Commit Graph

325 Commits (ad8b909ce98cce5e955b10a3cbe04f3e868ecb70)

Author SHA1 Message Date
Erik Johnston faeb369f15 Fix missing invalidations for receipt storage 2018-02-21 15:19:54 +00:00
Erik Johnston 3dec9c66b3 Split out RoomMemberStore 2018-02-21 12:07:26 +00:00
Erik Johnston 46244b2759 Split AS stores 2018-02-21 11:49:34 +00:00
Erik Johnston 27b094f382 Split out get_events and co into a worker store 2018-02-21 11:41:48 +00:00
Erik Johnston d15d237b0d Split out EventPushActionWorkerStore 2018-02-21 11:01:13 +00:00
Erik Johnston 6f72765371 Split PusherStore 2018-02-21 10:54:21 +00:00
Erik Johnston cbaad969f9 Split PushRulesStore 2018-02-21 10:43:31 +00:00
Erik Johnston ca9b9d9703 Split AccountDataStore and TagStore 2018-02-21 10:15:04 +00:00
Erik Johnston 95e4cffd85 Fix comment 2018-02-20 17:58:40 +00:00
Erik Johnston e316bbb4c0 Use abstract base class to access stream IDs 2018-02-20 17:43:57 +00:00
Erik Johnston f5ac4dc2d4 Split ReceiptsStore 2018-02-20 16:28:28 +00:00
Erik Johnston 106906a65e Don't serialize current state over replication 2018-02-15 13:53:18 +00:00
Erik Johnston ef344b10e5 Don't log errors propogated from send_event 2018-02-15 11:03:49 +00:00
Erik Johnston 8ec2e638be Add event_creator worker 2018-02-07 10:32:32 +00:00
Erik Johnston 24dd73028a Add replication http endpoint for event sending 2018-02-07 10:32:32 +00:00
Erik Johnston 3d33eef6fc
Store state groups separately from events (#2784)
* Split state group persist into seperate storage func

* Add per database engine code for state group id gen

* Move store_state_group to StateReadStore

This allows other workers to use it, and so resolve state.

* Hook up store_state_group

* Fix tests

* Rename _store_mult_state_groups_txn

* Rename StateGroupReadStore

* Remove redundant _have_persisted_state_group_txn

* Update comments

* Comment compute_event_context

* Set start val for state_group_id_seq

... otherwise we try to recreate old state groups

* Update comments

* Don't store state for outliers

* Update comment

* Update docstring as state groups are ints
2018-02-06 14:31:24 +00:00
Richard van der Hoff 5c3c32f16f Metrics for number of RDATA commands received
I found myself wishing we had this.
2018-01-15 17:45:55 +00:00
Richard van der Hoff 0edf085b68 Fix some logcontext leaks in replication resource
The @measure_func annotations rely on the wrapped function respecting the
logcontext rules. Add the necessary yields to make this work.
2017-11-23 23:19:43 +00:00
Richard van der Hoff 35a4b63240 Pull out bits of StateStore to a mixin
... so that we don't need to secretly gut-wrench it for use in the slaved
stores. I haven't done the other stores yet, but we should. I'm tired of the
workers breaking every time we tweak the stores because I forgot to gut-wrench
the right method.

