The following is the scenerio of this problem.
Server A <-> Server B
Server A uses FederatedX Plugin to connect Server B's Table (called DB.TableA)
Because sometimes there will be Got an error reading communication packets. error for the failed processes, so I set an event to query ServerB's table (called DB.TableB) every hour, and there still are errors for this event and origional failed processes.
I check the network, and changes them to better environment, still happened.
I modified max_allowed_packet to 1G from Server A and B, modified timeout (net_read_timeout, net_write_timeout to 300 and 600 secs), still happened.
The execution time for failed processes are between 1 sec to 1 miniute only, and the content is writting data from Server A to Server B.
And few month later, the failed process for this problem increasing, I need to find the solution for this problem soon.
Once I found this issue and it says need to add FLUSH TABLE ServerB.DB.TableA/B eventually to solve this problem, and I do FLUSH TABLE every hour, there is no error now (for event to query ServerB's DB.TableB and the processes to write to Server B's DB.TableA).
Is it still need to do FLUSH TABLE eventually or make the FeferatedX code change to do FLUSH TABLE automatically?