I can explain in detail, but i havnot received yet accurate information.
also due to security issues, it is difficult to disclose the details.
please appreciate your understanding.
What are you using to measure connections concentrated on a single secondary?
→ I don’t know but they are using 3rd monitoring solution.
The connection of MongoDB is checking in real time through the monitoring solution.
During rush hour, other secondary nodes maintain a normal level of connection, and a specific secondary node has connections about x20 times more than other nodes.
What specific MongoDB driver or client version is the affected application using?
→ java mongodb driver version 2.14
What is your version of MongoDB server?
→ MongoDB 3.4.x
when rush hour, there is no regular pattern other than what happens.
What does your connection string look like (with any hostnames or user credentials redacted)?
→ I don’t know for this contents.
Is there a pattern for the hour of the day when the secondary reads appear to target a specific server?
→ There is no regular pattern that except in when the issue occurs during rush hour.
Does the observed effect appear to have a common duration. (full hour, half hour, …)?
→ Because an issue occurred and the service was affected, the secondary node was excluded from the replica set grop. so I don’t know exactly this contents.
With a specific time of day correlation my first suspicion would be to look for a scheduled job (eg backup or batch process) which might be targeting one secondary.
→ I was received contents that there was no such thing, but I will check again.
When analyzing issue,
- What should I check in the log?
- Would i be helpful that check settings value in the mongodb options?