Context CSN timestamp

Hello,

I have a strange problem of synchronization, since yesterday my slave servers have a small difference of 2 or 3 minutes with the master. I mean the context CSN of the slave is 3 mn earlier than contextCSN of the master.

My first question is the following : how the timestamp of the contextCSN of the slave is computed ? Is it a copy of the tilmestamp from the master ? Or is it based on the localtime of the slaves ?

My second question is that maybe such a small difference is « normal » (as the contextCSN of slave is progressing that means that replication is not fully stopped just a bit delayed) and I should only worry for a greater difference of time than one minute.

Thanks in advance.

Fred