文章目录

• • 一. 问题引入
  • • 1. 场景描述
    • 2. 日志简析
  • 二. 初级问题分析与解决
  • • 1. 问题分析
    • • 1.1. yarn的调度器设置
      • 1.2. 程序设置
    • 2. 问题解决
  • 三. （性能）新的问题
  • • 1. 问题描述
    • 2. 理想化的最优方案
    • 3. "PlanB"的解决方案
  • 四. 反思与迭代

一. 问题引入

1. 场景描述

使用flink引擎，处理hdfs到hive的任务，hdfs的文件数有4000个，这里设置并行度为20，提交任务运行。

2. 日志简析

任务提交之后发现报错，我们简单分析下yarn的日志：

1. 申请的资源超过了yarn最大的container资源限制，也就是说一个taskexecutor所需的资源过大Could not compute the container Resource from the given TaskExecutorProcessSpec TaskExecutorProcessSpec {cpuCores=10.0, frameworkHeapSize=128.000mb (134217728 bytes), frameworkOffHeapSize=128.000mb (134217728 bytes), taskHeapSize=5.200gb (5583457416 bytes), taskOffHeapSize=0 bytes, networkMemSize=1024.000mb (1073741824 bytes), managedMemorySize=4.300gb (4617089912 bytes), jvmMetaspaceSize=256.000mb (268435456 bytes), jvmOverheadSize=1024.000mb (1073741824 bytes)}. This usually indicates the requested resource is larger than Yarn's max container resource limit.2. 接着开始请求一个新的worker，这里的worker应该也是container ，那此时正在pend的数量为1.Requesting new worker with resource spec WorkerResourceSpec {cpuCores=10.0, taskHeapSize=5.200gb (5583457416 bytes), taskOffHeapSize=0 bytes, networkMemSize=1024.000mb (1073741824 bytes), managedMemSize=4.300gb (4617089912 bytes)}, current pending count: 1.3. 但同样的这个container超过了yarn的资源，这时直接放弃分配资源Requested container resource (<memory:12288, vCores:10>) exceeds the max limitation of the Yarn cluster (<memory:12288, vCores:4>). Will not allocate resource.4. 如此在反复这样执行，似乎陷入到了死循环。最后任务部署超时而报错。。。

