Here are the configs for on-prem customers willing to apply and avoid adding more hardware cost.
9.4.0 and above most of the indexing configs are automated that’s why dropped from 9.4.0 suggested list.
Note: Assuming replication queue is full for most of the indexers and as a result indexing pipeline is also full however indexers do have plenty of idle cpu and IO is not an issue.
On-prem Splunk version 9.4.0 and above
Indexes.conf
[default]
maxMemMB=100
Server.conf
[queue]
autoAdjustQueue=true ( It can be applied on on any splunk instance UF/HF/SH/IDX)
Splunk version 9.1 to 9.3.x
Indexes.conf
[default]
maxMemMB=100
maxConcurrentOptimizes=2
maxRunningProcessGroups=32
processTrackerServiceInterval=0
Server.conf
[general]
parallelIngestionPipelines = 4
[queue=indexQueue]
maxSize=500MB
[queue=parsingQueue]
maxSize=500MB
[queue=httpInputQ]
maxSize = 500MB
maxMemMB, will try to minimize creation of tsidx files as much as possible at the cost of higher memory usage by mothership(main splunkd).
maxConcurrentOptimizes, on indexing side it’s internally 1 no matter what the setting is set to. But on target replication side launching more splunk-optimize processes means pausing receiver until that splunk-optimize process is launched. So reducing it to keep receiver do more of indexing work than launching splunk-optimize process. With 9.4.0, both source (indexprocessor) and target(replication in thread) will internally auto adjust it to 1.
maxRunningProcessGroups, allow more splunk-optimize processes concurrently. With 9.4.0, it's auto.
processTrackerServiceInterval, run splunk-optimize processes ASAP. With 9.4.0, you don't have to change.
parallelIngestionPipelines, have more receivers on target side. With 9.4.0, you can enable auto scaling of pipelines.
maxSize, don’t let huge batch ingestion by HEC client block queues and receive 503. With 9.4.0 autoAdjustQueue set to true, it's no more a fix size.
