This tutorial shows the installation of a Nginx web server on Debian 9 together with MySQL or MariaDB as database, PHP 7 and free Let's encrypt SSL certificate. Nginx web server is known for its stability, rich feature set, simple configuration, and low resource consumption.

MySQL 8 second release candidate is out (MySQL 8.0.4). Besides fixes to replication issues we have also delivered a couple of enhancements in this release. Let me quickly summarize them.

• Additional instrumentation for Group Replication (WL#9856). We have instrumented mutexes and condition synchronization objects on the group communication library.

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Changing configuration settings in MySQL wasn’t always easy. Of course it’s possible to change things (hopefully), but keeping track of everything is not always obvious. This is where configuration management systems like puppet, chef, ansible, … excels in making our life easier.

/etc/my.cnf

With MySQL 8.0, we worked in making your life easier (and the life of configuration management systems easier too).

Let’s first illustrate the problematic very naively:

As you can see, we can modify this configuration variable, but after a restart of MySQL, this change is lost, this behavior, of course is something known by all MySQL DBAs. The usual solution is then to also modify the configuration file (/etc/my.cnf in most cases).

SET PERSIST …

Yesterday MySQL 8.0.4-rc came out. The Release Notes are quite long.
But caution: Do a BACKUP before upgrading...

I experienced some nice surprises. First I have to admit that I did not read the Release Notes or anything else. Reading manuals is for Girlies! Possibly something is written in there which is of importance. But I expect that it just works as usual...

I downloaded MySQL 8.0.4-rc and just want to upgrade my MySQL 8.0.3-rc testing system, where we did the 1M tables test.

First I got:

[MY-011096] No data dictionary version number found.
[MY-010020] Data Dictionary initialization failed.
[MY-010119] Aborting

Hmmm... Maybe something was not clean with the old system. So downgrade again:

[ERROR] [000000] InnoDB: Unsupported redo log format. The redo log was …

Yesterday MySQL 8.0.4-rc came out. The Release Notes are quite long.
But caution: Do a BACKUP before upgrading...

I experienced some nice surprises. First I have to admit that I did not read the Release Notes or anything else. Reading manuals is for Girlies! Possibly something is written in there which is of importance. But I expect that it just works as usual...

I downloaded MySQL 8.0.4-rc and just want to upgrade my MySQL 8.0.3-rc testing system, where we did the 1M tables test.

First I got:

[MY-011096] No data dictionary version number found.
[MY-010020] Data Dictionary initialization failed.
[MY-010119] Aborting

Hmmm... Maybe something was not clean with the old system. So downgrade again:

[ERROR] [000000] InnoDB: Unsupported redo log format. The redo log was …

Starting with the MySQL Community 8.0.4-RC we are unifying on OpenSSL as the default TLS/SSL library for both MySQL Enterprise Edition and MySQL Community Edition. Previously, MySQL Community Edition used YaSSL.

Why make this change?

• Community Requests – Supporting OpenSSL in the MySQL Community Edition has been one of the most frequently requested features.

…

The MySQL Development team is very happy to announce that MySQL 8.0.4, the second 8.0 Release Candidate (RC2), is now available for download at dev.mysql.com (8.0.4 adds features to 8.0.3, 8.0.2, 8.0.1 and 8.0.0). The source code is available at GitHub.…

MySQL crash-safe replication is an old feature (~4 years as of MySQL 5.6), but it’s not consistently understood or applied. The MySQL manual on the topic, 16.3.2 Handling an Unexpected Halt of a Replication Slave, is correct and authoritative, but unless you grok MySQL replication that page doesn’t make it obvious why crash-safe replication works. Other blog posts explain why, but sometimes add other considerations, making it unclear which settings are necessary and sufficient.

MySQL crash-safe replication is an old feature (~4 years as of MySQL 5.6), but it’s not consistently understood or applied. The MySQL manual on the topic, 16.3.2 Handling an Unexpected Halt of a Replication Slave, is correct and authoritative, but unless you grok MySQL replication that page doesn’t make it obvious why crash-safe replication works. Other blog posts explain why, but sometimes add other considerations, making it unclear which settings are necessary and sufficient.

MySQL crash-safe replication is an old feature (~4 years as of MySQL 5.6), but it’s not consistently understood or applied. The MySQL manual on the topic, 16.3.2 Handling an Unexpected Halt of a Replication Slave, is correct and authoritative, but unless you grok MySQL replication that page doesn’t make it obvious why crash-safe replication works. Other blog posts explain why, but sometimes add other considerations, making it unclear which settings are necessary and sufficient. The aim of this blog post is total enlightenment, a full crash-safe-spiritual awakening. Light the censers and let us begin at the beginning…