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Tickwise
ErrorVelocity & proxySIG-VE-013

Backend connection dropped mid-session

Platforms
Velocity · whole network
Verified
Verified
Confidence
Confidence 80%

What it looks like in the log

Any one of these lines is enough. The agent matches them locally, on your server.

logs/latest.log
  • encountered a problem.
  • BackendPlaySessionHandler

Symptoms

  • Players are thrown off the server during play: “Your connection to <server> encountered a problem.”
  • In the proxy log: “[server connection] <player> -> <server>: exception encountered in …BackendPlaySessionHandler”

Cause

The proxy's connection to the backend dropped while the player was already on the server: the backend crashed, hung or restarted, or the network reset the connection.

Possible causes

  • The backend crashed or was restarted (Connection reset by peer) — the cloud correlates this with a backend crash/restart (NW-01)
  • The backend hung/is lagging badly and the connection drops on a timeout or protocol error
  • Network problems between the proxy and the backend (different hosts/data centres, a congested link, conntrack)
  • noteVelocity kick messages are translatable and can be overridden; the primary source is the Velocity agent's API events

How to fixLow risk

  1. Look at the exception under the exception encountered in …BackendPlaySessionHandler line and the time of the event.
  2. Check the backend's latest.log for the same ±2 minutes: a crash, watchdog (“The server has stopped responding!”), OutOfMemoryError, a restart.
  3. If the backend was running normally, check the network between the proxy and the backend (packet loss, conntrack limits, link congestion).
  4. Keep a working fallback server in try so players are moved rather than disconnected from the network.

Translated from the Russian original; log lines are quoted verbatim.

Sources