +Finally, you need to start your worker processes. This can be done with either +`synctl` or your distribution's preferred service manager such as `systemd`. We +recommend the use of `systemd` where available: for information on setting up +`systemd` to start synapse workers, see +[systemd-with-workers](systemd-with-workers). To use `synctl`, see below. + +### **Experimental** support for replication over redis + +As of Synapse v1.13.0, it is possible to configure Synapse to send replication +via a [Redis pub/sub channel](https://redis.io/topics/pubsub). This is an +alternative to direct TCP connections to the master: rather than all the +workers connecting to the master, all the workers and the master connect to +Redis, which relays replication commands between processes. This can give a +significant cpu saving on the master and will be a prerequisite for upcoming +performance improvements. + +Note that this support is currently experimental; you may experience lost +messages and similar problems! It is strongly recommended that admins setting +up workers for the first time use direct TCP replication as above. + +To configure Synapse to use Redis: + +1. Install Redis following the normal procedure for your distribution - for + example, on Debian, `apt install redis-server`. (It is safe to use an + existing Redis deployment if you have one: we use a pub/sub stream named + according to the `server_name` of your synapse server.) +2. Check Redis is running and accessible: you should be able to `echo PING | nc -q1 + localhost 6379` and get a response of `+PONG`. +3. Install the python prerequisites. If you installed synapse into a + virtualenv, this can be done with: + ```sh + pip install matrix-synapse[redis] + ``` + The debian packages from matrix.org already include the required + dependencies. +4. Add config to the shared configuration (`homeserver.yaml`): + ```yaml + redis: + enabled: true + ``` + Optional parameters which can go alongside `enabled` are `host`, `port`, + `password`. Normally none of these are required. +5. Restart master and all workers. + +Once redis replication is in use, `worker_replication_port` is redundant and +can be removed from the worker configuration files. Similarly, the +configuration for the `listener` for the TCP replication port can be removed +from the main configuration file. Note that the HTTP replication port is +still required. + +### Using synctl + +If you want to use `synctl` to manage your synapse processes, you will need to +create an an additional configuration file for the master synapse process. That +configuration should look like this: + +```yaml +worker_app: synapse.app.homeserver +``` + +Additionally, each worker app must be configured with the name of a "pid file", +to which it will write its process ID when it starts. For example, for a +synchrotron, you might write: + +```yaml +worker_pid_file: /home/matrix/synapse/synchrotron.pid +``` + +Finally, to actually run your worker-based synapse, you must pass synctl the `-a` commandline option to tell it to operate on all the worker configurations found in the given directory, e.g.: @@ -168,20 +233,42 @@ endpoints matching the following regular expressions: ^/_matrix/federation/v1/make_join/ ^/_matrix/federation/v1/make_leave/ ^/_matrix/federation/v1/send_join/ + ^/_matrix/federation/v2/send_join/ ^/_matrix/federation/v1/send_leave/ + ^/_matrix/federation/v2/send_leave/ ^/_matrix/federation/v1/invite/ + ^/_matrix/federation/v2/invite/ ^/_matrix/federation/v1/query_auth/ ^/_matrix/federation/v1/event_auth/ ^/_matrix/federation/v1/exchange_third_party_invite/ + ^/_matrix/federation/v1/user/devices/ ^/_matrix/federation/v1/send/ + ^/_matrix/federation/v1/get_groups_publicised$ ^/_matrix/key/v2/query +Additionally, the following REST endpoints can be handled for GET requests: + + ^/_matrix/federation/v1/groups/ + The above endpoints should all be routed to the federation_reader worker by the reverse-proxy configuration. The `^/_matrix/federation/v1/send/` endpoint must only be handled by a single instance. +Note that `federation` must be added to the listener resources in the worker config: + +```yaml +worker_app: synapse.app.federation_reader +... +worker_listeners: + - type: http + port: <port> + resources: + - names: + - federation +``` + ### `synapse.app.federation_sender` Handles sending federation traffic to other servers. Doesn't handle any @@ -196,16 +283,30 @@ Handles the media repository. It can handle all endpoints starting with: /_matrix/media/ -And the following regular expressions matching media-specific administration APIs: +... and the following regular expressions matching media-specific administration APIs: ^/_synapse/admin/v1/purge_media_cache$ - ^/_synapse/admin/v1/room/.*/media$ + ^/_synapse/admin/v1/room/.*/media.*$ + ^/_synapse/admin/v1/user/.*/media.*$ + ^/_synapse/admin/v1/media/.*$ ^/_synapse/admin/v1/quarantine_media/.*$ You should also set `enable_media_repo: False` in the shared configuration file to stop the main synapse running background jobs related to managing the media repository. +In the `media_repository` worker configuration file, configure the http listener to +expose the `media` resource. For example: + +```yaml + worker_listeners: + - type: http + port: 8085 + resources: + - names: + - media +``` + Note this worker cannot be load-balanced: only one instance should be active. ### `synapse.app.client_reader` @@ -224,15 +325,22 @@ following regular expressions: ^/_matrix/client/(api/v1|r0|unstable)/keys/changes$ ^/_matrix/client/versions$ ^/_matrix/client/(api/v1|r0|unstable)/voip/turnServer$ + ^/_matrix/client/(api/v1|r0|unstable)/joined_groups$ + ^/_matrix/client/(api/v1|r0|unstable)/publicised_groups$ + ^/_matrix/client/(api/v1|r0|unstable)/publicised_groups/ Additionally, the following REST endpoints can be handled for GET requests: ^/_matrix/client/(api/v1|r0|unstable)/pushrules/.*$ + ^/_matrix/client/(api/v1|r0|unstable)/groups/.*$ + ^/_matrix/client/(api/v1|r0|unstable)/user/[^/]*/account_data/ + ^/_matrix/client/(api/v1|r0|unstable)/user/[^/]*/rooms/[^/]*/account_data/ Additionally, the following REST endpoints can be handled, but all requests must be routed to the same instance: ^/_matrix/client/(r0|unstable)/register$ + ^/_matrix/client/(r0|unstable)/auth/.*/fallback/web$ Pagination requests can also be handled, but all requests with the same path room must be routed to the same instance. Additionally, care must be taken to @@ -248,6 +356,10 @@ the following regular expressions: ^/_matrix/client/(api/v1|r0|unstable)/user_directory/search$ +When using this worker you must also set `update_user_directory: False` in the +shared configuration file to stop the main synapse running background +jobs related to updating the user directory. + ### `synapse.app.frontend_proxy` Proxies some frequently-requested client endpoints to add caching and remove @@ -276,6 +388,7 @@ file. For example: Handles some event creation. It can handle REST endpoints matching: ^/_matrix/client/(api/v1|r0|unstable)/rooms/.*/send + ^/_matrix/client/(api/v1|r0|unstable)/rooms/.*/state/ ^/_matrix/client/(api/v1|r0|unstable)/rooms/.*/(join|invite|leave|ban|unban|kick)$ ^/_matrix/client/(api/v1|r0|unstable)/join/ ^/_matrix/client/(api/v1|r0|unstable)/profile/ |