[HBASE-16402] RegionServerCoprocessorHost should be initialized before RpcServer starts

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.98.22
• Assignee: Guanghao Zhang
• Reporter: Guanghao Zhang
• Created: 11/Aug/16 23:58
• Updated: 12/Aug/16 12:48
• Resolved: 12/Aug/16 04:51

Description

We found NPE in our 0.98 production cluster because RegionServerCoprocessorHost is not initialized before RpcServer start service.

      // Try and register with the Master; tell it we are here.  Break if
      // server is stopped or the clusterup flag is down or hdfs went wacky.
      while (keepLooping()) {
        RegionServerStartupResponse w = reportForDuty();
        if (w == null) {
          LOG.warn("reportForDuty failed; sleeping and then retrying.");
          this.sleeper.sleep();
        } else {
          handleReportForDutyResponse(w);
          break;
        }
      }

      // Initialize the RegionServerCoprocessorHost now that our ephemeral
      // node was created by reportForDuty, in case any coprocessors want
      // to use ZooKeeper
      this.rsHost = new RegionServerCoprocessorHost(this, this.conf);

RpcServer start service in handleReportForDutyResponse(), then it can serve rpc call replicateWALEntry(). But the RegionServerCoprocessorHost is not initialized and it is used in replicateWALEntry, so it will throw a NPE.