Hello, is there any way to update client's tls cert( 90000+) quickly?

Can you be more specific about what the issue is you are trying to solve?

In the case that my server certificate is about to expire, I must update the client’s certificate.I have to build other one kolide whith different domain, because I can't update and restart kolide and 90000+ osquery at same time.

You don't actually need to restart Fleet and the osqueryd agents at the exact same time. If the agents cannot connect to Fleet they will continue running the same schedule of queries and buffering logs until they can reconnect.

Thanks. It seems that I need to use other tools to update the agent's certificate after fleet's updating.