High availability for MySQL has become increasingly relevant given the ever increasing rate of adoption and implementation. It’s no secret to anyone in the community that the popularity of MySQL has become noteworthy. I still remember my start with MySQL in the early 5.0 days and people told me that I may not want to consider wasting my time training on a database that didn’t have a large industry adoption, but look at where we are now! One of my favorite pages to cite when trying to exhibit this fact is the db-engines.com ranking trend page where we can see that MySQL is right up there and contending with enterprise products such as Microsoft SQL Server and Oracle.

MySQL has gone from being part of the ever famous LAMP stack for users looking to set up their first website to seeing adoption from major technical players such as …

Having good historial metrics monitoring in place is critical for properly operating, maintaining and troubleshooting database systems, and Percona Monitoring and Management is one of the options we recommend to our clients for this.

One common concern among potential users is how using this may impact their database’s performance. As I could not find any conclusive information about this, I set out to do some basic tests and this post shows my results.

To begin, let me describe my setup. I used the following Google Cloud instances:

• One 4 vCPU instance for the MySQL server
• One 2 vCPU instance for the sysbench client
• One 1 vCPU instance for the PMM server

I used Percona Server 5.7 and PMM 1.5.3 installed via Docker. Slow query log was enabled with long_query_time set to 0 …

While investigating alternatives to migrate to Google Cloud SQL, I encountered a lack of support for external masters. However, it’s possible to overcome this limitation by replicating into Google Cloud SQL using Tungsten replicator.

Cloud SQL is Google’s database-as-a-service solution, similar to RDS for Amazon Web Services. You can get a fully managed database in only a few clicks (or API calls). At the time of writing this, the only supported databases are MySQL and Postgres.

Cloud SQL alternatives

Google offers two different options for MySQL deployments.

1st generation instances:

• Only MySQL versions 5.5 and 5.6 can provisioned
• Max memory is limited to 16 Gb
• Max of 250 Gb storage (up to 500 Gb with Silver or higher support package)
• MyISAM and InnoDB
• Asynchronous replication for read replicas

2nd generation instances:

Recently there have been several issues reported to me about DDL activity causing MySQL crash scenarios. In one case it stemmed from dropping multiple databases, one after the other in rapid succession. But in the case that I was recently dealing with directly, where we were upgrading to MySQL 5.7, it was the result of mysql_upgrade running an ALTER TABLE FORCE on a 2.2Tb table in order to convert it to the new microsecond precision supporting data format.

The issue occurred after the intermediate table had been completely filled with all the necessary data and right when MySQL would swap out the existing table for the intermediate. After a period of time MySQL crashed and the following InnoDB monitor output was found in the error log.

2017-11-19T00:22:44.070363Z 7 [ERROR] InnoDB: The age of the last checkpoint is 379157140, which exceeds the log group capacity 377483674.
InnoDB: …

In this post I will show you how to leverage Github’s gh-ost hooks for greatly improving visibility of ongoing schema changes for your organization.

One of the potential uses of gh-ost hooks is to send status updates. I will present you with some examples of how to do that via email and Slack.

What are gh-ost hooks?

gh-ost has built-in support for hooks, i.e. external scripts with predefined names, that will be called by gh-ost at certain points of a schema change operation.

The complete list is available here, but the most useful gh-ost hooks for me are:

• gh-ost-on-startup-hook
  • called at the start of a schema change operation
• gh-ost-on-status-hook
  • ran …

This edition of Log Buffer covers Cloud, Oracle, SQL Server and MySQL and much more.

Cloud:

Introducing managed SSL for Google App Engine

Using Cloud Foundry CUPS to inject Spring Security credentials into a Spring Boot Application

ClusterControl in the Cloud – All Our Resources

Monitoring Amazon Aurora Audit Events with Amazon CloudWatch

Integrating Teradata with Amazon …

While cloud technologies are roaring ahead in full force; the traditional RDBMS like Oracle, Microsoft SQL Server and MySQL are adapting pretty fast. This Log Buffer Edition covers blogs related to that and more.

Oracle:

Oracle JET Simple Table with Fake JSON Server

Every time any page is requested from your website by a human or another program or an automated bot, the event is tracked in a log file that is stored on the web server.

Gitora 2 enabled developers to manage database objects that support the CREATE OR REPLACE command, namely PACKAGES, PROCEDURES, FUNCTIONS, TRIGGERS, VIEWS, …

As we know, replication is only supported officially between consecutive major MySQL versions, and only from a lower version master to a higher version slave.

This means for example, the following scenario is supported:
5.6 master –> 5.7 slave

while these two scenarios are not supported:
5.5 master –> 5.7 slave
5.7 master –> 5.6 slave

That being said, in some contexts (e.g a MySQL upgrade) it can be valuable to be able to replicate from a master that is using a newer version of MySQL to an older version slave.

This could be used as part of a rollback strategy, and/or be needed in the case of upgrading a master-master replication topology.

The idea of the article is to provide you …

As we know, replication is only supported officially between consecutive major MySQL versions, and only from a lower version master to a higher version slave.

This means for example, the following scenario is supported:
5.6 master –> 5.7 slave

while these two scenarios are not supported:
5.5 master –> 5.7 slave
5.7 master –> 5.6 slave

That being said, in some contexts (e.g a MySQL upgrade) it can be valuable to be able to replicate from a master that is using a newer version of MySQL to an older version slave.

This could be used as part of a rollback strategy, and/or be needed in the case of upgrading a master-master replication topology.

The idea of the article is to provide you …

This Log Buffer Edition covers Oracle, SQL Server and MySQL.

Oracle:

Protecting Financial Data with Oracle WebCenter and Adobe LiveCycle

Oracle Forms 12c oracle.security.jps.JpsException Error after Database change

The Future of Content Management: Oracle Content & Experience Cloud

Today Oracle released a very large „monster“ Upgrade. This July 2017 Update includes the first time the new RU „Release …