上面的日志说的比较明白，就是：申请的资源超过了yarn最大的container资源限制。
 
 
再放出点堆栈信息，供日后参考分析：

2022-11-18 10:12:12,938 WARN  org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager [] - Failed requesting worker with resource spec WorkerResourceSpec {cpuCores=10.0, taskHeapSize=5.200gb (5583457416 bytes), taskOffHeapSize=0 bytes, networkMemSize=1024.000mb (1073741824 bytes), managedMemSize=4.300gb (4617089912 bytes)}, current pending count: 0
org.apache.flink.runtime.resourcemanager.exceptions.ResourceManagerException: Could not compute the container Resource from the given TaskExecutorProcessSpec TaskExecutorProcessSpec {cpuCores=10.0, frameworkHeapSize=128.000mb (134217728 bytes), frameworkOffHeapSize=128.000mb (134217728 bytes), taskHeapSize=5.200gb (5583457416 bytes), taskOffHeapSize=0 bytes, networkMemSize=1024.000mb (1073741824 bytes), managedMemorySize=4.300gb (4617089912 bytes), jvmMetaspaceSize=256.000mb (268435456 bytes), jvmOverheadSize=1024.000mb (1073741824 bytes)}. This usually indicates the requested resource is larger than Yarn's max container resource limit.。。。at akka.dispatch.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) [flink-dist_2.12-1.12.7.jar:1.12.7]
2022-11-18 10:12:12,939 INFO  org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager [] - Requesting new worker with resource spec WorkerResourceSpec {cpuCores=10.0, taskHeapSize=5.200gb (5583457416 bytes), taskOffHeapSize=0 bytes, networkMemSize=1024.000mb (1073741824 bytes), managedMemSize=4.300gb (4617089912 bytes)}, current pending count: 1.
2022-11-18 10:12:12,940 WARN  org.apache.flink.yarn.TaskExecutorProcessSpecContainerResourcePriorityAdapter [] - Requested container resource () exceeds the max limitation of the Yarn cluster (). Will not allocate resource.
2022-11-18 10:12:12,940 WARN  org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager [] - Failed requesting worker with resource spec WorkerResourceSpec {cpuCores=10.0, taskHeapSize=5.200gb (5583457416 bytes), taskOffHeapSize=0 bytes, networkMemSize=1024.000mb (1073741824 bytes), managedMemSize=4.300gb (4617089912 bytes)}, current pending count: 0
org.apache.flink.runtime.resourcemanager.exceptions.ResourceManagerException: Could not compute the container Resource from the given TaskExecutorProcessSpec TaskExecutorProcessSpec {cpuCores=10.0, frameworkHeapSize=128.000mb (134217728 bytes), frameworkOffHeapSize=128.000mb (134217728 bytes), taskHeapSize=5.200gb (5583457416 bytes), taskOffHeapSize=0 bytes, networkMemSize=1024.000mb (1073741824 bytes), managedMemorySize=4.300gb (4617089912 bytes), jvmMetaspaceSize=256.000mb (268435456 bytes), jvmOverheadSize=1024.000mb (1073741824 bytes)}. This usually indicates the requested resource is larger than Yarn's max container resource limit.。。。at akka.dispatch.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) [flink-dist_2.12-1.12.7.jar:1.12.7]
2022-11-18 10:12:12,941 INFO  org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager [] - Requesting new worker with resource spec WorkerResourceSpec {cpuCores=10.0, taskHeapSize=5.200gb (5583457416 bytes), taskOffHeapSize=0 bytes, networkMemSize=1024.000mb (1073741824 bytes), managedMemSize=4.300gb (4617089912 bytes)}, current pending count: 1.
2022-11-18 10:12:12,941 WARN  org.apache.flink.yarn.TaskExecutorProcessSpecContainerResourcePriorityAdapter [] - Requested container resource () exceeds the max limitation of the Yarn cluster (). Will not allocate resource.
2022-11-18 10:12:12,941 WARN  org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager [] - Failed requesting worker with resource spec WorkerResourceSpec {cpuCores=10.0, taskHeapSize=5.200gb (5583457416 bytes), taskOffHeapSize=0 bytes, networkMemSize=1024.000mb (1073741824 bytes), managedMemSize=4.300gb (4617089912 bytes)}, current pending count: 0
org.apache.flink.runtime.resourcemanager.exceptions.ResourceManagerException: Could not compute the container Resource from the given TaskExecutorProcessSpec TaskExecutorProcessSpec {cpuCores=10.0, frameworkHeapSize=128.000mb (134217728 bytes), frameworkOffHeapSize=128.000mb (134217728 bytes), taskHeapSize=5.200gb (5583457416 bytes), taskOffHeapSize=0 bytes, networkMemSize=1024.000mb (1073741824 bytes), managedMemorySize=4.300gb (4617089912 bytes), jvmMetaspaceSize=256.000mb (268435456 bytes), jvmOverheadSize=1024.000mb (1073741824 bytes)}. This usually indicates the requested resource is larger than Yarn's max container resource limit.at org.apache.flink.yarn.YarnResourceManagerDriver.requestResource(YarnResourceManagerDriver.java:254) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestNewWorker(ActiveResourceManager.java:249) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestWorkerIfRequired(ActiveResourceManager.java:310) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.lambda$requestNewWorker$0(ActiveResourceManager.java:261) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.uniHandleStage(CompletableFuture.java:834) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.handle(CompletableFuture.java:2155) ~[?:1.8.0_152]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestNewWorker(ActiveResourceManager.java:251) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestWorkerIfRequired(ActiveResourceManager.java:310) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.lambda$requestNewWorker$0(ActiveResourceManager.java:261) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.uniHandleStage(CompletableFuture.java:834) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.handle(CompletableFuture.java:2155) ~[?:1.8.0_152]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestNewWorker(ActiveResourceManager.java:251) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestWorkerIfRequired(ActiveResourceManager.java:310) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.lambda$requestNewWorker$0(ActiveResourceManager.java:261) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.uniHandleStage(CompletableFuture.java:834) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.handle(CompletableFuture.java:2155) ~[?:1.8.0_152]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestNewWorker(ActiveResourceManager.java:251) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestWorkerIfRequired(ActiveResourceManager.java:310) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.lambda$requestNewWorker$0(ActiveResourceManager.java:261) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.uniHandleStage(CompletableFuture.java:834) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.handle(CompletableFuture.java:2155) ~[?:1.8.0_152]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestNewWorker(ActiveResourceManager.java:251) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestWorkerIfRequired(ActiveResourceManager.java:310) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.lambda$requestNewWorker$0(ActiveResourceManager.java:261) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.uniHandleStage(CompletableFuture