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author | Achilleas Pipinellis <axilleas@axilleas.me> | 2016-01-20 22:12:25 +0000 |
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committer | Achilleas Pipinellis <axilleas@axilleas.me> | 2016-01-20 22:12:25 +0000 |
commit | fa9d306b01c16d48ca3e828aa0aed1da5c7c4079 (patch) | |
tree | 1b2c806d4fcf2af9214c40d884354698801741c9 | |
parent | 3e7092a83ab0fc6cb259627c8ecc0e259f77ca7c (diff) | |
parent | dd59fc213c6cf2a2efb39eda241f453bbd1e82c7 (diff) | |
download | gitlab-ce-fa9d306b01c16d48ca3e828aa0aed1da5c7c4079.tar.gz |
Merge branch 'metrics-documentation' into 'master'
Added documentation for GitLab Metrics
This adds documentation for the metrics code I recently added.
Two notes:
* I'm referring to this feature as "GitLab Metrics" everywhere simply
because the code resides in the `Gitlab::Metrics` namespace. A
different name is fine, though I think just "Metrics" might be a bit
too abstract.
* Grafana isn't covered since it's fairly straight-forward to setup
(there's nothing really special we can cover). I think we _should_
cover it once we start shipping it with Omnibus.
I assigned @axil since he's our technical writer/documentation guru,
feel free to re-assign if needed.
cc @sytses @axil @dzaporozhets @JobV
See merge request !2484
-rw-r--r-- | doc/README.md | 1 | ||||
-rw-r--r-- | doc/integration/README.md | 1 | ||||
-rw-r--r-- | doc/monitoring/performance/gitlab_configuration.md | 39 | ||||
-rw-r--r-- | doc/monitoring/performance/img/metrics_gitlab_configuration_settings.png | bin | 0 -> 45148 bytes | |||
-rw-r--r-- | doc/monitoring/performance/influxdb_configuration.md | 192 | ||||
-rw-r--r-- | doc/monitoring/performance/influxdb_schema.md | 87 | ||||
-rw-r--r-- | doc/monitoring/performance/introduction.md | 64 |
7 files changed, 384 insertions, 0 deletions
diff --git a/doc/README.md b/doc/README.md index 7d4f84857e0..1efed2871f9 100644 --- a/doc/README.md +++ b/doc/README.md @@ -67,6 +67,7 @@ - [Reply by email](incoming_email/README.md) Allow users to comment on issues and merge requests by replying to notification emails. - [Migrate GitLab CI to CE/EE](migrate_ci_to_ce/README.md) Follow this guide to migrate your existing GitLab CI data to GitLab CE/EE. - [Git LFS configuration](workflow/lfs/lfs_administration.md) +- [GitLab Performance Monitoring](monitoring/performance/introduction.md) Configure GitLab and InfluxDB for measuring performance metrics ## Contributor documentation diff --git a/doc/integration/README.md b/doc/integration/README.md index 5edac746c7b..297e4f6e7bf 100644 --- a/doc/integration/README.md +++ b/doc/integration/README.md @@ -15,6 +15,7 @@ See the documentation below for details on how to configure these services. - [OAuth2 provider](oauth_provider.md) OAuth2 application creation - [Gmail actions buttons](gmail_action_buttons_for_gitlab.md) Adds GitLab actions to messages - [reCAPTCHA](recaptcha.md) Configure GitLab to use Google reCAPTCHA for new users +- [GitLab Performance Monitoring](metrics/introduction.md) Configure GitLab and InfluxDB for measuring performance metrics GitLab Enterprise Edition contains [advanced Jenkins support][jenkins]. diff --git a/doc/monitoring/performance/gitlab_configuration.md b/doc/monitoring/performance/gitlab_configuration.md new file mode 100644 index 00000000000..b856e7935a3 --- /dev/null +++ b/doc/monitoring/performance/gitlab_configuration.md @@ -0,0 +1,39 @@ +# GitLab Configuration + +GitLab Performance Monitoring is disabled by default. To enable it and change any of its +settings, navigate to the Admin area in **Settings > Metrics** +(`/admin/application_settings`). + +The minimum required settings you need to set are the InfluxDB host and port. +Make sure _Enable InfluxDB Metrics_ is checked and hit **Save** to save the +changes. + +--- + +![GitLab Performance Monitoring Admin Settings](img/metrics_gitlab_configuration_settings.png) + +--- + +Finally, a restart of all GitLab processes is required for the changes to take +effect: + +```bash +# For Omnibus installations +sudo gitlab-ctl restart + +# For installations from source +sudo service gitlab restart +``` + +## Pending Migrations + +When any migrations are pending, the metrics are disabled until the migrations +have been performed. + +--- + +Read more on: + +- [Introduction to GitLab Performance Monitoring](introduction.md) +- [InfluxDB Configuration](influxdb_configuration.md) +- [InfluxDB Schema](influxdb_schema.md) diff --git a/doc/monitoring/performance/img/metrics_gitlab_configuration_settings.png b/doc/monitoring/performance/img/metrics_gitlab_configuration_settings.png Binary files differnew file mode 100644 index 00000000000..14d82b6ac98 --- /dev/null +++ b/doc/monitoring/performance/img/metrics_gitlab_configuration_settings.png diff --git a/doc/monitoring/performance/influxdb_configuration.md b/doc/monitoring/performance/influxdb_configuration.md new file mode 100644 index 00000000000..3a2b598b78f --- /dev/null +++ b/doc/monitoring/performance/influxdb_configuration.md @@ -0,0 +1,192 @@ +# InfluxDB Configuration + +The default settings provided by [InfluxDB] are not sufficient for a high traffic +GitLab environment. The settings discussed in this document are based on the +settings GitLab uses for GitLab.com, depending on your own needs you may need to +further adjust them. + +If you are intending to run InfluxDB on the same server as GitLab, make sure +you have plenty of RAM since InfluxDB can use quite a bit depending on traffic. + +Unless you are going with a budget setup, it's advised to run it separately. + +## Requirements + +- InfluxDB 0.9.5 or newer +- A fairly modern version of Linux +- At least 4GB of RAM +- At least 10GB of storage for InfluxDB data + +Note that the RAM and storage requirements can differ greatly depending on the +amount of data received/stored. To limit the amount of stored data users can +look into [InfluxDB Retention Policies][influxdb-retention]. + +## Installation + +Installing InfluxDB is out of the scope of this document. Please refer to the +[InfluxDB documentation]. + +## InfluxDB Server Settings + +Since InfluxDB has many settings that users may wish to customize themselves +(e.g. what port to run InfluxDB on), we'll only cover the essentials. + +The configuration file in question is usually located at +`/etc/influxdb/influxdb.conf`. Whenever you make a change in this file, +InfluxDB needs to be restarted. + +### Storage Engine + +InfluxDB comes with different storage engines and as of InfluxDB 0.9.5 a new +storage engine is available, called [TSM Tree]. All users **must** use the new +`tsm1` storage engine as this [will be the default engine][tsm1-commit] in +upcoming InfluxDB releases. + +Make sure you have the following in your configuration file: + +``` +[data] + dir = "/var/lib/influxdb/data" + engine = "tsm1" +``` + +### Admin Panel + +Production environments should have the InfluxDB admin panel **disabled**. This +feature can be disabled by adding the following to your InfluxDB configuration +file: + +``` +[admin] + enabled = false +``` + +### HTTP + +HTTP is required when using the [InfluxDB CLI] or other tools such as Grafana, +thus it should be enabled. When enabling make sure to _also_ enable +authentication: + +``` +[http] + enabled = true + auth-enabled = true +``` + +_**Note:** Before you enable authentication, you might want to [create an +admin user](#create-a-new-admin-user)._ + +### UDP + +GitLab writes data to InfluxDB via UDP and thus this must be enabled. Enabling +UDP can be done using the following settings: + +``` +[[udp]] + enabled = true + bind-address = ":8089" + database = "gitlab" + batch-size = 1000 + batch-pending = 5 + batch-timeout = "1s" + read-buffer = 209715200 +``` + +This does the following: + +1. Enable UDP and bind it to port 8089 for all addresses. +2. Store any data received in the "gitlab" database. +3. Define a batch of points to be 1000 points in size and allow a maximum of + 5 batches _or_ flush them automatically after 1 second. +4. Define a UDP read buffer size of 200 MB. + +One of the most important settings here is the UDP read buffer size as if this +value is set too low, packets will be dropped. You must also make sure the OS +buffer size is set to the same value, the default value is almost never enough. + +To set the OS buffer size to 200 MB, on Linux you can run the following command: + +```bash +sysctl -w net.core.rmem_max=209715200 +``` + +To make this permanent, add the following to `/etc/sysctl.conf` and restart the +server: + +```bash +net.core.rmem_max=209715200 +``` + +It is **very important** to make sure the buffer sizes are large enough to +handle all data sent to InfluxDB as otherwise you _will_ lose data. The above +buffer sizes are based on the traffic for GitLab.com. Depending on the amount of +traffic, users may be able to use a smaller buffer size, but we highly recommend +using _at least_ 100 MB. + +When