[HADOOP-11772] RPC Invoker relies on static ClientCache which has synchronized(this) blocks

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Component/s: ipc, performance
• Target Version/s: 2.7.1
• Hadoop Flags: Incompatible change, Reviewed
• Release Note: The Client#call() methods that are deprecated since 0.23 have been removed.
• Assignee: Haohui Mai
• Reporter: Gopal Vijayaraghavan
• Created: 28/Mar/15 04:49
• Updated: 30/Aug/16 01:29
• Resolved: 21/May/15 03:15

Description

  private static ClientCache CLIENTS=new ClientCache();
...
    this.client = CLIENTS.getClient(conf, factory);

Meanwhile in ClientCache

public synchronized Client getClient(Configuration conf,
      SocketFactory factory, Class<? extends Writable> valueClass) {
...
   Client client = clients.get(factory);
    if (client == null) {
      client = new Client(valueClass, conf, factory);
      clients.put(factory, client);
    } else {
      client.incCount();
    }

All invokers end up calling these methods, resulting in IPC clients choking up.

Issue Links

• breaks: HADOOP-12052 IPC client downgrades all exception types to IOE, breaks callers trying to use them
• breaks: SLIDER-896 TestClientBasicArgs.testListUnknownRM fails on Windows