php - Docker-缓存的已装载卷同步延迟

Question

我正在使用macOS上的docker compose构建本地开发环境。我们有多个用php编写并与Symfony一起运行的应用程序。该代码通过一个卷附加到容器上。与Linux主机相比，我遇到了非常差的性能。

原来，问题是由基于osxfs的挂载卷引起的，osxfs是一种共享文件系统解决方案，仅适用于Mac的Docker。

这个问题在这里很好地解释了:https://blog.docker.com/2017/05/user-guided-caching-in-docker-for-mac/

引入已装入卷的缓存模式后，性能已大大提高。但是，它允许在主机上的更新出现在容器中之前有一些延迟。该文档不是专门针对此延迟的。您知道主机上和容器内的代码之间的同步速度有多快吗？

volumes:
  - ./php_code:/var/www:cached

Answer 1

使用 NFS (不适用于High Sierra-more details here)

docker-machine-nfs ${DOCKER_MACHINE_NAME} --mount-opts="noacl,async,nolock,vers=3,udp,noatime,actimeo=1"

将 PHP缓存保留在容器中-例如在/tmp/app_cache/*中-或者在内存/dev/shm/app_cache/*中(不推荐)

要在容器中保留缓存，请在 AppKernel.php中更改(对于Symfony 4.0 Kernel.php)

...    
public function getCacheDir()
{
    if ($this->environment === 'env') {
        // Store in RAM.
        // return '/dev/shm/symfony_docker_test/cache/'.$this->environment;

        // Store in docker container (not docker-machine unless docker-compose volume is mounted).
        return '/tmp/symfony_cache/cache/' . $this->environment;
    }

    return dirname(__DIR__).'/var/cache/'.$this->getEnvironment();
}
...

解决方案的结果提到了 和 :cached

Time taken for tests:   20.396 seconds
Complete requests:      100
Failed requests:        0
Total transferred:      82700 bytes
HTML transferred:       31900 bytes
Requests per second:    4.90 [#/sec] (mean)
Time per request:       203.963 [ms] (mean)
Time per request:       203.963 [ms] (mean, across all concurrent requests)
Transfer rate:          3.96 [Kbytes/sec] received

提及解决方案的结果 不含 :cached

Time taken for tests:   18.911 seconds
Complete requests:      100
Failed requests:        0
Total transferred:      82700 bytes
HTML transferred:       31900 bytes
Requests per second:    5.29 [#/sec] (mean)
Time per request:       189.111 [ms] (mean)
Time per request:       189.111 [ms] (mean, across all concurrent requests)
Transfer rate:          4.27 [Kbytes/sec] received