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Bind port 3839 is busy

By default agents use port 3839 as listening port for incoming connections. This error will pop up if the agent was not able to bind to the given port - it's being used by another process.


In most cases this error appears if two agents are installed on same computer - Management Server agent (installed by Management Console automatically) and another one installed here manually. 

To verify what other process uses the port:
Windows: netstat -ano | findstr 3839  //see the last column for the process PID
Linux: sudo netstat -ano | grep 3839 

There are several ways to fix it: 
1) Leave only one agent on the computer, if the port is indeed occupied by an agent. You cannot uninstall Management Server agent though. 

2) If the port is used by a third app, or your need two agents on this computer, set the agent to listen to a different port. Open Agent's config and add listening_port parameter there: 

 { "listening_port": 3840,
  "folders_storage_path": "%DOWNLOADS%",
  "management_server": {
    "host": "host:8444",
    "cert_authority_fingerprint": "9...3a",
    "bootstrap_token": "Y...U",
    "disable_cert_check": false

Put the preferred port there and restart the agent.

3) Create new Agent profile for this agent only and change "Bind port" option there. Use this profile for this agent only when creating a job. 

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