diff options
Diffstat (limited to 'doc/development')
| -rw-r--r-- | doc/development/migration_style_guide.md | 16 | ||||
| -rw-r--r-- | doc/development/polling.md | 11 |
2 files changed, 25 insertions, 2 deletions
diff --git a/doc/development/migration_style_guide.md b/doc/development/migration_style_guide.md index fd8335d251e..587922d0136 100644 --- a/doc/development/migration_style_guide.md +++ b/doc/development/migration_style_guide.md @@ -58,10 +58,22 @@ migration was tested. ## Removing indices -If you need to remove index, please add a condition like in following example: +When removing an index make sure to use the method `remove_concurrent_index` instead +of the regular `remove_index` method. The `remove_concurrent_index` method +automatically drops concurrent indexes when using PostgreSQL, removing the +need for downtime. To use this method you must disable transactions by calling +the method `disable_ddl_transaction!` in the body of your migration class like +so: ```ruby -remove_index :namespaces, column: :name if index_exists?(:namespaces, :name) +class MyMigration < ActiveRecord::Migration + include Gitlab::Database::MigrationHelpers + disable_ddl_transaction! + + def up + remove_concurrent_index :table_name, :column_name if index_exists?(:table_name, :column_name) + end +end ``` ## Adding indices diff --git a/doc/development/polling.md b/doc/development/polling.md index e5a717f712b..05e19f0c515 100644 --- a/doc/development/polling.md +++ b/doc/development/polling.md @@ -22,7 +22,12 @@ Instead you should use polling mechanism with ETag caching in Redis. ## How it works +Cache Miss: +  + +Cache Hit: +  1. Whenever a resource changes we generate a random value and store it in @@ -39,6 +44,12 @@ Instead you should use polling mechanism with ETag caching in Redis. 1. If the `If-None-Match` header does not match the current value in Redis we have to generate a new response, because the resource changed. +Do not use query parameters (for example `?scope=all`) for endpoints where you +want to enable ETag caching. The middleware takes into account only the request +path and ignores query parameters. All parameters should be included in the +request path. By doing this we avoid query parameter ordering problems and make +route matching easier. + For more information see: - [RFC 7232](https://tools.ietf.org/html/rfc7232) - [ETag proposal](https://gitlab.com/gitlab-org/gitlab-ce/issues/26926) |