HBASE-26108 add option to disable scanMetrics in TableSnapshotInputFormat

Author: Huaxiang Sun

hbase-mapreduce/src/main/java/org/apache/hadoop/hbase/mapreduce/TableSnapshotInputFormatImpl.java

@@ -107,6 +107,14 @@ public class TableSnapshotInputFormatImpl {
   public static final String SNAPSHOT_INPUTFORMAT_ROW_LIMIT_PER_INPUTSPLIT =
       "hbase.TableSnapshotInputFormat.row.limit.per.inputsplit";
 
+  /**
+   * Whether to enable scan metrics on Scan, default to true
+   */
+  public static final String  SNAPSHOT_INPUTFORMAT_SCAN_METRICS_ENABLED =
+    "hbase.TableSnapshotInputFormat.scan_metrics.enabled";
+
+  public static final boolean SNAPSHOT_INPUTFORMAT_SCAN_METRICS_ENABLED_DEFAULT = true;
+
   /**
    * Implementation class for InputSplit logic common between mapred and mapreduce.
    */
@@ -240,7 +248,6 @@ public void initialize(InputSplit split, Configuration conf) throws IOException
       scan.setIsolationLevel(IsolationLevel.READ_UNCOMMITTED);
       // disable caching of data blocks
       scan.setCacheBlocks(false);
-      scan.setScanMetricsEnabled(true);
 
       scanner =
           new ClientSideRegionScanner(conf, fs, new Path(split.restoreDir), htd, hri, scan, null);
@@ -381,6 +388,10 @@ public static List<InputSplit> getSplits(Scan scan, SnapshotManifest manifest,
     boolean localityEnabled = conf.getBoolean(SNAPSHOT_INPUTFORMAT_LOCALITY_ENABLED_KEY,
                                               SNAPSHOT_INPUTFORMAT_LOCALITY_ENABLED_DEFAULT);
 
+    boolean scanMetricsEnabled = conf.getBoolean(SNAPSHOT_INPUTFORMAT_SCAN_METRICS_ENABLED,
+      SNAPSHOT_INPUTFORMAT_SCAN_METRICS_ENABLED_DEFAULT);
+    scan.setScanMetricsEnabled(scanMetricsEnabled);
+
     List<InputSplit> splits = new ArrayList<>();
     for (RegionInfo hri : regionManifests) {
       // load region descriptor