arp: optimize interface name resolution #3133
Merged
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
github.com/jsimonetti/rtnetlink provides a high level rtnl wrapper around the lower level rtnetlink functions, which essentially does all that we need. The rtnl.Conn.Neighbors uses an internal cache for resolving interface indexes to names, so it makes at most one rtnetlink call per interface to resolve the name. Using this high level wrapper hugely simplifies our code and makes it easier to understand and maintain. Fixes: prometheus#3075 Signed-off-by: Daniel Swarbrick <[email protected]>
dswarbrick
force-pushed
the
arp-rtnetlink
branch
from
6613f53 to
5ad0fdd
Compare
|
Any news regarding this PR? |
|
the issue being fixed is pretty problematic in e.g. calico based kubernetes clusters which have a lot of devices: workaround until this is merged and released is to switch back to gathering via procfs via
(limiting devices via |
|
@SuperQ Can we get this merged before the next release? |
|
@SuperQ Yeah PTAL |
|
I plan to backport this as a patch in the Debian package prometheus-node-exporter 1.8.2, since the first trixie freeze date is probably not far away. It would still be nice to see this merged upstream however, since it fixes a fairly important bug. |
SuperQ
approved these changes
Jan 10, 2025
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Outdated suggestions cannot be applied.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.
Go net package's net.InterfaceByIndex fetches the entire interface table behind the scenes, despite us specifying the interface index that we are interested in. This results in an exponential amount of rtnetlink traffic (and thus
recvfromsyscalls) as the number of interfaces in a host increases.Fixes: #3075