@BeforeClass
  public static void setUpBeforeClass() throws Exception {
    // Tweak default timeout values down for faster recovery
    TEST_UTIL.getConfiguration().setInt("hbase.regionserver.logroll.errors.tolerated", 2);
    TEST_UTIL.getConfiguration().setInt("hbase.rpc.timeout", 10 * 1000);

    // Increase the amount of time between client retries
    TEST_UTIL.getConfiguration().setLong("hbase.client.pause", 5 * 1000);

    // lower the namenode & datanode heartbeat so the namenode
    // quickly detects datanode failures
    TEST_UTIL.getConfiguration().setInt("dfs.namenode.heartbeat.recheck-interval", 5000);
    TEST_UTIL.getConfiguration().setInt("dfs.heartbeat.interval", 1);
    // the namenode might still try to choose the recently-dead datanode
    // for a pipeline, so try to a new pipeline multiple times
    TEST_UTIL.getConfiguration().setInt("dfs.client.block.write.retries", 10);
    TEST_UTIL.getConfiguration().set(WALFactory.WAL_PROVIDER, "asyncfs");
  }
Tests for conditions that should trigger RegionServer aborts when rolling the current WAL fails.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestLogRollAbort.java