Syed Shameerur Rahman created YARN-11834:
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Summary: Application Stuck In ACCEPTED State due to race condition
Key: YARN-11834
URL: https://issues.apache.org/jira/browse/YARN-11834
Project: Hadoop YARN
Issue Type: Bug
Components: capacity scheduler
Reporter: Syed Shameerur Rahman
Assignee: Syed Shameerur Rahman
It was noted that in a Hadoop 3.4.1 YARN deployment, Spark application was
stuck in ACCEPTED state even though the cluster had enough resources.
*Steps to replicate*
1. Launch YARN cluster total capacity ≥ 1.59 TB memory, 660 vCores or more
{{{}2.Apply the following properties{}}}{*}{*}
*{{capacity-scheduler}}*
*{{{}"yarn.scheduler.capacity.node-locality-delay": "-1",
"yarn.scheduler.capacity.resource-calculator":
"org.apache.hadoop.yarn.util.resource.DominantResourceCalculator"{}}}{{{},{}}}*
{*}{{"}}{*}{*}{{}}{*}{*}{{{}yarn.scheduler.capacity.schedule-asynchronously.enable{}}}{{{}"
: "true"{}}}{*}
*{{yarn-site}}*
*{{"yarn.log-aggregation-enable": "true",}}*
*{{{}"yarn.log-aggregation.retain-check-interval-seconds": "300",
"yarn.log-aggregation.retain-seconds": "-1",
"yarn.scheduler.capacity.max-parallel-apps": "1"{}}}{{{}{}}}*
3. Submit multiple Spark jobs that launch a large number of containers. For
example:
{{spark-example --conf spark.dynamicAllocation.enabled=false --num-executors
2000 --driver-memory 1g --executor-memory 1g --executor-cores 1 SparkPi 1000}}
*Observations*
On analysis the logs, The following were the observations :
When Application 1 completes, there's a period where its resource requests are
still being processed or "honored" by the scheduler. During this transition
period, the following sequence could occur:
1. Application 1 completes and releases its resources
2. The scheduler is still processing some older allocation requests for
Application 1
3. During this processing, the *cul.canAssign flag* for the user is set to
false. Refer [Link#1
|https://github.com/apache/hadoop/blob/trunk/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/AbstractLeafQueue.java#L1670]and
[Link
#2|https://github.com/apache/hadoop/blob/trunk/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/AbstractLeafQueue.java#L1268]
4. Application 2 (which is new) tries to get resources
5. The scheduler checks the user's cul.canAssign flag, finds it's false (due to
[cache
implementation|https://github.com/apache/hadoop/blob/trunk/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/AbstractLeafQueue.java#L1241]),
and denies resources to Application 2
6. Application 2 remains in ACCEPTED state despite available resources
This race condition occurs because the user's resource usage state (tracked in
the CapacityUsageLimit object) isn't properly reset or synchronized
between the completion of one application and the scheduling of another.
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