docker之动态扩容

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背景

在用docker进行项目编译的时候，出现性能不足的情况，

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zhengkaideMacBook-Pro:blog zhengk$ docker stats b9e5ebd23a78
CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT     MEM %               NET I/O             BLOCK I/O           PIDS
b9e5ebd23a78        wizardly_meninsky   2.65%               1.752GiB / 1.952GiB   89.74%              965MB / 23.1MB      282GB / 7.76GB      85
CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT     MEM %               NET I/O             BLOCK I/O           PIDS
b9e5ebd23a78        wizardly_meninsky   2.65%               1.752GiB / 1.952GiB   89.74%              965MB / 23.1MB      282GB / 7.76GB      85
CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT   MEM %               NET I/O             BLOCK I/O           PIDS
b9e5ebd23a78        wizardly_meninsky   --                  -- / --             --                  --                  --                  --
CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT   MEM %               NET I/O             BLOCK I/O           PIDS
b9e5ebd23a78        wizardly_meninsky   --                  -- / --             --                  --                  --                  --
CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT   MEM %               NET I/O             BLOCK I/O           PIDS
b9e5ebd23a78        wizardly_meninsky   --                  -- / --             --                  --                  --                  --
CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT   MEM %               NET I/O             BLOCK I/O           PIDS
b9e5ebd23a78        wizardly_meninsky   --                  -- / --             --                  --                  --                  --

通过命令都无法显示性能情况。

不过可见，最大内存限制在1.952GiB。

动态扩容

  • 先找到docker容器的id

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    zhengkaideMacBook-Pro:blog zhengk$ docker ps -a
    CONTAINER ID        IMAGE                                             COMMAND             CREATED             STATUS                  PORTS               NAMES
    b9e5ebd23a78        hub.baidubce.com/paddlepaddle/paddle:latest-dev   "/bin/bash"         4 days ago          Up 2 days               22/tcp              wizardly_meninsky

  • 进行扩容

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    zhengkaideMacBook-Pro:blog zhengk$ docker update -m 3072m b9e5ebd23a78
    Error response from daemon: Cannot update container b9e5ebd23a78843361c3f92dbdb7b07dcf01a85087c4c7b14670dc5cc440433c: Memory limit should be smaller than already set memoryswap limit, update the memoryswap at the same time

    注：这里有一个错误提示，说要同步扩大memoryswap。

    命令修改如下：

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    zhengkaideMacBook-Pro:blog zhengk$ docker update -m 3072m --memory-swap -1 b9e5ebd23a78
    b9e5ebd23a78

  • 再次查看

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    zhengkaideMacBook-Pro:blog zhengk$ docker stats b9e5ebd23a78
    CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT     MEM %               NET I/O             BLOCK I/O           PIDS
    b9e5ebd23a78        wizardly_meninsky   2.65%               1.752GiB / 1.952GiB   89.74%              965MB / 23.1MB      282GB / 7.76GB      85

    发现没有什么变化，限制还是1.952GiB。

    这是由于docker在MacDesktop环境下默认限制了上限为2G。

    Advanced settings are:

    CPUs: By default, Docker Desktop for Mac is set to use half the number of processors available on the host machine. To increase processing power, set this to a higher number; to decrease, lower the number.

    Memory: By default, Docker Desktop for Mac is set to use 2 GB runtime memory, allocated from the total available memory on your Mac. To increase RAM, set this to a higher number; to decrease it, lower the number.

    Swap: Configure swap file size as needed. The default is 1 GB.

  • 修改Docker Desktop For Mac

    image-20190819234844808

  • 重启容器并查看

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    zhengkaideMacBook-Pro:blog zhengk$ docker stop b9e5ebd23a78
      b9e5ebd23a78
      zhengkaideMacBook-Pro:blog zhengk$ docker start b9e5ebd23a78
      b9e5ebd23a78
      zhengkaideMacBook-Pro:blog zhengk$ docker stats b9e5ebd23a78
      CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT   MEM %               NET I/O             BLOCK I/O           PIDS
      b9e5ebd23a78        wizardly_meninsky   0.00%               3.102MiB / 3GiB     0.10%               1.16kB / 0B         11.5MB / 0B         1
      CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT   MEM %               NET I/O             BLOCK I/O           PIDS
      b9e5ebd23a78        wizardly_meninsky   0.00%               3.055MiB / 3GiB     0.10%               1.16kB / 0B         11.5MB / 0B         1
      CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT   MEM %               NET I/O             BLOCK I/O           PIDS
      b9e5ebd23a78        wizardly_meninsky   0.00%               3.055MiB / 3GiB     0.10%               1.16kB / 0B         11.5MB / 0B         1
      CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT   MEM %               NET I/O             BLOCK I/O           PIDS
      b9e5ebd23a78        wizardly_meninsky   0.00%               3.055MiB / 3GiB     0.10%               1.16kB / 0B         11.5MB / 0B         1

扩展

对于桌面版的docker，还是要关注一下系统的配置，开始找了好久死活都没办法扩容。

对于常规的扩容，可参考帮助：

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zhengkaideMacBook-Pro:blog zhengk$ docker update --help

Usage:	docker update [OPTIONS] CONTAINER [CONTAINER...]

Update configuration of one or more containers

Options:
      --blkio-weight uint16        Block IO (relative weight), between 10 and 1000, or 0 to disable (default 0)
      --cpu-period int             Limit CPU CFS (Completely Fair Scheduler) period
      --cpu-quota int              Limit CPU CFS (Completely Fair Scheduler) quota
      --cpu-rt-period int          Limit the CPU real-time period in microseconds
      --cpu-rt-runtime int         Limit the CPU real-time runtime in microseconds
  -c, --cpu-shares int             CPU shares (relative weight)
      --cpus decimal               Number of CPUs
      --cpuset-cpus string         CPUs in which to allow execution (0-3, 0,1)
      --cpuset-mems string         MEMs in which to allow execution (0-3, 0,1)
      --kernel-memory bytes        Kernel memory limit
  -m, --memory bytes               Memory limit
      --memory-reservation bytes   Memory soft limit
      --memory-swap bytes          Swap limit equal to memory plus swap: '-1' to enable unlimited swap
      --pids-limit int             Tune container pids limit (set -1 for unlimited)
      --restart string             Restart policy to apply when a container exits
zhengkaideMacBook-Pro:blog zhengk$

使用命令动态修改之后，如果没重启的话

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zhengkaideMacBook-Pro:blog zhengk$ docker stats b9e5ebd23a78
CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT   MEM %               NET I/O             BLOCK I/O           PIDS
b9e5ebd23a78        wizardly_meninsky   0.00%               0B / 0B             0.00%               0B / 0B             0B / 0B             0
CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT   MEM %               NET I/O             BLOCK I/O           PIDS
b9e5ebd23a78        wizardly_meninsky   0.00%               0B / 0B             0.00%               0B / 0B             0B / 0B             0
CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT   MEM %               NET I/O             BLOCK I/O           PIDS
b9e5ebd23a78        wizardly_meninsky   0.00%               0B / 0B             0.00%               0B / 0B             0B / 0B             0

无法直观的看到有没有生效，所以建议还是重启一次。