Log error is occurring infrequently but easily fixed:
Notice: Undefined index: parse in /srv/mediawiki/php-1.30.0-wmf.6/extensions/TextExtracts/includes/ApiQueryExtracts.php on line 269
Offending code: https://github.com/wikimedia/mediawiki-extensions-TextExtracts/blob/master/includes/ApiQueryExtracts.php#L280
| Subject | Repo | Branch | Lines +/- | |
|---|---|---|---|---|
| When APIParse fails log the warning and return null | mediawiki/extensions/TextExtracts | master | +18 -1 |
Per chores email (25th) this keeps coming up so I'd like to nominate it for estimation/upcoming sprint.
I'm not sure if avoiding exception by returning empty text is a correct approach. API:Parsing_wikitext won't return parse data only when there is an error.
In that case we shouldn't mute error and silently return an empty string because then we store the response in cache for ParserCacheExpireTime which is 22 days.
First, we should log those pages to find the root cause instead of sweeping it under the rug and then or fix the broken behavior or handle API errors properly.
Change 369549 had a related patch set uploaded (by Pmiazga; owner: Pmiazga):
[mediawiki/extensions/TextExtracts@master] When APIParse fails log the warning and return null
Change 369549 merged by jenkins-bot:
[mediawiki/extensions/TextExtracts@master] When APIParse fails log the warning and return null
Note errors occurs very infrequently and we're not sure why it happens, so it's likely we won't be able to sign this off by looking at logstash.
I would recommend we sign off by simulating the issue locally and then reopen it if we see it occur again (this time we should have some better information in logs).
Note if we can find a way to replicate this we can sign off using https://logstash-beta.wmflabs.org
I added unset($data['parse']); to the offending function, towards the end of it. The API didn't fail unlike before.
We added an extra logging to find out why this happens in production as we couldn't reproduce it locally. Now we will stop logging the PHP notice error, we will log our custom error instead with a bit more information whats going on so we can fix it.