Home » Tag Archives: Concurrency (page 15)

Tag Archives: Concurrency

Java Executor Service Types

ExecutorService feature was come with Java 5. It extends Executor interface and provides thread pool feature to execute asynchronous short tasks. There are five ways to execute the tasks asyncronously by using ExecutorService interface provided Java 6. ExecutorService execService = Executors.newCachedThreadPool(); This method of the approach creates a thread pool that creates new threads as needed, but will reuse previously ...

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Java Concurrency – CyclicBarrier Example

CyclicBarrier in Java is a synchronizer introduced in JDK 5 on java.util.Concurrent package along with other concurrent utility like Counting Semaphore, BlockingQueue, ConcurrentHashMap etc. CyclicBarrier is similar to CountDownLatch which we have seen in last article and allows multiple threads to wait for each other (barrier) before proceeding. Also difference between CoundDownLatch and CyclicBarrier is a also very popular multi-threading ...

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Native vs Green threads

Native vs Green threads  Understanding a multi-threaded program have always been a wild goose chase for many programmers. There are always many aspects to consider when writing a multi-threaded program. Green threads vs Native Threads The difference between green threads vs native threads is something that programmers may be unaware of. Both are mechanisms are ways of achieving a ‘multi-threaded ...

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Concurrency – Sequential and Raw Thread

I worked on a project a while back, where the report flow was along these lines: User would request for a report The report request would be translated into smaller parts/sections The report for each part, based on the type of the part/section would be generated by a report generator The constituent report parts would be reassembled into a final ...

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Concurrency – Executors and Spring Integration

spring-interview-questions-answers

Thread Pool/Executors Based Implementation A better approach than the raw thread version, is a Thread pool based one, where an appropriate thread pool size is defined based on the system where the task is running – Number of CPU’s/(1-Blocking Coefficient of Task). Venkat Subramaniams book has more details: First I defined a custom task to generate the Report Part, given ...

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Java concurrency – Feedback from tasks

Picking up from where I left off in my last post about the java.util.concurrent package, it’s interesting and sometimes mandatory to get feedback from concurrent tasks after they are started. For example imagine an application that has to send email batches, besides from using a multi-threaded mechanism, you want to know how many of the intended emails were successfully dispatched, ...

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Java Thread deadlock – Case Study

This article will describe the complete root cause analysis of a recent Java deadlock problem observed from a Weblogic 11g production system running on the IBM JVM 1.6. This case study will also demonstrate the importance of mastering Thread Dump analysis skills; including for the IBM JVM Thread Dump format. Environment specifications – Java EE server: Oracle Weblogic Server 11g ...

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Latency, Throughput and Degree of Concurrency

chrisapotek asked. How do you define throughput and latency for your test? There is not a simple question, so I have replied with a post. Sustained Throughput I consider throughput to be the number of actions a process can perform over a sustained period of time, between 10 seconds and day. (Assuming you have a quite period over night to ...

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Threading stories: ThreadLocal in web applications

This week I spend reasonable time to eliminate all our ThreadLocal variables in our web applications. The reason was that they created classloader leaks and we coudn’t undeploy our applications properly anymore. Classloader leaks happen when a GC root keeps referencing an application object after the application was undeployed. If an application object is still referenced after undeploy, then the ...

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