News

Taxonomy upgrade extras: galeraclusterMySQL ClusterHigh Availability

Recently we had to set-up a 3-node Galera Cluster with a Load Balancer in front of it. Because Galera Cluster nodes (mysqld) still reply to TCP requests on port 3306 when they are expelled from the Cluster it is not sufficient to just leave it to the Load Balancer to check the port if a Galera node is properly running or not.

We used the wsrep_notify_cmd variable to hook our own script into the Galera Cluster which disables each Node on the Load Balancer when its state changed.

# my.cnf # [mysqld] wsrep_notify_cmd = /usr/local/bin/lvs_control.sh

The whole Galera Cluster Architecture looks as follows:

As Load Balancer we used the IPVS Load Balancer from the Linux Virtual Server (LVS) Project. This Load Balancer was made highly available with keepalived.

Our script to take a Galera Node out of the Load Balancer was the following:

#!/bin/bash -eu # # /etc/mysql/conf.d/wsrep.cnf # # [mysqld] # wsrep_notify_cmd = /usr/local/bin/lvs_control.sh # LOG="/tmp/lvs_control.log" LBIP="192.168.0.89" VIP="192.168.0.99" PORT="3306" LBUSER="galera" LBUSER="root" ETC="/etc/mysql/conf.d/wsrep.cnf" ETC="/home/mysql/data/mysql-5.5-wsrep-23.7-a/my.cnf" MYIP='' WEIGHT="100" DATE=$(date '+%Y-%m-%d %H:%M:%S') echo $DATE >>$LOG regex='^.*=\s*([0-9]+.[0-9]+.[0-9]+.[0-9]+).*' str=$(grep "^wsrep_node_incoming_address" $ETC 2>>$LOG) if [[ $str =~ $regex ]] ; then MYIP=${BASH_REMATCH[1]} else echo "Cannot find IP address in $str" >>$LOG exit 1 fi while [ $# -gt 0 ] ; do case $1 in --status) STATUS=$2 shift ;; --uuid) CLUSTER_UUID=$2 shift ;; --primary) PRIMARY=$2 shift ;; --index) INDEX=$2 shift ;; --members) MEMBERS=$2 shift ;; esac shift done # echo $* >> $LOG echo $STATUS >> $LOG # Undefined means node is shutting down # Synced means node is ready again if [ "$STATUS" != "Synced" ] ; then cmd="ssh $LBUSER@$LBIP 'sudo /sbin/ipvsadm -e -t $VIP:$PORT -r $MYIP -w 0'" else cmd="ssh $LBUSER@$LBIP 'sudo /sbin/ipvsadm -e -t $VIP:$PORT -r $MYIP -w $WEIGHT'" fi echo $cmd >>$LOG eval $cmd >>$LOG 2>&1 echo "ret=$?" >>$LOG exit 0

We assume that the same script can be used with little modifications for the Galera Load Balancer as well.

The new release of the MySQL Performance Monitor (mpm) is out!

New additions and improvements

• Easy to use templates
• Improved Security
• New Trigger Checks
• New Warnings Enabled
• Time Zone Shift Added
• New screens added
• Data transfer enabled

and much more (see below).

The MySQL Performance Monitor (mpm) for MySQL, Galera Cluster, Percona Server and MariaDB is a Monitoring Solution based on the Enterprise open source Monitor Zabbix.

It provides all the necessary modules to monitor MySQL performance metrics in detail and you can display them graphically.

New Features

Template improved for easier use - Security module added - Slave and MySQL templates fixed after feedback from customers - Innodb log information and pending I/O information added - Sort_buffer_size trigger added - Slave error skipped trigger added - Check for isolation level added - Binlog do and ignore filter warning enabled - Innodb deadlock trigger downgraded from warning to info - Time-shift feature implemented - Flush_time trigger added - MyISAM flush_time variable added - Read_buffer_size and max_allowed_package conflict implemented - Binlog_cache_size too small trigger back-ported from live - Read_buffer_size rule added - Max_allowed_packet and read_buffer_size added for rules - All 24 cores added to template items - Process memory graph with RAM size - Thread_stack_size too small alert implemented - Network packet graph reordered - Trigger for missing MaaS agent added - Server screens visually improved - Screens for Galera, network, CPU and server added - Transfer of data over HTTPS is possible now.

Download and Install

The most recent FromDual Performance Monitor for MySQL you can download from here... Or for more information you can reach us by e-mail at: contact@fromdual.com or by phone on +41 44 940 24 82.

