Examples with ExponentialClientBackoffPolicy org.apache.hadoop.hbase.client.backoff.ExponentialClientBackoffPolicy used on opensource projects

Example 6 with ExponentialClientBackoffPolicy

use of org.apache.hadoop.hbase.client.backoff.ExponentialClientBackoffPolicy in project hbase by apache.

the class TestClientPushback method testClientTracksServerPushback.

@Test(timeout = 60000)
public void testClientTracksServerPushback() throws Exception {
    Configuration conf = UTIL.getConfiguration();
    ClusterConnection conn = (ClusterConnection) ConnectionFactory.createConnection(conf);
    Table table = conn.getTable(tableName);
    HRegionServer rs = UTIL.getHBaseCluster().getRegionServer(0);
    Region region = rs.getOnlineRegions(tableName).get(0);
    LOG.debug("Writing some data to " + tableName);
    // write some data
    Put p = new Put(Bytes.toBytes("row"));
    p.addColumn(family, qualifier, Bytes.toBytes("value1"));
    table.put(p);
    // get the current load on RS. Hopefully memstore isn't flushed since we wrote the the data
    int load = (int) ((((HRegion) region).addAndGetMemstoreSize(new MemstoreSize(0, 0)) * 100) / flushSizeBytes);
    LOG.debug("Done writing some data to " + tableName);
    // get the stats for the region hosting our table
    ClientBackoffPolicy backoffPolicy = conn.getBackoffPolicy();
    assertTrue("Backoff policy is not correctly configured", backoffPolicy instanceof ExponentialClientBackoffPolicy);
    ServerStatisticTracker stats = conn.getStatisticsTracker();
    assertNotNull("No stats configured for the client!", stats);
    // get the names so we can query the stats
    ServerName server = rs.getServerName();
    byte[] regionName = region.getRegionInfo().getRegionName();
    // check to see we found some load on the memstore
    ServerStatistics serverStats = stats.getServerStatsForTesting(server);
    ServerStatistics.RegionStatistics regionStats = serverStats.getStatsForRegion(regionName);
    assertEquals("We did not find some load on the memstore", load, regionStats.getMemstoreLoadPercent());
    // check that the load reported produces a nonzero delay
    long backoffTime = backoffPolicy.getBackoffTime(server, regionName, serverStats);
    assertNotEquals("Reported load does not produce a backoff", backoffTime, 0);
    LOG.debug("Backoff calculated for " + region.getRegionInfo().getRegionNameAsString() + " @ " + server + " is " + backoffTime);
    // Reach into the connection and submit work directly to AsyncProcess so we can
    // monitor how long the submission was delayed via a callback
    List<Row> ops = new ArrayList<>(1);
    ops.add(p);
    final CountDownLatch latch = new CountDownLatch(1);
    final AtomicLong endTime = new AtomicLong();
    long startTime = EnvironmentEdgeManager.currentTime();
    BufferedMutatorImpl mutator = ((HTable) table).mutator;
    Batch.Callback<Result> callback = (byte[] r, byte[] row, Result result) -> {
        endTime.set(EnvironmentEdgeManager.currentTime());
        latch.countDown();
    };
    AsyncProcessTask<Result> task = AsyncProcessTask.newBuilder(callback).setPool(mutator.getPool()).setTableName(tableName).setRowAccess(ops).setSubmittedRows(AsyncProcessTask.SubmittedRows.AT_LEAST_ONE).setOperationTimeout(conn.getConnectionConfiguration().getOperationTimeout()).setRpcTimeout(60 * 1000).build();
    mutator.getAsyncProcess().submit(task);
    // Currently the ExponentialClientBackoffPolicy under these test conditions
    // produces a backoffTime of 151 milliseconds. This is long enough so the
    // wait and related checks below are reasonable. Revisit if the backoff
    // time reported by above debug logging has significantly deviated.
    String name = server.getServerName() + "," + Bytes.toStringBinary(regionName);
    MetricsConnection.RegionStats rsStats = conn.getConnectionMetrics().serverStats.get(server).get(regionName);
    assertEquals(name, rsStats.name);
    assertEquals(rsStats.heapOccupancyHist.getSnapshot().getMean(), (double) regionStats.getHeapOccupancyPercent(), 0.1);
    assertEquals(rsStats.memstoreLoadHist.getSnapshot().getMean(), (double) regionStats.getMemstoreLoadPercent(), 0.1);
    MetricsConnection.RunnerStats runnerStats = conn.getConnectionMetrics().runnerStats;
    assertEquals(runnerStats.delayRunners.getCount(), 1);
    assertEquals(runnerStats.normalRunners.getCount(), 1);
    assertEquals("", runnerStats.delayIntevalHist.getSnapshot().getMean(), (double) backoffTime, 0.1);
    latch.await(backoffTime * 2, TimeUnit.MILLISECONDS);
    assertNotEquals("AsyncProcess did not submit the work time", endTime.get(), 0);
    assertTrue("AsyncProcess did not delay long enough", endTime.get() - startTime >= backoffTime);
}