fixes https://github.com/matrix-org/synapse/issues/2655.
2017-11-14 11:43:58 +00:00
Richard van der Hoff 6cfee09be9 Make __init__ consitstent across Store heirarchy
Add db_conn parameters to the `__init__` methods of the *Store classes, so that
they are all consistent, which makes the multiple inheritance work correctly
(and so that we can later extract mixins which can be used in the slavedstores)
2017-11-13 10:46:07 +00:00
Richard van der Hoff eaaabc6c4f replace 'except:' with 'except Exception:'
what could possibly go wrong
2017-10-23 15:52:32 +01:00
hera f807f7f804 log when we get an exception handling replication updates 2017-10-12 11:51:24 +01:00
Erik Johnston 2cc998fed8 Fix replication. And notify 2017-07-20 17:13:18 +01:00
Erik Johnston 925b3638ff Reduce log levels in tcp replication 2017-07-11 10:04:21 +01:00
Erik Johnston 27f26e48b7 Serialize user ip command as json 2017-06-27 16:25:38 +01:00
Erik Johnston 8c23221666 Fix up 2017-06-27 15:53:45 +01:00
Erik Johnston 78cefd78d6 Make workers report to master for user ip updates 2017-06-27 14:58:10 +01:00
Erik Johnston dae9a00a28 Initialise exclusive_user_regex 2017-06-21 14:19:33 +01:00
Erik Johnston 8177563ebe Fix for workers 2017-06-21 13:57:49 +01:00
Erik Johnston 6aa5bc8635 Initial worker impl 2017-06-16 11:47:11 +01:00
Erik Johnston d53fe399eb Add cache for is_host_joined 2017-06-13 09:56:18 +01:00
Erik Johnston a837765e8c Merge pull request #2266 from matrix-org/erikj/host_in_room
Change is_host_joined to use current_state table
2017-06-12 09:49:51 +01:00
Erik Johnston 8060974344 Fix replication 2017-06-09 16:40:52 +01:00
Erik Johnston 2cac7623a5 Add missing notifier 2017-06-09 11:24:41 +01:00
Erik Johnston 298d83b340 Fix replication 2017-06-09 11:01:28 +01:00
Erik Johnston dfbda5e025 Faster cache for get_joined_hosts 2017-05-25 17:24:44 +01:00
Erik Johnston f85a415279 Add missing storage function to slave store 2017-05-22 16:31:24 +01:00
Erik Johnston 9ac263ed1b Add new storage functions to slave store 2017-05-04 14:29:03 +01:00
Erik Johnston e4f3431116 Remove unused cache 2017-04-24 13:27:38 +01:00
Erik Johnston 247c736b9b Merge pull request #2115 from matrix-org/erikj/dedupe_federation_repl
Reduce federation replication traffic
2017-04-12 11:07:13 +01:00
Erik Johnston 9c712a366f Move get_presence_list_* to SlaveStore 2017-04-11 16:07:33 +01:00
Erik Johnston 28a4649785 Remove HTTP replication APIs 2017-04-11 09:52:11 +01:00
Erik Johnston 29574fd5b3 Reduce federation presence replication traffic
This is mainly done by moving the calculation of where to send presence
updates from the presence handler to the transaction queue, so we only
need to send the presence event (and not the destinations) across the
replication connection. Before we were duplicating by sending the full
state across once per destination.
2017-04-10 16:48:30 +01:00
Erik Johnston 2e6f5a4910 Typo 2017-04-10 16:17:40 +01:00
Erik Johnston efcb6db688 Merge pull request #2109 from matrix-org/erikj/send_queue_fix
Fix up federation SendQueue and document types
2017-04-10 13:09:25 +01:00
Erik Johnston 0364d23210 Up replication ping timeout 2017-04-10 11:32:05 +01:00
Erik Johnston ab904caf33 Comments 2017-04-10 10:02:17 +01:00
Erik Johnston 98ce212093 Merge pull request #2103 from matrix-org/erikj/no-double-encode
Don't double encode replication data
2017-04-07 09:39:52 +01:00
Erik Johnston ad544c803a Document types of the replication streams 2017-04-06 13:28:52 +01:00
Erik Johnston 69b3fd485d Fix incorrect type when using InvalidateCacheCommand 2017-04-06 09:36:38 +01:00
Erik Johnston fcc803b2bf Add log lines 2017-04-05 17:13:44 +01:00
Erik Johnston 3f213d908d Rearrange metrics 2017-04-05 14:15:09 +01:00
Erik Johnston 1ca0e78ca1 Fix typo 2017-04-05 13:43:39 +01:00
Erik Johnston b43d3267e2 Fixup some metrics for tcp repl 2017-04-05 13:34:54 +01:00
Erik Johnston a5c401bd12 Merge pull request #2097 from matrix-org/erikj/repl_tcp_client
Move to using TCP replication
2017-04-05 09:36:21 +01:00
Erik Johnston a76886726b Merge pull request #2098 from matrix-org/erikj/repl_tcp_fix
Advance replication streams even if nothing is listening
2017-04-04 15:40:51 +01:00
Erik Johnston 4264ceb31c Fiddle tcp replication logging 2017-04-04 14:14:03 +01:00
Erik Johnston 023ee197be Advance replication streams even if nothing is listening
Otherwise the streams don't advance and steadily fall behind, so when a
worker does connect either a) they'll be streamed lots of old updates or
b) the connection will fail as the streams are too far behind.
2017-04-04 13:19:26 +01:00
Erik Johnston 3a1f3f8388 Change slave storage to use new replication interface
As the TCP replication uses a slightly different API and streams than
the HTTP replication.

