Why do I need layer-7 load balancer in front of Splunk Search Head Cluster

[xchang1226]

We are trying to add a load balancer in front of our Splunk Search Head Cluster (SHC), according to the official doc, we need layer-7/application level load balancer which provides session stickiness. The thing I don't quite understand is since SHC is doing replication across all members, why does user need to be on the same search head? We also have following in the web.conf to prevent logging user out due to session timeout. We are using SAML SSO, so user won't get a login screen even it times out. So does anyone know why we would need session stickiness?

tools.sessions.timeout = 3600
ui_inactivity_timeout = 0

[richgalloway · Accepted solution]

Without session stickiness users may see partial page loads and other strange behavior. Because SHC replication is not instant, users may be directed to a SH that does not have their KOs.