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What does mean "skipping topic update due to lock contention" in the Impala catalog service log file?

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New Contributor

Does anyone know what does mean the text like "IO729 05:56:15.224205 4764 CatalogServiceCatalog,java:1344] Table db_name.table_name (version=10446022, lastSeen=10446022) is skipping topic update (10448033, 10448495] due to lock contention" in the Impala catalog service log file?
Thank you in advance!

1 ACCEPTED SOLUTION

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Master Collaborator

Hi @Iga21207 ,

 

So how it works in catalod is when you run any refresh commands then that is executed sequentially and once that is completed then it goes to next one. It doesn't run in parallel as per the catalogd which is a single threaded operation. There is a lock that catalogd thread creates on class getCatalogObjects().

 

So when you are refreshing(means they have not completed yet sequentially) and after that when the new request came in then the Catalog threw the error on that table as it can't get the lock because the lock is already there on previous table on which the refresh command was running.

 

Not sure on your CDH version, This may resolved in Higher version of CDP/CDH.

 

Note: If i answered your question please give a thumbs up and accept it as a solution.

 

Regards,

Chethan YM

 

 

View solution in original post

1 REPLY 1

avatar
Master Collaborator

Hi @Iga21207 ,

 

So how it works in catalod is when you run any refresh commands then that is executed sequentially and once that is completed then it goes to next one. It doesn't run in parallel as per the catalogd which is a single threaded operation. There is a lock that catalogd thread creates on class getCatalogObjects().

 

So when you are refreshing(means they have not completed yet sequentially) and after that when the new request came in then the Catalog threw the error on that table as it can't get the lock because the lock is already there on previous table on which the refresh command was running.

 

Not sure on your CDH version, This may resolved in Higher version of CDP/CDH.

 

Note: If i answered your question please give a thumbs up and accept it as a solution.

 

Regards,

Chethan YM