Example usage for org.apache.zookeeper Transaction setData

Introduction

In this page you can find the example usage for org.apache.zookeeper Transaction setData.

Prototype

public Transaction setData(final String path, byte[] data, int version) 

Source Link

Usage

From source file:com.twitter.distributedlog.impl.federated.FederatedZKLogMetadataStore.java

License:Apache License

void createLogInNamespaceSync(URI uri, String logName)
        throws InterruptedException, IOException, KeeperException {
    Transaction txn = zkc.get().transaction();
    // we don't have the zk version yet. set it to 0 instead of -1, to prevent non CAS operation.
    int zkVersion = null == zkSubnamespacesVersion.get() ? 0 : zkSubnamespacesVersion.get();
    txn.setData(zkSubnamespacesPath, uri.getPath().getBytes(UTF_8), zkVersion);
    String logPath = uri.getPath() + "/" + logName;
    txn.create(logPath, new byte[0], zkc.getDefaultACL(), CreateMode.PERSISTENT);
    try {//from   w  w  w  .  j  a v a2 s .  co m
        txn.commit();
        // if the transaction succeed, the zk version is advanced
        setZkSubnamespacesVersion(zkVersion + 1);
    } catch (KeeperException ke) {
        List<OpResult> opResults = ke.getResults();
        OpResult createResult = opResults.get(1);
        if (createResult instanceof OpResult.ErrorResult) {
            OpResult.ErrorResult errorResult = (OpResult.ErrorResult) createResult;
            if (Code.NODEEXISTS.intValue() == errorResult.getErr()) {
                throw new LogExistsException("Log " + logName + " already exists");
            }
        }
        OpResult setResult = opResults.get(0);
        if (setResult instanceof OpResult.ErrorResult) {
            OpResult.ErrorResult errorResult = (OpResult.ErrorResult) setResult;
            if (Code.BADVERSION.intValue() == errorResult.getErr()) {
                throw KeeperException.create(Code.BADVERSION);
            }
        }
        throw new ZKException("ZK exception in creating log " + logName + " in " + uri, ke);
    }
}

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From source file:org.apache.distributedlog.service.placement.ZKPlacementStateManager.java

License:Apache License

@Override
public void saveOwnership(TreeSet<ServerLoad> serverLoads) throws StateManagerSaveException {
    logger.info("saving ownership");
    try {//from w w w .j  av a2 s.  c  o m
        ZooKeeper zk = zkClient.get();
        // use timestamp as data so watchers will see any changes
        byte[] timestamp = ByteBuffer.allocate(8).putLong(System.currentTimeMillis()).array();

        if (zk.exists(serverLoadPath, false) == null) { //create path to rootnode if it does not yet exist
            createServerLoadPathIfNoExists(timestamp);
        }

        Transaction tx = zk.transaction();
        List<String> children = zk.getChildren(serverLoadPath, false);
        HashSet<String> servers = new HashSet<String>(children);
        tx.setData(serverLoadPath, timestamp, -1); // trigger the watcher that data has been updated
        for (ServerLoad serverLoad : serverLoads) {
            String server = serverToZkFormat(serverLoad.getServer());
            String serverPath = serverPath(server);
            if (servers.contains(server)) {
                servers.remove(server);
                tx.setData(serverPath, serverLoad.serialize(), -1);
            } else {
                tx.create(serverPath, serverLoad.serialize(), zkClient.getDefaultACL(), CreateMode.PERSISTENT);
            }
        }
        for (String server : servers) {
            tx.delete(serverPath(server), -1);
        }
        tx.commit();
    } catch (InterruptedException | IOException | KeeperException e) {
        throw new StateManagerSaveException(e);
    }
}

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