Perf improvement and refactor for the non-reliable disk buffer #3756
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
Build SUCCESS |
|
@kira-syslogng do stresstest |
|
@kira-syslogng test this please test branch=benedek-add-disk-buffer-tests; |
|
Kira-stress-test: Build SUCCESS |
|
Build SUCCESS |
OverOrion
previously approved these changes
Aug 13, 2021
Signed-off-by: László Várady <[email protected]>
This method can be removed from the LogQueue interface in the future in favor of the backlog and its rewind mechanism. Signed-off-by: László Várady <[email protected]>
push_head() is dead code, it is not used by syslog-ng. This method can be removed from the LogQueue interface in the future in favor of the backlog and its rewind mechanism. Subsequent commits are going to change the internals of the non-reliable disk-buffer's push() and pop() operations, this was the trigger for this cleanup. Signed-off-by: László Várady <[email protected]>
Signed-off-by: László Várady <[email protected]>
This is a refactor, the commit contains equivalent transformations based on the following considerations: This commit splits push_tail() into 3 push parts: qout, disk, and qoverflow - if qout has space in it and the disk is empty, we push into qout - we try to push into the disk buffer otherwise - when the disk push fails (full or write error), we push into qoverflow - once we reached the qoverflow area, we continue pushing message there instead of disk The above steps retain FIFO order if messages are moved from qoverflow to disk, and from disk to qout after each pop(). This is done by _move_disk(). Notes: Settings local_options.ack_needed to FALSE converts the subsequent log_msg_ack() call to a NOOP. It is cleaner not to call the ack method. The same is true for log_msg_ref() and log_msg_unref(). Signed-off-by: László Várady <[email protected]>
This is a refactor commit. Signed-off-by: László Várady <[email protected]>
unref() might free the message object, so ack() should be called first. Signed-off-by: László Várady <[email protected]>
Signed-off-by: László Várady <[email protected]>
Signed-off-by: László Várady <[email protected]>
This is a preparation step for simplifying the move logic of non-reliable queue segments. This commit does not change functionality, as _move_messages_from_overflow is already there to move messages from the overflow queue. Signed-off-by: László Várady <[email protected]>
Signed-off-by: László Várady <[email protected]>
The name of _get_next_message() can be misleading in this context, as it only reads from disk. Also, log_msg_ack() has no effect when adding a message from the disk to the qout queue. Signed-off-by: László Várady <[email protected]>
Signed-off-by: László Várady <[email protected]>
Signed-off-by: László Várady <[email protected]>
qbacklog is accessed only from an output thread, so locking is not necessary. Signed-off-by: László Várady <[email protected]>
Signed-off-by: László Várady <[email protected]>
MrAnno
force-pushed
the
diskq-perf-qbacklog-and-refact
branch
from
8a1936f to
557f2db
Compare
alltilla
approved these changes
Aug 13, 2021
|
@kira-syslogng test this please test branch=benedek-add-disk-buffer-tests; |
|
@kira-syslogng do stresstest |
OverOrion
approved these changes
Aug 13, 2021
|
FYI benedek-add-disk-buffer-tests has been merged. |
Whoops, my bad :( |
|
Build SUCCESS |
|
Kira-stress-test: Build FAILURE |
|
@kira-syslogng do stresstest |
|
Kira-stress-test: Build SUCCESS |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR refactors the non-reliable disk buffer and simplifies how messages are moved among queue segments.
(The trigger behind this refactor was to avoid unnecessarily (de)serialization and disk I/O operations in the move logic, but I had to drop those changes because they would have had unpleasant side effects.)
The last 2 commits improve the performance of the non-reliable disk buffer by using the entire qout when moving messages, and by eliminating a lock during qbacklog operations.
According to my measurements, this could increase the performance up to 20%.
No news file is needed, we'll add a news entry separately about the overall performance improvement we achieved.