Index: hbase-examples/src/test/java/org/apache/hadoop/hbase/coprocessor/example/TestBulkDeleteProtocol.java =================================================================== --- hbase-examples/src/test/java/org/apache/hadoop/hbase/coprocessor/example/TestBulkDeleteProtocol.java (revision 1440794) +++ hbase-examples/src/test/java/org/apache/hadoop/hbase/coprocessor/example/TestBulkDeleteProtocol.java (working copy) @@ -95,6 +95,7 @@ rows++; } assertEquals(0, rows); + ht.close(); } @Test @@ -118,6 +119,7 @@ rows++; } assertEquals(0, rows); + ht.close(); } private long invokeBulkDeleteProtocol(byte[] tableName, final Scan scan, final int rowBatchSize, @@ -147,6 +149,7 @@ for (BulkDeleteResponse response : result.values()) { noOfDeletedRows += response.getRowsDeleted(); } + ht.close(); return noOfDeletedRows; } @@ -177,6 +180,7 @@ rows++; } assertEquals(90, rows); + ht.close(); } @Test @@ -205,6 +209,7 @@ rows++; } assertEquals(100, rows); + ht.close(); } @Test @@ -235,6 +240,7 @@ rows++; } assertEquals(100, rows); + ht.close(); } @Test @@ -282,6 +288,7 @@ rows++; } assertEquals(100, rows); + ht.close(); } @Test @@ -328,6 +335,7 @@ rows++; } assertEquals(100, rows); + ht.close(); } @Test @@ -412,6 +420,7 @@ rows++; } assertEquals(100, rows); + ht.close(); } private HTable createTable(byte[] tableName) throws IOException { Index: hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestStoreScanner.java =================================================================== --- hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestStoreScanner.java (revision 1440794) +++ hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestStoreScanner.java (working copy) @@ -547,14 +547,14 @@ List scanners = scanFixture(kvs); Scan scan = new Scan(); scan.setMaxVersions(2); - HStore.ScanInfo scanInfo = new HStore.ScanInfo(Bytes.toBytes("cf"), + HStore.ScanInfo newScanInfo = new HStore.ScanInfo(Bytes.toBytes("cf"), 0 /* minVersions */, 2 /* maxVersions */, 500 /* ttl */, false /* keepDeletedCells */, 200, /* timeToPurgeDeletes */ KeyValue.COMPARATOR); StoreScanner scanner = - new StoreScanner(scan, scanInfo, + new StoreScanner(scan, newScanInfo, ScanType.MAJOR_COMPACT, null, scanners, HConstants.OLDEST_TIMESTAMP); List results = new ArrayList(); @@ -568,6 +568,7 @@ assertEquals(kvs[14], results.get(5)); assertEquals(kvs[15], results.get(6)); assertEquals(7, results.size()); + scanner.close(); }finally{ EnvironmentEdgeManagerTestHelper.reset(); } Index: hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java =================================================================== --- hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java (revision 1440794) +++ hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java (working copy) @@ -19,20 +19,31 @@ package org.apache.hadoop.hbase.regionserver; +import com.google.common.util.concurrent.ThreadFactoryBuilder; + import java.io.IOException; +import java.io.InterruptedIOException; import java.util.ArrayList; import java.util.List; import java.util.NavigableSet; +import java.util.concurrent.Callable; +import java.util.concurrent.CancellationException; +import java.util.concurrent.ExecutionException; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.Future; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.hbase.DoNotRetryIOException; +import org.apache.hadoop.hbase.HBaseConfiguration; import org.apache.hadoop.hbase.HConstants; import org.apache.hadoop.hbase.KeyValue; import org.apache.hadoop.hbase.client.Scan; import org.apache.hadoop.hbase.filter.Filter; import org.apache.hadoop.hbase.regionserver.HStore.ScanInfo; +import org.apache.hadoop.hbase.regionserver.StoreFileScanner; import org.apache.hadoop.hbase.util.Bytes; import org.apache.hadoop.hbase.util.EnvironmentEdgeManager; @@ -66,6 +77,21 @@ /** We don't ever expect to change this, the constant is just for clarity. */ static final boolean LAZY_SEEK_ENABLED_BY_DEFAULT = true; + /** + * A flag that enables StoreFileScanner parallel-seeking + */ + public static final String STORESCANNER_PARALLEL_SEEK_ENABLE = + "hbase.storescanner.parallel.seek.enable"; + static final boolean parallelSeek = HBaseConfiguration.create(). + getBoolean(STORESCANNER_PARALLEL_SEEK_ENABLE, false); + static