Create scanner after quota check

Author: Hernan Gelaf-Romer

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

@@ -418,6 +418,18 @@ public void run() {
     }
   }
 
+  static class RegionScannerContext {
+    final String scannerName;
+    final RegionScannerHolder holder;
+    final OperationQuota quota;
+
+    RegionScannerContext(String scannerName, RegionScannerHolder holder, OperationQuota quota) {
+      this.scannerName = scannerName;
+      this.holder = holder;
+      this.quota = quota;
+    }
+  }
+
   /**
    * Holder class which holds the RegionScanner, nextCallSeq and RpcCallbacks together.
    */
@@ -1267,12 +1279,12 @@ public int getScannersCount() {
 
   /** Returns The outstanding RegionScanner for <code>scannerId</code> or null if none found. */
   RegionScanner getScanner(long scannerId) {
-    RegionScannerHolder rsh = getRegionScannerHolder(scannerId);
+    RegionScannerHolder rsh = checkQuotaAndGetRegionScannerContext(scannerId);
     return rsh == null ? null : rsh.s;
   }
 
   /** Returns The associated RegionScannerHolder for <code>scannerId</code> or null. */
-  private RegionScannerHolder getRegionScannerHolder(long scannerId) {
+  private RegionScannerHolder checkQuotaAndGetRegionScannerContext(long scannerId) {
     return scanners.get(toScannerName(scannerId));
   }
 
@@ -1313,7 +1325,7 @@ public String getScanDetailsWithRequest(ScanRequest request) {
    * Get the vtime associated with the scanner. Currently the vtime is the number of "next" calls.
    */
   long getScannerVirtualTime(long scannerId) {
-    RegionScannerHolder rsh = getRegionScannerHolder(scannerId);
+    RegionScannerHolder rsh = checkQuotaAndGetRegionScannerContext(scannerId);
     return rsh == null ? 0L : rsh.getNextCallSeq();
   }
 
