In this post, we’ll discuss some insight I’ve gained regarding severe performance regression in MySQL 5.7 crash recovery.

Working on different InnoDB log file sizes in my previous post:

What is a big innodb_log_file_size?

I tried to understand how we can make InnoDB crash recovery faster, but found a rather surprising 5.7 crash recovery regression.

Basically, crash recovery in MySQL 5.7 is two times slower, due to this issue: https://bugs.mysql.com/bug.php?id=80788. InnoDB now performs the log scan twice, compared to a single scan in MySQL 5.6 (no surprise that there is performance degradation).

Fortunately, there is a proposed patch for MySQL 5.7, so I hope it will be improved soon.

As for general crash …

Please join us on Thursday June 9, at 10:00 am PDT (UTC-7) for the webinar Troubleshooting MySQL configuration issues.

MySQL Server is highly tunable. It has hundreds of configuration options which provide great tuning abilities and, at the same time, can be the source of various issues.

In this webinar you will learn which types of options MySQL Server supports, when they take effect and how to modify configuration safely. I will demonstrate best practices and tricks, used by Support engineers when they work with bug reports and customer issues which highly depend on configuration.

…

Percona is glad to announce the GA release of Percona Server 5.7.12-5 on June 6, 2016. Download the latest version from the Percona web site or from the Percona Software Repositories.

Based on MySQL 5.7.12, including all the bug fixes in it, Percona Server 5.7.12-5 is the current GA release in the Percona Server 5.7 series. All of Percona’s software is open-source and free, all the details of the release can be found in the …

We have had to revert back to TLSv1.0.

If you saw my previous post on TLSv1.0 (https://www.percona.com/blog/2016/05/23/percona-disabling-tlsv1-0-may-31st-2016/), you’ll know I  wanted to deprecate TLSv1.0 well ahead of PCI’s changes. We made the changes May 31st.

Unfortunately, it has become apparent that EL 5, which is in the final phases of End Of Life, does not support TLSv1.1 or TLSv1.2. As such, I have had to re-enable TLSv1.0 support so that these users employing EL 5 can still receive updates from our repositories.

If you are running EL 5 (RHEL 5 / CentOS 5 / Scientific Linux 5 / etc …), I …

Several months ago I reported on Default Users in MySQL 5.7. With the addition of the sys schema the server needs an extra user to secure operations. The problem with extra users is that, if you are not aware of their existence and why they are needed, you may easily mismanage them. For example, you may have a cleanup routine that you run when you use a new server, and the routine may have a command like

DELETE FROM mysql.user WHERE user != 'root';

This was good up to MySQL 5.6. Then the sys schema was added, and with it the user mysql.sys, which may cause errors if you try to re-create views in the sys schema.

The latest user sneaking below the radar is mysqlxsys. Like its predecessor, it …

I was surprised to find on one of my websites the message “Connect failed: Your password has expired. To log in you must change it using a client that supports expired passwords.

Not knowing that I was using a MySQL password expiry policy I reviewed the 5.7 documentation quickly which *clearly* states “The default default_password_lifetime value is 0, which disables automatic password expiration.”.

I then proceeded to investigate further, my steps are below the following comment.

However, it is always important with MySQL documentation and a new feature (in this case a 5.7 feature) to review release notes when installing versions or to least read ALL the documentation, because you may miss important information, such as.

…

Researching a performance issue, we came to a startling discovery:

MySQL 5.7 + binlogs is by default 37-45% slower than MySQL 5.6 + binlogs when otherwise using the default MySQL settings

Test server MySQL versions used:
i7, 8 threads, SSD, Centos 7.2.1511
mysql-5.6.30-linux-glibc2.5-x86_64
mysql-5.7.12-linux-glibc2.5-x86_64

mysqld –options:

--no-defaults --log-bin=mysql-bin --server-id=2

Run details:
Sysbench version 0.5, 4 threads, socket file connection

Sysbench Prepare: 

sysbench --test=/usr/share/doc/sysbench/tests/db/parallel_prepare.lua --oltp-auto-inc=off --mysql-engine-trx=yes --mysql-table-engine=innodb --oltp_table_size=1000000 --oltp_tables_count=1 --mysql-db=test --mysql-user=root --db-driver=mysql --mysql-socket=/path_to_socket_file/your_socket_file.sock …

Stephen O'Grady at RedMonk has launched a new Podcast called Hark. In his second episode, he and Agile programming guru Kent Beck have a thoughtful discussion around the ideas in O'Grady's book "The Software Paradox."  Even though software is "eating the world" and become more widespread and strategic, its economic value appears to be declining rapidly. Certainly, we've seen a shift in the …

As some already noticed it, I’ve recently joined the amazing MySQL family in Oracle.

I’m now part to the awesome MySQL Community Team and I will be mostly present in EMEA.

Why did I make such change ? Oracle offered me the opportunity to work in a domain I really like and I was already trying to represent the MySQL Community as much as I could but mostly in using my own free time (twitter, facebook, FOSDEM, …). Now this is my full time job !

Yes, OK, but why Oracle ? To be honest this answer is very easy to reply. Somebody interested in the MySQL Community for the last few years should be blind to not see the amount of work the MySQL engineering team is doing: many improvements and overall, many new features. I won’t be a lie if I say that Oracle’s MySQL is also the most active in innovating MySQL (JSON data type, X plugin, MySQL shell,… )

For all these reasons, I’m very proud to have made the …

In this blog, we’ll use some test results to look at the rationale for using provisioned IOPS volumes for AWS databases.

One piece of advice you often hear running MySQL, MongoDB or other databases in the AWS EC2 environment is that you should use volumes with provisioned IOPs. This kind of makes sense on the “marketing” level, where provisioned IOPS (io1) volumes are designed for IO-intensive database workloads, while General Purpose (gp2) volumes are not. But if you go to the AWS volume type description, you will find that gp2s are shown to have pretty good IO performance. So where do all these supposed database performance problems for Amazon Elastic Block Store (EBS), with no provisioned IOs, come from?

Here is what I found out running experiments with a beta of …