No connection could be made because the target machine actively refused it 127.0.0.1:8019

[mike_meirovitz]

Hi,

Can someone explain the reason for this error:

No connection could be made because the target machine actively refused it 127.0.0.1:8019

I got 8,340 of this error in ~10 hours of SmartConnector run. See the attached log file.

Thank you.

Mike

[ahmet191]

Hi,

I am not an expert and i couldn't look deep inside the log files but i would definetely check the firewall first. maybe shutdown for testing. second, i would change the port number also for testing. Maybe that one is already open or not closed in a right way. 

If i am guessing right, you are running ews server and is it have to be listening? I mean it is already a server. Then, it doesn't matter some client is connected or not. Thats why i am suspicious of server connection port and firewall. Like i said, i am not an expert. These are just my guesses but if you already solved this problem, could you please share the solution if it is okay

[Daniel_Cerone]

run a wireshark and see if there are any bottlenecks.

ensure the smartconnector service is running- it will refuse when not running.

check event viewer to see what may have occurred around the time of failure.

[markaldo]

Often, connectivity issues arise when something is hindering access to a specific port or hostname. This obstruction can be due to a firewall blocking the connection or the service-hosting process not listening on the designated port. This could result from the service not running, or it might be listening on an alternative port. Consequently, establishing a connection becomes impossible.

To diagnose the problem, you can try running the netstat -anb command from the command line to check if anything is listening on the intended port. If it returns no results, consider changing the port number. In Windows operating systems, you can use the netstat command via the command line (cmd.exe), while on Linux, you may need to use netstat -anp.

Occasionally, when the target machine 'actively refuses' the connection, it could be because the server's 'backlog' is full. In such cases, you might consider increasing the server's backlog, but it's also essential to implement retry logic in your client code to handle this situation. This is necessary because even with an extended backlog, the server could be handling numerous other requests on the same port at that time.