Re: function to count pending packets in TCP socket

[Anonymous Monk]

Dear Perl Monks,

More than a week has passed since my last post in this thread without any reply. Hence I am assuming that nobody knows a Perl function which returns the send_q value of a socket connection. Meanwhile I helped myself by calling the Linux ss command from Perl and parsing its output. However I see this rather a work around than a clean solution. It imposes OS dependency and it creates a risk my program may fail in future, should any Linux update change the output format of the ss command.

Therefore I am still interested, if a clean solution exists in Perl.

Best regards

Andreas

[Anonymous Monk]

The ss utility comes from iproute2 package. Sources are freely available for you to read and inspect. The utility is specific to Linux networking.

Send-Q is obtained either via netlink(7), or parsing /proc/net/tcp (hexadecimal field named tx_queue). You could do the same in perl program: use getpeername and match the right line. Inefficient and cumbersome, but it might suit your purposes.

Lastly, I would reconsider the approach of building HA/failover capabilities directly into application. Perhaps your questions are better answered on a networking related forum. HAProxy dot org for instance has a mailing list and archive. HtH.