| # Gerrit Postgres based persistent cache |
| |
| Gerrit lib module to swap existing persistent cache implementation |
| (that is H2 based) with implementation that stores data in Postgres. |
| Note that is uses [INSERT INTO ... ON CONFLICT DO UPDATE ...](https://stackoverflow.com/questions/17267417/how-to-upsert-merge-insert-on-duplicate-update-in-postgresql) |
| upsert syntax therefore it is Postgres *9.5+* compatible. |
| |
| ## How to build |
| |
| Build this module similarly to standalone build for any other, |
| bazel based Gerrit plugin: |
| |
| - Clone the cache-postgres source tree |
| - Run ```bazel build cache-postgres``` |
| - The ```cache-postgres.jar``` module is generated under ```/bazel-genfiles/cache-postgres.jar``` |
| |
| ## How install |
| |
| Copy ```cache-postgres.jar``` library to Gerrit ```/lib``` and add the following |
| two extra settings to ```gerrit.config```: |
| |
| ``` |
| [gerrit] |
| installModule = com.googlesource.gerrit.modules.cache.pg.CacheModule |
| |
| [cache] |
| url = jdbc:postgresql://localhost:5432/gerrit_caches?user=gerrit&password=gerrit |
| ``` |
| |
| ## Core Gerrit settings: section `cache` |
| |
| cache.url |
| : URI that specifies connection to existing DB (including both |
| username and passwword). |
| |
| cache.poolLimit |
| : Maximum number of open database connections. If the server needs |
| more than this number, request processing threads will wait up |
| to `cache.poolMaxWait` seconds for a connection to be released before |
| they abort with an exception. |
| Default value is taken from `database.poolLimit`. |
| |
| cache.poolMinIdle |
| : Minimum number of connections to keep idle in the pool. |
| Default is `4`. |
| |
| cache.poolMaxIdle |
| : Maximum number of connections to keep idle in the pool. If there |
| are more idle connections, connections will be closed instead of |
| being returned back to the pool. |
| Default is min(`cache.poolLimit`, `16`). |
| |
| cache.poolMaxWait |
| Maximum amount of time a request processing thread will wait to |
| acquire a database connection from the pool. If no connection is |
| released within this time period, the processing thread will abort |
| its current operations and return an error to the client. |
| Values should use common unit suffixes to express their setting: |
| * ms, milliseconds |
| * s, sec, second, seconds |
| * m, min, minute, minutes |
| * h, hr, hour, hours |
| |
| If a unit suffix is not specified, `milliseconds` is assumed. |
| Default is `30 seconds`. |
