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<Codis><JedisPool><DeadLock>

时间:2017-07-18 21:07:37      阅读:139      评论:0      收藏:0      [点我收藏+]

标签:alt   jedis   view   rac   spool   reads   img   dead   normal   

Overview

  • Background: I start a thread [call thread A below]in Spark driver to handle opening files in codis, in which I start six thread [call sub threads below]to handle the files in parallel.

  • What happened:

    • I found the codis openingFilePool never update since a given time.

    • So I looked into the Thread Dump tools of spark, and saw that thread A is always been WAITING. As below:
      技术分享

    •  

      The normal one is as follow:

      技术分享

    • See the difference?
      The thread should be TIMED_WAITING(sleep), not be WAITING(wait for some other threads to awake it)!
    • It seems there is a deadlock?

  • Thread A get a jedis instance from JedisResourcePool to get all opening files.

  • Then, the sub threads handle these opening files and interact with codis in pipeline. [I use try(Pipeline pipeline = CodisPool.getPool().getResource().pipelined())]

Possible causes

  • I am not sure this is because 1) there is no enough instance in JedisPool; or 2) there is a deadlock
    • try (Pipeline pipeline = CodisPool.getPool().getResource().pipelined())
      • I am not sure whether this code will close jedis and pipeline, or it will just close pipeline?

    • JedisResourcePool is not thread-safe?

      • Some says that we should sync when we getResource() from JedisResourcePool. I am not sure.

      • And also I think should I configure the number of Jedis pool. 

 

<Codis><JedisPool><DeadLock>

标签:alt   jedis   view   rac   spool   reads   img   dead   normal   

原文地址:http://www.cnblogs.com/wttttt/p/7202500.html

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