MySQL Bugs: #31410: failed: Lost connection to MySQL server at 'reading authorization packet', syste

Bug #31410	failed: Lost connection to MySQL server at 'reading authorization packet', syste
Submitted:	4 Oct 2007 20:40	Modified:	14 Oct 2007 18:25
Reporter:	Mariella Di Giacomo	Email Updates:
Status:	Not a Bug	Impact on me:	None
Category:	MySQL Server	Severity:	S2 (Serious)
Version:	5.1.22-rc	OS:	Linux (Linux 2.6.22.6 and Debian 4.0)
Assigned to:		CPU Architecture:	Any
Tags:	reading authorization packet : duplicate of bug 28359 ?

Description:
I have been running MySQL 5.1.22-rc on Linux.
The MySQL source code has been compiled with the following settings:

./configure CC=gcc CFLAGS="-DBIG_JOINS=1 -O2" CXX=g++ CXXFLAGS="-DBIG_JOINS=1 -felide-constructors -fno-rtti -O2" --prefix=/usr/local/mysql-5.1.22-rc --localstatedir=/usr/local/mysql-5.1.22-rc/data --libexecdir=/usr/local/mysql-5.1.22-rc/bin --datadir=/usr/local/mysql-5.1.22-rc/data -with-comment="Debian x86_64" --with-server-suffix="Debian x86_64"  --enable-shared --enable-static --enable-thread-safe-client --enable-assembler --enable-local-infile --with-big-tables --with-raid --with-mysqld-user=mysql --with-libwrap --with-mysqld-ldflags=-all-static --with-vio --with-bench --with-readline --with-extra-charsets=all --with-innodb --with-isam --with-archive-storage-engine --with-csv-storage-engine --with-federated-storage-engine --with-embedded-privilege-control --with-zlib-dir=bundled --with-ssl=bundled --with-partition

The MySQL server is accessed through Perl 5.8.8 and DBI-1.56 and DBD-mysql-4.005
from a remote host (Linux and Debian)

When I spawn 100 clients concurrently against MySQL server some of the clients cannot continue because of the following error:

failed: Lost connection to MySQL server at 'reading authorization packet', system error: 0

during connection

MySQL server had max_connections set to 256

Is this a replication bug of #28359 ?

Thanks,

Mariella

How to repeat:

Launch at least 100 concurrent jobs at the same time (each open a connection + send queries for quite a while and at the end closes the conenction) against MySQL server (e.g. using a Perl program)

Thank you for a problem report. Please, try to connect_timeout to higher values, 10 or even 60, and check if it solves the problem.

Using connect_timeout=60 fixed the problem.

Thanks,

Mariella

So, this is not a bug.

We increased the timeout to 60 seconds, and it helped only partially. The final solution was to switch the ethernet card from 100Mb/s to 1000Mb/s mode.

So still not a bug on MySQL side, but I hope this comment can help someone.