[keycloak-user] Out of memory error on Keycloak cluster

Hi, We are using Keycloak 1.9.2.Final and have a cluster with an hap and 3 keycloak nodes behind it. For the first time in about 4-6 months we received errors that java heap space out of memory and the nodes just went down. We had around 100k users as well as 35k active connections at the time. We have around 512MB heap space assigned. I am not able to reproduce it after restarting the nodes. Is there any reason that this could happen?