[HBASE-9048] HCM throws NullPointerException under load

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.98.0, 0.95.2, 0.94.11
• Component/s: Client
• Hadoop Flags: Reviewed
• Assignee: Jimmy Xiang
• Reporter: Jimmy Xiang
• Created: 26/Jul/13 21:21
• Updated: 21/Aug/13 00:08
• Resolved: 26/Jul/13 22:59

Description

HCM uses SoftValueSortedMap to cache region locations. Under load, some soft referred values may be GCed. So we should check if the value is null. Otherwise, NPE will be thrown:

        for (Map<byte[], HRegionLocation> tableLocations :
            cachedRegionLocations.values()) {
          for (Entry<byte[], HRegionLocation> e : tableLocations.entrySet()) {
       ===> if (serverName.equals(e.getValue().getServerName())) {
              tableLocations.remove(e.getKey());
              deletedSomething = true;
            }
          }
        }