[HBASE-12759] numMaxRegionsPerTable is not updated correctly in BaseLoadBalancer.regionMoved

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Duplicate
• Affects Version/s: 1.0.0
• Component/s: Balancer
• Assignee: Unassigned
• Reporter: Jianwei Cui
• Created: 26/Dec/14 02:46
• Updated: 17/Jun/22 18:44
• Resolved: 26/Aug/17 14:31

Description

numMaxRegionsPerTable will be updated in BaseLoadBalancer.regionMoved(...) as:

    void regionMoved(int region, int oldServer, int newServer) {
      ....
      int tableIndex = regionIndexToTableIndex[region];
      if (oldServer >= 0) {
        numRegionsPerServerPerTable[oldServer][tableIndex]--;
      }
      numRegionsPerServerPerTable[newServer][tableIndex]++;

      //check whether this caused maxRegionsPerTable in the new Server to be updated
      if (numRegionsPerServerPerTable[newServer][tableIndex] > numMaxRegionsPerTable[tableIndex]) {
        numRegionsPerServerPerTable[newServer][tableIndex] = numMaxRegionsPerTable[tableIndex];  // ==> should be: numMaxRegionsPerTable[tableIndex] = numRegionsPerServerPerTable[newServer][tableIndex];
      } else if (oldServer >= 0 && (numRegionsPerServerPerTable[oldServer][tableIndex] + 1)
          == numMaxRegionsPerTable[tableIndex]) {
        //recompute maxRegionsPerTable since the previous value was coming from the old server
        // ===> should reset numMaxRegionsPerTable[tableIndex] before recompute : numMaxRegionsPerTable[tableIndex] = 0;
        for (int serverIndex = 0 ; serverIndex < numRegionsPerServerPerTable.length; serverIndex++) {
          if (numRegionsPerServerPerTable[serverIndex][tableIndex] > numMaxRegionsPerTable[tableIndex]) {
            numMaxRegionsPerTable[tableIndex] = numRegionsPerServerPerTable[serverIndex][tableIndex];
          }
        }
      }

It seems that numMaxRegionsPerTable is not updated correctly as shown above.