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Displaying posts with tag: Percona (reset)
How to start Percona Xtradb Cluster on CentOS 7

Normally, when we want to start PXC (Percona XtraDB Cluster) on RHEL/CentOS 6 or older then that, we can simply start with init.d script or service command. i.e

shell> /etc/init.d/mysql start 
shell> /etc/init.d/mysql bootstrap-pxc
shell> service mysql start.

But, the way is changed from CentOS 7. Because systemd integration with RHEL/CentOS 7 is now available for Percona XtraDB Cluster (#1342223).

So now, we have to start mysql with systemctl command i.e

shell> systemctl start mysql

For boostrap,

shell> systemctl start mysql@bootstrap.service

I would also suggest to read one very informative post by Przemek for recovering PXC cluster. …

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Tweaking MySQL Galera Cluster to handle large databases - open_files_limit

September 18, 2014 By Severalnines

Galera Cluster is a popular choice for achieving high availability using synchronous replication. Though if you are planning to run huge sites with many DB objects (tables), a few tweaks are necessary. 


Yes, you might have been successful in loading your 1000s of databases and 1000s of tables, but what happens if you have a node failure and Galera recovery fails?


In this blog post we will show you how to determine one common error related to the open_files_limit that MySQL imposes, and also to spot another potential pitfall.




If you are using wsrep_sst_method=xtrabackup or wsrep_sst_method=xtrabackup-v2 then you will find a log file in the data directory of the donor node. This log file is called innobackup.backup.log.

140912 19:10:15  innobackupex: Done. …
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Puppet Module for ClusterControl - Adding Management and Monitoring to your Existing Database Clusters

September 10, 2014 By Severalnines

If you are automating your infrastructure using Puppet, then this blog is for you. We are glad to announce the availability of a Puppet module for ClusterControl. For those using Chef, we already published Chef cookbooks for Galera Cluster and ClusterControl some time back.  



ClusterControl on Puppet Forge


The ClusterControl module initial release is available on Puppet Forge, installing the module is as easy as:

$ puppet module install severalnines-clustercontrol


If you haven’t change the default module path, this module will be installed under /etc/puppet/modules/clustercontrol on …

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Announcing Severalnines Package Repository

September 9, 2014 By Severalnines

We are excited to announce the availability of YUM/APT repositories for ClusterControl, making new releases of ClusterControl  easily accessible using YUM or APT package managers. The repo is found at, with instructions provided on the landing page. Our Cluster Configurators will be using these repositories. As a result, users upgrading from s9s_upgrade_cmon starting from version v.1.2.8 will be configured with the package repository.


ClusterControl requires extra post-installation setup steps, such as generating an API token, configuring cmon/dcps database schema, grant privileges on cmon schema, setting up SSL and so on. We provide a post-installation script for this purpose at [Apache document …

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How to change AWS instance sizes for your Galera Cluster and optimize performance

September 3, 2014 By Severalnines

Running your database cluster on AWS is a great way to adapt to changing workloads by adding/removing instances, or by scaling up/down each instance. At Severalnines, we talk much more about scale-out than scale up, but there are cases where you might want to scale up an instance instead of scaling out. 

In this post, we’ll show you how to change instance sizes with respect to RAM, CPU and IOPS, and how to tune your Galera nodes accordingly. Moreover, this post assumes that instances are launched using Amazon VPC.


When do we need to upgrade an instance?


You typically need to upgrade an instance when you run out of server resources. This includes CPU, RAM, storage capacity, disk throughput and bandwidth. You must allow enough headroom for …

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How to Manage All Your MySQL or MariaDB Databases

September 1, 2014 By Severalnines

According to Forrester, a DBA in a large enterprise manages between 8 and 275 databases, with the industry average being 40 databases to a DBA. Larger databases usually require extra effort around tuning, backup, recovery and upgrade. Cloud, as well as automation and management tools can help improve the number of databases managed by one DBA.  


With that background, we were pretty excited to introduce support for management of single-instance MySQL and MariaDB databases in ClusterControl 1.2.6. The majority, if not all of the cluster users out there, use single-instance or master-slave replicated setups along their mission-critical …

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An Updated Description of Clustering Keys for TokuDB

Covering indexes can result in orders of magnitude performance improvements for queries. Bradley’s presentation on covering indexes describes what a covering index is, how it can effect performance, and why it works. However, the definition of a covering index can get cumbersome since MySQL limits the number of columns in a key to 16 (32 on MariaDB).

Tokutek introduced multiple clustering indexes into MySQL to address these problems. Zardosht describes the multiple clustering indexes feature and how clustering indexes differ from covering indexes. Zardosht also describes the …

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We’d love to go to Paris for the OpenStack Summit - please vote for our talks!

August 6, 2014 By Severalnines


Well over a thousand sessions have been submitted for the OpenStack Summit and two of them includes our good selves! We’ve submitted two talks with partners of ours: 


… and would love it if the talks were included in the final agenda. For that to happen, we need a few more of your votes today!


The OpenStack Summit is a five-day conference for developers, users, and …

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Awesome MySQL 5.7 improvements

Recently, I’ve had reason to poke at MySQL performance on some pretty cool hardware. Comparing MySQL 5.6 to MySQL 5.7 is a pretty interesting thing to do when you have many CPU cores.

The improvements to creating read views in InnoDB is absolutely huge for small statements with large concurrency – MySQL 5.7 completely removes this as a bottleneck – as much as doubling maximum SQL queries per second, which is a pretty impressive improvement.

I haven’t poked at the similar improvements in Percona Server on this hardware setup – so I can only really guess as to the performance characteristics of it… If comparing to older MySQL versions, Percona Server 5.5 is likely to outperform MySQL 5.5 thanks to this optimization.

But I have to say… MySQL 5.7 is impressive …

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How to Deploy Percona XtraDB Cluster without Internet Connection

May 23, 2014 By Severalnines

If you need to deploy a database cluster behind your corporate firewall, on servers with no internet access, then this blog is for you. Most of the installation tutorials out there require servers to have an internet connection, and that would not work very well with companies under strict policies and compliance guidelines. 

Our online Galera Configurator supports deployment without Internet connection for Percona XtraDB Cluster. You would need to prepare a minimum of four hosts (three DB nodes and one management node), generate a Deployment Package from the Configurator and copy it to the ClusterControl host. In this post, we will show you how to deploy Percona XtraDB Cluster 5.5 in an environment without internet connection on CentOS 6.5 (installed with minimal installation). Our setup is …

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Showing entries 61 to 70 of 335
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