HBASE-27756 Make request guardrail configs in RSRpcServices live upda…

…table (apache#5141)

Signed-off-by: Nick Dimiduk <ndimiduk@apache.org>

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/RSRpcServices.java

@@ -297,7 +297,7 @@ public class RSRpcServices extends HBaseRpcServicesBase<HRegionServer>
   // Request counter for rpc mutate
   final LongAdder rpcMutateRequestCount = new LongAdder();
 
-  private final long maxScannerResultSize;
+  private volatile long maxScannerResultSize;
 
   private ScannerIdGenerator scannerIdGenerator;
   private final ConcurrentMap<String, RegionScannerHolder> scanners = new ConcurrentHashMap<>();
@@ -323,12 +323,12 @@ public class RSRpcServices extends HBaseRpcServicesBase<HRegionServer>
   /**
    * Row size threshold for multi requests above which a warning is logged
    */
-  private final int rowSizeWarnThreshold;
+  private volatile int rowSizeWarnThreshold;
   /*
    * Whether we should reject requests with very high no of rows i.e. beyond threshold defined by
    * rowSizeWarnThreshold
    */
-  private final boolean rejectRowsWithSizeOverThreshold;
+  private volatile boolean rejectRowsWithSizeOverThreshold;
 
   final AtomicBoolean clearCompactionQueues = new AtomicBoolean(false);
 
@@ -1162,14 +1162,9 @@ private void closeAllScanners() {
   public RSRpcServices(final HRegionServer rs) throws IOException {
     super(rs, rs.getProcessName());
     final Configuration conf = rs.getConfiguration();
-    rowSizeWarnThreshold =
-      conf.getInt(HConstants.BATCH_ROWS_THRESHOLD_NAME, HConstants.BATCH_ROWS_THRESHOLD_DEFAULT);
-    rejectRowsWithSizeOverThreshold =
-      conf.getBoolean(REJECT_BATCH_ROWS_OVER_THRESHOLD, DEFAULT_REJECT_BATCH_ROWS_OVER_THRESHOLD);
+    setReloadableGuardrails(conf);
     scannerLeaseTimeoutPeriod = conf.getInt(HConstants.HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD,
       HConstants.DEFAULT_HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD);
-    maxScannerResultSize = conf.getLong(HConstants.HBASE_SERVER_SCANNER_MAX_RESULT_SIZE_KEY,
-      HConstants.DEFAULT_HBASE_SERVER_SCANNER_MAX_RESULT_SIZE);
     rpcTimeout =
       conf.getInt(HConstants.HBASE_RPC_TIMEOUT_KEY, HConstants.DEFAULT_HBASE_RPC_TIMEOUT);
     minimumScanTimeLimitDelta = conf.getLong(REGION_SERVER_RPC_MINIMUM_SCAN_TIME_LIMIT_DELTA,
@@ -3923,4 +3918,19 @@ public GetAllBootstrapNodesResponse getAllBootstrapNodes(RpcController controlle
       .forEachRemaining(server -> builder.addNode(ProtobufUtil.toServerName(server)));
     return builder.build();
   }
+
+  private void setReloadableGuardrails(Configuration conf) {
+    rowSizeWarnThreshold =
+      conf.getInt(HConstants.BATCH_ROWS_THRESHOLD_NAME, HConstants.BATCH_ROWS_THRESHOLD_DEFAULT);
+    rejectRowsWithSizeOverThreshold =
+      conf.getBoolean(REJECT_BATCH_ROWS_OVER_THRESHOLD, DEFAULT_REJECT_BATCH_ROWS_OVER_THRESHOLD);
+    maxScannerResultSize = conf.getLong(HConstants.HBASE_SERVER_SCANNER_MAX_RESULT_SIZE_KEY,
+      HConstants.DEFAULT_HBASE_SERVER_SCANNER_MAX_RESULT_SIZE);
+  }
+
+  @Override
+  public void onConfigurationChange(Configuration conf) {
+    super.onConfigurationChange(conf);
+    setReloadableGuardrails(conf);
+  }
 }