Add set mqd off heap #1392
Merged
Add set mqd off heap #1392
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
In Erlang VMs starting with version 19.0 have a new process_flag to store messages off the process heap. This is extremely useful for processes that can have huge numbers of messages in their mailbox. For CouchDB this is most usually observed when couch_server backs up with a large message queue which wedges the entire node. This utility function will set a process's message_queue_data flag to off_heap in a way that doesn't break builds of CouchDB on older Erlang VMs while automatically enabling the flag on VMs that do support it.
|
+1 although it would be nice to see ddoc_cache in here as well. |
This uses the new `couch_util:set_mqd_off_heap/0` function to set message queues to off_heap for some of our critical processes that receive a significant amount of load in terms of message volume.
davisp
force-pushed
the
add-set-mqd-off-heap
branch
from
8e6c8f7
to
93f5b41
Compare
|
@chewbranca Added to ddoc_cache_lru. |
chewbranca
approved these changes
Jun 18, 2018
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Outdated suggestions cannot be applied.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.
Overview
Use
process_flag(message_queue_data, off_heap)on critical processes on Erlang VMs that support it.Testing recommendations
make eunitChecklist