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---
stage: none
group: unassigned
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
---
# GitLab Developers Guide to service measurement
You can enable service measurement in order to debug any slow service's execution time, number of SQL calls, garbage collection stats, memory usage, etc.
## Measuring module
The measuring module is a tool that allows to measure a service's execution, and log:
- Service class name
- Execution time
- Number of SQL calls
- Detailed `gc` stats and diffs
- RSS memory usage
- Server worker ID
The measuring module logs these measurements into a structured log called [`service_measurement.log`](../administration/logs.md#service_measurementlog),
as a single entry for each service execution.
For GitLab.com, `service_measurement.log` is ingested in Elasticsearch and Kibana as part of our monitoring solution.
## How to use it
The measuring module allows you to easily measure and log execution of any service,
by just prepending `Measurable` in any Service class, on the last line of the file that the class resides in.
For example, to prepend a module into the `DummyService` class, you would use the following approach:
```ruby
class DummyService
def execute
# ...
end
end
DummyService.prepend(Measurable)
```
In case when you are prepending a module from the `EE` namespace with EE features, you need to prepend Measurable after prepending the `EE` module.
This way, `Measurable` is at the bottom of the ancestor chain, in order to measure execution of `EE` features as well:
```ruby
class DummyService
def execute
# ...
end
end
DummyService.prepend_if_ee('EE::DummyService')
DummyService.prepend(Measurable)
```
### Log additional attributes
In case you need to log some additional attributes, it is possible to define `extra_attributes_for_measurement` in the service class:
```ruby
def extra_attributes_for_measurement
{
project_path: @project.full_path,
user: current_user.name
}
end
```
After the measurement module is injected in the service, it is behind a generic feature flag.
To actually use it, you need to enable measuring for the desired service by enabling the feature flag.
### Enabling measurement using feature flags
In the following example, the `:gitlab_service_measuring_projects_import_service`
[feature flag](feature_flags/development.md#enabling-a-feature-flag-locally-in-development) is used to enable the measuring feature
for `Projects::ImportService`.
From ChatOps:
```shell
/chatops run feature set gitlab_service_measuring_projects_import_service true
```
|
