Two talks in the Dallas area this week. On Tuesday, the North Texas MySQL Users Group, a special interest group of the Dallas Oracle Users Group, is meeting and the subject will be MySQL 101. So please load MySQL and Workbench on a laptop (or try to) and we will go over the basics. RVP so we can get the right amount of pizza ordered!
Then on Thursday, I will present The Proper Care and Feeding of a MySQL database for Linux Administrators at the Dallas/Fort Worth Unix User Group meeting.
MySQL is a great database server. It has lots of flaws, but if you work with its strong points and try to minimize its weaknesses, it works fantastically well for a lot of use cases. Unfortunately, if you bang on its weak points, sometimes you get hit by falling bricks. A couple of its riskiest weak points relate to unavailability of an expected resource, particularly disk space and memory. For example, Stewart Smith has blogged about the interesting results you can get if you intentionally make malloc() fail.
I was thinking recently about what a DBA does, and decided to blog about what I think a DBA could/should do. Most DBAs I know are mired in day-to-day firefighting and time-consuming tedium. This forces them to operate in reactive mode (because they don’t have enough time to “get caught up”), and keeps them from more valuable things they could be doing. Here’s my short and incomplete list:
My three previous blog posts I already wrote from Froscon. In this post I still want to go back and mention some people I met and discussions I had.
The MySQL side
There were of course many MySQL people, with both SkySQL and Oracle sponsoring. It was great to meet Carsten from Oracle, who has joined the MySQL Sales Engineer team in Europe (he moved from an OpenOffice position). That's my former team, so it was great to see a new face!
Going there the person I was most looking forward to meet was Hana Hütter, formerly a MySQL account manager for Central Europe, and now doing the same at SkySQL. My first ever MySQL sales gig was with Hana, and Ralf Gebhart who is also now with SkySQL but was not at Froscon. While Ralf was there only that first time to teach me how to be a Sales Engineer, with Hana we then continued to sell MySQL into telecom companies in many European cities. I had not met Hana since I left Sun. It was …
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In late 2011 I attended a lecture by John
Wilkes on Google compute clusters, which link thousands of
commodity computers into huge task processing systems. At
this scale hardware faults are common. Google puts a lot of
effort into making failures harmless by managing hardware
efficiently and using fault-tolerant application programming
models. This is not just good for application up-time.
It also allows Google to operate on cheaper hardware with
higher failure rates, hence offers a competitive advantage in
data center operation.
It's becoming apparent we all have to think like Google to run
applications successfully in the cloud. At Continuent we run
our IT and an increasing amount of QA and development on Amazon Web Services …
MySQL server introduced support for the IPv6 protocol in version
5.5 (WL#798). However after some time it
turned out that the support is not as functional as it could
be. In MySQL 5.6 we are trying to extend the functionality
and improve the easiness of use.
Bind address in 5.5 Let's recall for a moment how the MySQL
server handles client connections. There is only one server
socket and it can be bound to any IP address. The IP address
to bind the server socket to can be specified via
the --bind-address command line option.
There are two main statements in the phrase above:
There's a great post over at the MySQL Performance Blog about visualization tools for pt-query-digest. If you haven't heard of the Percona Toolkit, you should get to know more about it. It is the successor to Maatkit and Aspersa, and is a great collection of utilities for MySQL database administrators. pt-query-digest can parse the slow query log, the general query log, the binlog, TCP dump
Overview MySQL supports Stored Programs since 5.0, where they
were introduced in a very draft stage. A "Stored Program" is
a general term for stored procedures, stored functions,
triggers and events. Since then stored program support has
been gradually improved. Another major milestone is coming
in the 5.6 release. We have finally fixed the infamous
problem that Stored Programs could not detect metadata
changes!
Let's consider a simple example:
> CREATE TABLE t1(a INT);
> CREATE PROCEDURE p1()
SELECT * FROM t1;
At this point the p1 definition is stored in the data
dictionary (mysql.proc internal table).
> CALL p1();
Now, p1 is loaded from the data dictionary, parsed into an
internal representation and cached within the server.
p1 can now be called several …
"Life is", goes a saying in my native Finland, a country not known for using superfluous words. While this saying may take compactness a tad too far, it's a great way to say "things happen", mostly to stoically adapt, sometimes to justify actions taken in order to adapt. The brevity of the expression adds not just to the perceived wisdom, but also makes resistance futile. The expected and usual reaction is agreement; I have yet to experience a situation where somebody would counterargue that "life is not".
Monitoring MySQL servers is no rocket science provided you know what to monitor. MySQL gives a comprehensive list of variables to check your server’s health and performance. Let me walk you through the crucial variables you should be monitoring. Lets assume that you have one or more MySQL servers, which have been setup and running fine. Here are the top 10 things to monitor on your MySQL.
1. MySQL availability
Yes, this is the first thing you should be looking at!
It would not make sense to monitor your MySQL if its not even
available. MySQL downtime is simply not acceptable in production.
At the same time ensuring zero downtime does not guarantee
maximum performance.
You can execute
-mysqladmin -h 192.168.1.95 -u root -p status
to know if MySQL is running or you can just ping MySQL using service mysqld status if you are using RedHat Linux.
2. Presence of insecure users and …
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