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How to Deploy Galera Cluster for MySQL using Docker Containers

Virtual Machines are great, and very useful when trying out new software. However, they might be an unnecessarily heavyweight solution when testing clusters, especially if these consist of multiple nodes running exactly the same software. Each VM runs a full-blown OS image. On the other hand, Linux Containers (LXC) are an efficient alternative to OS-level virtualization and can run multiple isolated systems on a single host. Docker is a wrapper around LXC, it automates the deployment of applications inside containers. 

How to Cluster Liferay with MySQL Galera and Ceph for High Availability and Performance

Liferay is an open-source content management system written in Java. It is used by a number of high traffic sites, as this survey suggests. 

Active-active Alfresco cluster with MySQL Galera and GlusterFS

Alfresco is a popular collaboration tool available on the open-source market. It is Java based, and has a content repository, web application framework and web content management system. For critical large-scale implementations that require 24*7 uptime, a multi-node cluster would be appropriate. Since Alfresco depends on external components such as the database and the filesystem, clustering the Alfresco instances only would not be enough.

Installing ClusterControl on Existing MongoDB Replica Set using bootstrap script

So, your development project has been humming along nicely on MongoDB, until it was time to deploy the application. That's when you called your operations person and things got uncomfortable. NoSQL, document database, collections, replica sets, sharding, config servers, query servers,... What the hell's going on here?

Deploying an Active-Active FreeRadius Cluster with MySQL NDB or Galera

MySQL Cluster is a popular backend for FreeRADIUS, as it provides a scalable backend to store user and accounting data. However, there are situations when the backend database becomes a centralized datastore for additional applications and services, and needs to take a more general-purpose role. NDB usually works very well for FreeRADIUS data, but for wider use cases and reporting type applications, InnoDB can be a better storage engine.

OpenStack Metering: How to Install Ceilometer with MongoDB

According to Wikipedia, a ceilometer is a device that uses a laser or other light source to determine the height of a cloud base. And it is also the name of the framework for monitoring and metering OpenStack. It collects measurements within OpenStack so that no two agents would need to be written to collect the same data.

Avoiding Deadlocks in Galera - Set up HAProxy for single-node writes and multi-node reads

Galera cluster has known limitations, one of them is that it uses cluster-wide optimistic locking. This may cause some transactions to rollback. With an increasing number of writeable masters, the transaction rollback rate may increase, especially if there is write contention on the same dataset. It is of course possible to retry the transaction and perhaps it will COMMIT in the retries, but this will add to the transaction latency. However, some designs are deadlock prone, e.g sequence tables. In this blog we present how you can minimize the risk for deadlocks due to the design of Galera. 

From the Field - Live Migration from MMM to MariaDB Galera Cluster

This is a guest post from Igor Shevtsov, a MySQL DBA based in Twickenham, UK. Igor has had the opportunity to deploy and manage different types of high availability MySQL solutions, and we invited him to share his experience. Igor can be contacted by email or LinkedIn.

Migrating MySQL Galera Cluster to a new Data Center without Downtime

Are you tired and frustrated with your hosting or cloud provider? Have you seen a constant degradation in service levels and responsiveness? Or was the public cloud a bit too expensive after all, and you’re ready to move everything to in-house servers? Welcome to the club. Data migrations are painful and scary. Running a migration with scheduled downtime is hard enough as it is, but for certain applications, a prolonged period of downtime is not acceptable. Without the right strategy, a migration might leave you with inconsistent or lost data, hours of downtime and a negative impact to your business. This is why it is so hard to switch hosting or cloud providers. Once your data is in somebody else’s infrastructure, they’ve got you by the balls.

Severalnines on AWS Marketplace: Getting Started

Good news for AWS users! We are now available on AWS Marketplace. This allows you, with a single click of a button, to deploy ClusterControl in just a few minutes. Once ClusterControl is deployed, you can have it monitor your existing database clusters, or use it as a deployment server to set up new clusters. The AMI is free, so you only pay for the hardware/network resources that you actually consume.