We’re running a Graylog multi-node environment with four Graylog nodes and I’ve a question regarding the correct order/sequence on how we should update the Graylog version.
In short: Should the Master-Node be updated first, last or does the order have no impact on the update?
In more detail:
We have two Graylog servers dedicated to Users (UI-Host0 + UI-Host1). Basically a Graylog installation with web-frontend enabled but no Inputs configured. The other two Graylog servers are dedicated to collect/receive and process log messages (Collector-Host0 + Collector-Host1).
Our Users access the frontend thru a hardware loadbalancer which is configured in fail-over-mode so Client requests get shipped to UI-Host0 and in case of downtime they get forwarded to the UI-Host1. Both Collector-Hosts are also behind a hardware loadbalancer which forwards incoming logs round-robin-style.
So we can have one UI-Host and one Collector-Host down at the same time. Since our UI-Host0 is configured as Master-Node (Graylog) I wonder about the order of updating the hosts to the latest Graylog version.
I’ve searched in the docs and the community but could not find a precise answer to this question.