/** Start the jobtracker. */
public void startJobTracker() {
startJobTracker(true);
}
public MiniMRCluster(
int jobTrackerPort,
int taskTrackerPort,
int numTaskTrackers,
String namenode,
int numDir,
String[] racks,
String[] hosts,
UserGroupInformation ugi,
JobConf conf,
int numTrackerToExclude)
throws IOException {
if (racks != null && racks.length < numTaskTrackers) {
LOG.error(
"Invalid number of racks specified. It should be at least "
+ "equal to the number of tasktrackers");
shutdown();
}
if (hosts != null && numTaskTrackers > hosts.length) {
throw new IllegalArgumentException(
"The length of hosts ["
+ hosts.length
+ "] is less than the number of tasktrackers ["
+ numTaskTrackers
+ "].");
}
// Generate rack names if required
if (racks == null) {
System.out.println("Generating rack names for tasktrackers");
racks = new String[numTaskTrackers];
for (int i = 0; i < racks.length; ++i) {
racks[i] = NetworkTopology.DEFAULT_RACK;
}
}
// Generate some hostnames if required
if (hosts == null) {
System.out.println("Generating host names for tasktrackers");
hosts = new String[numTaskTrackers];
for (int i = 0; i < numTaskTrackers; i++) {
hosts[i] = "host" + i + ".foo.com";
}
}
this.jobTrackerPort = jobTrackerPort;
this.taskTrackerPort = taskTrackerPort;
this.jobTrackerInfoPort = 0;
this.numTaskTrackers = 0;
this.namenode = namenode;
this.ugi = ugi;
this.conf = conf; // this is the conf the mr starts with
this.numTrackerToExclude = numTrackerToExclude;
// start the jobtracker
startJobTracker();
// Create the TaskTrackers
for (int idx = 0; idx < numTaskTrackers; idx++) {
String rack = null;
String host = null;
if (racks != null) {
rack = racks[idx];
}
if (hosts != null) {
host = hosts[idx];
}
startTaskTracker(host, rack, idx, numDir);
}
this.job = createJobConf(conf);
waitUntilIdle();
}