enabling UDP, users should take care to not expose the port to the public, +as doing so will allow anybody to write data into your InfluxDB database (as +[InfluxDB's UDP protocol][udp] doesn't support authentication). We recommend either +whitelisting the allowed IP addresses/ranges, or setting up a VLAN and only +allowing traffic from members of said VLAN. + +## Create a new admin user + +If you want to [enable authentication](#http), you might want to [create an +admin user][influx-admin]: + +``` +influx -execute "CREATE USER jeff WITH PASSWORD '1234' WITH ALL PRIVILEGES" +``` + +## Create the `gitlab` database + +Once you get InfluxDB up and running, you need to create a database for GitLab. +Make sure you have changed the [storage engine](#storage-engine) to `tsm1` +before creating a database. + +_**Note:** If you [created an admin user](#create-a-new-admin-user) and enabled +[HTTP authentication](#http), remember to append the username (`-username <username>`) +and password (`-password <password>`) you set earlier to the commands below._ + +Run the following command to create a database named `gitlab`: + +```bash +influx -execute 'CREATE DATABASE gitlab' +``` + +The name **must** be `gitlab`, do not use any other name. + +Next, make sure that the database was successfully created: + +```bash +influx -execute 'SHOW DATABASES' +``` + +The output should be similar to: + +``` +name: databases +--------------- +name +_internal +gitlab +``` + +That's it! Now your GitLab instance should send data to InfluxDB. + +--- + +Read more on: + +- [Introduction to GitLab Performance Monitoring](introduction.md) +- [GitLab Configuration](gitlab_configuration.md) +- [InfluxDB Schema](influxdb_schema.md) + +[influxdb-retention]: https://docs.influxdata.com/influxdb/v0.9/query_language/database_management/#retention-policy-management +[influxdb documentation]: https://docs.influxdata.com/influxdb/v0.9/ +[influxdb cli]: https://docs.influxdata.com/influxdb/v0.9/tools/shell/ +[udp]: https://docs.influxdata.com/influxdb/v0.9/write_protocols/udp/ +[influxdb]: https://influxdata.com/time-series-platform/influxdb/ +[tsm tree]: https://influxdata.com/blog/new-storage-engine-time-structured-merge-tree/ +[tsm1-commit]: https://github.com/influxdata/influxdb/commit/15d723dc77651bac83e09e2b1c94be480966cb0d +[influx-admin]: https://docs.influxdata.com/influxdb/v0.9/administration/authentication_and_authorization/#create-a-new-admin-user diff --git a/doc/monitoring/performance/influxdb_schema.md b/doc/monitoring/performance/influxdb_schema.md new file mode 100644 index 00000000000..a5a8aebd2d1 --- /dev/null +++ b/doc/monitoring/performance/influxdb_schema.md @@ -0,0 +1,87 @@ +# InfluxDB Schema + +The following measurements are currently stored in InfluxDB: + +- `PROCESS_file_descriptors` +- `PROCESS_gc_statistics` +- `PROCESS_memory_usage` +- `PROCESS_method_calls` +- `PROCESS_object_counts` +- `PROCESS_transactions` +- `PROCESS_views` + +Here, `PROCESS` is replaced with either `rails` or `sidekiq` depending on the +process type. In all series, any form of duration is stored in milliseconds. + +## PROCESS_file_descriptors + +This measurement contains the number of open file descriptors over time. The +value field `value` contains the number of descriptors. + +## PROCESS_gc_statistics + +This measurement contains Ruby garbage collection statistics such as the amount +of minor/major GC runs (relative to the last sampling interval), the time spent +in garbage collection cycles, and all fields/values returned by `GC.stat`. + +## PROCESS_memory_usage + +This measurement contains the process' memory usage (in bytes) over time. The +value field `value` contains the number of bytes. + +## PROCESS_method_calls + +This measurement contains the methods called during a transaction along with +their duration, and a name of the transaction action that invoked the method (if +available). The method call duration is stored in the value field `duration`, +while the method name is stored in the tag `method`. The tag `action` contains +the full name of the transaction action. Both the `method` and `action` fields +are in the following format: + +``` +ClassName#method_name +``` + +For example, a method called by the `show` method in the `UsersController` class +would have `action` set to `UsersController#show`. + +## PROCESS_object_counts + +This measurement is used to store retained Ruby objects (per class) and the +amount of retained objects. The number