[LU-13045] WBC2: batch metadata update

• Type: Technical task
• Resolution: Unresolved
• Priority: Major
• Assignee: Qian Yingjin
• Reporter: Qian Yingjin

Description

During flush under WBC, a client could send a batch of metadata updates to MDT to improve the metadata performance a lot.

 

For batch metadata updates, the following points need to consider:

• If batch metadata updates need to return with locks (in case of WBC EX lock revocation), it needs to grant a batch of locks to the client and the client needs to cache the returned batch of locks on its DLM lock namespace. 
• Transaction:
• Recovery: VBR
• Dependency:
  • The client must ensure the dependencies in batching metadata updates must be ordered.
  • Each metadata update action in batching metadata update request should be executed one by one in a single thread on MDT;
  • If want to improve the performance of batching metadata update request by executing metadata updates in parallel in multiple threads, the MDT must carefully handle the dependencies.
  • When DNE involves, the client also needs to consider the dependencies among MDTs when do a batching metadata updates which is same as boosting batching metadata updates using multiple threads..

 

 

Issue Links

• is related to: LU-14139 batched statahead processing