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Displaying posts with tag: mysql server (reset)
MySQL Documentation: Indexes in Release Notes

We've recently made a change "in the background", adding an index to each of our release note documents. For an (ample) example, look at the MySQL 5.7 release notes' index page.

The index should make it a lot easier for users to spot (and track) changes of particular features throughout the versions of a MySQL release series (for example, MySQL 5.7 or 8.0).

Release note indexes are automatically updated as new changelogs are created; this is one of the advantages of our highly automated documentation infrastructure -- keeping indexes updated manually would simply not be possible.

Update (2017-07-03): New screenshot, reflecting more readable / less cluttered links to individual release notes.

Making HAProxy 1.5 replication lag aware in MySQL

HAProxy is frequently used as a software load balancer in the MySQL world. Peter Boros, in a past post, explained how to set it up with Percona XtraDB Cluster (PXC) so that it only sends queries to available nodes. The same approach can be used in a regular master-slaves setup to spread the read load across multiple slaves. However with MySQL replication, another factor comes into play: replication lag. In this case the approach mentioned for Percona XtraDB Cluster does not work that well as the check we presented only returns ‘up’ or ‘down’. We would like to be able to tune the weight of a replica inside HAProxy depending on its replication lag. This is what we will do in this post using HAProxy 1.5.

Agent …

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Recent MySQL Announced Releases

Recently a several releases of MySQL Server were announced to our mailing lists. Do not miss following news:

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Percona Playback 0.6 for MySQL now available

Percona is glad to announce the release of Percona Playback 0.6 for MySQL on April 9, 2013. Downloads are available from our download site and Percona Software Repositories.

Percona Playback for MySQL is a tool for replaying the load of one database server to another. Currently it can read queries from MySQL query-log and MySQL tcpdump files and run them on other MySQL server. With Percona Playback you can measure how a server or database upgrade, change in my.cnf or schema change can affect the overall performance of your MySQL database server.

Percona Playback …

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A Visual Guide to the MySQL Performance Schema

If you haven’t explored the MySQL Performance Schema yet, this is a good place to start.  This is Performance Schema 101, a basic introduction to the MySQL 5.6 performance_schema, which records runtime statistics from the MySQL database. The performance_schema is intended to provide access to useful information about server execution while having minimal impact on server performance.  Performance_schema is the name of both the storage engine and the database itself, and it was initially implemented  in MySQL 5.5. In MySQL 5.6 the engineers added quite a bit of new instrumentation.

The performance_schema database uses views or temporary tables that actually use little to no persistent disk storage .Memory allocation is all done at server startup, so there is no ongoing memory reallocation or sizing, which is great for performance.

I categorize the performance_schema …

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The InnoDB Quick Reference Guide is now available

I’m pleased to announce that my first book, the InnoDB Quick Reference Guide, is now available from Packt Publishing and you can download it by clicking here. It covers the most common topics of InnoDB usage in the enterprise, including: general overview of its use and benefits, detailed explanation of seventeen static variables and seven dynamic variables, load testing methodology, maintenance and monitoring, as well as troubleshooting and useful analytics for the engine. The current version of MySQL ships with InnoDB as the default table engine, so whether you program your MySQL enabled applications with PHP, Python, Perl or otherwise, you’ll likely benefit from this concise but comprehensive reference guide for InnoDB databases.

Here are the chapter overviews …

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Super Python: three applications involving IRC bot master, MySQL optimization, and Website stress testing.

In my ongoing efforts to migrate my fun side projects and coding experiments from SVN to Git I’ve come across some of my favorite Python based apps – which are all available in their respective repos on BitBucket, as follows:

IRC Bot Commander

  • What it does: it’s an IRC bot that takes commands and does your bidding on whichever remote server the bot is installed on.
  • How it does it: the bot runs on whatever server you install it on, then it connects to the IRC server and channel you configured it to connect to and it waits for you to give it commands, then it execs the commands and returns the output to your IRC chat window.

MacroBase – MySQL Analytics

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Simple MySQL: using TRIGGERs to keep datetime columns updated without direct SQL calls

If you’ve ever used non-opensource code, or applications that you don’t have complete control over, then you may have run into situations you need to alter data on a per-row basis but been unable to do so for lack of application SQL access. The solution to this type of problem is to use a MySQL TRIGGER, which allows us to execute arbitrary SQL commands when defined events occur. Why is this useful and how does it work? Well…

For example, I have a freeRADIUS server that uses MySQL as a backend for the user authentication, and one of my server applications (HostBill) provides a freeRADIUS plugin that allows my users to manage their RADIUS accounts; however the default freeRADIUS schema lacks a DATETIME column on the user table. When a user is created (INSERT) or has their password changed (UPDATE) I have no row data that tells me the dates when these operations were issued. Typically this would be a trivial change: issue an ALTER TABLE …

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OpenCode: MySQL procedures + python + shell code repositories now public

I write a fair number of scripts on this site and have posted a lot of code over the years. Generally if I am not pasting the code to be viewed on the webpage then I link to a file that a user can download; which leads to a lot of mish-mash code that doesn’t have a home. I’ve always kept the code files in a private SVN repo over the years but have recently moved them all to BitBucket Git repositories. So here they are: lots of code samples and useful bits of programming to save time.

Generic Shell Scripts:
Generic Python Scripts:
Generic MySQL Stored Procs: …

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Simple MySQL: Converting ANSI SQL to SQLite3

I was digging through some old project code and found this script. Sometimes one finds oneself in an odd situation and needs to convert regular SQL, say from a MySQL database dump, into SQLite3 format. There’s not too much else to say, but here is a script that helps with the process. It can likely be improved but this handles the items that came up during conversion on initial runs.

# AUTHOR: Matt Reid
# DATE: 2011-03-22
if [ "x$1" == "x" ]; then
   echo "Usage: $0 "
cat $1 |
grep -v ' KEY "' |   
grep -v ' UNIQUE KEY "' |
grep -v ' PRIMARY KEY ' |
sed '/^SET/d' |          
sed 's/ unsigned / /g' | 
sed 's/ auto_increment/ primary key autoincrement/g' |
sed 's/ smallint([0-9]*) / integer /g' | 
sed 's/ tinyint([0-9]*) / integer /g' |  
sed 's/ int([0-9]*) / integer /g' |      
sed 's/ character set [^ ]* / /g' |      
sed 's/ enum([^)]*) / varchar(255) /g' | 
sed 's/ on …
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