/**
* Validates lazy persisted blocks are evicted from RAM_DISK based on LRU.
*
* @throws IOException
* @throws InterruptedException
*/
@Test
public void testRamDiskEvictionIsLru() throws Exception {
final int NUM_PATHS = 5;
startUpCluster(true, NUM_PATHS + EVICTION_LOW_WATERMARK);
final String METHOD_NAME = GenericTestUtils.getMethodName();
Path paths[] = new Path[NUM_PATHS * 2];
for (int i = 0; i < paths.length; i++) {
paths[i] = new Path("/" + METHOD_NAME + "." + i + ".dat");
}
for (int i = 0; i < NUM_PATHS; i++) {
makeTestFile(paths[i], BLOCK_SIZE, true);
}
// Sleep for a short time to allow the lazy writer thread to do its job.
Thread.sleep(3 * LAZY_WRITER_INTERVAL_SEC * 1000);
for (int i = 0; i < NUM_PATHS; ++i) {
ensureFileReplicasOnStorageType(paths[i], RAM_DISK);
}
// Open the files for read in a random order.
ArrayList<Integer> indexes = new ArrayList<Integer>(NUM_PATHS);
for (int i = 0; i < NUM_PATHS; ++i) {
indexes.add(i);
}
Collections.shuffle(indexes);
for (int i = 0; i < NUM_PATHS; ++i) {
LOG.info("Touching file " + paths[indexes.get(i)]);
DFSTestUtil.readFile(fs, paths[indexes.get(i)]);
}
// Create an equal number of new files ensuring that the previous
// files are evicted in the same order they were read.
for (int i = 0; i < NUM_PATHS; ++i) {
makeTestFile(paths[i + NUM_PATHS], BLOCK_SIZE, true);
triggerBlockReport();
Thread.sleep(3000);
ensureFileReplicasOnStorageType(paths[i + NUM_PATHS], RAM_DISK);
ensureFileReplicasOnStorageType(paths[indexes.get(i)], DEFAULT);
for (int j = i + 1; j < NUM_PATHS; ++j) {
ensureFileReplicasOnStorageType(paths[indexes.get(j)], RAM_DISK);
}
}
verifyRamDiskJMXMetric("RamDiskBlocksWrite", NUM_PATHS * 2);
verifyRamDiskJMXMetric("RamDiskBlocksWriteFallback", 0);
verifyRamDiskJMXMetric("RamDiskBytesWrite", BLOCK_SIZE * NUM_PATHS * 2);
verifyRamDiskJMXMetric("RamDiskBlocksReadHits", NUM_PATHS);
verifyRamDiskJMXMetric("RamDiskBlocksEvicted", NUM_PATHS);
verifyRamDiskJMXMetric("RamDiskBlocksEvictedWithoutRead", 0);
verifyRamDiskJMXMetric("RamDiskBlocksDeletedBeforeLazyPersisted", 0);
}
/**
* If the only available storage is RAM_DISK and the LAZY_PERSIST flag is not specified, then
* block placement should fail.
*
* @throws IOException
*/
@Test
public void testRamDiskNotChosenByDefault() throws IOException {
startUpCluster(true, -1);
final String METHOD_NAME = GenericTestUtils.getMethodName();
Path path = new Path("/" + METHOD_NAME + ".dat");
try {
makeTestFile(path, BLOCK_SIZE, false);
fail("Block placement to RAM_DISK should have failed without lazyPersist flag");
} catch (Throwable t) {
LOG.info("Got expected exception ", t);
}
}
/**
* Truncate to lazy persist file is denied.
