[EXTERNAL] Re: Aborted connection

Winfield, Alister Alister.Winfield at sky.uk
Mon May 4 13:15:44 CEST 2020


Ahh network tuning...

A black art that when needed soon turns into a set of rather random numbers that only work for a given set of dependencies. (kernel, hardware, application, etc). Some numbers give good performance for TCP but is terrible for UDP latency. Others can cause packet corruption that gets all the way to userland (overrun a nics hardware ring buffer 'post' checksum offload it’s a really entertaining one to diagnose).

Performance test from low to high loads including flash crowd load. Graph outcomes for all performance metrics.
Change one tunable (or related set), re-run and see if it's made a useful difference. Repeat again and again... be prepared to do it all again on the next upgrade. Or just pay for more and cheaper compute / hardware gaining resilience and scaling at the cost of power, space and cooling (if not public cloud).

Sad the auto-tuning and normal settings are almost always sub-optimal on any server that’s actually doing useful amounts of work.

A.


On 28/04/2020, 22:28, "Freeradius-Users on behalf of Aurélio de Souza Ribeiro Neto" <freeradius-users-bounces+alister.winfield=sky.uk at lists.freeradius.org on behalf of netolistas at mpc.com.br> wrote:

    Alan,


    >>        When it happens I have this messages in freeradius LOGs:
    >>
    >>        WARNING: (131915) WARNING: Module rlm_sql became unblocked
    >>        Error: Received conflicting packet from client ce-popfd-rb port
    >>    49756 - ID: 101 due to unfinished request in module sql.  Giving up on
    >>    old request
    >>
    >>        What I need to adjust do solve this issue?
    >    Make the MySQL server respond quickly.  The "rlm_sql became unblocked" message comes out because the SQL server didn't respond to one query for *many* seconds.
    >
    >    No amount of poking FreeRADIUS will fix this issue.  It's either a slow database, or a network issue which causes connections to be blocked.
    >
    >    Alan DeKok.
         You´re right! Was a network problem.

         I want to thank and share how I solved my "problem" .

         After check all my hardware and sure that I don´t have any problem,
    I found a problem in my Ubuntu TCP/IP tuning (database server)!

         I did the steps found in
    https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdom.as%2F2006%2F09%2F12%2Fmysql-tcp-network-tuning%2F&data=02%7C01%7Calister.winfield%40sky.uk%7C906bfd756f394912aad208d7ebbb176d%7C68b865d5cf184b2b82a4a4eddb9c5237%7C0%7C1%7C637237061101245052&sdata=tgXpTtIMj3rUAusBdJzdvY19ibMrLnxwgIUcUzFj5CE%3D&reserved=0

         and haven´t no more messags from module_rlm_sql!

         Thank you again

    Aurélio






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