merlimat opened a new pull request, #3825:
URL: https://github.com/apache/bookkeeper/pull/3825

   ### Motivation
   
   The option of triggering journal callbacks from a thread-pool instead of 
from the JournalForceWrite thread is not really helpful under any condition.
   
   The only thing this option does is to introduce an extra context switch to 
jump on this thread-pool and from there it will trigger the response, though 
basically no work is done in this thread-pool. It will just jump on the Netty 
IO-thread for the specific connection and from there the serialization and the 
socket write will be done.
   
   When using the thread-pool, one can see the effect of the extra-context 
switch and the contention on the execution.
   
   Additionally, when 0 threads are configured, we are using the Guava 
DirectExecutor which has non-zero overhead in the form of a mutex that is 
contended between multiple journal threads.


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]

Reply via email to