Tez execution engine properties
If the performance of low-latency analytical processing (LLAP) degrades, you can adjust Tez properties to tune Hive LLAP performance, but generally changing Tez properties is not necessary.
Tuning Tez
In Ambari, select Services > Tez > Configs to change general or advanced properties using guidelines in the following table. You can search for a property by entering it in the Filter field.
| Property | Guideline | Default |
|---|---|---|
tez.am.resource.memory.mb |
4 GB maximum for most sites. Generally, do not change the value of this property unless you change resources on the cluster. | Depends on your environment |
tez.session.am.dag.submit.timeout.secs
|
300 minimum |
300 |
tez.am.container.idle.release-timeout-min.millis
|
20000 minimum |
10000 |
tez.am.container.idle.release-timeout-max.millis
|
40000 minimum |
20000 |
tez.shuffle-vertex-manager.desired-task-input-size |
Increase for large ETL jobs that run too long. | No default value set |
tez.min.partition.factor |
Increase for more reducers. Decrease for fewer reducers. | 0.25 |
tez.max.partition.factor |
Increase for more reducers. Decrease for fewer reducers. | 2.0 |
tez.shuffle-vertex-manager.min-task-parallelism |
Set a value if reducer counts are too low, even if the
tez.shuffle-vertex-manager.min-src-fraction property is already
adjusted. |
No default value set |
tez.shuffle-vertex-manager.min-src-fraction |
Increase to start reducers later. Decrease to start reducers sooner. | 0.2 |
tez.shuffle-vertex-manager.max-src-fraction |
Increase to start reducers later. Decrease to start reducers sooner. | 0.4 |
hive.vectorized.execution.enabled
|
true |
0.4 |
hive.mapjoin.hybridgrace.hashtable
|
true for slower but safer processing. false for
faster processing. |
false |