of objects is stored in the `count` value +field while the class name is stored in the `type` tag. + +## PROCESS_transactions + +This measurement is used to store basic transaction details such as the time it +took to complete a transaction, how much time was spent in SQL queries, etc. The +following value fields are available: + +| Value | Description | +| ----- | ----------- | +| `duration` | The total duration of the transaction | +| `allocated_memory` | The amount of bytes allocated while the transaction was running. This value is only reliable when using single-threaded application servers | +| `method_duration` | The total time spent in method calls | +| `sql_duration` | The total time spent in SQL queries | +| `view_duration` | The total time spent in views | + +## PROCESS_views + +This measurement is used to store view rendering timings for a transaction. The +following value fields are available: + +| Value | Description | +| ----- | ----------- | +| `duration` | The rendering time of the view | +| `view` | The path of the view, relative to the application's root directory | + +The `action` tag contains the action name of the transaction that rendered the +view. + +--- + +Read more on: + +- [Introduction to GitLab Performance Monitoring](introduction.md) +- [GitLab Configuration](gitlab_configuration.md) +- [InfluxDB Configuration](influxdb_configuration.md) diff --git a/doc/monitoring/performance/introduction.md b/doc/monitoring/performance/introduction.md new file mode 100644 index 00000000000..f2460d31302 --- /dev/null +++ b/doc/monitoring/performance/introduction.md @@ -0,0 +1,64 @@ +# GitLab Performance Monitoring + +GitLab comes with its own application performance measuring system as of GitLab +8.4, simply called "GitLab Performance Monitoring". GitLab Performance Monitoring is available in both the +Community and Enterprise editions. + +Apart from this introduction, you are advised to read through the following +documents in order to understand and properly configure GitLab Performance Monitoring: + +- [GitLab Configuration](gitlab_configuration.md) +- [InfluxDB Configuration](influxdb_configuration.md) +- [InfluxDB Schema](influxdb_schema.md) + +## Introduction to GitLab Performance Monitoring + +GitLab Performance Monitoring makes it possible to measure a wide variety of statistics +including (but not limited to): + +- The time it took to complete a transaction (a web request or Sidekiq job). +- The time spent in running SQL queries and rendering HAML views. +- The time spent executing (instrumented) Ruby methods. +- Ruby object allocations, and retained objects in particular. +- System statistics such as the process' memory usage and open file descriptors. +- Ruby garbage collection statistics. + +Metrics data is written to [InfluxDB][influxdb] over [UDP][influxdb-udp]. Stored +data can be visualized using [Grafana][grafana] or any other application that +supports reading data from InfluxDB. Alternatively data can be queried using the +InfluxDB CLI. + +## Metric Types + +Two types of metrics are collected: + +1. Transaction specific metrics. +1. Sampled metrics, collected at a certain interval in a separate thread. + +### Transaction Metrics + +Transaction metrics are metrics that can be associated with a single +transaction. This includes statistics such as the transaction duration, timings +of any executed SQL queries, time spent rendering HAML views, etc. These metrics +are collected for every Rack request and Sidekiq job processed. + +### Sampled Metrics + +Sampled metrics are metrics that can't be associated with a single transaction. +Examples include garbage collection statistics and retained Ruby objects. These +metrics are collected at a regular interval. This interval is made up out of two +parts: + +1. A user defined interval. +1. A randomly generated offset added on top of the interval, the same offset + can't be used twice in a row. + +The actual interval can be anywhere between a half of the defined interval and a +half above the interval. For example, for a user defined interval of 15 seconds +the actual interval can be anywhere between 7.5 and 22.5. The interval is +re-generated for every sampling run instead of being generated once and re-used +for the duration of the process' lifetime. + +[influxdb]: https://influxdata.com/time-series-platform/influxdb/ +[influxdb-udp]: https://docs.influxdata.com/influxdb/v0.9/write_protocols/udp/ +[grafana]: http://grafana.org/ |