49 lines
1.7 KiB
Markdown
49 lines
1.7 KiB
Markdown
# Working with Prometheus Metrics
|
|
|
|
## Adding to the library
|
|
|
|
We strive to support the 2-4 most important metrics for each common system service that supports Prometheus. If you are looking for support for a particular exporter which has not yet been added to the library, additions can be made [to the `common_metrics.yml`](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/config/prometheus/common_metrics.yml) file.
|
|
|
|
### Query identifier
|
|
|
|
The requirement for adding a new metric is to make each query to have an unique identifier which is used to update the metric later when changed:
|
|
|
|
```yaml
|
|
- group: Response metrics (NGINX Ingress)
|
|
metrics:
|
|
- title: "Throughput"
|
|
y_label: "Requests / Sec"
|
|
queries:
|
|
- id: response_metrics_nginx_ingress_throughput_status_code
|
|
query_range: 'sum(rate(nginx_upstream_responses_total{upstream=~"%{kube_namespace}-%{ci_environment_slug}-.*"}[2m])) by (status_code)'
|
|
unit: req / sec
|
|
label: Status Code
|
|
```
|
|
|
|
### Update existing metrics
|
|
|
|
After you add or change existing _common_ metric you have to create a new database migration that will query and update all existing metrics.
|
|
|
|
NOTE: **Note:**
|
|
If a query metric (which is identified by `id:`) is removed it will not be removed from database by default.
|
|
You might want to add additional database migration that makes a decision what to do with removed one.
|
|
For example: you might be interested in migrating all dependent data to a different metric.
|
|
|
|
```ruby
|
|
class ImportCommonMetrics < ActiveRecord::Migration[4.2]
|
|
include Gitlab::Database::MigrationHelpers
|
|
|
|
require Rails.root.join('db/importers/common_metrics_importer.rb')
|
|
|
|
DOWNTIME = false
|
|
|
|
def up
|
|
Importers::CommonMetricsImporter.new.execute
|
|
end
|
|
|
|
def down
|
|
# no-op
|
|
end
|
|
end
|
|
```
|