private void createMasterCacheInfo() {
LOG.info("creating master cache info");
// check if the Cache node exists, if it doesn't create it
NimbusMaster.getInstance().getCacheInfoLock(cacheName);
info = NimbusMaster.getInstance().getCacheInfo(cacheName);
if (info == null) {
LOG.info("CacheInfo is null. Creating CacheZNode...");
info = new CacheInfo();
info.setName(cacheName);
info.setType(type);
info.setPort(port);
BigBitArray array =
new BigBitArray(
BigBitArray.makeMultipleOfEight(NimbusConf.getConf().getNumNimbusCachelets()));
info.setAvailabilityArray(array.getBytes());
getZooKeeper().ensurePaths(CACHE_ZNODE);
getZooKeeper().setDataVariable(CACHE_ZNODE, info.getByteRepresentation());
LOG.info(
"Creating Cache ZNode at "
+ CACHE_ZNODE
+ " with data of size "
+ info.getByteRepresentation().length);
} else {
LOG.info("CacheInfo is not null");
}
NimbusMaster.getInstance().releaseCacheInfoLock(cacheName);
if (NimbusConf.getConf().isSafetyNetEnabled()) {
// Fire up the Safety Net
Thread safetynet = new Thread(NimbusSafetyNet.getInstance());
safetynet.start();
}
}
/**
* Returns the ZooKeeper instance.
*
* @return The ZooKeeper instance.
*/
public static ZooKeeperAssistant getZooKeeper() {
if (s_zk == null) {
// Create ZK Instance
try {
LOG.info("Connecting to ZooKeeper at " + NimbusConf.getConf().getZooKeeperServers());
s_zk = new ZooKeeperAssistant();
} catch (NimbusException e) {
e.printStackTrace();
LOG.error("Failed to initialize ZooKeeper");
System.exit(-1);
}
}
return s_zk;
}
private void startCache() throws Exception {
LOG.info("Starting Nimbus cache");
Nimbus.getZooKeeper();
LOG.info("ZooKeeper finished");
// Set the Cache ZNode to the root + the Cache name
CACHE_ZNODE = ROOT_ZNODE + "/" + cacheName;
String cacheletName = InetAddress.getLocalHost().getHostName();
CACHELET_ZNODE = CACHE_ZNODE + "/" + cacheletName;
knownServers.put(InetAddress.getLocalHost().getHostName(), null);
// add shutdown hook
NimbusShutdownHook.createInstance(type);
LOG.info("making root node");
// ensure this root path exists
getZooKeeper().ensurePaths(ROOT_ZNODE);
LOG.info("done making root node");
if (type.equals(CacheType.MASTER)) {
createMasterCacheInfo();
} else {
// this info is for a non-master cache
info = NimbusMaster.getInstance().getCacheInfo(cacheName);
if (info == null) {
throw new RuntimeException("No info for " + cacheName);
}
}
// create my Cachelet
switch (info.getType()) {
case STATIC_SET:
cachelet =
new StaticSetCacheletServer(
info.getName(), cacheletName, info.getPort(), info.getType());
break;
case DYNAMIC_SET:
cachelet =
new DynamicSetCacheletServer(
info.getName(), cacheletName, info.getPort(), info.getType());
break;
case MASTER:
cachelet =
new MasterCacheletServer(info.getName(), cacheletName, info.getPort(), info.getType());
break;
case MAPSET:
cachelet =
new MapSetCacheletServer(info.getName(), cacheletName, info.getPort(), info.getType());
break;
case DYNAMIC_MAP:
cachelet =
new DynamicMapCacheletServer(
info.getName(), cacheletName, info.getPort(), info.getType());
break;
default:
LOG.error("Unkown type " + info.getType().toString() + ". Shutting down");
System.exit(0);
}
Thread t = new Thread(cachelet);
t.start();
// add myself to ZooKeeper
LOG.info("Creating my ZNode at " + CACHELET_ZNODE);
getZooKeeper().ensurePaths(CACHELET_ZNODE);
if (NimbusConf.getConf().isSafetyNetEnabled()) {
// this while loop manages connections to other Cachelets
// if a Cachelet connects, then create a new thread to handle
// communication to that Cachelet and wait for more connections
LOG.info("Starting heartbeat cycle...");
long hbInterval = NimbusConf.getConf().getCacheletHeartbeatInterval();
getZooKeeper().setDataVariable(CACHELET_ZNODE, BytesUtil.EMPTY_BYTES);
while (!false) {
Thread.sleep(hbInterval);
getZooKeeper().setDataVariable(CACHELET_ZNODE, BytesUtil.EMPTY_BYTES);
}
} else {
LOG.info("Safety net is disabled... simply sleeping this thread.");
while (!false) {
Thread.sleep(Integer.MAX_VALUE);
}
}
}
/**
* Returns a random Nimbus Server machine address.
*
* @return A random Nimbus Server machine address.
*/
public static String getRandomNimbusHost() {
String[] hosts = NimbusConf.getConf().getNimbusCacheletAddresses().split(",");
return hosts[Math.abs(rndm.nextInt()) % hosts.length];
}
