Hi All, Currently we have *100* as the default value for hive.server2.async.exec.threads <https://github.com/apache/hive/blob/68f8734b3b7db2fdc8bc0c11ad3c37eb2e2a808c/common/src/java/org/apache/hadoop/hive/conf/HiveConf.java#L4233-L4234> and hive.server2.async.exec.wait.queue.size <https://github.com/apache/hive/blob/68f8734b3b7db2fdc8bc0c11ad3c37eb2e2a808c/common/src/java/org/apache/hadoop/hive/conf/HiveConf.java#L4238-L4240> configurations related to HS2 Async thread pool which is used for handling the client requests/queries coming to the HS2.
Recently our most of the customers reported saying below error on beeline *0: jdbc:hive2://localhost> show databases;* *Error: The background threadpool cannot accept new task for execution, please retry the operation (state=,code=0)* HS2 server logs shows below exception *Caused by: java.util.concurrent.RejectedExecutionException: Task java.util.concurrent.FutureTask@24363395 rejected from java.util.concurrent.ThreadPoolExecutor@54ef7045[Running, pool size = 100, active threads = 100, queued tasks = 100, completed tasks = 682504]* *at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2063) ~[?:1.8.0_342] at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:830) ~[?:1.8.0_342] at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1379) ~[?:1.8.0_342] at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:112) ~[?:1.8.0_342] at org.apache.hive.service.cli.session.SessionManager.submitBackgroundOperation(SessionManager.java:760) ~[hive-service-3.1.3] at org.apache.hive.service.cli.session.HiveSessionImpl.submitBackgroundOperation(HiveSessionImpl.java:598) ~[hive-service-3.1.3] at org.apache.hive.service.cli.operation.SQLOperation.runInternal(SQLOperation.java:279) ~[hive-service-3.1.3] ... 50 more* So here for most of the customers load the default value 100 is not sufficient so their queries are getting rejected. An average around 20+ customers are reproting this issue per year. May be most of the other organizations customers also facing this issue. So I am proposing to increase this default value from *100* to *250* for smooth handling of customer load. Please provide your valuable suggestions regarding this. Thanks & Regards, Dayakar