*
* @throws IOException
*/
@Test
public void testTruncateIsDenied() throws IOException {
startUpCluster(true, -1);
final String METHOD_NAME = GenericTestUtils.getMethodName();
Path path = new Path("/" + METHOD_NAME + ".dat");
makeTestFile(path, BLOCK_SIZE, true);
try {
client.truncate(path.toString(), BLOCK_SIZE / 2);
fail("Truncate to LazyPersist file did not fail as expected");
} catch (Throwable t) {
LOG.info("Got expected exception ", t);
}
}
public void run() {
System.out.println("Writer " + id + " starting... ");
int i = 0;
try {
for (i = 0; i < paths.length; i++) {
makeRandomTestFile(paths[i], BLOCK_SIZE, true, seed);
// eviction may faiL when all blocks are not persisted yet.
// ensureFileReplicasOnStorageType(paths[i], RAM_DISK);
}
} catch (IOException e) {
bFail.set(true);
LOG.error(
"Writer exception: writer id:" + id + " testfile: " + paths[i].toString() + " " + e);
} finally {
latch.countDown();
}
}
/**
* Append to lazy persist file is denied.
*
* @throws IOException
*/
@Test
public void testAppendIsDenied() throws IOException {
startUpCluster(true, -1);
final String METHOD_NAME = GenericTestUtils.getMethodName();
Path path = new Path("/" + METHOD_NAME + ".dat");
makeTestFile(path, BLOCK_SIZE, true);
try {
client
.append(path.toString(), BUFFER_LENGTH, EnumSet.of(CreateFlag.APPEND), null, null)
.close();
fail("Append to LazyPersist file did not fail as expected");
} catch (Throwable t) {
LOG.info("Got expected exception ", t);
}
}
@Test
public void testDnRestartWithUnsavedReplicas() throws IOException, InterruptedException {
startUpCluster(true, 1);
FsDatasetTestUtil.stopLazyWriter(cluster.getDataNodes().get(0));
final String METHOD_NAME = GenericTestUtils.getMethodName();
Path path1 = new Path("/" + METHOD_NAME + ".01.dat");
makeTestFile(path1, BLOCK_SIZE, true);
ensureFileReplicasOnStorageType(path1, RAM_DISK);
LOG.info("Restarting the DataNode");
cluster.restartDataNode(0, true);
cluster.waitActive();
// Ensure that the replica is still on transient storage.
ensureFileReplicasOnStorageType(path1, RAM_DISK);
}
@Test
public void testLazyPersistBlocksAreSaved() throws IOException, InterruptedException {
startUpCluster(true, -1);
final String METHOD_NAME = GenericTestUtils.getMethodName();
Path path = new Path("/" + METHOD_NAME + ".dat");
// Create a test file
makeTestFile(path, BLOCK_SIZE * 10, true);
LocatedBlocks locatedBlocks = ensureFileReplicasOnStorageType(path, RAM_DISK);
// Sleep for a short time to allow the lazy writer thread to do its job
Thread.sleep(6 * LAZY_WRITER_INTERVAL_SEC * 1000);
LOG.info("Verifying copy was saved to lazyPersist/");
// Make sure that there is a saved copy of the replica on persistent
// storage.
ensureLazyPersistBlocksAreSaved(locatedBlocks);
}
@Test
public void testDnRestartWithSavedReplicas() throws IOException, InterruptedException {
startUpCluster(true, -1);
final String METHOD_NAME = GenericTestUtils.getMethodName();
Path path1 = new Path("/" + METHOD_NAME + ".01.dat");
makeTestFile(path1, BLOCK_SIZE, true);
ensureFileReplicasOnStorageType(path1, RAM_DISK);
// Sleep for a short time to allow the lazy writer thread to do its job.
// However the block replica should not be evicted from RAM_DISK yet.
Thread.sleep(3 * LAZY_WRITER_INTERVAL_SEC * 1000);
ensureFileReplicasOnStorageType(path1, RAM_DISK);
LOG.info("Restarting the DataNode");
cluster.restartDataNode(0, true);
cluster.waitActive();
triggerBlockReport();
// Ensure that the replica is now on persistent storage.
ensureFileReplicasOnStorageType(path1, DEFAULT);
}
