Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.

Writing to you on the ground from FOSSASIA 2018, where I gave a track introduction yesterday since we have a pretty awesome database track most Saturday, and generally, all MySQL focused on Sunday. There’s even a list of talks by Oracle MySQL’ers (yes, there’s more than just Oracle folk, but for that, you got to get the schedule).

The Percona Live Community Dinner happens again this year during Percona Live 2018, at Pedro’s on 24 April 2018. It starts at 7 pm, and I highly recommend you purchase the …

Recently I blogged about the new default authentication plugin in MySQL 8.0 and I got some comments complaining that this new authentication plugin is breaking half of applications.

So first of all, if you are using an old connector or a connector (like the one for Go) not yet supporting caching_sha2_passwordas authentication plugin, you are still able to use the old one. If you have created a new user for your application not supporting the new authentication method, you just have to run the …

MySQL 8.0.4rc was just released as "Pre-General Availability Draft: 2018-03-19".

• https://dev.mysql.com/doc/refman/8.0/en/mysql-nutshell.html
• https://dev.mysql.com/doc/relnotes/mysql/8.0/en/

I decided to take a quick peek and note my impressions here.  Some of this is old news for many as this release has been talked about for awhile but I added my thoughts anyway.. 
First thing I noticed was a simple issue of using the updated mysql client. My older version was still in my path that resulted in 
ERROR 2059 (HY000): Authentication plugin 'caching_sha2_password' cannot be loaded

• …

Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.

SCALE16x is over. Percona had a large showing — both Peter Zaitsev & myself had talks, and the booth in the expo hall saw Rick Golba, Marc Sherwood, and Dave Avery also pop by. The lead scanner suggests we had several hundred conversations — read Dave Avery’s summary. My talk went well, though during Q&A the number of questions I got about MariaDB Server was quite interesting (considering it wasn’t part of my talk!). It is clear people are concerned about compatibility (because I spent close to 45 minutes after my talk answering Q&A outside too).

I got to catch up with …

Today, yet another blog post about improvements in MySQL 8.0 related to Performance_Schema. Before MySQL 8.0 it was not always easy to get an example of the queries you could find in Performance_Schema when looking for statements summaries. You had to link several tables (even from sys) to achieve this goal as I explained it in this post.

Now in MySQL 8.0, we have changed the table events_statements_summary_by_digest. This table now contains 6 extra columns:

• QUANTILE_95 : stores the 95th percentile of the statement latency, in …

With MySQL 8.0, the error logging subsystem has been redesigned to use the new component architecture.

Thanks to this new redesign, now the log events can be filtered, the output can be sent to multiple destinations (different formats like JSON). All that is controlled by system variables.

This work gives the possibility for a log event to become the raw material for log processing by more modern and automated systems like filebeat for beats, …

In MySQL 8.0, the engineers have added useful meta-data to the table SETUP_INSTRUMENT. This table lists the classes of instrumented objects for which events can be collected.

To the NAME, ENABLES and TIMED columns, were added PROPERTIES, VOLATILITY and DOCUMENTATION.

Let’s have a quick look at these new columns:

PROPERTIES can have the following values

• global_statistics: only global summaries are available for this instrument. Example: memory/performance_schema/metadata_locks that return the memory used for table performance_schema.metadata_locks
• …

MySQL 8.0’s new default authentication plugin means more secure connections for users connections but also for replication… but you need to be aware of it !

Yesterday Giuseppe – the datacharmer – Maxia, submitted a bug related to a strange behavior of MySQL’s replication.

He observed that after creating a new user for replication (using the new authentication method, caching_sha2_password), when he created the slave as usual, replication was not starting… Slave_IO_Running was constantly in “Connecting” and the Last_IO_Error was:

Last_IO_Error: error connecting to master 'repl2@127.0.0.1:24011' - …

With MySQL 8.0, engineers improved the visibility of data locking. Usually it was not that easy to deal with the output of SHOW ENGINE INNODB STATUS and mixing Information_Schema tables like INNODB_LOCKS and INNODB_LOCK_WAITS.

So in MySQL 8.0 we instrument data locks in Performance_Schema and we changed the SYS Schema view related to the InnoDB Locks Wait too.

This means that when a transaction A is locking row R, and transaction B is waiting on this very same row, B is effectively blocked by A. What we added is extra instrumentation to expose which data is locked (R), who owns the lock (A), and who is waiting for the data (B).

Testing

Let’s have a look at this simple scenario in MySQL 5.7.21 and 8.0.4 to compare:

2 clients starting a …

As you may already know, MySQL 8.0 is coming with SQL Roles . I’ve already quoted them before in some posts (here and here). Giuseppe Maxia is doing a great job testing and promoting them (thank you for that!). Of course he also made some remarks on …