cgroups

Why docker run `--oom-kill-disable` is not effective , but `echo 1 > memory.oom_control` is effective in myself System!

萝らか妹 提交于 2020-03-21 06:51:22
问题 When I run one container for docker run --oom-kill-disable, it is not effective; But when I "echo 1 > memory.oom_control", it is effective. docker version: Client: Version: 17.12.0-ce API version: 1.35 Go version: go1.9.2 Git commit: c97c6d6 Built: Wed Dec 27 20:05:38 2017 OS/Arch: linux/amd64 Server: Engine: Version: 17.12.0-ce API version: 1.35 (minimum version 1.12) Go version: go1.9.2 Git commit: c97c6d6 Built: Wed Dec 27 20:12:29 2017 OS/Arch: linux/amd64 Experimental: false 1.sudo

一行 kubenetes 1.9 代码引发的血案(与 CentOS 7.x 内核兼容性问题)

霸气de小男生 提交于 2020-03-12 11:18:27
生产环境发现不定时 Java 应用出现 coredump 故障,测试环境不定时出现写入 /cgroup/memory 报 no space left on device 的故障,导致整个 kubernetes node 节点无法使用。设置会随着堆积的 cgroup 越来越多,docker ps 执行异常,直到把内存吃光,机器挂死。 典型报错: kubelet.ns-k8s-node001.root.log.ERROR.20180214-113740.15702:1593018:E0320 04:59:09.572336 15702 remote_runtime.go:92] RunPodSandbox from runtime service failed: rpc error: code = Unknown desc = failed to start sa ndbox container for pod “osp-xxx-com-ljqm19-54bf7678b8-bvz9s”: Error response from daemon: oci runtime error: container_linux.go:247: starting container process caused “process_linux.go:258: applying cgroup

What is root CGROUP?

爱⌒轻易说出口 提交于 2020-03-05 04:08:18
问题 here it is mentioned: In the classic mode, which may ultimately be deprecated, but is still fully supported, there can be several separate cgroup hierarchies. Each hierarchy starts its life as a root cgroup , which initially holds all processes. What is root CGROUP? In a Linux process model. 回答1: Your article is talking about "classic" vs. "unified" (cgroup v2) cgroups: https://lwn.net/Articles/606699/ As was recently reported, the 3.16 Linux kernel will have under-development support for a

What is root CGROUP?

谁说我不能喝 提交于 2020-03-05 04:06:05
问题 here it is mentioned: In the classic mode, which may ultimately be deprecated, but is still fully supported, there can be several separate cgroup hierarchies. Each hierarchy starts its life as a root cgroup , which initially holds all processes. What is root CGROUP? In a Linux process model. 回答1: Your article is talking about "classic" vs. "unified" (cgroup v2) cgroups: https://lwn.net/Articles/606699/ As was recently reported, the 3.16 Linux kernel will have under-development support for a

Docker技术入门与实战笔记

梦想与她 提交于 2020-03-02 21:57:08
Docker 一.底层技术支持cgroups/LXC/AUFS 1.cgroups cgroups 进程分组化管理,Linux内核提供原生支持。通过分组实现对系统资源的限制与分配。 cgroups中的重要概念是“子系统”,也就是资源控制器,每种子系统就是一个资源的分配器.比如cpu子系统是控制cpu时间分配的。首先挂载子系统,然后才有control group的。比如先挂载memory子系统,然后在memory子系统中创建一个cgroup节点,在这个节点中,将需要控制的进程id写入,并且将控制的属性写入,这就完成了内存的资源限制。 2.LXC LXC是Linux containers的简称,是一种基于容器的操作系统层级的虚拟化技术。 借助于namespace的隔离机制和cgroup限额功能,LXC提供了一套统一的API和工具来建立和管理container。 LXC旨在提供一个共享kernel的OS级虚拟化方法,在执行时不用重复加载Kernel,且container的kernel与host共享. 3.联合文件系统(UnionFS) 联合文件系统(UnionFS)是一种分层、轻量级并且高性能的文件系统。 联合文件系统是 Docker 镜像的基础。镜像可以通过分层来进行继承,基于基础镜像可以制作各种具体的应用镜像。 AuFS是ubantu上最常用的联合文件系统。

