Example usage for org.apache.hadoop.hdfs.server.protocol NamespaceInfo NamespaceInfo

Introduction

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

Prototype

public NamespaceInfo() 

Source Link

Usage

From source file:common.DataNode.java

License:Apache License

private NamespaceInfo handshake() throws IOException {
    NamespaceInfo nsInfo = new NamespaceInfo();
    while (shouldRun) {
        try {//from ww  w . ja  v a2  s . c  o m
            nsInfo = namenode.versionRequest();
            break;
        } catch (SocketTimeoutException e) { // namenode is busy
            LOG.info("Problem connecting to server: " + getNameNodeAddr());
            try {
                Thread.sleep(1000);
            } catch (InterruptedException ie) {
            }
        }
    }
    String errorMsg = null;
    // verify build version
    if (!nsInfo.getBuildVersion().equals(Storage.getBuildVersion())) {
        errorMsg = "Incompatible build versions: namenode BV = " + nsInfo.getBuildVersion() + "; datanode BV = "
                + Storage.getBuildVersion();
        LOG.fatal(errorMsg);
        try {
            namenode.errorReport(dnRegistration, DatanodeProtocol.NOTIFY, errorMsg);
        } catch (SocketTimeoutException e) { // namenode is busy
            LOG.info("Problem connecting to server: " + getNameNodeAddr());
        }
        throw new IOException(errorMsg);
    }
    assert FSConstants.LAYOUT_VERSION == nsInfo
            .getLayoutVersion() : "Data-node and name-node layout versions must be the same." + "Expected: "
                    + FSConstants.LAYOUT_VERSION + " actual " + nsInfo.getLayoutVersion();
    return nsInfo;
}

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