dendrite/roomserver
Neil Alexander f7cfa75886
Limit database connections (#980, #564) (#998)
* Limit database connections (#564)

- Add new options to the config file database:
      max_open_conns: 100
      max_idle_conns: 2
      conn_max_lifetime: -1
- Implement connection parameter setup on the *DB (database/sql) in internal/sqlutil/trace.go:Open()
- Propagate the values in the form of DbProperties interface via all the
  Open() and NewDatabase() functions

Signed-off-by: Tomas Jirka <tomas.jirka@email.cz>

* Fix wasm builds

* Remove file accidentally added from working tree

Co-authored-by: Tomas Jirka <tomas.jirka@email.cz>
2020-05-01 13:34:53 +01:00
..
api Consolidation of roomserver APIs (#994) 2020-05-01 10:48:17 +01:00
auth Honour history_visibility when backfilling (#990) 2020-04-29 18:41:45 +01:00
internal Consolidation of roomserver APIs (#994) 2020-05-01 10:48:17 +01:00
state Honour history_visibility when backfilling (#990) 2020-04-29 18:41:45 +01:00
storage Limit database connections (#980, #564) (#998) 2020-05-01 13:34:53 +01:00
types Invites v2 endpoint (#952) 2020-04-03 14:29:06 +01:00
version Enable v5 rooms (#992) 2020-04-29 19:37:00 +01:00
README.md use go module for dependencies (#594) 2019-05-21 21:56:55 +01:00
roomserver.go Limit database connections (#980, #564) (#998) 2020-05-01 13:34:53 +01:00

RoomServer

RoomServer Internals

Numeric IDs

To save space matrix string identifiers are mapped to local numeric IDs. The numeric IDs are more efficient to manipulate and use less space to store. The numeric IDs are never exposed in the API the room server exposes. The numeric IDs are converted to string IDs before they leave the room server. The numeric ID for a string ID is never 0 to avoid being confused with go's default zero value. Zero is used to indicate that there was no corresponding string ID. Well-known event types and event state keys are preassigned numeric IDs.

State Snapshot Storage

The room server stores the state of the matrix room at each event. For efficiency the state is stored as blocks of 3-tuples of numeric IDs for the event type, event state key and event ID. For further efficiency the state snapshots are stored as the combination of up to 64 these blocks. This allows blocks of the room state to be reused in multiple snapshots.

The resulting database tables look something like this:

+-------------------------------------------------------------------+
| Events                                                            |
+---------+-------------------+------------------+------------------+
| EventNID| EventTypeNID      | EventStateKeyNID | StateSnapshotNID |
+---------+-------------------+------------------+------------------+
|       1 | m.room.create   1 | ""             1 | <nil>          0 |
|       2 | m.room.member   2 | "@user:foo"    2 | <nil>          0 |
|       3 | m.room.member   2 | "@user:bar"    3 | {1,2}          1 |
|       4 | m.room.message  3 | <nil>          0 | {1,2,3}        2 |
|       5 | m.room.member   2 | "@user:foo"    2 | {1,2,3}        2 |
|       6 | m.room.message  3 | <nil>          0 | {1,3,6}        3 |
+---------+-------------------+------------------+------------------+

+----------------------------------------+
| State Snapshots                        |
+-----------------------+----------------+
| EventStateSnapshotNID | StateBlockNIDs |
+-----------------------+----------------|
|                     1 |           {1}  |
|                     2 |         {1,2}  |
|                     3 |       {1,2,3}  |
+-----------------------+----------------+

+-----------------------------------------------------------------+
| State Blocks                                                    |
+---------------+-------------------+------------------+----------+
| StateBlockNID | EventTypeNID      | EventStateKeyNID | EventNID |
+---------------+-------------------+------------------+----------+
|             1 | m.room.create   1 | ""             1 |        1 |
|             1 | m.room.member   2 | "@user:foo"    2 |        2 |
|             2 | m.room.member   2 | "@user:bar"    3 |        3 |
|             3 | m.room.member   2 | "@user:foo"    2 |        6 |
+---------------+-------------------+------------------+----------+