Due to customer requests, we have added two of our advanced MySQL training courses in late April in Zurich, Switzerland. One course will be presented in German, the other in English.

The venue is the HSO in Zurich-Oerlikon.

The following dates has been set:

April 22 - 26Advanced MySQLHSO,​ ZurichApril 29 - Mai 3Advanced MySQLHSO,​ Zurich

Caution: the 2nd training contains May 1st (bank holiday). The training takes place regardless.

Remember to book now to reserve your place.

The MySQL SIG of DOAG invites you to join on February 27 at the Inside Hotel in Munich.
Topics of the SIG Event: MySQL Replication and new Features.

Taxonomy upgrade extras: trainingMySQL Clustermysql-training

The dates for the next MySQL Cluster (ndb) trainings with the Linux Hotel are scheduled now: March 11 - 12 2013 and September 23 - 24 2013.
You can book your training here.

Taxonomy upgrade extras: doagreplicationgaleramysql

On Tuesday, September 4, 2012 the next DOAG SIG MySQL meeting will take place in Hamburg (Germany) with the topic Replication.

Possible presentations are: MySQL Replication, Galera Cluster, Replication with Oracle GoldenGate, Replication with Zimory Scale and Tungsten Replicator.

The event will presumably be located at the Hotel Böttcherhof at Wöhlerstrasse 2.

FromDual is having a talk at Frankfurter Datenbanktage 2013, March 14/15

Taxonomy upgrade extras: High Availabilitymysqlconsultingclusterinnodbfromdualsupportgaleracodershipmysql-supportmysql-consulting

Helsinki, Finland, Uster, Switzerland – February 18, 2012 – Codership, the provider of Galera Cluster for MySQL, and FromDual, a MySQL consulting company, today announced collaboration to offer Galera Cluster technology and related support and consulting services for Galera users all over the world, especially in German speaking countries Germany, Austria and Switzerland (DACH). Galera Cluster is a synchronous, true multi-master replication cluster for MySQL using the well known InnoDB storage engine. Customers can deploy Galera Cluster locally in LAN environments, as geo-clusters over the WAN or as virtual cluster in the cloud.

Galera Cluster for MySQL is offered as open source software. It can be downloaded freely from www.codership.com. Many of Codership customers are using Galera Cluster for business critical applications. FromDual will be offering consulting and support services for Galera users, especially in German speaking countries. FromDual has years of competence in MySQL consulting and support. They have a deep understanding of clustering and replication technologies and how to implement them into production. FromDual is the perfect partner for Codership said Seppo Jaakola, CEO of Codership.

With Galera we get a great high availability (HA) product for MySQL which removes all the pain we had with the existing MySQL HA solutions. Our customers are always looking for better ways to solve MySQL replication, scalability and management issues to secure 24/7 business availability and growth for the future business. Galera Cluster does exactly that. We are happy to add Galera Cluster to our consulting and support portfolio with the top level support from Codership says Oli Sennhauser, Senior MySQL consultant and CEO of FromDual.

Galera Cluster is used by users who need highly available MySQL database back-ends with very fast fail-over time for business critical applications like Social networks, Gaming platforms, Telecom/VoiP solutions, Media and entertainment sites, Business Software as a Service (SaaS), Platform as a Service (PaaS), ERP systems, web-shops, e-commerce solutions or similar critical applications.

About FromDual GmbH

FromDual is a global acting, neutral and vendor independent consulting, support and training company for MySQL, Percona Server, MariaDB and Galera Cluster with numerous customers all over the world in the Telecom, Media, Public Service, Internet and Industry sector. FromDual is Oracle Silver Partner and Open Database Alliance (ODBA) Silver Partner. In addition to its MySQL services FromDual distributes its Performance Monitor for MySQL for local installations or as Software as a Service solution. For more information about FromDual, their products, consulting and support services, please visit www.fromdual.com.

Press contact:

FromDual GmbH
Oli Sennhauser, CEO
E-Mail: oli.sennhauser@fromdual.com
Cell: +41 79 830 09 33

About Codership Oy

Codership develops fundamentally new replication and clustering solutions for open source databases, adopting novel ideas from latest DBMS and distributed computing research. The founders of Codership have long experience in developing several widely used MySQL clustering solutions before starting Galera development in 2007. Already thousands of users have chosen Galera Cluster solution – the Codership's flagship open source product and Codership is working actively for and with this growing user community. For more information about Codership, products, consulting and support services, please visit www.codership.com.

Press contact:

Codership OY
Seppo Jaakola, CEO
E-Mail: seppo.jaakola@codership.com
Cell: +358 405 105 938