Yesterday I decided to upgrade the database server of lefred.be running the latest WordPress to MySQL 8.0.
The previous version was 5.7.19.
My dedicated server is still running on CentOS 6.x, and I had just to enable the MySQL Community 8.0 yum repository and upgrade the rpms:
# yum update mysql-community-server --enablerepo=mysql80-community
After the upgrade, I had to modify my.cnf to remove the lines related to the non regretted Query Cache:
#query_cache_type=0 …[Read more]
In this blog, I’ll look at how to do MySQL point in time recovery (PITR) correctly.
Sometimes we need to restore from a backup, and then replay the transactions that happened after the backup was taken. This is a common procedure in most disaster recovery plans, when for example you accidentally drop a table/database or run an update/delete without the “where” clause and lose data.
The usual way is to get a copy of your binlogs and use mysqlbinlog to replay those transactions. But this approach has many pitfalls that can make the whole PITR process a nightmare. Some examples:
MySQL 8.0.1 introduced a work with replication threads mutexes
in order to improve performance. In MySQL
8.0.2 the same work was extended, focusing in
usability, and revamped how replication deals
with disk-full conditions, improving the responsiveness of both
monitoring commands and administrative commands such as
KILL, as well as making status messages much more
precise and helpful.…
This post is following the story of MySQL 8.0 Performance &
Scalability started with article about 2.1M QPS obtained on Read-Only workloads. The
current story will cover now our progress in Read-Write
workloads..
Historically our Read-Only scalability was a big pain, as
Read-Only (RO) workloads were often slower than Read-Write
(sounds very odd: "add Writes to your Reads to go faster", but
this was our reality ;-)) -- and things were largely improved
here since MySQL 5.7 where we broke 1M QPS barrier and reached
1.6M QPS for the first time. However,
improving Writes or mixed Read+Writes (RW) workloads is a much
more complex story..
What are the main scalability show-stoppers …
The new data dictionary in MySQL 8.0 is mostly transparent to users upgrading, in that an import process is automatically run on first-start, and the semantics of DDL (creating tables, adding indexes etc) remain the same. There is however one major exception, and that is how failure cases are handled.…
Above the events announced on September 15, 2017 MySQL experts and / or MySQL Community team is going to attend following events below. Please mark your calendars for:
Dear MySQL users,
MySQL Connector/Net 6.9.10 is a maintenance release for the
6.9.x
series of the .NET driver for MySQL. It can be used for
production
environments.
It is appropriate for use with MySQL server versions 5.5-5.7.
It is now available in source and binary form from
http://dev.mysql.com/downloads/connector/net/#downloadsandmirrorsites
(note that not all mirror sites may be up to date at this
point-if you
can’t find this version on some mirror, please try again later or
choose
another download site.)
Changes in MySQL Connector/Net 6.9.10 (2017-10-23, General Availability)
Bugs Fixed
* Executing MySql.Web.Security.CreateUserAndAccount with
valid arguments returned an out-of-range exception.
Thanks to Stein Setvik for contributing to the …[Read more]
Percona announces the release of Percona Monitoring and Management 1.4.0.
This release introduces the support of external Prometheus
exporters so that you can create dashboards in the Metrics
monitor even for the monitoring services other than those
provided with PMM client packages. To attach an existing external
Prometheus exporter, run pmm-admin
add external:metrics NAME_OF_EXPORTER URL:PORT.
The list of attached monitoring services is now available not
only in the tabular format but also as a JSON file to enable
automatic verification of your configuration. To view the list of
monitoring services in the JSON format run pmm-admin list
--json.
In this release, Prometheus and Grafana have been upgraded. Prometheus …
[Read more]Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.
I spent all of this week at O’Reilly Velocity EU London. I gave a tutorial, a talk and generally networked with attendees (besides my normal evangelical duties). I’ll write some thoughts on it later (probably in a couple of weeks, as Open Source Summit Europe happens next week – and Percona has a booth there).
This will be a quick, short post.
Releases
A few security releases this past week, with some bug fixes as well:
Notes/errata/updates for Chapter 7:
See the official book errata at http://tahaghoghi.com/LearningMySQL/errata.php –
Chapter 7 includes pages 223 – 275.
Supplemental blog post – ORDER BY NULL – read the blog post and the comments!
GROUP BY and HAVING examples – Supplemental blog post. The example of HAVING in the text shows a use case where HAVING is the same function as WHERE. This blog posts shows examples of HAVING that you cannot do any other way.
In the section called “The GROUP BY clause”, on pages 231-232,
the book says:
“you can count any column in a group, and you’ll get the same
answer, so COUNT(artist_name) is the same as …
