This tutorial is showing how manual fix of GTID inconsistency but it can be VERY RISKY to mess up the InnoDB Cluster.   It purely serves as a tutorial how to troubleshoot and identify potential issues.

Environment
MySQL InnoDB Cluster being setup on Single Machine with 3 Nodes
Node 1 : Port 3306
Node 2 : Port 3316
Node 3 : Port 3326





The InnoDB Cluster Member Status is as follows





Retrieving the GTID executed on each member "SELECT @@gtid_executed;"






The 3 sets of GTIDs are the same and the InnoDB Cluster of 3 nodes is running properly.

Let to simulate a breakdown of Server (Kill the Instance with PORT 3326)
1.  Change the persisted variables group_replication_start_on_boot = off first
  …

Most databases grow in size over time. The growth is not always fast enough to impact the performance of the database, but there are definitely cases where that happens. When it does, we often wonder what could be done to reduce that impact and how can we ensure smooth database operations when dealing with data on a large scale.

First of all, let’s try to define what does a “large data volume” mean? For MySQL or MariaDB it is uncompressed InnoDB. InnoDB works in a way that it strongly benefits from available memory - mainly the InnoDB buffer pool. As long as the data fits there, disk access is minimized to handling writes only - reads are served out of the memory. What happens when the data outgrows memory? More and more data has to be …

Last year, we asked you a few questions in a blog poll and we received a great amount of feedback. This year, we wanted to follow up on those same survey questions to see what may have changed over the last 12 months. So with that in mind, we’re hoping you can take a minute or so to answer the first survey question in this series: What Keeps You Up At Night? Is it fixing emergencies? Bad queries? Cost concerns? Inquiring minds want to know!

Note: There is a poll embedded within this post, please visit the site to participate in this post's poll.

This poll question will be up for one month and will be maintained over in the sidebar should you wish to come back at a later date and take part. We look forward to seeing your responses!

I think it is often confusing to compare upstream MySQL and Percona Server for MySQL, and some helpful information can be found in the introductory notes. But what does that really mean for an ordinary DBA, especially if none of the known big extra features are important in a particular use case?

In this article, I would like to start a series of short blog posts highlighting small, often less known, but potentially useful features, available in Percona Server for MySQL. Let’s start with a relatively new feature.

Limit the disk space used by binary logs problem

Historically, dealing with binary logs and the disk space used by them was quite challenging. The only thing that let you control this is the …

Author: Robert Agar

The working life of a DBA is often centered on optimizing their systems to provide users with the best performance. There are many aspects of a MySQL implementation that can be tuned to increase its functionality. These improvements will result in a more efficient system and enhanced user experience.

One of the problems facing the DBA responsible for instituting performance tuning is to identify the particular areas to address that will impact the system in a positive manner. Approaching this task in a haphazard fashion is not advisable. Randomly modifying parameters is just as likely to cause further issues than to lead to performance gains. Luckily, there is a solution to this dilemma.

Conducting focused monitoring can be instrumental in enabling the DBA to pinpoint the source of performance degradation. Armed with this knowledge, informed decisions can be made regarding how …

Introduction In this article, we are going to test the MySQL 8 implementation of custom SQL CHECK constraints. Although the CHECK clause is a standard SQL feature, prior to MySQL 8.0.16, the clause was parsed and ignored, so this functionality could only be emulated via BEFORE INSERT and UPDATE triggers. Custom SQL CHECK constraints As I explained in this article, custom SQL CHECK constraints are very useful to ensure non-nullability constraints for JPA entity subclass-specific attributes when using the SINGLE TABLE JPA inheritance strategy. To understand the problem, consider we have the... Read More

The post MySQL 8 support for custom SQL CHECK constraints appeared first on Vlad Mihalcea.

Great SaaS – starts with great software. My company has been working on this mission since 2004.

It took a few years to get our solution right – to offer a geo-distributed MySQL database backend for billion-dollar businesses. And it took a few more years to polish it.

Today, we continue to improve it day-in, day-out.

But there is no doubt the patience and perseverance pays off:

While the number of Tungsten-clustered databases in-production is in the thousands, we average only one (1) new support request per day, and, because of this, we provide an average response time less than three (3) minutes.

Not enough is said about the people and values behind great software; so that’s what I want to talk about here. Continuent is an agile, globally-distributed, remote team that is much greater than the sum of its parts. Our software helps global enterprises …

There could be various requirements at application end which need realtime slaves. Let me introduce a solution to a problem we used to face how can we monitor whether our slaves are real time or they are lagging in Milliseconds. Unfortunately there is no built in feature in MySQL to get Replication Lag in MilliSeconds.
Perhaps there is a tool provisioned in pt-toolkit named as pt-heartbeat. It generates heartbeat events on master and monitoring system can monitor time difference on slave to calculate lag.
How to deploy pt-heartbeat in your environment (Assuming OS as UBUNTU xx.xx):

Step 1: …

In week 3 of our series, Benefits of SQL Diagnostic Manager for MySQL (formerly Monyog), we discuss how to identify and analyze problematic SQL queries using SQL Diagnostic Manager for MySQL. If you missed it, feel free to read our previous post on Agentless Monitoring and Cloud Readiness.

Find Problematic SQL Queries

MySQL and MariaDB currently lack advanced tools for profiling SQL queries (such as SQL Profiler of Microsoft’ SQL Server). While other monitoring tools for MySQL and MariaDB provide monitoring and advisory information on various system metrics, they do not pinpoint the problematic SQL queries. No amount of hardware upgrades and tuning of the parameters in the database server configuration file ‘my.cnf’ and the database server initialization file …

Ran into an interesting situation trying to configure a MySQL JDBC driver to connect over TLS (though the driver may call it SSL, TLS is the name for more recent versions of the protocol).

The error I was getting was pretty generic:

Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

With the relevant parts of the stacktrace, also being non helpful:

at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
        at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
        at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:835)
        at com.mysql.cj.jdbc.ConnectionImpl.(ConnectionImpl.java:455)
        at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240)
        at …