# Redis memory usage **URL:** \ **Category:** General\ **Tags:** docker, amazonwebservices\ **Created:** [June 6, 2017, 8:10pm UTC](https://forums.docker.com/t/redis-memory-usage/33228 "2017-06-06T20:10:48Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![roberto](https://avatars.discourse-cdn.com/v4/letter/r/8baadc/32.png) [@roberto](https://forums.docker.com/u/roberto)\ **Post date:** [June 6, 2017, 8:10pm UTC](https://forums.docker.com/t/redis-memory-usage/33228/1 "2017-06-06T20:10:48Z")
I’m running Redis as a docker service and when I login to the machine it was assigned to and run `docker stats` I get the following: ```auto CONTAINER CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS redis.1.wsqexigxdtraidyyphpmuunbm 0.08% 250.3MiB / 7.797GiB 3.13% 441MB / 190MB 0B / 175MB 0 ``` Specifically, note the mem usage of `250.3MiB`. When running `top`, however, I see it’s using less than 200M: ```auto 6662 999 20 0 197144 171788 1508 S 0.0 2.1 1:19.12 redis-server ``` The only process running in the container is Redis itself: ```auto ubuntu@prod-docker-4:~$ docker exec -t -i redis.1.wsqexigxdtraidyyphpmuunbm /bin/bash -c 'ps -efww' UID PID PPID C STIME TTY TIME CMD redis 1 0 3 19:23 ? 00:01:19 redis-server *:6379 root 21 0 0 20:06 ? 00:00:00 ps -efww ``` This doesn’t appear to be a fixed amount of “container overhead”, but rather ~1.5X ratio. 😕 Here are some more stats on Docker’s memory stats and the process memory usage: ```auto ps aux --sort -rss, docker stats, ratio 171788, 250.3MiB, 1.46 343828, 514.2MiB, 1.49 433940, 656.1MiB, 1.51 519956, 788.7MiB, 1.52 ``` Any ideas on where the additional memory is going? System info: ```auto ubuntu@prod-docker-4:~$ uname -a Linux prod-docker-4 3.13.0-119-generic #166-Ubuntu SMP Wed May 3 12:18:55 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux ubuntu@prod-docker-4:~$ cat /etc/issue.net Ubuntu 14.04.5 LTS ubuntu@prod-docker-4:~$ docker version Client: Version: 17.04.0-ce API version: 1.28 Go version: go1.7.5 Git commit: 4845c56 Built: Mon Apr 3 17:54:19 2017 OS/Arch: linux/amd64 Server: Version: 17.04.0-ce API version: 1.28 (minimum version 1.12) Go version: go1.7.5 Git commit: 4845c56 Built: Mon Apr 3 17:54:19 2017 OS/Arch: linux/amd64 Experimental: false ``` Thanks! ---
**Author:** ![junius](https://avatars.discourse-cdn.com/v4/letter/j/f08c70/32.png) [@junius](https://forums.docker.com/u/junius)\ **Post date:** [October 14, 2017, 5:15am UTC](https://forums.docker.com/t/redis-memory-usage/33228/2 "2017-10-14T05:15:44Z")
could connect to redis and run `info`. it would show the memory usage like below: ```auto # Memory used_memory:409964064 used_memory_human:390.97M used_memory_rss:422481920 used_memory_rss_human:402.91M used_memory_peak:409995904 used_memory_peak_human:391.00M used_memory_peak_perc:99.99% used_memory_overhead:126958696 used_memory_startup:487168 used_memory_dataset:283005368 used_memory_dataset_perc:69.11% total_system_memory:1044770816 total_system_memory_human:996.37M used_memory_lua:37888 used_memory_lua_human:37.00K maxmemory:0 maxmemory_human:0B maxmemory_policy:noeviction mem_fragmentation_ratio:1.03 mem_allocator:jemalloc-4.0.3 lazyfree_pending_objects:0 ``` ---
**Author:** ![fulcrum](https://sea3.discourse-cdn.com/docker/user_avatar/forums.docker.com/fulcrum/32/14034_2.png) [@fulcrum](https://forums.docker.com/u/fulcrum)\ **Post date:** [February 6, 2018, 5:06pm UTC](https://forums.docker.com/t/redis-memory-usage/33228/3 "2018-02-06T17:06:24Z")
@roberto : Did you ever find out the problem with this? Currently I am expericing the same issue. I have a docker container memory limit of 500MB, and a redis max-memory of 150 with a maxmemory-policy of allkeys-lru so I would expect to stay well below that 500MB limit. We have however had a few containers reach that and crash. Redis info memory shows redis not going above the threshold, however a top in the container shows a much larger redis process (I know there is overhead but 3x the size of max-memory) and ctop/docker stats shows something that doesn’t match that either. I have upgraded to the latest redis, 4.0.7 after trying this on 3.2. My docker version is older at 1.12.1, but I see you got this with 17.04 ---
**Author:** ![junius](https://avatars.discourse-cdn.com/v4/letter/j/f08c70/32.png) [@junius](https://forums.docker.com/u/junius)\ **Post date:** [February 7, 2018, 2:01am UTC](https://forums.docker.com/t/redis-memory-usage/33228/4 "2018-02-07T02:01:27Z")
If you are using Redis replication, the replication buffer could take like 512MB memory, and it is not included in Redis memory usage calculation. 2 refs: [redis replication buffer](https://redislabs.com/blog/top-redis-headaches-for-devops-replication-buffer), [Amazon ElasticCache Node size selection](http://docs.aws.amazon.com/AmazonElastiCache/latest/UserGuide/CacheNodes.SelectSize.html#CacheNodes.SelectSize.Redis). If not using Redis replication, not sure if there are some other Redis internal data structure that consumes memory. Probably Redis github issue is a better place to ask. ---
**Author:** ![roberto](https://avatars.discourse-cdn.com/v4/letter/r/8baadc/32.png) [@roberto](https://forums.docker.com/u/roberto)\ **Post date:** [February 7, 2018, 3:26pm UTC](https://forums.docker.com/t/redis-memory-usage/33228/5 "2018-02-07T15:26:56Z")
Hey all, It’s been a while since I’m thinking about this. I’m looking at a service right now and see this with the command `docker stats stack_redis.1.xxxxxxxxxxxxxxxxxxxxxxxxx`: ```auto CONTAINER CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS stack_redis.1.xxxxxxxxxxxxxxxxxxxxxxxxx 0.08% 23.83MiB / 64MiB 37.23% 145MB / 34.9MB 6.18MB / 6.02GB 3 ``` in `top` I’m now seeing this: ```auto PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 5183 docker 20 0 49696 25796 2972 S 0.0 0.3 48:54.01 redis-server ``` The discrepancy between `top` and `docker stats` is within 10% (comparing RES); then again this is a much, much smaller redis instance than the previous one. Docker info: ```auto aguilarr@prod-docker-5:~$ docker version Client: Version: 17.09.0-ce API version: 1.32 Go version: go1.8.3 Git commit: afdb6d4 Built: Tue Sep 26 22:42:18 2017 OS/Arch: linux/amd64 Server: Version: 17.09.0-ce API version: 1.32 (minimum version 1.12) Go version: go1.8.3 Git commit: afdb6d4 Built: Tue Sep 26 22:40:56 2017 OS/Arch: linux/amd64 Experimental: false ```