This breaks HTTP replication.
2017-04-03 15:34:19 +01:00
Erik Johnston 52bfa604e1 Add basic replication client handler and factory 2017-04-03 15:34:13 +01:00
Erik Johnston 0a6a966e2b Always advance stream tokens 2017-04-03 15:22:56 +01:00
Erik Johnston 1df7c28661 Use callbacks to notify tcp replication rather than deferreds 2017-03-31 15:42:51 +01:00
Erik Johnston 36d2b66f90 Add a timestamp to USER_SYNC command
This timestamp is used to indicate when the user last sync'd
2017-03-31 15:42:22 +01:00
Erik Johnston bfcf016714 Fix up docs 2017-03-31 11:19:24 +01:00
Erik Johnston 4d7fc7f977 Add server side resource for tcp replication 2017-03-30 13:24:45 +01:00
Erik Johnston 7450693435 Initial TCP protocol implementation
This defines the low level TCP replication protocol
2017-03-30 12:54:46 +01:00
Erik Johnston 8da6f0be48 Define the various streams we will replicate 2017-03-30 12:54:46 +01:00
Erik Johnston 11880103b1 Make federation send queue take the current position 2017-03-30 12:54:36 +01:00
Erik Johnston 24d35ab47b Add new storage functions for new replication
The new replication protocol will keep all the streams separate, rather
than muxing multiple streams into one.
2017-03-30 11:48:35 +01:00
Erik Johnston 09f79aaad0 Use presence replication stream to invalidate cache
Instead of using the cache invalidation replication stream to invalidate
the _get_presence_cache, we can instead rely on the presence replication
stream. This reduces the amount of replication traffic considerably.
2017-03-24 13:21:08 +00:00
Erik Johnston d58b1ffe94 Replace some calls to cursor_to_dict
cursor_to_dict can be surprisinglh expensive for large result sets, so lets
only call it when we need to.
2017-03-24 11:07:02 +00:00
Erik Johnston aac6d1fc9b PEP8 2017-03-20 13:47:56 +00:00
Erik Johnston 61f471f779 Don't send the full event json over replication 2017-03-17 15:50:01 +00:00
Richard van der Hoff 29ed09e80a Fix assertion to stop transaction queue getting wedged
... and update some docstrings to correctly reflect the types being used.

get_new_device_msgs_for_remote can return a long under some circumstances,
which was being stored in last_device_list_stream_id_by_dest, and was then
upsetting things on the next loop.
2017-03-15 12:16:55 +00:00
Erik Johnston 45c7f12d2a Add new storage function to slave store 2017-03-13 16:26:44 +00:00
Erik Johnston 8f267fa8a8 Fix it for the workers 2017-03-10 11:22:25 +00:00
Erik Johnston e933a2712d Don't log unknown cache warnings in workers 2017-02-28 16:22:41 +00:00
Erik Johnston 095b45c165 Aggregate event push actions 2017-02-14 13:39:41 +00:00
Erik Johnston 9e617cd4c2 Cache get_presence storage 2017-02-13 13:50:03 +00:00
Erik Johnston 6bba80241c Merge pull request #1912 from matrix-org/markjh/roominitialsync
Add db functions needed for room initial sync to slave
2017-02-13 12:20:21 +01:00
Mark Haines 3a46280ca3 Add db functions needed for room initial sync to slave 2017-02-13 11:16:53 +00:00
Erik Johnston 0f3e296cb7 Fix replication 2017-02-02 15:02:03 +00:00
Erik Johnston 458b6f4733 Only invalidate membership caches based on the cache stream
Before we completely invalidated get_users_in_room whenever we updated
any current_state_events table. This was way too aggressive.
2017-01-31 16:09:03 +00:00
Erik Johnston 3670025e64 Rename func 2017-01-30 14:11:31 +00:00
Erik Johnston 252b503fc8 Hook device list updates to replication 2017-01-27 14:31:35 +00:00
Erik Johnston a55fa2047f Insert delta of current_state_events to be more efficient 2017-01-20 17:10:18 +00:00
Erik Johnston 09cbcb78d3 Add cache to get_public_room_ids_at_stream_id 2016-12-12 14:41:51 +00:00
Erik Johnston f32fb65552 Add new API appservice specific public room list 2016-12-06 16:12:27 +00:00
Erik Johnston 26072df6af Ensure only main or federation_sender process can send federation traffic 2016-11-23 14:09:47 +00:00
Erik Johnston 4c79a63fd7 Explicit federation ack 2016-11-23 10:40:44 +00:00
Erik Johnston 90565d015e Invalidate retry cache in both directions 2016-11-22 17:45:44 +00:00
Erik Johnston 7c9cdb2245 Store federation stream positions in the database 2016-11-21 11:33:08 +00:00
Erik Johnston f8ee66250a Handle sending events and device messages over federation 2016-11-17 15:48:04 +00:00
Erik Johnston ed787cf09e Hook up the send queue and create a federation sender worker 2016-11-16 17:34:44 +00:00
Erik Johnston 668f91d707 Fix check of wrong variable 2016-10-11 13:57:22 +01:00
Erik Johnston 748d8fdc7b Reduce DB hits for replication
Some streams will occaisonally advance their positions without actually
having any new rows to send over federation. Currently this means that
the token will not advance on the workers, leading to them repeatedly
sending a slightly out of date token. This in turns requires the master
to hit the DB to check if there are any new rows, rather than hitting
the no op logic where we check if the given token matches the current
token.

