Rebuilding Materialized View does not work, saying there is another process re-building the MV.

[#1]

Hi Team,

I am trying to re-build my materialized view (ALTER MATERIALIZED VIEW <db>.<table> REBUILD;). However, I got an error message saying that there is another process re-building the MV.

Error message:
SQL Error [40000] [42000]: Error while compiling statement: FAILED: SemanticException org.apache.hadoop.hive.ql.parse.SemanticException: Another process is rebuilding the materialized view

I tried to check if there is any write lock on the MV or the table, however there is none. I also tried to re-build the MV, but then I got the same error again when I tried to rebuild.
Any idea why this is happening or how to check the "another process"?

[#2 · Accepted solution]

Hi @RobVi ,

Please try to follow the below steps from our article.

https://my.cloudera.com/knowledge/ERROR-quotFAILED-SemanticException?id=340510

Let us know if works.

Good Luck.

[#3]

Hi @Shmoo ,
Thank you for the suggestion. This works! The MV can be rebuilt after manually deleting the stale locks.
However, the next interesting question would be why do we get the stale lock? If we know why, we could prevent this from happening again, as an access to hive metastore is not something that we want to make available to all users.

[#4]

@RobVi Has the reply helped resolve your issue? If so, please mark the appropriate reply as the solution, as it will make it easier for others to find the answer in the future. Thanks