ExecutorService seekExecutor = null; + static { + if (parallelSeek) { + seekExecutor = Executors.newCachedThreadPool( + new ThreadFactoryBuilder().setDaemon(true).setNameFormat( + StoreScanner.class.getName() + "-seek-%d").build()); + } + } /** Used during unit testing to ensure that lazy seek does save seek ops */ protected static boolean lazySeekEnabledGlobally = @@ -127,8 +153,12 @@ scanner.requestSeek(matcher.getStartKey(), false, true); } } else { - for (KeyValueScanner scanner : scanners) { - scanner.seek(matcher.getStartKey()); + if (!parallelSeek) { + for (KeyValueScanner scanner : scanners) { + scanner.seek(matcher.getStartKey()); + } + } else { + parallelSeek(scanners, matcher.getStartKey()); } } @@ -166,8 +196,12 @@ scanners = selectScannersFrom(scanners); // Seek all scanners to the initial key - for(KeyValueScanner scanner : scanners) { - scanner.seek(matcher.getStartKey()); + if (!parallelSeek) { + for (KeyValueScanner scanner : scanners) { + scanner.seek(matcher.getStartKey()); + } + } else { + parallelSeek(scanners, matcher.getStartKey()); } // Combine all seeked scanners with a heap @@ -193,8 +227,12 @@ Long.MAX_VALUE, earliestPutTs, oldestUnexpiredTS); // Seek all scanners to the initial key - for (KeyValueScanner scanner : scanners) { - scanner.seek(matcher.getStartKey()); + if (!parallelSeek) { + for (KeyValueScanner scanner : scanners) { + scanner.seek(matcher.getStartKey()); + } + } else { + parallelSeek(scanners, matcher.getStartKey()); } heap = new KeyValueHeap(scanners, scanInfo.getComparator()); } @@ -512,8 +550,12 @@ * could have done it now by storing the scan object from the constructor */ List scanners = getScannersNoCompaction(); - for(KeyValueScanner scanner : scanners) { - scanner.seek(lastTopKey); + if (!parallelSeek) { + for (KeyValueScanner scanner : scanners) { + scanner.seek(lastTopKey); + } + } else { + parallelSeek(scanners, lastTopKey); } // Combine all seeked scanners with a heap @@ -555,6 +597,59 @@ } /** + * Seek storefiles in parallel to optimize IO latency as much as possible + * @param scanners the list {@link KeyValueScanner}s to be read from + * @param kv the KeyValue on which the operation is being requested + * @throws IOException + */ + private void parallelSeek(final List + scanners, final KeyValue kv) throws IOException { + if (scanners.isEmpty()) return; + + int storeFileScannerCount = scanners.size(); + List> futures = new ArrayList>(storeFileScannerCount); + for (KeyValueScanner scanner : scanners) { + if (scanner instanceof StoreFileScanner) { + Callable task = new ScannerSeekWorker(scanner, kv, + MultiVersionConsistencyControl.getThreadReadPoint()); + futures.add(seekExecutor.submit(task)); + } else { + scanner.seek(kv); + } + } + try { + for (Future future : futures) { + future.get(); + } + } catch (InterruptedException ie) { + throw new InterruptedIOException(ie.getMessage()); + } catch (ExecutionException e) { + throw new InterruptedIOException(e.getMessage()); + } catch (CancellationException ce) { + throw new InterruptedIOException(ce.getMessage()); + } + } + + private static class ScannerSeekWorker implements Callable { + private KeyValueScanner scanner; + private KeyValue keyValue; + private long readPoint; + + public ScannerSeekWorker(KeyValueScanner scanner, KeyValue keyValue, + long readPoint) { + this.scanner = scanner; + this.keyValue = keyValue; + this.readPoint = readPoint; + } + + public Void call() throws IOException { + MultiVersionConsistencyControl.setThreadReadPoint(readPoint); + scanner.seek(keyValue); + return null; + } + } + + /** * Used in testing. * @return all scanners in no particular order */ Index: hbase-server/src/main/resources/hbase-default.xml =================================================================== --- hbase-server/src/main/resources/hbase-default.xml (revision 1440794) +++ hbase-server/src/main/resources/hbase-default.xml (working copy) @@ -442,6 +442,14 @@ + hbase.storescanner.parallel.seek.enable + false + + Enables StoreFileScanner parallel-seeking in StoreScanner, + a feature which can reduce response latency under special conditions. + + + hbase.mapreduce.hfileoutputformat.blocksize 65536 The mapreduce HFileOutputFormat writes storefiles/hfiles.