MySQL 5.5.20

The packages of MySQL 5.5.20 are now available for Debian 6.0 “Squeeze” on both amd64 and i386 architectures, with the following changes :

  • the mysql-common package should now work with MySQL 5.1 packages without any problem (unknown configuration variables in /etc/mysql/my.cnf have been commented out)
  • mysql-server-5.5 now supports Linux native asynchronous IO

As usual, please read the full Changelog carefully before upgrading.

38 replies on “MySQL 5.5.20”

Wooo! Finally! Last night, I tried the “official” Oracle .deb that they released and it was a disaster. Immediately went back to using the dotdeb package(s). Glad to see the latest build on the repo. Installed without a hitch.

Was Linux native asynchronous IO just not built into the 5.5.19 package? I do believe that’s been a feature of MySQL 5.5.x for some time now.

When trying to upgrade, i received a message:

“The following packages have been kept back:
mysql-server-5.5 mysql-server-core-5.5”


Having same issue. Is it safe to force-install these packages, or I’m risking to break dependencies?

I’ve been installing the packages via F.A.I. with the debconf that I’ll paste below. This had been working for 5.0, 5.1 and even 5.5, but stopped working with .20. Was there a recent change in the syntax?

mysql-server-5.5 mysql-server-5.5/root_password password myfakerootpassword
mysql-server-5.5 mysql-server-5.5/root_password_again password myfakerootpassword
mysql-server-5.5 mysql-server-5.5/root_password seen true
mysql-server-5.5 mysql-server-5.5/root_password_again seen true

@thomas : the Linux native AIO support will be enabled in MySQL if your Linux kernel supports it as well. You can check it in your MySQL client :

mysql> show variables like 'innodb_use_native_aio';
| Variable_name | Value |
| innodb_use_native_aio | ON |
1 row in set (0.00 sec)

I ran apt-get install mysql-server-5.5 on my INTEL XENON and got the AMD 64 bit version. Any way to specify intel?

Whats your experience with mysql 5.5?
Whats about the preformance between mysql 5.1 and 5.5?

@Gullaume Thanks for your fast answer. I must waiting for upgrading to squeeze, because not all webpages are php 5.3 compatible… 🙁

@Stefan : first of all, you can “freeze” your PHP 5.2 packages to use them on Squeeze.

About MySQL 5.1 and 5.5 comparison, all that you should know is that upgrading is not enough to have better performance. A well-configured MySQL 5.1 server will be better than a MySQL 5.5 server that keeps its default configuration (regardless of the hosted application).

You can keep your MySQL 5.1 server, but you also have to take care of its usage/configuration :
– use the appropriate storage engines (InnoDB is good)
– be sure to optimize your schema and queries (using slow query log, percona toolkit, EXPLAIN and profiling)
– don’t use a too large query cache (its single mutex design can lower the performance)
– adjust your configuration to have less memory allocated to each connection
– allocate the fred memory to the InnoDB buffer pool (in case you use as main storage engine).
– validate your changes with
– monitor your server metrics with Cacti, Monyog or equivalent tools.
– …

MySQL 5.5 brings a lot of improvements and tools, but you can still use a fine tuned MySQL 5.1 server without any performance issue.

DO !!!NOT!!! install this version!! I came across a very painful bug right after the upgrade. Dotdeb please, I beg you to revert to previous version.

fixing the issue by setting right owner solves literally nothing – mysql f#cks everything up again with next run of repair/optimize..

@acidofil : what an alarming (and also misleading) comment… Changing /var/lib/mysql/* files owner is a very special use case that most users won’t encounter. Did you try the myisamcheck trick?

please explain why it’s misleading? I did NOT change /var/lib/mysql/* owner/permissions! The problem occurred without doing anything except the upgrade process.

Indeed I did try “myisamchk -ofv table”, it helps(so does changing the owner manually btw).. BUT right after the repair mysql changes owner again to the wrong one so running one more optimize/repair gets you right to the start again..

@acidofil : that’s strange. The upgrade process went fine many times here.

– which distribution are you using? Debian Squeeze. Any Ubuntu?
– which user is your MySQL server running?
– which MySQL version did you upgrade from? From which repository?
– which MySQL exact version did you upgrade to?
– are you running a i386 or amd64 server?
– what are the permissions on your crashed tables? (ls -la)
– any message or warning during the upgrade process or in your /var/log/syslog?
– …

I tried to reproduce the bug by upgrading a stock Debian Lenny (amd64) from MySQL 5.1.58 (from Dotdeb) to MySQL 5.5.20 (from Dotdeb too). All the files and directories in /var/lib/mysql/ were belonging to mysql:mysql during the whole process. No issue.

– squeeze, 2.6.32-5-amd64
– mysql
– it was previous version from dotdeb, have no idea which was it tho 🙁
– ^^ amd64
– “-rw-rw—- 1 mysql mysql” is correct one
“-rw-rw—- 1 mysql ssh” is wrong one which mysql sets right after running repair/optimize.
– no, everything went 100% fine during upgrade, even myisam-recover. The problem occurs with first run of optimize/repair on any table from any database on upgraded version..

Have you tried running optimize/repair on any of the old tables after the upgrade?

I’ve noticed it actually works fine on any NEWLY created tables, but on tables from before-upgrade it crashes the data and throws “Can’t change ownership of the file ‘/var/lib/mysql/xxx/xxx.MYD” and changes the ownership.. Guess i’ll just do dump of all databases and put it back via mysql \.file …

anyway, thanx for interest, and mostly for dotdeb! ]

weirrd 🙁 Anyway.. I found out that changing tables engine from MYISAM to INNODB and back to MYISAM solves this issue.. so if someone else is having this problem, this is the way!

mysql Ver 14.14 Distrib 5.5.20, for debian-linux-gnu (x86_64) using readline 6.1

Server version: 5.5.20-1~dotdeb.0 (Debian)

Root’s password can’t be configured, user debian-sys-maint can’t be created.

dpkg: error processing mysql-server (–configure):
dependency problems – leaving unconfigured
configured to not write apport reports
Errors were encountered while processing:
E: Sub-process /usr/bin/dpkg returned an error code (1)

@huluwa : thanks for this multiple-comments report. I’ll try to reproduce the bug, but the lack of info will not help. Which distribution are you using? What is your sources.list? amd64 or i386? In short terms, describe your environment. Anything more precise in your log files (especially syslog and dpkg.log?)

@Guillaume Thanks for your reply.
Here are some details.

Debian 6.0 i386
deb squeeze main contrib non-free
deb squeeze/updates main contrib non-free
deb stable all
deb-src stable all

On my virtual machine & some VPSes, like buyvm, cinfu.
When I use apt-get install mysql, the error will be reproduced.



no intsallproblems on Vserver @ Debian 6.0

root@lola:~# mysql -V
mysql Ver 14.14 Distrib 5.5.20, for debian-linux-gnu (x86_64) using readline 6.1

root@lola:~# uname -r

install missing: libterm-readkey-perl (ubuntu 12.04.1 / 12.04.2 stuff, same 5.5 version tho.)

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