[OAK-6622] Configure default core pool size for thread pool used by oak-lucene

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.7.7, 1.8.0
• Component/s: lucene
• Assignee: Chetan Mehrotra
• Reporter: Chetan Mehrotra
• Created: 06/Sep/17 10:23
• Updated: 14/Sep/17 13:02
• Resolved: 06/Sep/17 11:21

Description

LuceneIndexProviderService currently configures a thread pool like below

 ThreadPoolExecutor executor = new ThreadPoolExecutor(
          0,  //corePoolSize
          5, //maxPoolSize
         60L, 
         TimeUnit.SECONDS,
         new LinkedBlockingQueue<Runnable>(), //Unbounded queue
         new ThreadFactory() {

Per ThreadPoolExecutor

If there are more than corePoolSize but less than maximumPoolSize threads running, a new thread will be created only if the queue is full

Due to this currently the thread pool created by oak-lucene would only have 1 thread to handle all task as the queue is unbounded one. And if for some reason this thread gets stuck (due to some lock) then it would prevent other task in pool from further processing.

Issue Links

• supercedes: OAK-6619 Async indexer thread may get stuck in CopyOnWriteDirectory close method