Support socket timeout in SysLogHandler to prevent indefinite blocking on socket creation

[hodamarr]

Feature or enhancement

Proposal:

Hi,
In the current implementation of the SysLogHandler class from the logging.handlers module, if the specified address does not respond or is unreachable, the createSocket method may block indefinitely. This is problematic because there is no way to set a socket timeout during the connection's creation without overriding the entire createSocket method.

The only way to add timeout is to override the whole createSocket method (if I use super().createSocket() it will get stuck on this line)

my suggestion:

class SysLogHandler(logging.Handler):
    def __init__(self, address=('localhost', SYSLOG_UDP_PORT), 
                 facility=LOG_USER, socktype=None, timeout=None):
        # Existing initialization
        self.timeout = timeout  # New timeout parameter
        self.createSocket()
    
    def createSocket(self):
        # Existing code ....
        try:
            sock = socket.socket(af, socktype, proto)
            **if self.timeout:
                     sock.setttimeout(self.timeout)**
            # Existing code ........

Thanks

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-126400: Add TCP socket timeout to SysLogHandler to prevent blocking #126716

[Zheaoli]

If I remember correct, the SysLog is based on the UDP protocol. I'm sure the timeout is useful for UDP

[hodamarr]

If I remember correct, the SysLog is based on the UDP protocol. I'm sure the timeout is useful for UDP

Syslog uses both UDP and TCP. A timeout is crucial to avoid blocking the process if the service is unreachable or slow to respond. In my case, I'm using TCP, and the server is unreachable, causing my process to be blocked indefinitely. Adding timeout support to SysLogHandler would allow the application to fail gracefully in such scenarios, instead of hanging due to network issues.

[hodamarr]

Hey @picnixz I can take care of this—could you assign me to it?

[picnixz]

Before starting the implementation, I wonder whether this should count as a bug fix or not (and whether there is another way to fix it). So let's ask @vsajip first.

[hodamarr]

Sure, let me know when its okay to open a pull request.
@vsajip @picnixz

[vsajip]

Yes, this seems a reasonable feature to add. You're welcome to submit a PR with docs/tests.