org.apache.hadoop.hive.ql.exec.errors.MapAggrMemErrorHeuristic Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
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package org.apache.hadoop.hive.ql.exec.errors;
import java.util.List;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.mapred.JobConf;
/**
* Detects out-of-memory errors when hash tables in map-based aggregation group
* by queries take up too much memory.
*
* Conditions to check
*
* 1. The query contains a group by.
* 2. Map-side aggregation is turned on.
* 3. There is a out of memory exception in the log.
*/
public class MapAggrMemErrorHeuristic extends RegexErrorHeuristic {
private static final String OUT_OF_MEMORY_REGEX = "OutOfMemoryError";
private boolean configMatches = false;
public MapAggrMemErrorHeuristic() {
setQueryRegex("group by");
getLogRegexes().add(OUT_OF_MEMORY_REGEX);
}
@Override
public void init(String query, JobConf conf) {
super.init(query, conf);
configMatches = HiveConf.getBoolVar(conf, HiveConf.ConfVars.HIVEMAPSIDEAGGREGATE);
}
@Override
public ErrorAndSolution getErrorAndSolution() {
ErrorAndSolution es = null;
if(getQueryMatches() && configMatches) {
List matchingLines = getRegexToLogLines().get(OUT_OF_MEMORY_REGEX);
if (matchingLines.size() > 0) {
String confName = HiveConf.ConfVars.HIVEMAPAGGRHASHMEMORY.toString();
float confValue = HiveConf.getFloatVar(getConf(),
HiveConf.ConfVars.HIVEMAPAGGRHASHMEMORY);
es = new ErrorAndSolution(
"Out of memory due to hash maps used in map-side aggregation.",
"Currently " + confName + " is set to " + confValue + ". " +
"Try setting it to a lower value. i.e " +
"'set " + confName + " = " + confValue/2 + ";'");
}
}
reset();
return es;
}
}