Article - CS319279

Tunnel stability and throughput is greatly reduced when approaching maxConnections value specified on the Apache Tomcat HTTP(S) Connector used by ThingWorx Platform

Modified: 08-Jun-2021   


Applies To

  • ThingWorx Platform 7.4 to 9.1

Description

  • VNC (Virtual Network Computing) sessions connected through Tunnels and Edge Microserver (EMS/WSEMS) are disconnected when there is a lot of load on ThingWorx
  • Screen Sharing sessions using ThingWorx Tunnels drop at random
  • Apache Tomcat parameter maxConnections seems to be affecting tunnel performance and stability
  • Approaching 10000 total HTTP connections (including Tunnels) on ThingWorx Platform causes sudden drops in tunnel stability
  • The number of http-nio-<port>-exec-<num> threads have maxed out in Stacktrace
  • How to increase http-nio-<port>-exec-<num> threads to make sure websocket connections are going to ThingWorx
  • WSEMS log from the Edge Device shows the following:
    • {"level":"FORCE","timestamp":"<Date Time>","origin":"SDK","content":"TUNNEL CREATED. Entity: <Entity Name>, tid: <ID>, target: <Target Socket>"}
      {"level":"FORCE","timestamp":"<Date Time>","origin":"SDK","content":"TUNNEL STARTED. Entity: <Entity Name>, tid: <ID>, target: <Target Socket>"}
      {"level":"FORCE","timestamp":"<Date Time>","origin":"SDK","content":"TUNNEL ENDED. Entity: <Entity Name>, Peer: <Peer>, tid: <ID>, target: <Target Socket>"}
  • Error in the ApplicationLog.log file located in <ThingworxStorage>\logs
    • <Date Time> [L: ERROR] [O: c.t.w.t.WSTunnelServer] [I: ] [U: ] [S: ] [T: http-nio-0.0.0.0-443-exec-820] Error occurred in web socket: An existing connection was forcibly closed by the remote host 
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