| commit | da553843afb53429c76281460e43871a11128206 | [log] [tgz] |
|---|---|---|
| author | Daniele Sassoli <danielesassoli@gmail.com> | Mon Oct 30 15:46:36 2023 +0000 |
| committer | Daniele Sassoli <danielesassoli@gmail.com> | Thu Nov 02 00:40:16 2023 +0000 |
| tree | 6339479c57979374d63c3abd962dbd5e2fa25293 | |
| parent | a26ab72dd3b75ff95b8684bc8c9a60a1aed2b8a0 [diff] |
Rename config.md to metrics.md config.md only contained information on metrics, makes more sense for it to be name metrics.md Change-Id: Ie35774e52aa97351c0b7c351c6084b428fe52b7d
Allow having a single entry point to check the availability of the services that Gerrit exposes.
Clone or link this plugin to the plugins directory of Gerrit‘s source tree, and then run bazel build on the plugin’s directory.
Example:
git clone --recursive https://gerrit.googlesource.com/gerrit git clone https://gerrit.googlesource.com/plugins/healthcheck pushd gerrit/plugins && ln -s ../../healthcheck . && popd cd gerrit && bazel build plugins/healthcheck
The output plugin jar is created in:
bazel-genfiles/plugins/healthcheck/healthcheck.jar
Copy the healthcheck.jar into the Gerrit's /plugins directory and wait for the plugin to be automatically loaded. The healthcheck plugin is compatible with both primary Gerrit setups and Gerrit replicas. The only difference to bear in mind is that some checks will be automatically disabled on replicas (e.g. query changes) because the associated subsystem is switched off.
The healthcheck plugin exposes a single endpoint under its root URL and provides a JSON output of the Gerrit health status.
The HTTP status code returned indicates whether Gerrit is healthy (HTTP status 200) or has some issues (HTTP status 500).
The HTTP response payload is a JSON output that contains the details of the checks performed.
Each check returns a JSON payload with the following information:
ts: epoch timestamp in millis of the individual check
elapsed: elapsed time in millis to complete the check
result: result of the health check
Example of a healthy Gerrit response:
GET /config/server/healthcheck~status
200 OK
Content-Type: application/json
)]}'
{
"ts": 139402910202,
"elapsed": 100,
"querychanges": {
"ts": 139402910202,
"elapsed": 20,
"result": "passed"
},
"reviewdb": {
"ts": 139402910202,
"elapsed": 50,
"result": "passed"
},
"projectslist": {
"ts": 139402910202,
"elapsed": 100,
"result": "passed"
},
"jgit": {
"ts": 139402910202,
"elapsed": 80,
"result": "passed"
}
}
Example of a Gerrit instance with the projects list timing out:
GET /config/server/healthcheck~status
500 ERROR
Content-Type: application/json
)]}'
{
"ts": 139402910202,
"elapsed": 100,
"querychanges": {
"ts": 139402910202,
"elapsed": 20,
"result": "passed"
},
"reviewdb": {
"ts": 139402910202,
"elapsed": 50,
"result": "passed"
},
"projectslist": {
"ts": 139402910202,
"elapsed": 100,
"result": "timeout"
},
"jgit": {
"ts": 139402910202,
"elapsed": 80,
"result": "passed"
}
}
It's also possible to artificially make the healthcheck fail by placing a file at a configurable path specified like:
[healtcheck] failFileFlaPath="data/healthcheck/fail"
This will make the healthcheck endpoint return 500 even if the node is otherwise healthy. This is useful when a node needs to be removed from the pool of available Gerrit instance while it undergoes maintenance.
NOTE: If the path starts with / then even paths outside of Gerrit‘s home will be checked. If the path starts WITHOUT / then the path is relative to Gerrit’s home.
NOTE: The file needs to be a real file rather than a symlink.
As for all other endpoints in Gerrit, some metrics are automatically emitted when the /config/server/healthcheck~status endpoint is hit (thanks to the Dropwizard library).
Some additional metrics are also produced to give extra insights on their result about results and latency of healthcheck sub component, such as jgit, reviewdb, etc.
More information can be found in the metrics.md file.