Getting Data In

Indexer recv-q high and certain sources lagging. How do I fix that?

vcarbona
Path Finder

Noticing from netstat there are high recv-q numbers on the indexer. We also notice some sources lagging in the indexer. The ports with the high recv-q are from the forwarders which contain these particular sources.

Our setting in limits.conf on the indexer is the following:
[thruput]

throughput limiting at index time

maxKBps = 0

We don't have excessive cpu, memory, or io on the indexer. Indexers will typically have about 35 connections from forwarders open. We also have a ulimit set to 4096.

Our current workaround is to restart the indexer but it reappears on other indexers of the same server group. Obviously this is starting to become an annoyance.

Anything else we should be checking?

Tags (3)
1 Solution

vcarbona
Path Finder

We've done a few things since then to control this issue:
1) Set our ulimit to 10240 on all indexers (But this didn't in itself resolve the problem yet helped out with the load)
2) We've also added the following line to the offending forwarder's outputs.conf under the [tcpout] stanza and restarted the forwarder:
forceTimebasedAutoLB = true

This latter solution has helped out tremendously so far in forcing data to be load balanced. It appears the default behavior is to stream it to one indexer until the "batch" of data is done. The setting appears to force it to another indexer.
Thanks for asking by the way! Almost forgot I posted the question awhile back 🙂

View solution in original post

vcarbona
Path Finder

We've done a few things since then to control this issue:
1) Set our ulimit to 10240 on all indexers (But this didn't in itself resolve the problem yet helped out with the load)
2) We've also added the following line to the offending forwarder's outputs.conf under the [tcpout] stanza and restarted the forwarder:
forceTimebasedAutoLB = true

This latter solution has helped out tremendously so far in forcing data to be load balanced. It appears the default behavior is to stream it to one indexer until the "batch" of data is done. The setting appears to force it to another indexer.
Thanks for asking by the way! Almost forgot I posted the question awhile back 🙂

omgwut56k
Path Finder

Did you find a solution?

0 Karma
Got questions? Get answers!

Join the Splunk Community Slack to learn, troubleshoot, and make connections with fellow Splunk practitioners in real time!

Meet up IRL or virtually!

Join Splunk User Groups to connect and learn in-person by region or remotely by topic or industry.

Get Updates on the Splunk Community!

Event Series: The Agentic SOC: Trust Before Autonomy

AI is fundamentally changing security operations, but true progress requires more than just automation—it ...

Free Professional Services for .conf26 Attendees

This year at .conf26, we are doing something a little different. We are bringing the best minds from ...

Defend at Machine Speed: Your Guide to Security Sessions at .conf26

Splunk .conf26   With threats moving at machine speed and attack surfaces expanding across hybrid ...