.java:834) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.handle(CompletableFuture.java:2155) ~[?:1.8.0_152]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestNewWorker(ActiveResourceManager.java:251) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestWorkerIfRequired(ActiveResourceManager.java:310) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.lambda$requestNewWorker$0(ActiveResourceManager.java:261) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.uniHandleStage(CompletableFuture.java:834) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.handle(CompletableFuture.java:2155) ~[?:1.8.0_152]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestNewWorker(ActiveResourceManager.java:251) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestWorkerIfRequired(ActiveResourceManager.java:310) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.lambda$requestNewWorker$0(ActiveResourceManager.java:261) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.uniHandleStage(CompletableFuture.java:834) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.handle(CompletableFuture.java:2155) ~[?:1.8.0_152]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestNewWorker(ActiveResourceManager.java:251) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestWorkerIfRequired(ActiveResourceManager.java:310) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.lambda$requestNewWorker$0(ActiveResourceManager.java:261) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.uniHandleStage(CompletableFuture.java:834) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.handle(CompletableFuture.java:2155) ~[?:1.8.0_152]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestNewWorker(ActiveResourceManager.java:251) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestWorkerIfRequired(ActiveResourceManager.java:310) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.lambda$requestNewWorker$0(ActiveResourceManager.java:261) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.uniHandleStage(CompletableFuture.java:834) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.handle(CompletableFuture.java:2155) ~[?:1.8.0_152]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestNewWorker(ActiveResourceManager.java:251) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestWorkerIfRequired(ActiveResourceManager.java:310) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.lambda$requestNewWorker$0(ActiveResourceManager.java:261) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.uniHandleStage(CompletableFuture.java:834) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.handle(CompletableFuture.java:2155) ~[?:1.8.0_152]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestNewWorker(ActiveResourceManager.java:251) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestWorkerIfRequired(ActiveResourceManager.java:310) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.lambda$requestNewWorker$0(ActiveResourceManager.java:261) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.uniHandleStage(CompletableFuture.java:834) ~[?:1.8.0_152]at java.util.concurrent.CompletableFuture.handle(CompletableFuture.java:2155) ~[?:1.8.0_152]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.requestNewWorker(ActiveResourceManager.java:251) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.active.ActiveResourceManager.startNewWorker(ActiveResourceManager.java:160) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.ResourceManager$ResourceActionsImpl.allocateResource(ResourceManager.java:1382) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.slotmanager.SlotManagerImpl.allocateResource(SlotManagerImpl.java:1058) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.slotmanager.SlotManagerImpl.fulfillPendingSlotRequestWithPendingTaskManagerSlot(SlotManagerImpl.java:954) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.slotmanager.SlotManagerImpl.lambda$internalRequestSlot$9(SlotManagerImpl.java:943) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.util.OptionalConsumer.ifNotPresent(OptionalConsumer.java:51) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.slotmanager.SlotManagerImpl.internalRequestSlot(SlotManagerImpl.java:941) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.slotmanager.SlotManagerImpl.registerSlotRequest(SlotManagerImpl.java:410) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.resourcemanager.ResourceManager.requestSlot(ResourceManager.java:529) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_152]at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_152]at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_152]at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_152]at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleRpcInvocation(AkkaRpcActor.java:305) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleRpcMessage(AkkaRpcActor.java:212) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.rpc.akka.FencedAkkaRpcActor.handleRpcMessage(FencedAkkaRpcActor.java:77) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleMessage(AkkaRpcActor.java:158) ~[flink-dist_2.12-1.12.7.jar:1.12.7]at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:26) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:21) [flink-dist_2.12-1.12.7.jar:1.12.7]at scala.PartialFunction.applyOrElse(PartialFunction.scala:123) [flink-dist_2.12-1.12.7.jar:1.12.7]at scala.PartialFunction.applyOrElse$(PartialFunction.scala:122) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.japi.pf.UnitCaseStatement.applyOrElse(CaseStatements.scala:21) [flink-dist_2.12-1.12.7.jar:1.12.7]at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:171) [flink-dist_2.12-1.12.7.jar:1.12.7]at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:172) [flink-dist_2.12-1.12.7.jar:1.12.7]at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:172) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.actor.Actor.aroundReceive(Actor.scala:517) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.actor.Actor.aroundReceive$(Actor.scala:515) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.actor.AbstractActor.aroundReceive(AbstractActor.scala:225) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.actor.ActorCell.receiveMessage(ActorCell.scala:592) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.actor.ActorCell.invoke(ActorCell.scala:561) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:258) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.dispatch.Mailbox.run(Mailbox.scala:225) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.dispatch.Mailbox.exec(Mailbox.scala:235) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.dispatch.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.dispatch.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.dispatch.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) [flink-dist_2.12-1.12.7.jar:1.12.7]at akka.dispatch.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) [flink-dist_2.12-1.12.7.jar:1.12.7]

