Recover when connection cannot be established straight at startup #414
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
When the connection to the PostgreSQL instance cannot be established straight at startup, a race condition can happen when autoDiscoverDatabases is true. If discoverDatabaseDSNs fails, no dsn is set as the master database, and, if scrapeDSN succeeds, checkMapVersions will have omitted the default metrics in the server metric map. The metric map won't be updated unless the version returned by the PostgreSQL instance changes. With this patch, scrapeDSN won't be run unless discoverDatabaseDSNs succeeded and thus the race condition is eliminated. Signed-off-by: Yann Soubeyrand <yann.soubeyrand@camptocamp.com>
| Closing in favor of #415 (I used master branch instead of a feature branch and didn't manage to change the PR's branch). |
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit. This suggestion is invalid because no changes were made to the code. Suggestions cannot be applied while the pull request is closed. Suggestions cannot be applied while viewing a subset of changes. Only one suggestion per line can be applied in a batch. Add this suggestion to a batch that can be applied as a single commit. Applying suggestions on deleted lines is not supported. You must change the existing code in this line in order to create a valid suggestion. Outdated suggestions cannot be applied. This suggestion has been applied or marked resolved. Suggestions cannot be applied from pending reviews. Suggestions cannot be applied on multi-line comments. Suggestions cannot be applied while the pull request is queued to merge. Suggestion cannot be applied right now. Please check back later.
When the connection to the PostgreSQL instance cannot be established straight at startup, a race condition can happen when autoDiscoverDatabases is true. If discoverDatabaseDSNs fails, no dsn is set as the master database, and, if scrapeDSN succeeds, checkMapVersions will have omitted the default metrics in the server metric map. The metric map won't be updated unless the version returned by the PostgreSQL instance changes. With this patch, scrapeDSN won't be run unless discoverDatabaseDSNs succeeded and thus the race condition is eliminated.