spark docker java kubernetes 获取cpu内核/线程数问题
升级服务从spark2.3.0-hadoop2.8 至 spark2.4.0 hadoop3.0
一日后导致spark streaming kafka消费数据积压
服务不是传统的部署在yarn上，而是布在kubernetes(1.13.2)上 https://spark.apache.org/docs/latest/running-on-kubernetes.html
因为近期对集群有大操作，以为是集群的io瓶颈导致的积压，作了几项针对io优化，但没什么效果
一直盯着服务日志和服务器的负载情况
突然发现一点不对，spark相关服务的cpu占用一直在100%-200%之间，长时间停留在100%
集群相关机器是32核，cpu占用100%可以理解为只用了单核，这里明显有问题
猜测数据积压，很可能不是io瓶颈，而是计算瓶颈(服务内部有分词，分类，聚类计算等计算密集操作)
程序内部会根据cpu核心作优化
获取环境内核数的方法
def GetCpuCoreNum(): Int = {
Runtime.getRuntime.availableProcessors
}
打印内核心数
spark 2.4.0
root@consume-topic-qk-nwd-7d84585f5-kh7z5:/usr/spark-2.4.0# java -version java version "1.8.0_202" Java(TM) SE Runtime Environment (build 1.8.0_202-b08) Java HotSpot(TM) 64-Bit Server VM (build 25.202-b08, mixed mode) [cuidapeng@wx-k8s-4 ~]$ kb logs consume-topic-qk-nwd-7d84585f5-kh7z5 |more 2019-03-04 15:21:59 WARN NativeCodeLoader:60 - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable Cpu core Num 1 2019-03-04 15:22:00 INFO SparkContext:54 - Running Spark version 2.4.0 2019-03-04 15:22:00 INFO SparkContext:54 - Submitted application: topic-quick 2019-03-04 15:22:00 INFO SecurityManager:54 - Changing view acls to: root 2019-03-04 15:22:00 INFO SecurityManager:54 - Changing modify acls to: root 2019-03-04 15:22:00 INFO SecurityManager:54 - Changing view acls groups to: 2019-03-04 15:22:00 INFO SecurityManager:54 - Changing modify acls groups to: 2019-03-04 15:22:00 INFO SecurityManager:54 - SecurityManager: authentication disabled; ui acls disabled; users with view permissions: Set(root); groups with view permissions: Set(); users with m odify permissions: Set(root); groups with modify permissions: Set() 2019-03-04 15:22:00 INFO Utils:54 - Successfully started service 'sparkDriver' on port 33016. 2019-03-04 15:22:00 INFO SparkEnv:54 - Registering MapOutputTracker 2019-03-04 15:22:01 INFO SparkEnv:54 - Registering BlockManagerMaster 2019-03-04 15:22:01 INFO BlockManagerMasterEndpoint:54 - Using org.apache.spark.storage.DefaultTopologyMapper for getting topology information 2019-03-04 15:22:01 INFO BlockManagerMasterEndpoint:54 - BlockManagerMasterEndpoint up 2019-03-04 15:22:01 INFO DiskBlockManager:54 - Created local directory at /tmp/blockmgr-dc0c496e-e5ab-4d07-a518-440f2336f65c 2019-03-04 15:22:01 INFO MemoryStore:54 - MemoryStore started with capacity 4.5 GB 2019-03-04 15:22:01 INFO SparkEnv:54 - Registering OutputCommitCoordinator 2019-03-04 15:22:01 INFO log:192 - Logging initialized @2888ms
Cpu core Num 1 服务变为单核计算,积压的原因就在这里
果然猜测正确，回滚版本至2.3.0
回滚至spark 2.3.0
root@consume-topic-dt-nwd-67b7fd6dd5-jztpb:/usr/spark-2.3.0# java -version java version "1.8.0_131" Java(TM) SE Runtime Environment (build 1.8.0_131-b11) Java HotSpot(TM) 64-Bit Server VM (build 25.131-b11, mixed mode) 2019-03-04 15:16:22 WARN NativeCodeLoader:62 - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable Cpu core Num 32 2019-03-04 15:16:23 INFO SparkContext:54 - Running Spark version 2.3.0 2019-03-04 15:16:23 INFO SparkContext:54 - Submitted application: topic-dt 2019-03-04 15:16:23 INFO SecurityManager:54 - Changing view acls to: root 2019-03-04 15:16:23 INFO SecurityManager:54 - Changing modify acls to: root 2019-03-04 15:16:23 INFO SecurityManager:54 - Changing view acls groups to: 2019-03-04 15:16:23 INFO SecurityManager:54 - Changing modify acls groups to: 2019-03-04 15:16:23 INFO SecurityManager:54 - SecurityManager: authentication disabled; ui acls disabled; users with view permissions: Set(root); groups with view permissions: Set(); users with m odify permissions: Set(root); groups with modify permissions: Set() 2019-03-04 15:16:23 INFO Utils:54 - Successfully started service 'sparkDriver' on port 40616. 2019-03-04 15:16:23 INFO SparkEnv:54 - Registering MapOutputTracker 2019-03-04 15:16:23 INFO SparkEnv:54 - Registering BlockManagerMaster 2019-03-04 15:16:23 INFO BlockManagerMasterEndpoint:54 - Using org.apache.spark.storage.DefaultTopologyMapper for getting topology information 2019-03-04 15:16:23 INFO BlockManagerMasterEndpoint:54 - BlockManagerMasterEndpoint up 2019-03-04 15:16:23 INFO DiskBlockManager:54 - Created local directory at /tmp/blockmgr-5dbf1194-477a-4001-8738-3da01b5a3f01 2019-03-04 15:16:23 INFO MemoryStore:54 - MemoryStore started with capacity 6.2 GB 2019-03-04 15:16:23 INFO SparkEnv:54 - Registering OutputCommitCoordinator 2019-03-04 15:16:24 INFO log:192 - Logging initialized @2867ms
Cpu core Num 32,32是物理机的内核数
阻塞并不是io引起的，而是runtime可用core变小导致，spark升级至2.4.0后，服务由32核并发执行变成单核执行
这实际不是spark的问题，而是jdk的问题
很早以前有需求限制docker内的core资源，要求jdk获取到core数docker限制的core数，当时印象是对jdk提了需求未来jdk9,10会实现，jdk8还实现不了，就把docker限制内核数的方案给否了，以分散服务调度的方式作计算资源的限制
对jdk8没想到这一点，却在这里踩了个坑
docker 控制cpu的相关参数
Usage: docker run [OPTIONS] IMAGE [COMMAND] [ARG...] Run a command in a new container Options: --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 CPU real-time period in microseconds --cpu-rt-runtime int Limit 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)
另外一点，服务是由kubernetes调度的，kubernetes在docker之上又作一层资源管理
kubernetes对cpu的控制有两种方案
一种是基于内核的 https://kubernetes.io/blog/2018/07/24/feature-highlight-cpu-manager/
一种是基于百分比的 https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/
手动分配cpu资源
resources: requests: cpu: 12 memory: "24Gi" limits: cpu: 12 memory: "24Gi"
更新服务
2019-03-04 16:24:57 WARN NativeCodeLoader:60 - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable Cpu core Num 12 2019-03-04 16:24:57 INFO SparkContext:54 - Running Spark version 2.4.0 2019-03-04 16:24:58 INFO SparkContext:54 - Submitted application: topic-dt 2019-03-04 16:24:58 INFO SecurityManager:54 - Changing view acls to: root 2019-03-04 16:24:58 INFO SecurityManager:54 - Changing modify acls to: root 2019-03-04 16:24:58 INFO SecurityManager:54 - Changing view acls groups to: 2019-03-04 16:24:58 INFO SecurityManager:54 - Changing modify acls groups to: 2019-03-04 16:24:58 INFO SecurityManager:54 - SecurityManager: authentication disabled; ui acls disabled; users with view permissions: Set(root); groups with view permissions: Set(); users with m odify permissions: Set(root); groups with modify permissions: Set() 2019-03-04 16:24:58 INFO Utils:54 - Successfully started service 'sparkDriver' on port 36429. 