The java application which is calling Endeca is intermittently not able to connect. That dump starts with this
SRVE0133E: An error occurred while parsing parameters. java.io.IOException: Async IO operation failed, reason: RC: 76 Socket is not connected
The Endeca request log is not seeing the request, which makes sense as there was no connection created.
Doing a netstat for the port on the Endeca instance I see: 1 LISTEN and 30 TIME_WAITs.
The request volume is 1 a second, at the most.
I am seeing a strange thing in the Dgraph log, one of these for each health check from the network load balancer. The health check is a telnet, as far as I know. I don't think it is related, but it is the same port.
Is there a firewall and/or load balancer between your java application and the Endeca MDEX? If so, are they setup bi-directionally? Is your java application running on linux? If so, what is your ulimit set to? http://webtools.live2support.com/linux/ulimit.php. If set too low, you could be running into a limit of the number of open handles (file and/or sockets) that your system will allow.