This commit changes the API to always return an entry if the position
for a stream has changed, allowing workers to advance their tokens
correctly.
2016-09-23 16:49:21 +01:00
Erik Johnston 995f2f032f Fix public room pagination for client_reader app 2016-09-16 14:48:21 +01:00
Erik Johnston 418bcd4309 Add new storage function to slave store 2016-09-16 08:37:39 +01:00
Erik Johnston cb3edec6af Use stream_change cache to make get_forward_extremeties_for_room cache more effective 2016-09-15 14:28:13 +01:00
Erik Johnston 55e6fc917c Add cache to get_forward_extremeties_for_room 2016-09-15 14:04:28 +01:00
Erik Johnston 211786ecd6 Stream public room changes down replication 2016-09-15 11:47:23 +01:00
Erik Johnston a4339de9de Correctly handle typing stream id resetting 2016-09-09 16:44:26 +01:00
Erik Johnston ab80d5e0a9 Drop replication log levels 2016-09-09 14:56:50 +01:00
Mark Haines 6a6cbfcf1e Track the max_stream_device_id in a separate table, since we delete from the inbox table 2016-09-09 11:48:23 +01:00
Mark Haines fa9d36e050 Merge branch 'develop' into markjh/direct_to_device_federation 2016-09-08 13:43:43 +01:00
Mark Haines 2a0159b8ae Fix the stream change cache to work over replication 2016-09-07 15:58:00 +01:00
Erik Johnston a99e933550 Add upgrade script that will slowly prune state_groups_state entries 2016-09-05 10:05:36 +01:00
Erik Johnston 44982606ee Merge pull request #1060 from matrix-org/erikj/state_ids
Assign state groups in state handler.
2016-09-01 14:20:42 +01:00
Erik Johnston 826ca61745 Add storage function to SlaveStore 2016-08-31 14:45:04 +01:00
Mark Haines 1aa3e1d287 Add a replication stream for direct to device messages 2016-08-31 10:38:58 +01:00
Erik Johnston 3e784eff74 Remove state replication stream 2016-08-30 16:51:36 +01:00
Erik Johnston 55fc17cf4b Merge pull request #1049 from matrix-org/erikj/presence_users_in_room
Use state handler instead of get_users_in_room/get_joined_hosts
2016-08-30 10:50:37 +01:00
Erik Johnston 41788bba50 Add to slave store 2016-08-30 09:55:17 +01:00
Erik Johnston 873f870e5a Add new direct message storage functions to slave store 2016-08-30 09:40:32 +01:00
Erik Johnston bed10f9880 Use state handler instead of get_users_in_room/get_joined_hosts 2016-08-26 14:54:30 +01:00
Erik Johnston 4daa397a00 Add is_host_joined to slave storage 2016-08-26 13:10:56 +01:00
Erik Johnston 50943ab942 Add new state storage funcs to replication 2016-08-26 09:57:32 +01:00
Erik Johnston 07229bbdae Add appservice worker 2016-08-18 14:59:55 +01:00
Erik Johnston a2427981b7 Use cached get_user_by_access_token in slaves 2016-08-16 11:24:32 +01:00
Erik Johnston d9664344ec Rename table. Add docs. 2016-08-15 11:45:57 +01:00
Erik Johnston 0be963472b Use cached version of get_aliases_for_room 2016-08-15 11:24:12 +01:00
Erik Johnston 64e7e11853 Implement cache replication stream 2016-08-15 11:16:45 +01:00
Erik Johnston 5aa024e501 Merge branch 'develop' of github.com:matrix-org/synapse into erikj/fed_reader 2016-07-29 11:24:56 +01:00
Mark Haines 0a7d3cd00f Create separate methods for getting messages to push
for the email and http pushers rather than trying to make a single
method that will work with their conflicting requirements.