二. 初级问题分析与解决

1. 问题分析

报错很明确，也就是我们向yarn多申请了资源。所以我们关注两点：yarn的调度器设置（规定了队列，每个任务申请的限制）、程序中是如何设置的并行度的。

1.1. yarn的调度器设置

打开yarn 看到Maximum Allocation限制为 ，具体的说，就是我们申请一个container最大内存能申请12G、最大核心数为4

 

1.2. 程序设置

看下运行的shell的伪代码

tmp_value=`echo $parallelism 10 | awk '{if($1 > $2) print 1; else print 0;}'`
if [ $tmp_value -eq 1 ] ;thentm=12288vcores=10numberOfTaskSlots=10
fi
..."yarn.containers.vcores":${vcores}
"taskmanager.numberOfTaskSlots":${numberOfTaskSlots}
...

这里可以看到冲突：当我们的并行度设置超过10时，vcores设置为10，但yarn最大让设置为4，所以会报错。。。

2. 问题解决

解决问题的方式也比较简单，让vcores最大保持为4，然后再运行。

这里我们设置整个job的并行度还是为20，然后申请一个container中vcores=4，那么按照一个并行度分配一个线程的逻辑

即一个taskmanager（container）中有4核对应有4个slot，那将会有20/4=5个taskmanager

三. （性能）新的问题

1. 问题描述

任务是跑起来了，但是出现了一个性能的问题：

先看下job的运行情况：

job的消费速度：

• 20并行度下，每个taskmanager的内存为12G，每秒消费11.28万条数据，那每分钟处理的速度是676.89万条/min，每小时4.06亿条/小时

• 2032.766839793899649 GB 每小时平均

• 5793.385493412613869 GB 累计2.85小时
   

最终的结果

• 53.14亿条
• 数据量有：3.03TB

• 消费每条数据的平均大小是：626byte。
• 1G=1,073,741,824 bytes

最终整个job运行完，花了11个小时：

客户的要求是1小时内完成，但速度太慢了。。。
 

2. 理想化的最优方案

客户集群的资源是够的，所以我们不考虑资源问题，那既然这样，因为hdfs的文件总共有4000个，再有yarn最大资源分配是4（core/container），所以我们部署一个4000并行度的任务，它将运行的最快！！！

所以我将并行度设置为4000时将会有1000个taskmanager启动。等一下。1000个？？？我心疼jobmanager一秒钟先。

果然，任务还没调度完，就失败了。。。

所以理想有些简单，也没有银弹。

3. "PlanB"的解决方案

既然一个jobmanager不能管理这么多的taskmanager，那就降低taskmanager的数量。
。。。经过多次尝试之后，这里最终给出了方案B的设置：

并行度设置为500，taskmanager启动了125个。

任务最终处理时间缩短到：23分钟

*********************************************
nErrors              |  0
nullErrors           |  0
duplicateErrors      |  0
conversionErrors     |  0
otherErrors          |  0
numWrite             |  3164002700
byteWrite            |  17123302298224
numRead              |  3164002700
writeDuration        |  545313434
byteRead             |  1983716362408
readDuration         |  539805057
snapshotWrite        |  6328005400
*********************************************2022-11-21 11:48:56 Start to stop flink job(3734d90205a13eff7cfa61b5c0c9686b)
2022-11-21 11:50:11 Success to stop flink job(3734d90205a13eff7cfa61b5c0c9686b)
2022-11-21 11:50:11 Flink process exit code is :0

四. 反思与迭代

针对上述的处理过程，发现几点值得思考和迭代：

1. 我们程序和yarn进行定时通讯，及时获取yarn中调度器的设置，然后动态设置最大核心数，充分利用资源的同时，也保证了程序的稳定；

2. 我们在设置并行度时，需要考虑jobmanager能够协调的taskmanager的数量，不是靠尝试。
    
   本文学到的经验是，设置125个taskmanager时，jobmanager是可以顶住压力的，但接下来可以分析分析flink的通讯相关的源码，以便能极大的发挥集群资源。
    
   其次对于jobmanager管理这么多节点是否可以设置flink的高可用，增加job运行的稳定度

还有一个小细节

3. taskmanager的内存使用有些浪费，如上图，并未充分利用内存资源，这点我们也需思考要如何优化。

仔细点我们也可以发现

4. 当container设置的核心数最大为4时，numberOfTaskSlots的设置其实无效了。