/**
* set current session to existing session object if a thread is running multiple sessions - it
* must call this method with the new session object when switching from one session to another.
*/
public static SessionState start(SessionState startSs) {
setCurrentSessionState(startSs);
if (startSs.hiveHist == null) {
if (startSs.getConf().getBoolVar(HiveConf.ConfVars.HIVE_SESSION_HISTORY_ENABLED)) {
startSs.hiveHist = new HiveHistoryImpl(startSs);
} else {
// Hive history is disabled, create a no-op proxy
startSs.hiveHist = HiveHistoryProxyHandler.getNoOpHiveHistoryProxy();
}
}
// Get the following out of the way when you start the session these take a
// while and should be done when we start up.
try {
// Hive object instance should be created with a copy of the conf object. If the conf is
// shared with SessionState, other parts of the code might update the config, but
// Hive.get(HiveConf) would not recognize the case when it needs refreshing
Hive.get(new HiveConf(startSs.conf)).getMSC();
UserGroupInformation sessionUGI = Utils.getUGI();
FileSystem.get(startSs.conf);
// Create scratch dirs for this session
startSs.createSessionDirs(sessionUGI.getShortUserName());
// Set temp file containing results to be sent to HiveClient
if (startSs.getTmpOutputFile() == null) {
try {
startSs.setTmpOutputFile(createTempFile(startSs.getConf()));
} catch (IOException e) {
throw new RuntimeException(e);
}
}
} catch (Exception e) {
// Catch-all due to some exec time dependencies on session state
// that would cause ClassNoFoundException otherwise
throw new RuntimeException(e);
}
if (HiveConf.getVar(startSs.getConf(), HiveConf.ConfVars.HIVE_EXECUTION_ENGINE).equals("tez")
&& (startSs.isHiveServerQuery == false)) {
try {
if (startSs.tezSessionState == null) {
startSs.tezSessionState = new TezSessionState(startSs.getSessionId());
}
if (!startSs.tezSessionState.isOpen()) {
startSs.tezSessionState.open(startSs.conf); // should use conf on session start-up
}
} catch (Exception e) {
throw new RuntimeException(e);
}
} else {
LOG.info("No Tez session required at this point. hive.execution.engine=mr.");
}
return startSs;
}
static void validateFiles(List<String> newFiles) throws IllegalArgumentException {
SessionState ss = SessionState.get();
Configuration conf = (ss == null) ? new Configuration() : ss.getConf();
for (String newFile : newFiles) {
try {
if (Utilities.realFile(newFile, conf) == null) {
String message = newFile + " does not exist";
throw new IllegalArgumentException(message);
}
} catch (IOException e) {
String message = "Unable to validate " + newFile;
throw new IllegalArgumentException(message, e);
}
}
}
/** Sets the given session state in the thread local var for sessions. */
public static void setCurrentSessionState(SessionState startSs) {
tss.set(startSs);
Thread.currentThread().setContextClassLoader(startSs.getConf().getClassLoader());
}