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Updated on 2024-11-29 GMT+08:00
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Why Is a Task Suspended When the ANALYZE TABLE Statement Is Executed and Resources Are Insufficient?

Question

When the analyze table statement is executed using spark-sql, the task is suspended and the information below is displayed. Why?

spark-sql> analyze table hivetable2 compute statistics;
Query ID = root_20160716174218_90f55869-000a-40b4-a908-533f63866fed
Total jobs = 1
Launching Job 1 out of 1
Number of reduce tasks is set to 0 since there's no reduce operator
16/07/20 17:40:56 WARN JobResourceUploader: Hadoop command-line option parsing not performed. Implement the Tool interface and execute your application with ToolRunner to remedy this.
Starting Job = job_1468982600676_0002, Tracking URL = http://10-120-175-107:8088/proxy/application_1468982600676_0002/
Kill Command = /opt/client/HDFS/hadoop/bin/hadoop job  -kill job_1468982600676_0002

Answer

When the statement is executed, the SQL statement starts the analyze table hivetable2 compute statistics MapReduce tasks. On the ResourceManager Web UI of Yarn, the task is not executed due to insufficient resources. As a result, the task is suspended.

Figure 1 ResourceManager web UI

You are advised to add noscan when running the analyze table statement. The function of this statement is the same as that of the analyze table hivetable2 compute statistics statement. The command is as follows:

spark-sql> analyze table hivetable2 compute statistics noscan

This command does not start MapReduce tasks and does not occupy Yarn resources. Therefore, the tasks can be executed.

Parent topic: Spark SQL and DataFrame