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fix(api): make PollForMediaWikiJobsJob skip soft-deleted wikis #1221

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fix(api): make PollForMediaWikiJobsJob skip soft-deleted wikis #1221

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fix(api): make PollForMediaWikiJobsJob skip soft-deleted wikis
dati18 Jul 30, 2026
3a7351f
fix(api): make PollForMediaWikiJobsJob skip soft-deleted wikis
dati18 Jul 30, 2026
668af07
Merge branch 'fix-pending-jobs' of github.com:wbstack/api into fix-pe…
dati18 Jul 30, 2026
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17 changes: 12 additions & 5 deletions app/Jobs/PollForMediaWikiJobsJob.php
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Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@
namespace App\Jobs;

use App\Services\MediaWikiHostResolver;
use App\Services\UnknownWikiDomainException;
use App\Wiki;
use Illuminate\Contracts\Queue\ShouldBeUnique;
use Illuminate\Contracts\Queue\ShouldQueue;
Expand All @@ -25,11 +26,17 @@ public function handle(MediaWikiHostResolver $mwHostResolver): void {
}

private function hasPendingJobs(string $wikiDomain): bool {
$response = Http::withHeaders([
'host' => $wikiDomain,
])->get(
$this->mwHostResolver->getBackendUrlForDomain($wikiDomain) . '/w/api.php?action=query&meta=siteinfo&siprop=statistics&format=json'
);
try {
$response = Http::withHeaders([
'host' => $wikiDomain,
])->get(
$this->mwHostResolver->getBackendUrlForDomain($wikiDomain) . '/w/api.php?action=query&meta=siteinfo&siprop=statistics&format=json'
);
} catch (UnknownWikiDomainException $e) {
Log::warning('Skipping wiki ' . $wikiDomain . ' for pending MediaWiki jobs: ' . $e->getMessage());

@tarrow tarrow Jul 30, 2026

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Does this help us much? Are we just turning an error into a warning? Maybe this is still useful though.

I guess the question is what causes this to happen? Such a long runtime for this job that race conditions are common?

@dati18 dati18 Jul 30, 2026 •
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Good question.

It does turn one failure mode from error to warning, but importantly it prevents a single stale domain from sabotaging the whole polling run.

To answer "Why this happens":

  1. The job reads a list of domains.
  2. Later, for each domain, resolver does another lookup.
  3. If a wiki is soft-deleted (or otherwise missing) between those moments, resolver throws UnknownWikiDomainException.

The root cause I think is "double-read on mutable data" under multiple updates. The longer the runtime, the longer the gap between 1 and 3, the higher the probability. So basically it's the gap between the time of "reading the data" vs "using the data"

@tarrow tarrow Jul 30, 2026

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nice! Sounds like we are getting closer to the root cause.

So could we refactor the job so we do this look up earlier? Or even in a single query?

I guess there might still be a case where the wiki really has now gone away

@dati18 dati18 Jul 30, 2026

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Good idea, so you want to weed out bad domains instead of just "skipping" it?

@tarrow tarrow Jul 31, 2026

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I think you are correct that there is a double read. Actually there is a triple read:

  1. once to get the list of Wikis
  2. once to get the backendHost
  3. once when then MW backendHost determines the configuration of the Wiki

I am suggesting we merge the first two cases into one and get the correct backend hosts at the same time as we get the list of Wikis. There is still a chance that by the time we get to polling the Wikis that the 3rd read fails because it has been deleted but this is still a better solution.

Are you sure that marking the job as failed is sabotaging the whole run? I assumed that the job would still iterate over all Wikis but it would retry (sooner than planned) because it was marked as failed.


return false;
}

if ($response->failed()) {
$this->job->markAsFailed();
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