Examples of org.apache.hadoop.dfs.MiniDFSCluster.startDataNodes()

org.apache.hadoop.dfs.MiniDFSCluster.startDataNodes()

Modify the config and start up the DataNodes. The info port for DataNodes is guaranteed to use a free port. @param conf the base configuration to use in starting the DataNodes. Thiswill be modified as necessary. @param numDataNodes Number of DataNodes to start; may be zero @param manageDfsDirs if true, the data directories for DataNodes will becreated and dfs.data.dir will be set in the conf @param operation the operation with which to start the DataNodes. If nullor StartupOption.FORMAT, then StartupOption.REGULAR will be used. @param racks array of strings indicating the rack that each DataNode is on @throws IllegalStateException if NameNode has been shutdown

          fileName.toString(), 0, (long)fileLen);
      assertEquals(blocks.locatedBlockCount(), 1);
      LocatedBlock block = blocks.get(0);
      
      // bring up a second datanode
      cluster.startDataNodes(conf, 1, true, null, null);
      cluster.waitActive();
      final int sndNode = 1;
      DataNode datanode = cluster.getDataNodes().get(sndNode);
      
      // replicate the block to the second datanode

      // keep a copy of all datanode descriptor
      DatanodeDescriptor[] datanodes = (DatanodeDescriptor[])
         namesystem.heartbeats.toArray(new DatanodeDescriptor[REPLICATION_FACTOR]);
      
      // start two new nodes
      cluster.startDataNodes(conf, 2, true, null, null);
      cluster.waitActive();
      
      // bring down first datanode
      DatanodeDescriptor datanode = datanodes[0];
      DataNodeProperties dnprop = cluster.stopDataNode(datanode.getName());

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