Title: “OOM command not allowed when used memory > ‘maxmemory’.” Last modified: November 4, 2021 --- # “OOM command not allowed when used memory > ‘maxmemory’.” * Resolved [johnsyin97](https://wordpress.org/support/users/johnsyin97/) * (@johnsyin97) * [4 years, 7 months ago](https://wordpress.org/support/topic/oom-command-not-allowed-when-used-memory-maxmemory/) * Hi I am using free redis instance in heroku, has previously connecting to it without issue, when check on it today I see that it is not connected with this error. Following is copied from diagnostics tab: * ``` Status: Not connected Client: Predis (v1.1.8) Drop-in: Valid Disabled: No Ping: PONG Errors: [ "OOM command not allowed when used memory > 'maxmemory'." ] PhpRedis: Not loaded Predis: 1.1.8 Credis: Not loaded PHP Version: 7.4.25 Plugin Version: 2.0.21 Redis Version: 6.2.3 Multisite: No Metrics: Disabled Metrics recorded: null Filesystem: Could not initialize filesystem. Global Prefix: "wp_" Blog Prefix: "wp_" WP_REDIS_DISABLED: false WP_REDIS_CLIENT: "predis" WP_REDIS_SCHEME: "redis" WP_REDIS_HOST: ".compute-1.amazonaws.com" WP_REDIS_PORT: 21029 WP_REDIS_MAXTTL: 2419200 WP_REDIS_PASSWORD: •••••••• Global Groups: [ "blog-details", "blog-id-cache", "blog-lookup", "global-posts", "networks", "rss", "sites", "site-details", "site-lookup", "site-options", "site-transient", "users", "useremail", "userlogins", "usermeta", "user_meta", "userslugs", "redis-cache", "blog_meta" ] Ignored Groups: [ "counts", "plugins", "themes", "blog-details", "blog-id-cache", "blog-lookup", "global-posts", "networks", "rss", "sites", "site-details", "site-lookup", "site-options", "site-transient", "users", "useremail", "userlogins", "usermeta", "user_meta", "userslugs", "redis-cache", "blog_meta" ] Unflushable Groups: [] Drop-ins: [ "Redis Object Cache Drop-In v2.0.21 by Till Krüss" ] ``` - This topic was modified 4 years, 7 months ago by [johnsyin97](https://wordpress.org/support/users/johnsyin97/). Viewing 3 replies - 1 through 3 (of 3 total) * Plugin Author [Till Krüss](https://wordpress.org/support/users/tillkruess/) * (@tillkruess) * [4 years, 7 months ago](https://wordpress.org/support/topic/oom-command-not-allowed-when-used-memory-maxmemory/#post-15037625) * You’re running out of Redis Memory. I’d strongly suggest setting a `WP_REDIS_MAXTTL` as well as an eviction policy: * [https://devcenter.heroku.com/articles/heroku-redis#maxmemory-policy](https://devcenter.heroku.com/articles/heroku-redis#maxmemory-policy) * [The Old Man](https://wordpress.org/support/users/graham-smith/) * (@graham-smith) * [4 years, 6 months ago](https://wordpress.org/support/topic/oom-command-not-allowed-when-used-memory-maxmemory/#post-15115618) * Hi, * Just wanted to say thanks for this topic and the advice. * Although I don’t use Heroku as per the OP, I do use and recommend the free version of this plugin. * I’ve just spent 2.5 hours trying to log into my WordPress site, successfully resetting the pw, etc, only still to find I was unable to log in, either the normal site or the Admin Dashboard. There were no errors displayed, no clue anything was up. * Then it occurred to me to look at the error log for the site (d’oh), and it was full of errors reporting: * `AH01071: Got error 'PHP message: RedisException: OOM command not allowed when used memory > 'maxmemory'. in /home/mysite/public_html/dev/wp-content/object- cache.php` * I came here and found this topic. I found my Redis pool memory was full. I added the WP Redis TTL Config constant but it didn’t start to flush keys (older than a week). * Then it dawned on me. A few months back I’d upgraded to Redis 6 and in setting it up, when I checked, I’d selected a Volatile-LFU policy, then forgot all about it. So it was only expiring keys with a volatile TTL, which it seems are er, none. * After changing the redis.conf to maxmemory-policy allkeys-lru, restarting Redis, immediately Redis started flushing keys. * Guess, what? I immediately was able to log in to my site! * So hopefully this may help someone else who has exhausted all the usual reasons and causes. * Thanks to [@tillkruess](https://wordpress.org/support/users/tillkruess/) and [@johnsyin97](https://wordpress.org/support/users/johnsyin97/) for the push in the right direction! - This reply was modified 4 years, 6 months ago by [The Old Man](https://wordpress.org/support/users/graham-smith/). * Plugin Author [Till Krüss](https://wordpress.org/support/users/tillkruess/) * (@tillkruess) * [4 years, 6 months ago](https://wordpress.org/support/topic/oom-command-not-allowed-when-used-memory-maxmemory/#post-15115871) * Happy to hear it worked out! 🥰 Viewing 3 replies - 1 through 3 (of 3 total) The topic ‘“OOM command not allowed when used memory > ‘maxmemory’.”’ is closed to new replies. * ![](https://ps.w.org/redis-cache/assets/icon-256x256.gif?rev=2568513) * [Redis Object Cache](https://wordpress.org/plugins/redis-cache/) * [Support Threads](https://wordpress.org/support/plugin/redis-cache/) * [Active Topics](https://wordpress.org/support/plugin/redis-cache/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/redis-cache/unresolved/) * [Reviews](https://wordpress.org/support/plugin/redis-cache/reviews/) * 3 replies * 3 participants * Last reply from: [Till Krüss](https://wordpress.org/support/users/tillkruess/) * Last activity: [4 years, 6 months ago](https://wordpress.org/support/topic/oom-command-not-allowed-when-used-memory-maxmemory/#post-15115871) * Status: resolved