executor

ThreadPool does not run tasks in sequence

由 ☆樱花仙子☆ 提交于 2019-12-12 11:31:17
问题 I am using the Executor framework specifically Executors.newCachedThreadPool(); I have a list of Runnable s e.g. 100. The first 50, each create a value (stored in a list) to be used by the last 50. I thought that if I pass the Runnable s in the executor.execute() in the order they are in the list, they would be also executed in the same order. But this is not happening. The tasks seem to be executed in random order and they are interleaved, not executed in sequence. Is this how it is suppose

Performance Improvement for each thread using different unique id

由 本秂侑毒 提交于 2019-12-11 19:52:30
问题 Problem Statement is:- Each thread uses unique ID between 1 and 1000 and program has to run for 60 minutes or more, So in that 60 minutes it is possible that all the ID's will get finished so I need to reuse those ID's again, I know several ways to do it, one way is the below that I wrote by taking help from StackOverflow, but when I tried running this, what I found is that, after few minutes of run this program gets very slow and it takes lot of time to print the ID on the console. And also

Java Executor 框架

由 删除回忆录丶 提交于 2019-12-11 16:51:24
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> Executor框架是指java5中引入的一系列并发库中与executor相关的功能类，包括Executor、Executors、ExecutorService、CompletionService、Future、Callable等。（图片引用自http://www.javaclubcn.com/a/jichuzhishi/2012/1116/170.html） 本篇博文分析Executor中几个比较重要的接口和类。 Executor 1 public interface Executor { 2 void execute(Runnable command); 3 } Executor接口是Executor框架中最基础的部分，定义了一个用于执行Runnable的execute方法。它没有直接的实现类，有一个重要的子接口ExecutorService。 ExecutorService 1 // 继承自Executor接口 2 public interface ExecutorService extends Executor { 3 /** 4 * 关闭方法，调用后执行之前提交的任务，不再接受新的任务 5 */ 6 void shutdown(); 7 /** 8 * 从语义上可以看出是立即停止的意思

Executor框架结构与主要成员（一）

由 北慕城南 提交于 2019-12-11 16:46:11
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 本文分两部分来介绍Executor：Executor的结构和Executor框架包含的成员组件 1、Executor框架的结构 Executor主要由3大部分组成。 1.1、任务。包含被执行任务需要实现的接口：Runnable接口或Callable接口。 1.2、任务的执行。包括任务执行机制的核心接口Executor，以及继承自Executor接口的ExecutorService接口。Executor有两个关键类实现了ExecutorService接口（ThreadPoolExecutor和ScheduledThreadPoolExecutor） 1.3、异步计算的结果。包括接口Future和实现Future接口的FutureTask类。 下面是这些类和接口的简介。 Executor是一个接口，它是Executor框架的基础，它将任务的提交和任务的执行分离开来。 ThreadPoolExecutor是线程池的核心实现类，用来执行被提交的任务。 ScheduledThreadPoolExecutor是一个实现类，可以在给定的延迟后运行命令，或者定期执行命令。SchduledThreadPoolExecutor比Timer更灵活，功能更强大。 Future接口和实现Future接口的FutureTask类

Spring TaskExecutor unbounded queue

由 怎甘沉沦 提交于 2019-12-11 15:55:51
问题 I implemented the Spring-TaskExecutor (which is the equivalent of the JDK 1.5's Executor.) to process notifications notifications receiving from external systems. Interface with only one method: public interface AsynchronousService { void executeAsynchronously(Runnable task); } and the corresponding implementation: public class AsynchronousServiceImpl implements AsynchronousService { private TaskExecutor taskExecutor; @Override public void executeAsynchronously(Runnable task) { taskExecutor

spark thriftserver运维

由 我的未来我决定 提交于 2019-12-11 11:34:38
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> spark thriftserver 运维： 在root @spark_master_machine 机器上 启动 thriftserver ======================================================================================================================================================================== /root/ cdh /spark/spark-1.4.1-bin-hadoop2.6/ sbin /start-thriftserver.sh \ -- hiveconf hive.server2.thrift.port=10000 \ -- hiveconf hive.server2.thrift.bind.host=spark_master_machine \ --master spark://spark_master_machine:7077 --executor-memory 24g --executor-cores 8 --total-executor-cores 136 --driver-memory 10g --driver

laggy Listview with ImageView and Executor Framework

由 不问归期 提交于 2019-12-11 11:22:01
问题 I have a ListView with custom items, like this one: The grey square is an ImageView. The data to fill the ListView comes from a database in the form of a Cursor. But the images are not directly stored in the database, but in the SDCard, the database only holds a String reference to them. In the beginning I was decoding the Image into a Bitmap from the overriden CursorAdapter's bindView() callback method: Bitmap bmp = BitmapFactory.decodeFile(imageLocation); holder.imageHolder.setImageBitmap

Add executors dynamically based on a condition in java

由 风格不统一 提交于 2019-12-11 10:44:20
问题 If StrTemp.equals(true) , I want code as below (I have 2 threads here): ExecutorService executor = Executors.newFixedThreadPool(2); Future<String> f1 = executor.submit(new Callable<String >() { public String call() throws Exception { return dao.getS4PricingResponse(pricingRequestTemp); } }); Future<String> f2 = executor.submit(new Callable<String>() { public String call() throws Exception { return dao.getS4ProductResponse(productRequestTemp); } }); If it's not true I want three threads to be

Does a Future instantly return false for isDone() right after an executor submit()

由 Deadly 提交于 2019-12-11 04:12:15
问题 Could not find a documentation about the future state of an executor.submit() call. Example: byte[] b = new byte[ 4000000 ]; new Random().nextBytes( b ); Callable<byte[]> c = new SorterCallable( b ); ExecutorService executor = Executors.newCachedThreadPool(); Future<byte[]> result = executor.submit( c ); boolean futureState = result.isDone(); The question is if the returned Future<byte[]> object returns false when calling isDone() right after submit? Or is it also possible that futureState is

spark资源调度和任务调度

由 不问归期 提交于 2019-12-10 23:36:57
资源调度： （1）executor默认在集群中分散启动，可通过 参数配置 集中在某个work启动，不过分散启动有利于数据本地化。 （2）如果spark-submit提交任务时，如果不指定--executor-cores，则spark会在每个work中启动一个executor并消耗掉work中的所有core和1G的内存。 （3）如果只设置--executor-cores而不设置--total-executor-cores则会，每启动一个executor耗费--executor-cores配置的核，而且也会消耗掉所有work中的core，直到不能在启动executor为止。 （4）只有指定--executor-cores并且指定--total-executor-cores，才会限定住 executor的个数 和 每个executor需要的core个数 。 任务调度： 按照action算子划分job，每个job由DAGSchedule划分stage，由finalRdd开始由后向前递归划分stage，划分stage的关键方法是submitStage： private def submitStage(stage: Stage) { val jobId = activeJobForStage(stage) if (jobId.isDefined) { logDebug("submitStage
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