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Make the auto compressor uploadable to pypi (#75)

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Erik Johnston
2021-09-28 16:57:13 +01:00
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@@ -3,7 +3,7 @@
This workspace contains experimental tools that attempt to reduce the number of
rows in the `state_groups_state` table inside of a Synapse Postgresql database.
# Automated tool: auto_compressor
# Automated tool: synapse_auto_compressor
## Introduction:
@@ -11,7 +11,7 @@ This tool is significantly more simple to use than the manual tool (described be
It scans through all of the rows in the `state_groups` database table from the start. When
it finds a group that hasn't been compressed, it runs the compressor for a while on that
group's room, saving where it got up to. After compressing a number of these chunks it stops,
saving where it got up to for the next run of the `auto_compressor`.
saving where it got up to for the next run of the `synapse_auto_compressor`.
It creates three extra tables in the database: `state_compressor_state` which stores the
information needed to stop and start the compressor for each room, `state_compressor_progress`
@@ -21,41 +21,42 @@ which stores how far through the `state_groups` table the compressor has scanned
The tool can be run manually when you are running out of space, or be scheduled to run
periodically.
## Building
## Building
This tool requires `cargo` to be installed. See https://www.rust-lang.org/tools/install
for instructions on how to do this.
To build `auto_compressor`, clone this repository and navigate to the `autocompressor/`
subdirectory. Then execute `cargo build`.
To build `synapse_auto_compressor`, clone this repository and navigate to the
`synapse_auto_compressor/` subdirectory. Then execute `cargo build`.
This will create an executable and store it in `auto_compressor/target/debug/auto_compressor`.
This will create an executable and store it in
`synapse_auto_compressor/target/debug/synapse_auto_compressor`.
## Example usage
```
$ auto_compressor -p postgresql://user:pass@localhost/synapse -c 500 -n 100
$ synapse_auto_compressor -p postgresql://user:pass@localhost/synapse -c 500 -n 100
```
## Running Options
- -p [POSTGRES_LOCATION] **Required**
- -p [POSTGRES_LOCATION] **Required**
The configuration for connecting to the Postgres database. This should be of the form
`"postgresql://username:password@mydomain.com/database"` or a key-value pair
string: `"user=username password=password dbname=database host=mydomain.com"`
See https://docs.rs/tokio-postgres/0.7.2/tokio_postgres/config/struct.Config.html
for the full details.
- -c [CHUNK_SIZE] **Required**
- -c [CHUNK_SIZE] **Required**
The number of state groups to work on at once. All of the entries from state_groups_state are
requested from the database for state groups that are worked on. Therefore small chunk
sizes may be needed on machines with low memory. Note: if the compressor fails to find
space savings on the chunk as a whole (which may well happen in rooms with lots of backfill
in) then the entire chunk is skipped.
- -n [CHUNKS_TO_COMPRESS] **Required**
- -n [CHUNKS_TO_COMPRESS] **Required**
*CHUNKS_TO_COMPRESS* chunks of size *CHUNK_SIZE* will be compressed. The higher this
number is set to, the longer the compressor will run for.
- -d [LEVELS]
- -d [LEVELS]
Sizes of each new level in the compression algorithm, as a comma-separated list.
The first entry in the list is for the lowest, most granular level, with each
subsequent entry being for the next highest level. The number of entries in the
@@ -67,14 +68,14 @@ given set of state. [defaults to "100,50,25"]
## Scheduling the compressor
The automatic tool may put some strain on the database, so it might be best to schedule
it to run at a quiet time for the server. This could be done by creating an executable
script and scheduling it with something like
script and scheduling it with something like
[cron](https://www.man7.org/linux/man-pages/man1/crontab.1.html).
# Manual tool: synapse_compress_state
## Introduction
A manual tool that reads in the rows from `state_groups_state` and `state_group_edges`
A manual tool that reads in the rows from `state_groups_state` and `state_group_edges`
tables for a specified room and calculates the changes that could be made that
(hopefully) will significantly reduce the number of rows.
@@ -85,7 +86,7 @@ that if `-t` is given then each change to a particular state group is wrapped
in a transaction). If you do wish to send the changes to the database automatically
then the `-c` flag can be set.
The SQL generated is safe to apply against the database with Synapse running.
The SQL generated is safe to apply against the database with Synapse running.
This is because the `state_groups` and `state_groups_state` tables are append-only:
once written to the database, they are never modified. There is therefore no danger
of a modification racing against a running Synapse. Further, this script makes its
@@ -95,7 +96,7 @@ from any of the queries that Synapse performs.
The tool will also ensure that the generated state deltas do give the same state
as the existing state deltas before generating any SQL.
## Building
## Building
This tool requires `cargo` to be installed. See https://www.rust-lang.org/tools/install
for instructions on how to do this.
@@ -125,54 +126,54 @@ $ psql synapse < out.data
## Running Options
- -p [POSTGRES_LOCATION] **Required**
- -p [POSTGRES_LOCATION] **Required**
The configuration for connecting to the Postgres database. This should be of the form
`"postgresql://username:password@mydomain.com/database"` or a key-value pair
string: `"user=username password=password dbname=database host=mydomain.com"`
See https://docs.rs/tokio-postgres/0.7.2/tokio_postgres/config/struct.Config.html
for the full details.
