Session duration

Hi,

I have a load balancer serving 2 droplets (both are healthy 100% - Debian do-kube-1.16.6-do.2 in SFO2 running a NodeJS application). Looking at the graphs for the load balancer, the session duration is currently running at around 900 seconds. The graph shows some abrupt spikes of some 100+ seconds. The graph creeps, spikes and occasionally returns to 0.

Not able to figure out what triggers these. There are no corresponding errors in the nginx monitoring logs. I see that the information for this graph says “This is the average TCP session time measured at the Load Balancer and is useful for detecting anomalies.”

Are these session times & the behaviour normal? I am new to K8S, nginx & load balancers. Any help would be much appreciated.

Thanks, KSA