@@ -3134,9 +3146,8 @@ private RegionScannerHolder getRegionScanner(ScanRequest request) throws IOExcep
    * @return Pair with scannerName key to use with this new Scanner and its RegionScannerHolder
    *         value.
    */
-  private Pair<String, RegionScannerHolder> newRegionScanner(ScanRequest request,
+  private Pair<String, RegionScannerHolder> newRegionScanner(ScanRequest request, HRegion region,
     ScanResponse.Builder builder) throws IOException {
-    HRegion region = getRegion(request.getRegion());
     rejectIfInStandByState(region);
     ClientProtos.Scan protoScan = request.getScan();
     boolean isLoadingCfsOnDemandSet = protoScan.hasLoadColumnFamiliesOnDemand();
@@ -3553,22 +3564,10 @@ public ScanResponse scan(final RpcController controller, final ScanRequest reque
     }
     requestCount.increment();
     rpcScanRequestCount.increment();
-    RegionScannerHolder rsh;
+    RegionScannerContext rsx;
     ScanResponse.Builder builder = ScanResponse.newBuilder();
-    String scannerName;
     try {
-      if (request.hasScannerId()) {
-        // The downstream projects such as AsyncHBase in OpenTSDB need this value. See HBASE-18000
-        // for more details.
-        long scannerId = request.getScannerId();
-        builder.setScannerId(scannerId);
-        scannerName = toScannerName(scannerId);
-        rsh = getRegionScanner(request);
-      } else {
-        Pair<String, RegionScannerHolder> scannerNameAndRSH = newRegionScanner(request, builder);
-        scannerName = scannerNameAndRSH.getFirst();
-        rsh = scannerNameAndRSH.getSecond();
-      }
+      rsx = checkQuotaAndGetRegionScannerContext(request, builder);
     } catch (IOException e) {
       if (e == SCANNER_ALREADY_CLOSED) {
         // Now we will close scanner automatically if there are no more results for this region but
@@ -3577,6 +3576,9 @@ public ScanResponse scan(final RpcController controller, final ScanRequest reque
       }
       throw new ServiceException(e);
     }
+    String scannerName = rsx.scannerName;
+    RegionScannerHolder rsh = rsx.holder;
+    OperationQuota quota = rsx.quota;
     if (rsh.fullRegionScan) {
       rpcFullScanRequestCount.increment();
     }
@@ -3599,14 +3601,6 @@ public ScanResponse scan(final RpcController controller, final ScanRequest reque
       }
       return builder.build();
     }
-    OperationQuota quota;
-    try {
-      quota = getRpcQuotaManager().checkScanQuota(region, request, maxScannerResultSize,
-        rsh.getMaxBlockBytesScanned(), rsh.getPrevBlockBytesScannedDifference());
-    } catch (IOException e) {
-      addScannerLeaseBack(lease);
-      throw new ServiceException(e);
-    }
     try {
       checkScanNextCallSeq(request, rsh);
     } catch (OutOfOrderScannerNextException e) {
@@ -3990,4 +3984,26 @@ public GetCachedFilesListResponse getCachedFilesList(RpcController controller,
     });
     return responseBuilder.addAllCachedFiles(fullyCachedFiles).build();
   }
+
+  RegionScannerContext checkQuotaAndGetRegionScannerContext(ScanRequest request,
+    ScanResponse.Builder builder) throws IOException {
+    if (request.hasScannerId()) {
+      // The downstream projects such as AsyncHBase in OpenTSDB need this value. See HBASE-18000
+      // for more details.
+      long scannerId = request.getScannerId();
+      builder.setScannerId(scannerId);
+      String scannerName = toScannerName(scannerId);
+      RegionScannerHolder rsh = getRegionScanner(request);
+      OperationQuota quota =
+        getRpcQuotaManager().checkScanQuota(rsh.r, request, maxScannerResultSize,
+          rsh.getMaxBlockBytesScanned(), rsh.getPrevBlockBytesScannedDifference());
+      return new RegionScannerContext(scannerName, rsh, quota);
+    }
+
+    HRegion region = getRegion(request.getRegion());
+    OperationQuota quota =
+      getRpcQuotaManager().checkScanQuota(region, request, maxScannerResultSize, 0L, 0L);
+    Pair<String, RegionScannerHolder> pair = newRegionScanner(request, region, builder);
+    return new RegionScannerContext(pair.getFirst(), pair.getSecond(), quota);
+  }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/quotas/TestNoopOperationQuota.java

@@ -0,0 +1,74 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.quotas;
+
+import java.util.List;
+import org.apache.hadoop.hbase.Cell;
+import org.apache.hadoop.hbase.client.Mutation;
+import org.apache.hadoop.hbase.client.Result;
+
+import org.apache.hadoop.hbase.shaded.protobuf.generated.ClientProtos;
+
+public class TestNoopOperationQuota implements OperationQuota {
+  public static final TestNoopOperationQuota INSTANCE = new TestNoopOperationQuota();
+
+  @Override
+  public void checkBatchQuota(int numWrites, int numReads) throws RpcThrottlingException {
+  }
+
+  @Override
+  public void checkScanQuota(ClientProtos.ScanRequest scanRequest, long maxScannerResultSize,
+    long maxBlockBytesScanned, long prevBlockBytesScannedDifference) throws RpcThrottlingException {
+
+  }
+
+  @Override
+  public void close() {
+
+  }
+
+  @Override
+  public void addGetResult(Result result) {
+
+  }
+
+  @Override
+  public void addScanResult(List<Result> results) {
+
+  }
+
+  @Override
+  public void addScanResultCells(List<Cell> cells) {
+
+  }
+
+  @Override
+  public void addMutation(Mutation mutation) {
+
+  }
+
+  @Override
+  public long getReadAvailable() {
+    return 0L;
+  }
+
+  @Override
+  public long getReadConsumed() {
+    return 0;
+  }
+}