Example usage for org.apache.hadoop.hdfs.server.protocol DatanodeProtocol DNA_REGISTER

Introduction

In this page you can find the example usage for org.apache.hadoop.hdfs.server.protocol DatanodeProtocol DNA_REGISTER.

Prototype

int DNA_REGISTER

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Usage

From source file:common.DataNode.java

License:Apache License

/**
 * //  w w  w  .j  av  a  2 s  .  c  om
 * @param cmd
 * @return true if further processing may be required or false otherwise. 
 * @throws IOException
 */
private boolean processCommand(DatanodeCommand cmd) throws IOException {
    if (cmd == null)
        return true;
    final BlockCommand bcmd = cmd instanceof BlockCommand ? (BlockCommand) cmd : null;

    switch (cmd.getAction()) {
    case DatanodeProtocol.DNA_TRANSFER:
        // Send a copy of a block to another datanode
        transferBlocks(bcmd.getBlocks(), bcmd.getTargets());
        myMetrics.blocksReplicated.inc(bcmd.getBlocks().length);
        break;
    case DatanodeProtocol.DNA_INVALIDATE:
        //
        // Some local block(s) are obsolete and can be 
        // safely garbage-collected.
        //
        Block toDelete[] = bcmd.getBlocks();
        try {
            if (blockScanner != null) {
                blockScanner.deleteBlocks(toDelete);
            }
            data.invalidate(toDelete);
        } catch (IOException e) {
            checkDiskError();
            throw e;
        }
        myMetrics.blocksRemoved.inc(toDelete.length);
        break;
    case DatanodeProtocol.DNA_SHUTDOWN:
        // shut down the data node
        this.shutdown();
        return false;
    case DatanodeProtocol.DNA_REGISTER:
        // namenode requested a registration - at start or if NN lost contact
        LOG.info("DatanodeCommand action: DNA_REGISTER");
        if (shouldRun) {
            register();
        }
        break;
    case DatanodeProtocol.DNA_FINALIZE:
        storage.finalizeUpgrade();
        break;
    case UpgradeCommand.UC_ACTION_START_UPGRADE:
        // start distributed upgrade here
        processDistributedUpgradeCommand((UpgradeCommand) cmd);
        break;
    case DatanodeProtocol.DNA_RECOVERBLOCK:
        recoverBlocks(((BlockRecoveryCommand) cmd).getRecoveringBlocks());
        break;
    case DatanodeProtocol.DNA_ACCESSKEYUPDATE:
        LOG.info("DatanodeCommand action: DNA_ACCESSKEYUPDATE");
        if (isAccessTokenEnabled) {
            accessTokenHandler.setKeys(((KeyUpdateCommand) cmd).getExportedKeys());
        }
        break;
    default:
        LOG.warn("Unknown DatanodeCommand action: " + cmd.getAction());
    }
    return true;
}

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