Andrew Wong has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/15830 )

Change subject: [fs] fixed file num low live ratio metadata compaction policy 
when startup
......................................................................


Patch Set 4:

(10 comments)

http://gerrit.cloudera.org:8080/#/c/15830/4//COMMIT_MSG
Commit Message:

http://gerrit.cloudera.org:8080/#/c/15830/4//COMMIT_MSG@7
PS4, Line 7: [fs] fixed file num low live ratio metadata compaction policy when
           : startup
nit: keep the title on a single line


http://gerrit.cloudera.org:8080/#/c/15830/4//COMMIT_MSG@10
PS4, Line 10: it loads all low live ratio metadata into memory,
nit: I wasn't sure what "low live ratio metadata" referred to. Could you also 
add a small description here, e.g.

"it loads all low live ratio metadata into memory (i.e. metadata for containers 
that contain a low number of live blocks), and this is..."


http://gerrit.cloudera.org:8080/#/c/15830/4//COMMIT_MSG@11
PS4, Line 11: controll
nit: "control" with one 'l'


http://gerrit.cloudera.org:8080/#/c/15830/4//COMMIT_MSG@16
PS4, Line 16: excess
nit: "exceed"


http://gerrit.cloudera.org:8080/#/c/15830/4//COMMIT_MSG@18
PS4, Line 18: livemetadata
nit: add a space: "live metadata"


http://gerrit.cloudera.org:8080/#/c/15830/4//COMMIT_MSG@29
PS4, Line 29: rting(Not
nit: add a space in between "starting (", and "Not" should be lower cased.


http://gerrit.cloudera.org:8080/#/c/15830/4//COMMIT_MSG@30
PS4, Line 30: excess
nit: "exceeds"


http://gerrit.cloudera.org:8080/#/c/15830/4/src/kudu/fs/log_block_manager.cc
File src/kudu/fs/log_block_manager.cc:

http://gerrit.cloudera.org:8080/#/c/15830/4/src/kudu/fs/log_block_manager.cc@119
PS4, Line 119: DEFINE_int32(max_num_low_live_ratio_metadata_file_to_compact, -1,
nit: can you put this up by log_container_live_metadata_before_compact_ratio so 
the compaction-related flags are adjacent to one another?


http://gerrit.cloudera.org:8080/#/c/15830/4/src/kudu/fs/log_block_manager.cc@120
PS4, Line 120:
nit: spell out "number"


http://gerrit.cloudera.org:8080/#/c/15830/4/src/kudu/fs/log_block_manager.cc@2668
PS4, Line 2668:       low_live_ratio_metadata_to_compact_num_.Increment();
Using the number of metadata files seems kind of odd, given it requires some 
experimentation or knowledge beforehand about what is being stored in memory to 
use it effectively.

Would it be possible to measure size via BlockRecordPB::ByteSizeLong() and 
limit the number of bytes we're allowed to collect for compaction instead? As 
far as I can tell, ByteSizeLong() is the post-encoding size, so it may not be 
accurate. But if we could get the in-memory size of the records, we could apply 
some bytes limit, which seems more natural.



--
To view, visit http://gerrit.cloudera.org:8080/15830
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: Ifad1d6de4e61a1ddcfb35743abd71b57d6418896
Gerrit-Change-Number: 15830
Gerrit-PatchSet: 4
Gerrit-Owner: wangning <[email protected]>
Gerrit-Reviewer: Andrew Wong <[email protected]>
Gerrit-Reviewer: Hao Hao <[email protected]>
Gerrit-Reviewer: Kudu Jenkins (120)
Gerrit-Reviewer: wangning <[email protected]>
Gerrit-Comment-Date: Thu, 14 May 2020 03:51:36 +0000
Gerrit-HasComments: Yes

Reply via email to