Automated failover is pretty much a must have for many applications - uptime is taken for granted. It’s quite hard to accept that an application is down for 20 or 30 minutes because someone has to be paged to log in and investigate the situation before taking action.

In the real world, replication setups tend to grow over time to become complex, sometimes messy. And there are constraints. For instance, not every node in a setup makes a good master candidate. Maybe the hardware differs and some of the replicas have less powerful hardware as they are dedicated to handle some specific types of the workload? Maybe you are in the middle of migration to a new MySQL version and some of the slaves have already been upgraded? You’d rather not have a master in more recent version replicating to old replicas, as this can break replication. If you have two datacenters, one active and one for disaster recovery, you may prefer to pick master …

MySQL 8.0 has come with a list of new features for DBA’s ,we will discuss the new feature in MySQL 8.0 which supports Descending index.Prior to MySQL 8.0 (i.e MySQL 5.6 and 5.7) creating desc index syntax was supported but desc keyword was ignored, Now in MySQL 8.0 release descending index is extended are supported.

What is index?

• Indexes play an important role in performance optimization  and they are used frequently to speed up access to particular data and reduce disk I/O operations .
• To understand index easily you can imagine a book,every book has an index with content referring to a page number.If you want to search something in a book you first refer to the index and get the page number and then get the information in the page,like this the indexes in MySQL will tell you the row with matching data.

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Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.

Hello again after the hiatus last week. I’m en route to Portland for OSCON, and am very excited as it is the conference’s 20th anniversary! I hope to see some of you at my talk on July 19.

On July 18, join me for a webinar: MariaDB 10.3 vs. MySQL 8.0 at 9:00 AM PDT (UTC-7) / 12:00 PM EDT (UTC-4). I’m also feverishly working on an update to MySQL vs. MariaDB: Reality Check, now that both MySQL 8.0 and MariaDB Server 10.3 are generally available.

Rather important: …

What if I want the cluster to be less sensitive to network, especially WAN latency?

Continuent Clustering supports having clusters at multiple sites with active-active replication meshing them together.

This is extraordinarily powerful, yet at times high network latency can make it harder for messaging between the sites to arrive in a timely manner.

This is evidenced by seeing the following in the Manager log files named tmsvc.log:

2018/07/08 16:51:05 | db3 |  INFO [Rule_0604$u58$_DETECT_UNREACHABLE_REMOTE_SERVICE1555959201] - CONSEQUENCE: [Sun Jul 08 16:51:04 UTC 2018] CLUSTER global/omega(state=UNREACHABLE)
...
2018/07/08 16:51:42 | db3 |  INFO [Rule_2025$u58$_REPORT_COMPONENT_STATE_TRANSITIONS1542395297] - CLUSTER 'omega@global' STATE TRANSITION UNREACHABLE => ONLINE

The delta is 37 seconds in the above example between state=UNREACHABLE and UNREACHABLE => ONLINE

The default …

Recently, Dimitri published the results of measuring MySQL 8.0 on Intel Optane storage device. In this blog post, I wanted to look at this in more detail and explore the performance of MySQL 8, MySQL 5.7 and Percona Server for MySQL using a similar set up. The Intel Optane is a very capable device, so I was puzzled that Dimitri chose MySQL options that are either not safe or not recommended for production workloads.

Since we have an Intel Optane in our labs, I wanted to run a similar benchmark, but using settings that we would recommend our customers to use, namely:

• use innodb_checksum
• use innodb_doublewrite
• use binary logs with sync_binlog=1
• enable (by default) Performance …

Before you attempt to perform any schema changes on your production databases, you should make sure that you have a rock solid rollback plan; and that your change procedure has been successfully tested and validated in a separate environment. At the same time, it’s your responsibility to make sure that the change causes none or the least possible impact acceptable to the business. It’s definitely not an easy task.

In this article, we will take a look at how to perform database changes on MySQL and MariaDB in a controlled way. We will talk about some good habits in your day-to-day DBA work. We’ll focus on pre-requirements and tasks during the actual operations and problems that you may face when you deal with database schema changes. We will also talk about open source tools that may help you in the process.

Test and rollback scenarios

Backup

There are many ways to lose your data. Schema upgrade failure is …

Oracle has done a great technical work with MySQL. Specifically a nice job has been done around security. There is one useful feature that exists in Oracle MySQL and that currently does not exist in MariaDB. Oracle MySQL offers the possibility from within the server to generate asymetric key pairs. It is then possible use ...continue reading "Porting this Oracle MySQL feature to MariaDB would be great ;-)"

MySQL stored procedures, functions and triggers are tempting constructs for application developers. However, as I discovered, there can be an impact on database performance when using MySQL stored routines. Not being entirely sure of what I was seeing during a customer visit, I set out to create some simple tests to measure the impact of triggers on database performance. The outcome might surprise you.

Why stored routines are not optimal performance wise: short version

Recently, I worked with a customer to profile the performance of triggers and stored routines. What I’ve learned about stored routines: “dead” code (the code in a branch which will never run) can still significantly slow down the response time of a function/procedure/trigger. We will need to be careful to clean up what we do not need.

Profiling MySQL stored functions

Let’s compare these four simple stored functions (in MySQL 5.7): …

In the old days, when we wanted to strengthen our skills the only option was to buy a good book. Nowadays one can find a lot of resources on the Internet, however quality is often poor. Fortunately there are still some great people who are brave enough to write new books that will help a new generation of women and men to build modern applications with MySQL the world's most popular open source database. Let me introduce you 3 MySQL books : Introducing the MySQL 8 Document Store / MySQL and JSON: A Practical Programming Guide / Pro MySQL NDB Cluster

Missed our Continuent Clustering 6.0 webinar and technical deep dive? Don’t sweat it. Watch these recordings of our presentations and find out what’s new and latest for multisite, multimaster clustering, what’s changed, improvements that we’ve made under the hood, and how this will improve the quality and support for your multimaster MySQL/Percona/MariaDB deployments.

In our technical deep dive, we take a detailed look at the new deployment model, how the different components work together, and how you can now manage and support your new multimaster environment using Continuent Clustering 6.0. We cover the new integration of the replication, how that affects your deployment, and how that alters …