boolean checkMetaRegion()

in hbase-hbck2/src/main/java/org/apache/hbase/hbck1/HBaseFsck.java [3967:4019]
47 lines of code
12 McCabe index (conditional complexity)

  boolean checkMetaRegion() throws IOException, KeeperException, InterruptedException {
    Map<Integer, HbckInfo> metaRegions = new HashMap<>();
    for (HbckInfo value : regionInfoMap.values()) {
      if (value.metaEntry != null && value.metaEntry.isMetaRegion()) {
        metaRegions.put(value.getReplicaId(), value);
      }
    }
    int metaReplication = admin.getDescriptor(TableName.META_TABLE_NAME)
        .getRegionReplication();
    boolean noProblem = true;
    // There will be always entries in regionInfoMap corresponding to hbase:meta & its replicas
    // Check the deployed servers. It should be exactly one server for each replica.
    for (int i = 0; i < metaReplication; i++) {
      HbckInfo metaHbckInfo = metaRegions.remove(i);
      List<ServerName> servers = new ArrayList<>();
      if (metaHbckInfo != null) {
        servers = metaHbckInfo.deployedOn;
      }
      if (servers.size() != 1) {
        noProblem = false;
        if (servers.isEmpty()) {
          assignMetaReplica(i);
        } else if (servers.size() > 1) {
          errors.reportError(ErrorReporter.ERROR_CODE.MULTI_META_REGION,
            "hbase:meta, replicaId " + metaHbckInfo.getReplicaId() +
                " is found on more than one region.");
          if (shouldFixAssignments()) {
            errors.print("Trying to fix a problem with hbase:meta, replicaId " +
                         metaHbckInfo.getReplicaId() +"..");
            setShouldRerun();
            // try fix it (treat is a dupe assignment)
            HBaseFsckRepair.fixMultiAssignment(connection, metaHbckInfo.metaEntry, servers);
          }
        }
      }
    }
    // unassign whatever is remaining in metaRegions. They are excess replicas.
    for (Map.Entry<Integer, HbckInfo> entry : metaRegions.entrySet()) {
      noProblem = false;
      errors.reportError(ErrorReporter.ERROR_CODE.SHOULD_NOT_BE_DEPLOYED,
          "hbase:meta replicas are deployed in excess. Configured " + metaReplication +
          ", deployed " + metaRegions.size());
      if (shouldFixAssignments()) {
        errors.print("Trying to undeploy excess replica, replicaId: " + entry.getKey() +
            " of hbase:meta..");
        setShouldRerun();
        unassignMetaReplica(entry.getValue());
      }
    }
    // if noProblem is false, rerun hbck with hopefully fixed META
    // if noProblem is true, no errors, so continue normally
    return noProblem;
  }