EDIT: Video from today’s #DBHangOps!

Hey there peeps!

February 27th at 12:00pm PST it is! Check back here for more info and keep a watchful eye on the twitter search (and feel free to join the conversation!). The topics we’re looking to cover this week are:

• Day-to-day pain points (what takes more time than it should?)
  • rolling restarts and upgrades
  • Performing checksums on your data
    $ /usr/bin/pt-table-checksum \
--quiet \
--ignore-databases=mysql,percona,information_schema,per
formance_schema \
--lock-wait-time=50 \
--chunk-size-limit=0 \
--no-check-plan \
--no-check-binlog-format \
--max-lag=1 \
--replicate percona.checksums \
…

In a recent post we showed you how to migrate a SQL Server database to MySQL. There, we used the oficial Microsoft ODBC driver and that’s OK if you are running MySQL Workbench in Windows. But what if your desktop OS is some Linux variant or Mac OS X?

It turns out that Microsoft has recently released an ODBC driver for Linux. However, you can’t use this driver with MySQL Workbench for Linux. (Actually you can, but you would have to rebuild Workbench). The main reason is that this ODBC driver was linked against unixODBC (an ODBC driver manager), while Workbench uses another ODBC driver manager: iODBC and the two of them can’t coexist in the same system.

So for Linux …

I’m pleased to announce that my first book, the InnoDB Quick Reference Guide, is now available from Packt Publishing and you can download it by clicking here. It covers the most common topics of InnoDB usage in the enterprise, including: general overview of its use and benefits, detailed explanation of seventeen static variables and seven dynamic variables, load testing methodology, maintenance and monitoring, as well as troubleshooting and useful analytics for the engine. The current version of MySQL ships with InnoDB as the default table engine, so whether you program your MySQL enabled applications with PHP, Python, Perl or otherwise, you’ll likely benefit from this concise but comprehensive reference guide for InnoDB databases.

Here are the chapter overviews …

This post is the next part following the initial article about MySQL 5.6 vs 5.5 benchmark results (and MySQL 5.6 scalability).

The focus in this article is on the "tuning impact" used during the published tests, and also I have for you few more test results to present which were missed initially -- Sysbench tests using 8 tables instead of a single one (as it does by default).

All my.conf setting I've used during the tests was already presented within an initial article, so let's go directly to details about special tuning setting. While many parameters are pretty important (like use or not use O_DIRECT, choose a right REDO log and Buffer Pool size, flush or not …

As promised, this is the first part of details about MySQL 5.6 vs 5.5 benchmark results I've published earlier last week. The following graphs are representing scalability results obtained for both MySQL versions on the published tests (and I have yet more test results to present to you, but these test's are still running)..

Few remarks based on comments and discussions I've got since then:

• I'm using a "true" 32cores server (true 32 cores, each one yet has 2 threads (HT), so 64 threads in total)
• I'm not using "CPU threads" terminology as I'm finding it confusing (for ex. when you're reading "16 CPU threads" you may not really know if there were 16cores with HT-disabled, or 8cores with HT-enabled)..
• during all the tests I've disabled HT (as it took days and days more to test …

UPDATE: Here’s the recording, enjoy!

Hello everybody!

#DBHangOps coming at you this week, Wednesday 1/30/12 at 12:00pm PST. Be sure to check out this blog post tomorrow or check this twitter search to grab the link to join the Google Hangout.

This week’s topics were:
* bug fixes in recent versions
* Plugins
** authorization plugins (e.g. LDAP)
** audit plugin API — http://dev.mysql.com/doc/refman/5.5/en/writing-audit-plugins.html
*** state transitions of records in MySQL with a plugin?
* InnoDB Status variables from twitter — https://github.com/twitter/mysql/wiki/InnoDB-Status-Variables
* Table alters/schema changes
** Twitter patch for non-blocking alter table (throws a different error than “lock_wait_timeout”) — …

This article was initially planned to follow the previous posts about RW (Read+Write) workloads on MySQL & Linux (part#1, part#2)... But, when I've started to run real MySQL/InnoDB IO-bound tests on the Fusion-io card, I've quickly realized that I'm hitting so hot internal contentions within InnoDB code, that I'm simply unable to use storage capacity on its full power.. So, I've moved to another server (having SSD only), and then continued with it (as to explain RW limits it'll be pretty enough). Also, curiously, on this server XFS performance on writes is way better than EXT4 (while on the the previous server XFS got some unexpected problems, seems to be known bugs)..

So far, for the …

yum

It’s often pain to guess package names when you need to install stuff on, lets say, CentOS. So there is a list, although maybe not full, of what I needed to get another VM build and run MariaDB server and to execute at least some tests on it (all done via yum install):

cmake
gcc
ncurses-devel
bison
g++
gcc-c++
aclocal
automake
libtool
perl-DBD-MySQL
gdb
libaio-devel
openssl-devel

Same in one line, for lazy me:
sudo yum install cmake gcc ncurses-devel bison g++ gcc-c++ perl-DBD-MySQL gdb libaio-devel openssl-devel

To install bzr (if it’s not in the official repo):

su -c ‘rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-2.noarch.rpm’
(check the architecture)

and then can use yum install
bzr

Another story (taken …

well, I incremented max_allowed_packet from 16M to 512M
anyway, I got the same error on the next clean import.
so decided to find a workaround.
so, how to get the data separated from the ddl statements:

# get the tables names into the insert statement, its better to have that in file for future usage
sed '/^INSERT INTO/!d;s/ VALUES.*$//' jiradb.20130118.sql | sort | uniq > tablas.como.nombres.txt

then how to get the data separated:

root@jiragg:[Fri Jan 18 15:26:33]:[/usr/local/BACKUP]$ cat make.inserts.sh
#!/bin/sh
# trim function thank to http://stackoverflow.com/questions/369758/how-to-trim-whitespace-from-bash-variable
# and http://codesnippets.joyent.com/posts/show/1816
trim() {
    local var=$1
    var="${var#"${var%%[![:space:]]*}"}"   # remove leading whitespace characters
    var="${var%"${var##*[![:space:]]}"}"   # remove trailing whitespace characters
    echo -n "$var"
}

while read tabname
do …

We assume the new disk is /dev/sdb1 formatted as ext3
and it will be mounted as /data

# 0. make sure there is no mysqlm mysql data directory :
yum remove mysql mysql-server -y 
test -d /data/mysql/ && rm -rf /data/mysql/
test -d /var/lib/mysql/ && rm -rf /var/lib/mysql/

# 1. install Mysql
yum install mysql mysql-server -y

# 2. check the mysql  status
service mysqld status

# 3. start the mysqld if not started
service mysqld start

# 4. check the mysql status again
service mysqld status

# 5. stop mysqld in case its started, and check thre is n mysql process:
service mysqld stop
ps axu | grep mysql

# 6. make sure the /data partition is added to the /etc/fstab. If not add it:
test  `cat  /etc/fstab | grep /data | wc -l ` -eq 0  && echo "/dev/sdb1 /data ext3  defaults 1 1" >>  /etc/fstab

# 7. make sure the /data partition is mounted, 
test  `cat /proc/mounts  | grep /data | grep -v grep | wc -l` -eq 0 && mount /data

# 8. disable selinx …