Example usage for org.apache.cassandra.hadoop.cql3 CqlConfigHelper getInputCluster

Introduction

In this page you can find the example usage for org.apache.cassandra.hadoop.cql3 CqlConfigHelper getInputCluster.

Prototype

public static Cluster getInputCluster(String[] hosts, Configuration conf) 

Source Link

Usage

From source file:grakn.core.server.session.reader.GraknCqlBridgeRecordReader.java

License:Open Source License

@Override
public void initialize(InputSplit split, TaskAttemptContext context) throws IOException {
    this.split = (ColumnFamilySplit) split;
    Configuration conf = HadoopCompat.getConfiguration(context);
    totalRowCount = (this.split.getLength() < Long.MAX_VALUE) ? (int) this.split.getLength()
            : ConfigHelper.getInputSplitSize(conf);
    cfName = ConfigHelper.getInputColumnFamily(conf);
    keyspace = ConfigHelper.getInputKeyspace(conf);
    partitioner = ConfigHelper.getInputPartitioner(conf);
    inputColumns = CqlConfigHelper.getInputcolumns(conf);
    userDefinedWhereClauses = CqlConfigHelper.getInputWhereClauses(conf);

    try {/*from  ww  w.j a v a 2  s  .c om*/
        if (cluster != null) {
            return;
        }
        // create a Cluster instance
        String[] locations = split.getLocations();
        // Previous implementation of this class was instantiating a new Clutser with the following comment:
        // "disregard the conf as it brings some unforeseen issues."
        // Cluster.builder().addContactPoints(locations).build();

        // The above ignores the config so it's not possible to use it when we need to change default ports
        // as they won't be correctly propagated. So now we create Cluster using conf.
        // If this keeps breaking we might need to investigate further.
        cluster = CqlConfigHelper.getInputCluster(ConfigHelper.getInputInitialAddress(conf).split(","), conf);
    } catch (Exception e) {
        throw new RuntimeException(
                "Unable to create cluster for table: " + cfName + ", in keyspace: " + keyspace, e);
    }
    // cluster should be represent to a valid cluster now
    session = cluster.connect(quote(keyspace));
    Preconditions.checkState(session != null, "Can't create connection session");
    //get negotiated serialization protocol
    nativeProtocolVersion = cluster.getConfiguration().getProtocolOptions().getProtocolVersion().toInt();

    // If the user provides a CQL query then we will use it without validation
    // otherwise we will fall back to building a query using the:
    //   inputColumns
    //   whereClauses
    cqlQuery = CqlConfigHelper.getInputCql(conf);
    // validate that the user hasn't tried to give us a custom query along with input columns
    // and where clauses
    if (StringUtils.isNotEmpty(cqlQuery)
            && (StringUtils.isNotEmpty(inputColumns) || StringUtils.isNotEmpty(userDefinedWhereClauses))) {
        throw new AssertionError("Cannot define a custom query with input columns and / or where clauses");
    }

    if (StringUtils.isEmpty(cqlQuery)) {
        cqlQuery = buildQuery();
    }
    log.trace("cqlQuery {}", cqlQuery);
    distinctKeyIterator = new DistinctKeyIterator();
    log.trace("created {}", distinctKeyIterator);
}

---