2019-03-04 16:24:58 INFO SparkEnv:54 - Registering MapOutputTracker 2019-03-04 16:24:58 INFO SparkEnv:54 - Registering BlockManagerMaster 2019-03-04 16:24:58 INFO BlockManagerMasterEndpoint:54 - Using org.apache.spark.storage.DefaultTopologyMapper for getting topology information 2019-03-04 16:24:58 INFO BlockManagerMasterEndpoint:54 - BlockManagerMasterEndpoint up 2019-03-04 16:24:58 INFO DiskBlockManager:54 - Created local directory at /tmp/blockmgr-764f35a8-ea7f-4057-8123-22cbbe2d9a39 2019-03-04 16:24:58 INFO MemoryStore:54 - MemoryStore started with capacity 6.2 GB 2019-03-04 16:24:58 INFO SparkEnv:54 - Registering OutputCommitCoordinator 2019-03-04 16:24:58 INFO log:192 - Logging initialized @2855ms
Cpu core Num 12 生效
kubernetes(docker) 和spark(jdk)之间core有一个兼容性问题
jdk 1.8.0_131 在docker内 获取的是主机上的内核数
jdk 1.8.0_202 在docker内 获取的是docker被限制的内核数,kubernetes不指定resource默认限制为1
升级至spark2.4.0-hadoop3.0(jdk 1.8.0_202),同时kubernetes同时指定内核数，也可以切换jdk至低版本，但需要重新打docker镜像。
指定内核数
Name: wx-k8s-8 Roles: <none> Labels: beta.kubernetes.io/arch=amd64 beta.kubernetes.io/os=linux flannel.alpha.coreos.com/backend-type: vxlan flannel.alpha.coreos.com/kube-subnet-manager: true kubeadm.alpha.kubernetes.io/cri-socket: /var/run/dockershim.sock node.alpha.kubernetes.io/ttl: 0 volumes.kubernetes.io/controller-managed-attach-detach: true CreationTimestamp: Thu, 24 Jan 2019 14:11:15 +0800 Taints: <none> Unschedulable: false Conditions: Type Status LastHeartbeatTime LastTransitionTime Reason Message ---- ------ ----------------- ------------------ ------ ------- MemoryPressure False Mon, 04 Mar 2019 17:27:16 +0800 Thu, 24 Jan 2019 14:11:15 +0800 KubeletHasSufficientMemory kubelet has sufficient memory available DiskPressure False Mon, 04 Mar 2019 17:27:16 +0800 Thu, 24 Jan 2019 14:11:15 +0800 KubeletHasNoDiskPressure kubelet has no disk pressure PIDPressure False Mon, 04 Mar 2019 17:27:16 +0800 Thu, 24 Jan 2019 14:11:15 +0800 KubeletHasSufficientPID kubelet has sufficient PID available Ready True Mon, 04 Mar 2019 17:27:16 +0800 Thu, 24 Jan 2019 14:24:48 +0800 KubeletReady kubelet is posting ready status Addresses: Capacity: cpu: 32 ephemeral-storage: 1951511544Ki hugepages-1Gi: 0 hugepages-2Mi: 0 memory: 65758072Ki pods: 110 Allocatable: cpu: 32 ephemeral-storage: 1798513035973 hugepages-1Gi: 0 hugepages-2Mi: 0 memory: 65655672Ki pods: 110 System Info: Container Runtime Version: docker://17.3.2 Kubelet Version: v1.13.2 Kube-Proxy Version: v1.13.2 PodCIDR: 10.244.7.0/24 Non-terminated Pods: (15 in total) Namespace Name CPU Requests CPU Limits Memory Requests Memory Limits AGE --------- ---- ------------ ---------- --------------- ------------- --- kube-system kube-flannel-ds-l594f 100m (0%) 100m (0%) 50Mi (0%) 50Mi (0%) 11d kube-system kube-proxy-vckxf 0 (0%) 0 (0%) 0 (0%) 0 (0%) 39d Allocated resources: (Total limits may be over 100 percent, i.e., overcommitted.) Resource Requests Limits -------- -------- ------ cpu 20100m (62%) 100m (0%) memory 45106Mi (70%) 61490Mi (95%) ephemeral-storage 0 (0%) 0 (0%) Events: <none
