Bug #80853 [Opn]: Apparent memory leak in PHP 8 not present in 7.4

Edit report at https://bugs.php.net/bug.php?id=80853&edit=1 ID: 80853 Updated by: nikic@php.net Reported by: zach at yembo dot ai Summary: Apparent memory leak in PHP 8 not present in 7.4 Status: Open Type: Bug Package: Reproducible crash Operating System: Alpine Linux PHP Version: 8.0.3 Block user comment: N Private report: N New Comment: I'd usually run the program under "USE_ZEND_ALLOC=0 valgrind --tool=massif php" to get memory profile, but I'm not sure if that works well for this kind of long-running code. Previous Comments: ------------------------------------------------------------------------ [2021-03-10 19:59:51] zach at yembo dot ai Description: ------------ Our product has an AWS SQS queue listener microservice that is an infinite loop that long polls SQS and processes messages as they come in. When using the php:7.4-fpm-alpine3.13 image from Docker Hub, the code runs indefinitely with no issues. However, when running the exact same application code using the php:8.0-fpm-alpine3.13 base image, we are seeing Kubernetes kill the pod due to exhausting the upper memory limit. We plotted the output of kubectl top pods over time, and found a long, slow climb over the course of 3-4 hours until the pod reaches the memory limit. Like many memory issues, I don't see any one smoking gun in the code. Since the 7.4 image works ok, I suspect there is a memory leak either introduced or exacerbated in PHP 8. The codebase is fairly large and I'm not sure what particular area is causing the issue. Does anyone have ideas on how to pinpoint or where to look? These links look generally related, but I'm not sure if there's any good way to tell if this is the same issue we are facing: 1. https://phabricator.wikimedia.org/T247990 2. https://bugs.php.net/bug.php?id=79519 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=80853&edit=1