使用k8s容器钩子确保服务安全退出

人盡茶涼 提交于 2020-02-29 21:45:43
Kubernetes为容器提供了生命周期钩子。 钩子能使容器感知其生命周期内的事件,并且当相应的生命周期钩子被调用时运行指定的代码。 @[TOC] 容器生命周期的钩子 Kubernetes为容器提供了生命周期钩子。 钩子能使容器感知其生命周期内的事件,并且当相应的生命周期钩子被调用时运行指定的代码。 容器钩子分为两类触发点:容器创建后PostStart和容器终止前PreStop。 PostStart 这个钩子在容器创建后立即执行。 但是,并不能保证钩子将在容器ENTRYPOINT之前运行。 没有参数传递给处理程序。 容器ENTRYPOINT和钩子执行是异步操作。 如果钩子花费太长时间以至于容器不能运行或者挂起, 容器将不能达到running状态 PreStop 这个钩子在容器终止之前立即被调用。 它是阻塞的,意味着它是同步的, 所以它必须在删除容器的调用发出之前完成 如果钩子在执行期间挂起, Pod阶段将停留在running状态并且永不会达到failed状态。 如果PostStart或者PreStop钩子失败, 容器将会被kill。 用户应该使他们的钩子处理程序尽可能的轻量。 钩子处理程序的实现 容器可以通过实现和注册该钩子的处理程序来访问钩子。 可以为容器实现两种类型的钩子处理程序: Exec - 在容器的cgroups和命名空间内执行一个特定的命令,比如pre-stop.sh。

docker系列--cgroups解读

痴心易碎 提交于 2020-02-29 05:09:17
理解docker,主要从namesapce,cgroups,联合文件,运行时(runC),网络几个方面。接下来我们会花一些时间,分别介绍。 docker系列--namespace解读 docker系列--cgroups解读 docker系列--unionfs解读 docker系列--runC解读 docker系列--网络模式解读 namesapce主要是隔离作用,cgroups主要是资源限制,联合文件主要用于镜像分层存储和管理,runC是运行时,遵循了oci接口,一般来说基于libcontainer。网络主要是docker单机网络和多主机通信模式。 cgroups简介 cgroups是什么? Cgroup是control group的简写,属于Linux内核提供的一个特性,用于限制和隔离一组进程对系统资源的使用,也就是做资源QoS,这些资源主要包括CPU、内存、block I/O和网络带宽。Cgroup从2.6.24开始进入内核主线,目前各大发行版都默认打开了Cgroup特性。 Cgroups提供了以下四大功能: 资源限制(Resource Limitation):cgroups可以对进程组使用的资源总额进行限制。如设定应用运行时使用内存的上限,一旦超过这个配额就发出OOM(Out of Memory)。 优先级分配(Prioritization)

ECS::TaskDefinition - What is the maximum value of 'Memory' property?

試著忘記壹切 提交于 2020-02-05 05:48:10
问题 here in this syntax of "ContainerDefinitions":[{Memory:500}] in AWS::ECS::TaskDefinition , Memory property refers to virtual address space(hard limit) of docker container process in root CGROUP. We are launching a jenkins container process on AWS EC2 using cloudformation resource type AWS::ECS::TaskDefinition . AWS EC2 is a 64 bit Linux OS. On 32 bit Linux OS, virtual address space of a process, can go upto 3 GB. On 64 bit Linux OS, virtual adress space of a process, can go upto Terabytes. We

How do I limit the memory resource of a group of docker containers?

♀尐吖头ヾ 提交于 2020-01-15 01:48:40
问题 I understand that I can use --memory and --memory-swap to limit memory resource per container. But, how do I limit memory resource per a group of containers? My system has 8GB RAM memory and consists of 2 docker containers. I want to set an 8 GB limit on both containers. I do not want to set a 4GB memory resource limit for each container as A container may use more than 4GB memory. Both containers won't use 4GB memory at the same time, so it would make sense to give the unused memory of

How to implement a memory intensive python script for test

倖福魔咒の 提交于 2019-12-23 09:36:14
问题 I've applied a cgroups rule to a specific user, and I'd like to test whether memory of the programs running from the above user has been limited as expected. I tried with the following script: import string import random if __name__ == '__main__': d = {} i = 0; for i in range(0, 100000000): val = ''.join(random.choice(string.ascii_uppercase + string.digits) for _ in range(200)) # generate ramdom string of size 200 d[i] = val if i % 10000 == 0: print i When I monitored the process via ps