The http pusher needs to get the messages in ascending stream order, and
doesn't want to miss a message.

The email pusher needs to get the messages in descending timestamp order,
and doesn't mind if it misses messages.
2016-07-28 20:24:24 +01:00
Erik Johnston ec8b217722 Add destination retry to slave store 2016-07-28 17:35:53 +01:00
Erik Johnston 76b89d0edb Add slace storage functions for public room list 2016-07-28 17:03:40 +01:00
Erik Johnston 0fcbca531f Add get_auth_chain to slave store 2016-07-28 16:36:28 +01:00
Erik Johnston 6ede23ff1b Add more key storage funcs into slave store 2016-07-28 15:41:26 +01:00
Erik Johnston aede7248ab Split out a FederationReader process 2016-07-21 17:37:44 +01:00
David Baker 46b7362304 pep8 2016-06-24 11:44:57 +01:00
David Baker 870c45913e Use similar naming we use in email notifs for push
Fixes https://github.com/vector-im/vector-web/issues/1654
2016-06-24 11:41:11 +01:00
Erik Johnston 05e01f21d7 Remove event fetching from DB threads 2016-06-03 17:22:13 +01:00
Mark Haines 20eccd84d4 Merge pull request #827 from matrix-org/markjh/more_slaved_methods
Add methods to events, account data and receipt slaves
2016-06-03 11:46:21 +01:00
Mark Haines b09f348530 Merge pull request #824 from matrix-org/markjh/slaved_presence_store
Add a slaved store for presence
2016-06-03 11:26:33 +01:00
Mark Haines 81cf449daa Add methods to events, account data and receipt slaves
Adds the methods needed by /sync to the slaved events,
account data and receipt stores.
2016-06-03 11:19:27 +01:00
Mark Haines 3ae915b27e Add a slaved store for presence 2016-06-03 11:05:53 +01:00
Mark Haines f88d747f79 Add a comment explaining why the filter cache doesn't need exipiring 2016-06-03 11:03:10 +01:00
Mark Haines 0eae075723 Add slaved stores for filters, tokens, and push rules 2016-06-03 10:58:03 +01:00
Mark Haines 70599ce925 Allow external processes to mark a user as syncing. (#812)
* Add infrastructure to the presence handler to track sync requests in external processes

* Expire stale entries for dead external processes

* Add an http endpoint for making users as syncing

Add some docstrings and comments.

