In a previous post we went into detail about how to implement Tungsten-specific checks. In this post we will focus on the other standard Nagios checks that would help keep your cluster nodes healthy.

Your database cluster contains your most business-critical data. The slave nodes must be online, healthy and in sync with the master in order to be viable failover candidates.

This means keeping a close watch on the health of the databases nodes from many perspectives, from ensuring sufficient disk space to testing that replication traffic is flowing.

A robust monitoring setup is essential for cluster health and viability – if your replicator goes offline and you do not know about it, then that slave becomes effectively useless because it has stale data.

Nagios Checks The Power of Persistence

One …

Your database cluster contains your most business-critical data. The slave nodes must be online, healthy and in sync with the master in order to be viable failover candidates.

This means keeping a close watch on the health of the databases nodes from many perspectives, from ensuring sufficient disk space to testing that replication traffic is flowing.

A robust monitoring setup is essential for cluster health and viability – if your replicator goes offline and you do not know about it, then that slave becomes effectively useless because it has stale data.

Big Brother is Watching You! The Power of Nagios

Even while you sleep, your servers are busy, and you simply cannot keep watch all the time. Now, more than ever, with global deployments, it is literally impossible to watch everything all the time.

Enter Nagios, you best big brother ever. As a long-time player in the monitoring market, Nagios has both …

Continuent Clustering support true distributed multimaster clustering. In this topology, there are cross-site replicator services for each remote site. In a 3-site configuration, there are a total of 9 replication streams to manage.

Continuent Clustering also offers a graphical administration tool called the Tungsten Dashboard to help with your management burden. The GUI makes the deployment much easier to visualize and administer.

For our example, we will have a Composite Multimaster dataservice called global with three active, writable member clusters (one per site), east, west and north.

Dashboard Summary View

In the summary, collapsed view, the composite service and all member clusters are listed with associated information and controls. Note that the Type for the composite dataservice global is CompMM …

In this blog post, we talk about how to run applications across multiple clouds (i.e. AWS, Google Cloud, Microsoft Azure) using Continuent Clustering. You want your business-critical applications to withstand node, datacenter, availability-zone or regional failures. For SaaS apps, you also want to bring data close to your application users for faster response times and a better user experience. With cross-cloud capability, Continuent also helps avoid lock-in to any particular cloud provider.

The key to success for the database layer is to be available and respond rapidly.

From both a business and operational perspective, spreading the application across cloud environments from different vendors provides significant protection against vendor-specific outages and vendor lock-in. Running on multiple platforms provides greater …

After having explained how to achieve HA for MySQL Router for people who doesn’t want to install the MySQL Router on the application servers and after having illustrated how to use Pacemaker, this article explains how to setup HA for MySQL Router using keepalived.

Keepalived is very popular, maybe because it’s also very easy to use. We can of course use 2 or more servers. The principle is the same as on the previous articles, if the router dies, the virtual IP used by the application server(s) to connect to MySQL is sent to another machine where mysqlrouter is still running.

Let’s have a look at the configuration, in this case we use 2 machines, mysql1 and …

This article will explain how to setup HA for MySQL Router as described in a previous article about where should the router stand.

For this setup, I will use Pacemaker (part of RedHat High Availability Add-on and available on RHEL, CentOS, Oracle Linux, …).

Of course we need a MySQL InnoDB Cluster but we won’t really use it for the HA setup of the MySQL Router.

Installing Pacemaker

The first step is to install pacemaker on all the machines we will use for our “MySQL Router Cluster”:

# yum install pacemaker pcs resource-agents

Now we need to start the pcsd service and enable it at boot (on all machines):

# systemctl start pcsd.service 
# systemctl enable pcsd.service

It’s time now to setup authentication, this operation is again …

As you know, MySQL InnoDB Cluster is composed of 3 elements:

• a group replication cluster of at least 3 servers
• the MySQL Shell used to manage the cluster
• the MySQL Router that send the traffic from the application server(s) to the cluster

When presenting the solution in conferences, one the main question is Where should I put the router ? and the answer is always the same: the best place to install the router is the application server !

The router is a very lightweight process that gets its configuration from the cluster’s metadata and doesn’t require a lot of resources or maintenance.

So the ideal setup is the following:

However for many (obscure?) reasons, sometimes people doesn’t want to have the MySQL …

As promised, here is a post more detailed on how to create a MySQL InnoDB Cluster using MySQL Shell and the AdminAPI.

First of all, as a good practice is never enough repeated, whatever the version of MySQL you are using, please use the latest MySQL Shell ! So if you are using 5.7, please use MySQL Shell 8.0.11. See this compatibility matrix or this official one.

dba class

The AdminAPI can be accessed by the MySQL Shell via the dba object. The reference manual for this class is here. The Shell …

I’m just back from a trip in Barcelona where I presented MySQL 8.0 InnoDB Cluster (at dataops and Barcelona MySQL Meetup) and the majority of feedback was great, but I also had some comments on the demos I showed. The first one was:

This is a joke of course (maybe it’s true for some), people found it very easy and they liked it.

But then, the second one was that all I showed wasn’t easy to find, some people who already played with the solution didn’t succeeded in creating a cluster so easily… not because they had errors or encountered bugs, but more because they just didn’t know how to do it.

The goal of this …

MySQL 8.0.11 seems to be around the corner and the new MySQL Shell will take advantage of all the new improvements made in MySQL 8.0 like SET PERSIST, RESTART, … see this previous post.

In the video below, I show you how easy it’s to deploy a MySQL InnoDB Cluster using the Shell that connects remotely to all the instances:

…