clintropolis commented on PR #18727:
URL: https://github.com/apache/druid/pull/18727#issuecomment-3524893239

   >While we're at it, do you think we could add an explicit segment scan time 
metric? That is, the time it takes to fully load a segment from disk into 
memory (the Segment object)?
   
   We discussed this a bit offline, but for the sake of visibility for everyone 
else, `query/segment/time` is this basically, though it does not separate time 
spent reading from disk from time spent doing stuff since it sort of happens 
incrementally as the mmap file is paged into memory from disk. I'm not sure the 
best way to collect that measurement, but it would sure be useful.
   
   Also to clarify, `query/wait/time` is the time a segment spent waiting for a 
slot on the processing pool, before it gets to the point of doing any work or 
even reading anything from the segment, while `query/segment/time` starts where 
wait/time stops and ends when the internal sequence is fully consumed (so in 
some sense is dependent on how fast the caller consumes the sequence too). 
`query/segmentAndCache/time` includes time to check results cache + 
`query/segment/time` if there is no cache results. 


-- 
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]


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to