Periodic ES ReadTimeout Error

I have a 2 node es cluster (4 core 16GB) config. I am getting read timeout error on 10th minute of every hour. All the scheduled processes from the application is stopped. So nothing scheduled from application side. So I would like to know if there is any schedule internal to es that run every hour. I have not changed any time related config in the elasticsearch.yml.

In one of the thread it was mentioned that GC stops all the communication until it finishes. I checked the logs and it shows that application threads are stopped every minute for around ~0.0009 seconds. Does es or jvm run anything periodically?

Can someone provide me few more pointers to debug the issue.
I am using es version 6.5.3