From: emailforalex at gmail dot com Operating system: any PHP version: 5.2.6 PHP Bug Type: Feature/Change Request Bug description: Memcache reads/writes are not synchronized
Description: ------------ This "bug" is incredibly hard to track down and reproduce, but is a major issue for high-volume sites using memcache. There is no synchronization mechanism built in when multiple servers serving multiple requests are all trying to read/write to a memcache machine. A race condition occurs where one request (r1) reads from the cache, then a second request (r2) reads from the cache, then r1 writes the same key back to the cache and r2 proceeds to also write that key to the cache. In effect, r2 overwrites the changes by r1. The issue was discovered while using the symfony framework which stores an array of all of its keys in the cache to allow for pattern-based searching of the keys. What sometimes happened is that two writes in a row would happen as described above, and the keys that were added to the array during the first write disappeared. -- Edit bug report at http://bugs.php.net/?id=45558&edit=1 -- Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=45558&r=trysnapshot52 Try a CVS snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=45558&r=trysnapshot53 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=45558&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=45558&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=45558&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=45558&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=45558&r=needscript Try newer version: http://bugs.php.net/fix.php?id=45558&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=45558&r=support Expected behavior: http://bugs.php.net/fix.php?id=45558&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=45558&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=45558&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=45558&r=globals PHP 4 support discontinued: http://bugs.php.net/fix.php?id=45558&r=php4 Daylight Savings: http://bugs.php.net/fix.php?id=45558&r=dst IIS Stability: http://bugs.php.net/fix.php?id=45558&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=45558&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=45558&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=45558&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=45558&r=mysqlcfg