* Fixes
2016-06-02 15:20:15 +01:00
Mark Haines 0cb441fedd Move typing handler out of the Handlers object 2016-05-17 15:58:46 +01:00
Mark Haines 3b86ecfa79 Move the presence handler out of the Handlers object 2016-05-16 18:56:37 +01:00
Mark Haines 0466454b00 Assert that stream replicated stream positions are ints 2016-05-13 17:33:44 +01:00
Mark Haines 1f71f386f6 Merge branch 'develop' into dbkr/email_notifs_on_pusher 2016-05-13 16:59:56 +01:00
Mark Haines 206eb9fd94 Shift some of the state_group methods into the SlavedEventStore 2016-05-13 16:58:14 +01:00
Mark Haines 3abab26458 Add a slaved datastore for account data 2016-05-13 15:34:06 +01:00
Mark Haines 0e792e7903 Log the stream IDs in an order that makes sense 2016-05-13 11:54:44 +01:00
Mark Haines 3547e66bc6 Make sure we advance our stream position 2016-05-13 11:53:00 +01:00
David Baker 5f46be19a7 Pass through get_events to pusher too 2016-05-10 18:43:40 +02:00
David Baker d46b18a00f Pass through _get_event_txn 2016-05-10 18:27:06 +02:00
Erik Johnston 8940281d1b Don't warn 2016-05-05 15:10:03 +01:00
Erik Johnston 5d8a93a10e Add some log information at returned replication streams 2016-05-05 10:29:21 +01:00
Mark Haines 8d7ad44331 Report per request metrics for all of the things using request_handler 2016-04-28 10:57:49 +01:00
Mark Haines 8a65666454 Fix backfill replication to advance the stream correctly 2016-04-27 15:38:43 +01:00
Mark Haines 78741cf025 Merge pull request #743 from matrix-org/markjh/slave_pushers
Replicate the pushers
2016-04-21 17:21:29 +01:00
Mark Haines 31719ad124 Merge pull request #744 from matrix-org/markjh/replication_remove_pusher
Add a replication endpoint for deleting pushers
2016-04-21 17:10:49 +01:00
Mark Haines cfe1ff4bdb Add a replication endpoint for deleting pushers 2016-04-21 16:33:05 +01:00
Mark Haines d4823efad9 Replicate the pushers 2016-04-21 16:18:00 +01:00
Mark Haines c0d8e0eb63 Replicate push actions 2016-04-21 15:25:58 +01:00
Mark Haines f52dd35ac3 Merge pull request #738 from matrix-org/markjh/slaved_receipts
Add a slaved receipts store
2016-04-19 17:31:59 +01:00
Mark Haines 5bbd424ee0 Add a slaved receipts store 2016-04-19 17:14:08 +01:00
Mark Haines e99365f601 Replicate get_invited_rooms_for_user 2016-04-19 15:22:14 +01:00
Mark Haines ceb599e789 Add tests for redactions 2016-04-07 16:52:07 +01:00
Mark Haines 60ec9793fb Add tests for get_latest_event_ids_in_room and get_current_state 2016-04-07 13:17:56 +01:00
Mark Haines 6bfec56796 Test that room membership is replicated 2016-04-06 16:20:13 +01:00
Mark Haines 75fb9ac1be Add a slaved events store class
Add a test to check that get_room_names_and_aliases does the same
thing on both the master and on the slave data store.
2016-04-06 14:18:35 +01:00
Mark Haines 1d4deff25a Separate generating the replication response...
from doing the http request parsing to make it easier
to write unit tests for replication.
2016-04-05 11:23:57 +01:00
Mark Haines 62e395f0e3 Merge pull request #676 from matrix-org/markjh/replicate_stateIII
Add replication streams for ex outliers and current state resets
2016-03-31 11:20:57 +01:00
Mark Haines 2ec5426035 Use a namedtuple rather than tuple unpacking 2016-03-31 10:33:02 +01:00
Matthew Hodgson 9113316b0e typo 2016-03-30 17:29:42 +01:00
Mark Haines 1fbb094c6f Add replication streams for ex outliers and current state resets 2016-03-30 17:19:56 +01:00
Mark Haines 31a9eceda5 Add a replication stream for state groups 2016-03-30 16:01:58 +01:00
Mark Haines b6e8420aee Add replication stream for pushers 2016-03-15 17:33:10 +00:00
Mark Haines ebcbb23226 s/stream_ordering/event_stream_ordering/ in push 2016-03-04 16:15:23 +00:00
Mark Haines 2223204eba Hook push rules up to the replication API 2016-03-02 17:26:20 +00:00
Mark Haines 60a0f81c7a Add a /replication API for extracting the updates that happened on
synapse

This is necessary for replicating the data in synapse to be visible to a
separate service because presence and typing notifications aren't stored
in a database so won't be visible to another process.

This API can be used to either get the raw data by requesting the tables
themselves or to just receive notifications for updates by following the
streams meta-stream.

Returns updates for each table requested a JSON array of arrays with a
row for each row in the table.

Each table is prefixed by a header row with the: name of the table,
current stream_id position for the table, number of rows, number of
columns and the names of the columns.
This is followed by the rows that have been added to the server since
the requester last asked.

The API has a timeout and is hooked up to the notifier so that a slave
can long poll for updates.
2016-03-01 14:49:41 +00:00