Dealing with the failure of a MySQL master is not simple. The most common solution is to promote a slave as the new master but in an environment where you have many slaves, the asynchronous implementation of replication gets in your way. The problem is that each slave might be in a different state:
some could be very close to the dead master, some could be missing the latest transactions, and
Earlier this week, I presented a webinar on MySQL High Availability options for MySQL – what they are and how to choose the most appropriate one for your application.
The replay of this webinar can now be viewed here or if you just want to look at the charts then scroll down. At the end of this post, I include a summary of the Q&A from the webinar.
How important is your data? Can you afford to lose it? What about just some of it? What would be the impact if you couldn’t access it for a minute, an hour, a day or a week?
Different applications can have very different requirements for High Availability. Some need 100% …
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Last weekend I got to present to the MySQL Developers Room at
FOSDEM in Brussels.
The subject of my presentation was NoSQL and SQL the best
of both worlds…
There’s a lot of excitement around NoSQL Data Stores with the promise of simple access patterns, flexible schemas, scalability and High Availability. The downside comes in the form of losing ACID transactions, consistency, flexible queries and data integrity checks. What if you could have the best of both worlds? This session shows how MySQL Cluster provides simultaneous SQL and native NoSQL access to your data – whether a simple key-value API (Memcached), REST, JavaScript, Java or C++. You will hear how the MySQL Cluster architecture delivers in-memory real-time performance, 99.999% availability, on-line maintenance and linear, horizontal scalability …
[Read more]February 4, 2015 By Severalnines Check Out Our Latest Technical Resources for MySQL, MariaDB & MongoDB Clusters
Like every month, we have created new content and tools for you; here is a summary of what we’ve published. Please do check it out and let us know if you have any comments or feedback.
New Live Technical Webinars
A DevOps Guide to Database Infrastructure Automation for eCommerce
Tuesday, February 17th
Infrastructure automation isn’t easy, but it’s not rocket science either, says Riaan Nolan. Automation is a worthwhile investment for retailers serious about eCommerce, but deciding on which …
[Read more]Oracle have just made availble the Release Candidate for MySQL Cluster 7.4 (MySQL Cluster 7.4.3) – it can be downloaded from the development release tab here. Note that this is not a GA release and so we wouldn’t recommend using it in production.
The delta between this RC and the 7.4.2 DMR can be viewed in the MySQL Cluster 7.4.3 Release Notes
There are three main focus areas for this RC and the purpose of this post is to briefly introduce them:
Check Out Our Latest Technical Resources for MySQL, MariaDB & MongoDB Clusters
Like every month this year, we have created new content and tools for you; here is a summary of what we’ve published this December. Please do check it out and let us know if you have any comments or feedback.
And thank you for following us in the past 12 months and for your fidelity; we look forward to “seeing” you next year as well and wish you a great start to 2015!
New Live Technical Webinars
Infrastructure automation isn’t easy, but it’s not rocket science either, says Riaan Nolan. Riaan has been in operations for the past decade, and has built over a dozen eCommerce …
[Read more]Amazon recently announced RDS Aurora a new addition to their database as a service offerings. Here’s Mark Callaghan’s take on what’s happening under the hood and thoughts from Fusheng Han. Amazon is uniquely positioned with RDS to take on offerings like Clustrix. So it’s definitely worth reading Dave Anselmi’s take on Aurora. Join 28,000 others […]
August 28, 2014 By Severalnines Check Out Our Latest Resources for MySQL, MariaDB & MongoDB Clusters
Here is a summary of resources & tools that we’ve made available to you in the past weeks. If you have any questions on these, feel free to contact us!
New Technical Webinars
Performance Tuning of HAProxy for Database Load Balancing
09 September 2014 - with Baptiste Assmann of HAProxy Technologies
Do you know what HAProxy can tell you about your application and database instances? Do you know the difference …
[Read more]
Just released - the all new MySQL Cluster training course.
This MySQL Cluster training teaches you how to install and configure a real-time database cluster at the core of your application. Expert instructors will teach you how to design and maintain your clusters for high availability and scalability by using MySQL Cluster's open-source and enterprise components.
This 4-day training course is a must for those who want to learn about MySQL Cluster as you will not only learn about the concepts and features but you will get extensive hands-on experience. You can follow this training course from your own desk via a live-virtual training or by traveling to an education center to follow this course.
Be the first to influence the schedule for this …
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The other day, I was discussing high availability (HA)
with other people. The discussion was going in the
direction of, as the application was only using INSERT ... ON DUPLICATE KEY
UPDATE (ODKU) and traffic could be replayed,
promoting a slave in case of the failure of the master was easy:
replaying traffic would make all the slaves converge
back to a common state. It looks as this could work but it
might not be as simple. Before going into the details,
let's take a step back and look into HA in general.
tl;dr: be careful when using row-based replication when
replicating ODKU as slaves will stop replicating if a row is
present on the master and missing on slave (or vice-versa).
High Availability by Promoting a Slave as the new Master
Let's suppose we are working …
