我正在尝试强制容器使用超出允许范围的内存,但无法使其正常工作。该容器是使用docker compose定义的堆栈的一部分,并以群体模式部署到docker。
Docker允许容器超出我设置的50M限制。我原本希望docker杀死容器,抛出错误等。
有人可以帮助我解释为什么Docker不在此处强制执行内存限制吗?
docker-compose.yml中的容器被定义为具有50M的内存限制,然后我设置了一个非常简单的PHP测试,该测试将尝试分配200M。我已将PHP内存限制定义为128M。
这是我的docker-compose.yml
version: "3"
services:
nginx:
image: nginx:latest
restart: unless-stopped
volumes:
- ./deploy/nginx/nginx.conf:/etc/nginx/nginx.conf
- ./public:/usr/share/nginx/html
ports:
- "8180:80"
links:
- app
app:
image: 127.0.0.1:5000/wpdemo
build:
context: .
dockerfile: Dockerfile-app
restart: unless-stopped
volumes:
- .:/var/www/html
links:
- mysql
deploy:
resources:
limits:
cpus: '0.50'
memory: 50M
reservations:
cpus: '0.25'
memory: 20M
mysql:
image: mysql:5.7
restart: unless-stopped
ports:
- "13306:3306"
environment:
MYSQL_ALLOW_EMPTY_PASSWORD: 'yes'
volumes:
- ~/docker/volumes/mysql:/var/lib/mysql
而不是docker杀死容器,它允许它占用所需的内存,PHP最终停止了将以下错误抛出错误的进程:
“ PHP消息:PHP致命错误:在第4行的/var/www/html/public/index.php中,耗尽了125829120字节的允许内存大小(尝试分配67108872字节)”
我正在使用Ubuntu 18.04。
uname -a
Linux 4.18.10-041810-generic #201809260332 SMP Wed Sep 26 07:34:01 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
Docker版本18.06.1-ce,内部版本e68fc7a
docker-compose版本1.17.1,构建未知的docker-py版本:2.5.1 CPython版本:2.7.15rc1 OpenSSL版本:OpenSSL 1.1.0g 2017年11月2日
这是应用容器上“ docker stats”的输出:
CONTAINER ID NAME CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS
679c8495ac1d stackdemo_app.1.hr3ufwlskhdafre39aqrshxyu 0.00% 43.81MiB / 50MiB 87.62% 106kB / 389kB 2.05GB / 10.6GB 5
这是“ docker info”的输出:
Containers: 36
Running: 5
Paused: 0
Stopped: 31
Images: 450
Server Version: 18.06.1-ce
Storage Driver: overlay2
Backing Filesystem: extfs
Supports d_type: true
Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
Volume: local
Network: bridge host macvlan null overlay
Log: awslogs fluentd gcplogs gelf journald json-file logentries splunk syslog
Swarm: active
NodeID: wnegv5lp41wfs3epfrua489or
Is Manager: true
ClusterID: hq7o176yffjglxzb9pu3fiomr
Managers: 1
Nodes: 1
Orchestration:
Task History Retention Limit: 5
Raft:
Snapshot Interval: 10000
Number of Old Snapshots to Retain: 0
Heartbeat Tick: 1
Election Tick: 10
Dispatcher:
Heartbeat Period: 5 seconds
CA Configuration:
Expiry Duration: 3 months
Force Rotate: 0
Autolock Managers: false
Root Rotation In Progress: false
Node Address: 192.168.1.120
Manager Addresses:
192.168.1.120:2377
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 468a545b9edcd5932818eb9de8e72413e616e86e
runc version: 69663f0bd4b60df09991c08812a60108003fa340
init version: fec3683
Security Options:
apparmor
seccomp
Profile: default
Kernel Version: 4.18.10-041810-generic
Operating System: Ubuntu 18.04.1 LTS
OSType: linux
Architecture: x86_64
CPUs: 8
Total Memory: 15.49GiB
Name: rafxps15
ID: QEX7:FEB3:J76L:DCAQ:SO4S:SWVE:4XPI:PI6R:YM4C:MV4I:C3PM:FLOQ
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
127.0.0.0/8
Live Restore Enabled: false
WARNING: No swap limit support
答案 0 :(得分:1)
正如您在评论中所述,交换已在主机上启用,但尚不支持cgroups中的交换限制。
根据此启用swap limit support。请注意,重新启动系统至关重要。
最后,应设置—-memory-swap
标志。如果要防止PHP应用程序访问交换,则应将其设置为相同的值—-memory
。有关memory swap settings的更多详细信息。