@Test
public void testZkClientWhenZKIsDownAndRestarts() throws Exception {
// Iterate updating the timestamp and check the final value
long previousMaxTimestamp = INITIAL_MAX_TS_VALUE;
for (int i = 0; i < ITERATION_COUNT; i++) {
long newMaxTimestamp = previousMaxTimestamp + 1_000_000;
storage.updateMaxTimestamp(previousMaxTimestamp, newMaxTimestamp);
previousMaxTimestamp = newMaxTimestamp;
}
assertEquals(storage.getMaxTimestamp(), 1_000_000 * ITERATION_COUNT);
// Stop ZK Server, expect the IO exception, reconnect and get the right value
LOG.info("Stopping ZK Server");
zkServer.stop();
LOG.info("ZK Server Stopped");
try {
storage.getMaxTimestamp();
fail();
} catch (IOException ioe) {
LOG.info("Expected exception", ioe);
}
LOG.info("Restarting ZK again");
zkServer.restart();
assertEquals(storage.getMaxTimestamp(), 1_000_000 * ITERATION_COUNT);
}
@Test
public void testZkClientLosingSession() throws Exception {
// Cut the session in the server through the client
long sessionId = zkClient.getZookeeperClient().getZooKeeper().getSessionId();
byte[] sessionPasswd = zkClient.getZookeeperClient().getZooKeeper().getSessionPasswd();
ZooKeeper zk = new ZooKeeper(ZK_CLUSTER, 1000, null, sessionId, sessionPasswd);
zk.close();
LOG.info("ZKClient session closed");
// Iterate updating the timestamp and check the final value
long previousMaxTimestamp = INITIAL_MAX_TS_VALUE;
for (int i = 0; i < ITERATION_COUNT; i++) {
long newMaxTimestamp = previousMaxTimestamp + 1_000_000;
storage.updateMaxTimestamp(previousMaxTimestamp, newMaxTimestamp);
LOG.info("Updating timestamp. Previous/New {}/{}", previousMaxTimestamp, newMaxTimestamp);
previousMaxTimestamp = newMaxTimestamp;
}
assertEquals(storage.getMaxTimestamp(), 1_000_000 * ITERATION_COUNT);
}
@Test
public void testBasicFunctionality() throws Exception {
// Check ZNode for timestamp exists (storage instantiation should create it)
Stat zNodeStats = zkClient.checkExists().forPath(TIMESTAMP_ZNODE);
assertEquals(zNodeStats.getVersion(), 0);
// Initial checks
assertEquals(storage.getMaxTimestamp(), INITIAL_MAX_TS_VALUE);
byte[] data = zkClient.getData().forPath(TIMESTAMP_ZNODE);
assertEquals(data.length, BYTES_IN_LONG);
// Check new timestamp does not allow negative values...
try {
storage.updateMaxTimestamp(INITIAL_MAX_TS_VALUE, NEGATIVE_TS);
fail();
} catch (IllegalArgumentException e) {
LOG.info("Expected exception", e);
}
// ...nor is less than previous timestamp
try {
storage.updateMaxTimestamp(1, 0);
fail();
} catch (IllegalArgumentException e) {
LOG.info("Expected exception", e);
}
// Check that the original version is still there
zNodeStats = zkClient.checkExists().forPath(TIMESTAMP_ZNODE);
assertEquals(zNodeStats.getVersion(), 0);
// Iterate updating the timestamp and check the final value
long previousMaxTimestamp = INITIAL_MAX_TS_VALUE;
for (int i = 0; i < ITERATION_COUNT; i++) {
long newMaxTimestamp = previousMaxTimestamp + 1_000_000;
storage.updateMaxTimestamp(previousMaxTimestamp, newMaxTimestamp);
previousMaxTimestamp = newMaxTimestamp;
}
assertEquals(storage.getMaxTimestamp(), 1_000_000 * ITERATION_COUNT);
// Check the znode version has changed accordingly
zNodeStats = zkClient.checkExists().forPath(TIMESTAMP_ZNODE);
assertEquals(zNodeStats.getVersion(), ITERATION_COUNT);
// Check exceptions
doThrow(new RuntimeException()).when(storageInternalZKClient).getData();
try {
storage.getMaxTimestamp();
fail();
} catch (IOException e) {
LOG.info("Expected exception", e);
}
doThrow(new RuntimeException()).when(storageInternalZKClient).setData();
try {
storage.updateMaxTimestamp(INITIAL_MAX_TS_VALUE, INITIAL_MAX_TS_VALUE + 1_000_000);
fail();
} catch (IOException e) {
LOG.info("Expected exception", e);
}
// Reset the mock and double-check last result
Mockito.reset(storageInternalZKClient);
assertEquals(storage.getMaxTimestamp(), 1_000_000 * ITERATION_COUNT);
// Finally check the znode version is still the same
zNodeStats = zkClient.checkExists().forPath(TIMESTAMP_ZNODE);
assertEquals(zNodeStats.getVersion(), ITERATION_COUNT);
}