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 …

We’re delighted to announce a ClusterControl Template for Zabbix, so Zabbix users can now get information about the status of their database clusters, backups and alarms. We have previously published integrations with other monitoring systems including Nagios and PagerDuty.

This template is built using the ClusterControl REST API to retrieve monitoring data. Thus, you need to have a ClusterControl API token and URL configured in the template’s configuration file. This simplifies the initial configuration, and allows users to extend the current monitoring data.

…

WebAssign develops higher education online instructional tools for faculty and students, and more than one million students at over 2,300 educational institutions use WebAssign each year. Last year, WebAssign experienced a large outage that impacted their ability to provide timely online grading and assessments; they took this opportunity to look for new tools that would improve insights into their database activities and ensure service level requirements.

“MEM for MySQL wasn’t able to provide per-query metrics or fault diagnosis, which is a level of detail that we value,” said Valerie Parham, DBA, WebAssign. “Instead, releases would appear fine, but then a problem would pop up and we’d have to do a hot-fix so it didn’t turn into an outage, which placed undue stress on everyone.”

WebAssign looked at a number of solutions, including Percona Cloud Tools, but none offered the same level of full query insight and …

As a MySQL DBA I already know the data changes that happen on my system. I have logs for that.

However, it’s a common problem that several years into the life of an application, the current developers won’t know where in the codebase queries come from. It’s often hard for them to find the location in the code if queries are formed dynamically; the pattern I show them to optimize doesn’t match anything in the code.

I stumbled on a trick a couple years ago that has been invaluable in tracking down these problematic queries: query comments.

Here’s an example:

When a query generally shows up in a slow query log, it might look something like this:

# Time: 150217 10:26:01
# User@Host: comments[comments] @ localhost []  Id:    13
# Query_time: 0.000231  Lock_time: 0.000108 Rows_sent: 3  Rows_examined: 3
SET timestamp=1424186761;
select * from cars;

That logging shows me who executed the query …

#DBHangOps 02/19/15 -- Long Query Time, Operational TokuDB, and more!

Hello everybody!

Join in #DBHangOps this Thursday, February, 19, 2015 at 11:00am pacific (19:00 GMT), to participate in the discussion about:

• Learnings from operating TokuDB
• What's a good long_query_time?
• Testing your backups
• MySQL 5.7 defaults suggestions

You can check out the event page at https://plus.google.com/events/cohut2qncrbkrrmbs868kjorvbo on Thursday to participate.

As always, you can still watch the #DBHangOps twitter search, the @DBHangOps twitter feed, or this blog post to get a link for the google hangout on …

There were so many valuable articles already written by others over past years explaining all details about InnoDB transaction isolation modes and how to deal with this. So, I'll avoid to repeat what was already said ;-) -- my attention attracted the performance study made by PeterZ and published in the following article: http://www.percona.com/blog/2015/01/14/mysql-performance-implications-of-innodb-isolation-modes/ -- the article is very good and providing a good analyze of the observed problem which is solved by using READ-COMMITTED transaction isolation instead of REPEATABLE-READ (which is default in InnoDB).. The natural question is coming then: why don't we have then the READ-COMMITTED mode by default?.. Is there any danger?..

Let's then investigate together..

First of all, you should …

MySQL meets NoSQL with JSON UDF

I recently got back from FOSDEM, in Brussels, Belgium. While I was there I got to see a great talk by Sveta Smirnova, about her MySQL 5.7 Labs release JSON UDF functions. It is important to note that while the UDF come in a 5.7 release it is absolutely possible to compile and use the UDF with earlier versions of MySQL because the UDF interface has not changed for a long time. However, the UDF should still be considered alpha/preview level of quality and should not be used in production yet! For this example I am using Percona Server 5.6 with the UDF.

That being said, the proof-of-concept that I’m about to present here uses only one JSON function (JSON_EXTRACT) and it has worked well enough in my testing to present my idea here. The JSON functions will probably be GA sometime soon anyway, and this is a useful test of the JSON_EXTRACT function. …

Within the MySQL data directory, the InnoDB storage engine creates two types of files — the data files and the redo log files. Each data file (or ibd file) belongs to exactly one tablespace. Each tablespace is given a unique identifier called the space_id. One tablespace can have 1 or more data files. If a tablespace has more than one data file, then the data files have a specific order or sequence. The data files can be thought of as being concatenated to each other in that specific order.

The data file is made up of a series of equal sized pages. Each page in the data file is given a unique number identifier called the page number (page_no). The first page of the first ibd file is given the page_no of 0. The page number of the first page of the second ibd file of the tablespace is …

Taxonomy upgrade extras: MySQL Enterprise Monitormonitoringeventhandlermpmperformance monitor

MySQL Enterprise Monitor (MEM) has by default no Event Handlers created and activated. These Event Handlers you have to define yourself according to your needs.

In this article we discuss how to create MySQL Enterprise Monitor Event …

What kinds of aliveness/health checks should we build into Nagios? Which metrics should we monitor with thresholds to raise alarms, and what should the thresholds be? What graphs should we build of status counters, which graphs should we examine and what do they mean?

In this webinar, Baron Schwartz answers these database monitoring questions and more.

If you did not have a chance to join the webinar, the slide deck is embedded below. You can also register for a recording here.