Error: No buffer space available (maximum connections reached?)

Error: No buffer space available (maximum connections reached?)

TIBCO Spotfire Web Player might go unresponsive with the following error in the server.log file.

WARN 2020-01-21T10:10:15,690+0000 [heartbeat-63568] server.http.HttpCallable: Failed to send HeartBeatCommand request to 'https://company.domain.com:9443/spotfire/nodemanager/command' : No buffer space available (maximum connections reached?): connect org.springframework.web.client.ResourceAccessException: I/O error on POST request for "https://company.domain.com:9443/spotfire/nodemanager/command": No buffer space available (maximum connections reached?): connect; nested exception is java.net.SocketException: No buffer space available (maximum connections reached?): connect Caused by: java.net.SocketException: No buffer space available (maximum connections reached?): connect

This issue can be seen if the TIBCO Spotfire Node Manager server has too many active client connections due to which the ephemeral TCP ports are all used up and in this case no more can be allocated to a new client connection request. The default number of ephemeral TCP ports is 5000 but if all those are continuously occupied, this number needs to be increased. The workaround to get rid of this issue is to follow the steps below.

1. Open "Registry Editor" with administrator privilege
2. Navigate to "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters"
3. Add a variable name "MaxUserPort" type REG_DWORD and set its value to 65534.
4. Reboot the TIBCO Spotfire Node Manager machine