- -r [ROOM_ID] **Required**
- -r [ROOM_ID] **Required**
The room to process (this is the value found in the `rooms` table of the database
not the common name for the room - it should look like: "!wOlkWNmgkAZFxbTaqj:matrix.org".
- -b [MIN_STATE_GROUP]
- -b [MIN_STATE_GROUP]
The state group to start processing from (non-inclusive).
- -n [GROUPS_TO_COMPRESS]
- -n [GROUPS_TO_COMPRESS]
How many groups to load into memory to compress (starting
from the 1st group in the room or the group specified by -b).
- -l [LEVELS]
- -l [LEVELS]
Sizes of each new level in the compression algorithm, as a comma-separated list.
The first entry in the list is for the lowest, most granular level, with each
The first entry in the list is for the lowest, most granular level, with each
subsequent entry being for the next highest level. The number of entries in the
list determines the number of levels that will be used. The sum of the sizes of
the levels affects the performance of fetching the state from the database, as the
sum of the sizes is the upper bound on the number of iterations needed to fetch a
given set of state. [defaults to "100,50,25"]
- -m [COUNT]
- -m [COUNT]
If the compressor cannot save this many rows from the database then it will stop early.
- -s [MAX_STATE_GROUP]
- -s [MAX_STATE_GROUP]
If a max_state_group is specified then only state groups with id's lower than this
number can be compressed.
- -o [FILE]
- -o [FILE]
File to output the SQL transactions to (for later running on the database).
- -t
- -t
If this flag is set then each change to a particular state group is wrapped in a
transaction. This should be done if you wish to apply the changes while synapse is
still running.
- -c
- -c
If this flag is set then the changes the compressor makes will be committed to the
database. This should be safe to use while synapse is running as it wraps the changes
to every state group in it's own transaction (as if the transaction flag was set).
- -g
- -g
If this flag is set then output the node and edge information for the state_group
directed graph built up from the predecessor state_group links. These can be looked
at in something like Gephi (https://gephi.org).
@@ -196,10 +197,10 @@ $ docker-compose down
# Using the synapse_compress_state library
If you want to use the compressor in another project, it is recomended that you
use jemalloc `https://github.com/gnzlbg/jemallocator`.
use jemalloc `https://github.com/gnzlbg/jemallocator`.
To prevent the progress bars from being shown, use the `no-progress-bars` feature.
(See `auto_compressor/Cargo.toml` for an example)
(See `synapse_auto_compressor/Cargo.toml` for an example)
# Troubleshooting
@@ -216,29 +217,29 @@ from the machine where Postgres is running, the url will be the following:
### From remote machine
If you wish to connect from a different machine, you'll need to edit your Postgres settings to allow
remote connections. This requires updating the
remote connections. This requires updating the
[`pg_hba.conf`](https://www.postgresql.org/docs/current/auth-pg-hba-conf.html) and the `listen_addresses`
setting in [`postgresql.conf`](https://www.postgresql.org/docs/current/runtime-config-connection.html)
## Printing debugging logs
The amount of output the tools produce can be altered by setting the RUST_LOG
environment variable to something.
The amount of output the tools produce can be altered by setting the RUST_LOG
environment variable to something.
To get more logs when running the auto_compressor tool try the following:
To get more logs when running the synapse_auto_compressor tool try the following:
```
$ RUST_LOG=debug auto_compressor -p postgresql://user:pass@localhost/synapse -c 50 -n 100
$ RUST_LOG=debug synapse_auto_compressor -p postgresql://user:pass@localhost/synapse -c 50 -n 100
```
If you want to suppress all the debugging info you are getting from the
If you want to suppress all the debugging info you are getting from the
Postgres client then try:
```
RUST_LOG=auto_compressor=debug,synapse_compress_state=debug auto_compressor [etc.]
RUST_LOG=synapse_auto_compressor=debug,synapse_compress_state=debug synapse_auto_compressor [etc.]
```
This will only print the debugging information from those two packages. For more info see
This will only print the debugging information from those two packages. For more info see
https://docs.rs/env_logger/0.9.0/env_logger/.
## Building difficulties
@@ -248,7 +249,7 @@ and building on Linux will also require `pkg-config`
This can be done on Ubuntu with: `$ apt-get install libssl-dev pkg-config`
Note that building requires quite a lot of memory and out-of-memory errors might not be
Note that building requires quite a lot of memory and out-of-memory errors might not be
obvious. It's recomended you only build these tools on machines with at least 2GB of RAM.
## Auto Compressor skips chunks when running on already compressed room
@@ -265,8 +266,8 @@ be a large problem.
## Compressor is trying to increase the number of rows
Backfilling can lead to issues with compression. The auto_compressor will
skip chunks it can't reduce the size of and so this should help jump over the backfilled
Backfilling can lead to issues with compression. The synapse_auto_compressor will
skip chunks it can't reduce the size of and so this should help jump over the backfilled
state_groups. Lots of state resolution might also impact the ability to use the compressor.
To examine the state_group hierarchy run the manual tool on a room with the `-g` option