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Update docs for database load balancing logs

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The database load balancing docs had some mention of the logs that
needed to be updated, and the logs doc had an absolute link to
gitlab.com instead of a relative link to a markdown file.
This commit is contained in:
Hordur Freyr Yngvason 2019-09-05 22:39:51 +00:00 committed by Evan Read
parent a3281912a4
commit 15b2e48843
2 changed files with 15 additions and 18 deletions
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29
doc/administration/database_load_balancing.md
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@ -212,28 +212,25 @@ without it immediately leading to errors being presented to the users.
## Logging
The load balancer logs various messages, such as:
The load balancer logs various events in
[`database_load_balancing.log`](logs.md#database_load_balancinglog-premium-only), such as
- When a host is marked as offline
- When a host comes back online
- When all secondaries are offline
- When a read is retried on a different host due to a query conflict
Each log message contains the tag `[DB-LB]` to make searching/filtering of such
log entries easier. For example:
The log is structured with each entry a JSON object containing at least:
```
[DB-LB] Host 10.123.2.5 came back online
[DB-LB] Marking host 10.123.2.7 as offline
[DB-LB] Marking host 10.123.2.7 as offline
[DB-LB] Marking host 10.123.2.7 as offline
[DB-LB] Marking host 10.123.2.7 as offline
[DB-LB] Marking host 10.123.2.7 as offline
[DB-LB] Host 10.123.2.6 came back online
[DB-LB] Marking host 10.123.2.7 as offline
[DB-LB] Marking host 10.123.2.7 as offline
[DB-LB] Marking host 10.123.2.7 as offline
[DB-LB] Host 10.123.2.7 came back online
[DB-LB] Host 10.123.2.7 came back online
- An `event` field useful for filtering.
- A human-readable `message` field.
- Some event-specific metadata. For example, `db_host`
- Contextual information that is always logged. For example, `severity` and `time`.
For example:
```json
{"severity":"INFO","time":"2019-09-02T12:12:01.728Z","correlation_id":"abcdefg","event":"host_online","message":"Host came back online","db_host":"111.222.333.444","db_port":null,"tag":"rails.database_load_balancing","environment":"production","hostname":"web-example-1","fqdn":"gitlab.example.com","path":null,"params":null}
```
## Handling Stale Reads

4
doc/administration/logs.md
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@ -339,11 +339,11 @@ installations from source.
[Rack Attack]: ../security/rack_attack.md
[Rate Limit]: ../user/admin_area/settings/rate_limits_on_raw_endpoints.md
## `database_load_balancing.log`
## `database_load_balancing.log` **(PREMIUM ONLY)**
> [Introduced](https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/15442) in GitLab 12.3.
This log is used for observability of [Database Load Balancing](database_load_balancing.md).
Contains details of GitLab's [Database Load Balancing](database_load_balancing.md).
It is stored at:
- `/var/log/gitlab/gitlab-rails/database_load_balancing.log` for Omnibus GitLab packages.