Carrying on with my MySQL 5.7 Labs Multi Source Replication scenario, I wanted to evaluate performance impact via MySQL Enterprise Monitor.

Whilst I opened my environment, I remember that I had generated lots of different skeleton scripts that allowed me to deploy the 50 servers quickly, and I didn’t want to add each of my targets 1 by 1 in MEM. So, I used one of the many features available, “Add Bulk MySQL Instances”.

So, I’ve got 50 (3001-3050) masters but only 1 slave (3100).

By default, MEM monitors it’s own repository, i.e. the 1/1 server being monitored in the All group.

I want to add my slave in first, because that’s how I’m organizing things, and I’ll take the opportunity to create the monitoring group I want to …

A customer asked whether we they could have 10 or more masters consolidate all the data into a single central slave. After getting a bit more information from them and seeing the application functionality, it was clear that MySQL Labs 5.7.5 Multi Source Replication could be a good candidate. Why?:
– Each master is independent from the rest of the masters.
– One-way traffic: there is only one way to update a row, and that’s from the master.
– All the masters use the same schema and table, but no single master will ever need to, nor be able to update a row from another master.
– PK determined via app & master env.

Multisource replication is still in http://labs.mysql.com, but here’s what I did to test it out.

First, I read:
…

 Long time ago I wrote a blog post that we started using Semi-Synchronous replication in production at Facebook. We are running our own MySQL facebook-5.6 branch, which added many replication (including Semisync) patches. Some of them were also merged with WebScaleSQL.

 Recently I heard from people from community that they were suffering from Semisync performance issues in official MySQL 5.6. I took some time to review our previous MySQL bug reports, then realized that some important bugs were either still "verified" or inefficiently fixed. Two most affecting bug reports were …

Today I was doing some tests with XA transactions in MySQL 5.6.

The output of the XA RECOVER command to list transactions was hard to read because of the representation of the data column:

The good news is that 5.7 has transaction information in performance_schema:

mysql> select trx_id, isolation_level, state, xid, xa_state, access_mode 
    -> from performance_schema.events_transactions_current;
+-----------------+-----------------+--------+--------+----------+-------------+
| trx_id          | isolation_level | state  | xid    | xa_state | access_mode |
+-----------------+-----------------+--------+--------+----------+-------------+
|            NULL | REPEATABLE READ | ACTIVE | x-1    | PREPARED | READ WRITE  |
| 421476507015704 | REPEATABLE READ | …

As I mentioned on my last post, where I compared the default configurations options in 5.6 and 5.7, I have been doing some testing for a particular load in several versions of MySQL. What I have been checking is different ways to load a CSV file (the same file I used for testing the compression tools) into MySQL. For those seasoned MySQL DBAs and programmers, you probably know the answer, so you can jump over to my 5.6 versus 5.7 results. However, the first part of this post is dedicated for developers and MySQL beginners that want to know the answer to the title question, in a step-by-step fashion. I must say I also learned something, as I under- and over-estimated some of the effects of certain …

With the upcoming release of MySQL 5.7 I begin to see a problem which I think needs attention at least for 5.8 or whatever comes next. The GA release cycle is too long, being about 2 years and that means 3 years between upgrades in a production environment More people use MySQL and the data … Continue reading Making MySQL Better More Quickly

While doing some testing (that I published later here) on the still-in-development MySQL 5.7 I wanted to do some analysis on the configuration to see if the changes in performance were due to the code changes or just to the new MySQL defaults (something that is very common in the migration from 5.5 to 5.6 due to the default transaction log size and other InnoDB parameters). This is a quick post aiming to identify the global variables changed between these two versions.

You could tell me that you could just read the release notes, but my experience (and this is not an exception, as you will see) …

In a previous post, I covered porting MySQL 5.6 to POWER and subsequently, some new record performance numbers with MySQL 5.6.17 on POWER8.

Well, those following at home will be aware that not only is the next sentence sponsored by IBM Legal, but that MySQL 5.7 alleviates a bunch of the mutex contention that we saw with MySQL 5.6. The postings on this site are my own and don’t necessarily represent IBM’s positions, strategies or opinions.

In looking at MySQL performance on POWER, it’s inevitable that I should look at MySQL 5.7 and what’s coming up in the next stable release of MySQL.

Surprisingly, a bunch of the core code in InnoDB and MySQL dealing with mutexes has changed in MySQL 5.7 when …

MySQL, the original brand, the one developed by the MySQL team at Oracle, is steadily evolving. You can feel it if you try every new release that comes out of the milestone release cycle. Or even if you don’t try all of them, just testing a release once in a while gives you something to think about.

The engineers at Oracle are trying hard to improve the defaults. If you are the out-of-the-box type, and just install the new version on top of the previous one, leaving the same setup in place, you may be up for a for a few surprises. It’s the marketing, see? They tell you that just by replacing your old MySQL (5.1 or 5.5) with MySQL 5.6 you get 30% to 70% performance improvement. Which happens to be true, not only because the server is better, but also because they have changed the defaults. However, this change in defaults may come with some serious consequences for the ones who …

MySQL 5.6 has been GA for just over a year now. See MySQL 5.6.10 Release Notes.  Congratulations on your birthday! That is quite a long time. I was using it earlier in production because it worked and could do things that 5.5 could not do, but earlier versions were to use at your own risk, and indeed if prodded incorrectly would fall on the floor. That is fair enough because they were work in progress, yet if you poked them the right way they did a very good job.  Those dev versions have been long since upgraded which is good so they do not need quite as much care and attention.

So from where I see 5.6 it works very well. One big change that has made a large difference but which I think a lot of people may not really understand or use is the …