ODK Timing out during data pull

Hello Team,
My team conducting a survey can push data to ODK but during pulling of data we get the error below;
Error: retrieving next chunk of instances from server...

NOT ALL SUBMISSIONS RETRIEVED: Error fetching list of submissions: Fetch of
submission download chunk failed. Detailed error: Unexpected
java.net.SocketTimeoutException: Read timed out


Activity done:

Has anyone experienced this too? What more steps can i take to isolate the issue? How can i solve this?

We've already tried to;

  • increase tomcat Connection timeout
  • increase Java Heap Settings
  • increased MySQL interaction and wait timeouts
  • Verified network connection to the server

We are currently running ODK Aggregate 1.4.7 on Centos 6.7 , 5GB RAM, MySQL 5.1.73