Today a bunch of DB transactions hung open from mw1207. The offending apache threads showed this stack trace:

(gdb) zbacktrace
[0xbe6a1190] usleep()
/usr/local/apache/common-local/php-1.23wmf18/includes/objectcache/BagOStuff.php:188
[0xbe6a0ae8] lock()
/usr/local/apache/common-local/php-1.23wmf18/includes/filerepo/file/LocalFile.php:1832
[0xbe6a00b0] lock()
/usr/local/apache/common-local/php-1.23wmf18/includes/filerepo/file/LocalFile.php:1164
[0xbe69fc30] upload()
/usr/local/apache/common-local/php-1.23wmf18/includes/upload/UploadBase.php:692
[0xbe69e790] performUpload()
/usr/local/apache/common-local/php-1.23wmf18/includes/api/ApiUpload.php:649
[0xbe69e3e0] performUpload()
/usr/local/apache/common-local/php-1.23wmf18/includes/api/ApiUpload.php:144
[0xbe69cc98] getContextResult()
/usr/local/apache/common-local/php-1.23wmf18/includes/api/ApiUpload.php:111
[0xbe69c610] execute()
/usr/local/apache/common-local/php-1.23wmf18/includes/api/ApiMain.php:900
[0xbe69c050] executeAction()
/usr/local/apache/common-local/php-1.23wmf18/includes/api/ApiMain.php:364
[0xbe69be48] executeActionWithErrorHandling()
/usr/local/apache/common-local/php-1.23wmf18/includes/api/ApiMain.php:335
[0xbe69aee8] execute()
/usr/local/apache/common-local/php-1.23wmf18/api.php:86
[0xbe69add8] ??? /usr/local/apache/common-local/w/api.php:3

Paravoid noticed mw1207 twemproxy had stopped listening on port 11211. Restarting it caused the open txns to complete and the apache threads to continue as normal.

Mediawiki shouldn't wait forever if memcached is not responding.

Version: 1.23.0
Severity: major