If you are unfamiliar with what to monitor in MySQL, starting with looking at what popular Monitoring products monitor. For example, the following is the list of MySQL Cacti Plugin measurements.

Innodb Buffer Pool Activity

• Pages Created
• Pages Written
• Pages Read

Innodb Buffer Pool Pages

• Pool Size
• Database Pages
• Free Pages
• Modified Pages

Inoodb File I/O

• File Reads
• Files Writes
• Log Writes
• File Fsyncs

Innodb Pending I/O

• Aio Log Ios
• Aio Sync ios
• Buffer Pool Flushes
• Chkp Writes
• Ibuf Aio Reads
• Log Flushes
• Log Writes
• Normal Aio Reads …

As I outlined in Part 1 MySQL Proxy can be one tool for performing SQL analysis. The impact with any monitoring is the art of monitoring will affect the results, in this case the performance. I don’t recommend enabling this level of detailed monitoring in production, these techniques are designed for development, testing, and possibly stress testing.

This leads to the question, how do I monitor SQL in production? The simple answer to this question is, Sampling. Take a representative sample of your production system. The implementation of this depends on many factors including your programming technology stack, and your MySQL topology.

If for example you are using PHP, then defining MySQL proxy on a production system, and executing firewall rules to redirect incoming 3306 traffic to 4040 for a period of time, e.g. 2 …

In the past few weeks I've been implementing advanced search at Plaxo, working quite closely with Solr enterprise search server. Today, I saw this relatively detailed comparison between Solr and its main competitor Sphinx (full credit goes to StackOverflow user mausch who had been using Solr for the past 2 years). For those still confused, Solr and Sphinx are similar to MySQL FULLTEXT search, or for those even more confused, think Google (yeah, this is a bit of a stretch, I know).

Similarities

• Both Solr and Sphinx satisfy all of your requirements. They're fast and designed to index and search large bodies of data efficiently.
• Both have a long list of high-traffic sites …

Long before there was the official Query Analyzer (QUAN), a component of MySQL Enterprise, SQL analysis was possible using MySQL Proxy.

The following is an introduction to logging and query analysis with MySQL Proxy.

Get MySQL Proxy

You need to first download MySQL Proxy. In this example I am using the Linux RHEL5 64bit OS and Version 0.7.2

$ wget http://dev.mysql.com/get/Downloads/MySQL-Proxy/mysql-proxy-0.7.2-linux-rhel5-x86-64bit.tar.gz/from/http://mirror.trouble-free.net/mysql_mirror/
$ tar xvfz mysql-proxy-0.7.2-linux-rhel5-x86-64bit.tar.gz
$ ln -s mysql-proxy-0.7.2-linux-rhel5-x86-64bit mysql-proxy
$ export PATH=`pwd`/mysql-proxy/sbin:$PATH
$ mysql-proxy --help-all

Pre-requisites

MySQL Proxy uses TCP/IP, so it is important you connect via the actual …

I have several side projects when time permits and one is that of benchmarking various MySQL technologies (e.g. MySQL 5.0,5.1,5.4), variants (e.g. MariaDB, Drizzle) and storage engines (e.g. Tokutek, Innodb plugin) and even other products like Tokyo Cabinet which is gaining large implementations.

You have two options with benchmarks, the brute force approach such as Sysbench, TPC, sysbench, Juice Benchmark, iibench, mysqlslap, skyload. I prefer the realistic approach however these are always on client’s private data. What is first needed is better access to public data for benchmarks. I have compiled this list to date and I am seeking additional sources for reference.

• Feebase – Data is in clean loadable format
• IMDB – Not clean, but Roland Bouman is working on …

After the slow down due to vacation and warm weather we are ready for a series of educative Italian webinars on MySQL. Here is the list:

Semptember 10@10am CET - "Top 5 Tuning tips for MySQL"
Are your applications slow during peak times? Is the database running slowly? Do you find difficult to pinpoint performance problems? Then this webinar is for you!I will cover the top 5 tips to speed up your MySQL databases from a developer as well as DBA point of view.

October 8@10am CET - "Introduction to MySQL for Windows"
Do you know that MySQL is used extensively on Windows? Would you like to learn the tools that we provide?
Join this webinar! We will discuss the advantages of using MySQL on the …

I manage several mysql servers and often on these servers for security reasons the SUPER account is not allowed external network access, so access is made to localhost. When connecting to several hosts at the same time, for example from different ssh sessions, this can be inconvenient as the \h prompt only ever shows localhost and not the hostname of the server to which I’m connected.

The following small patch against 5.1.36 which can also be found here adds a new \H option which behaves the same as \h except in this case the hostname is shown.

diff --git a/Docs/mysql.info b/Docs/mysql.info
index 7747201..dffacfd 100644
--- a/Docs/mysql.info
+++ b/Docs/mysql.info
@@ -20512,6 +20512,8 @@ sequences.
 `\D'        The full current date
 `\d'        The default database
 `\h'        The server host
+`\H'        Same as `\h' except that if the server host is …

Before you think I’ve posted an animal story in my MySQL category please read on. For reference, The RAT and the CAT is something I wrote back in 2006, that explains the CAT part.

I was reviewing the website performance tonight of a client. I had access to an idle system so being lazy in collecting SQL after my initial audit of the system and MySQL, I turned on the General Query log and hit the home page. NOTE: Do not do this on a running production system, especially with any volume.

What I got was 77 lines of output (after I removed newlines in the queries). 74 were queries, and 72 were from the same table, via some unnecessarily complex sub-joins. I wish I could have laughed but it wasn’t really funny.

My Friday wisdom for writing SQL is this:

• Don’t write duplicate SQL statements
• Look the entire …

I just discovered today in the MySQL 5.1 Reference Manual a handy set of additional indexes in the System Navigation section.

• Index
• Standard Index
• C Function Index
• Command Index
• Function Index
• INFORMATION_SCHEMA Index
• Transaction Isolation Level Index
• JOIN Types Index
• Operator Index
• Option Index
• Privileges Index
• SQL Modes Index
• Status Variable Index
• Statement/Syntax Index
• System Variable Index

Perhaps they have been around for some time and I’ve not noticed, but there are much better then searching when you know the content type as per the index list on what you are searching for.

As a consultant I would be rich if I made money every time when asking “Have you checked the MySQL error log?”

Today’s special found in a 13GB MySQL server error log.

090819 22:49:37InnoDB: Warning: difficult to find free blocks from
InnoDB: the buffer pool (1101071 search iterations)! Consider
InnoDB: increasing the buffer pool size.
InnoDB: It is also possible that in your Unix version
InnoDB: fsync is very slow, or completely frozen inside
InnoDB: the OS kernel. Then upgrading to a newer version
InnoDB: of your operating system may help. Look at the
InnoDB: number of fsyncs in diagnostic info below.
InnoDB: Pending flushes (fsync) log: 0; buffer pool: 0
InnoDB: 167 OS file reads, 1 OS file writes, 1 OS fsyncs
InnoDB: Starting InnoDB Monitor to print further
InnoDB: diagnostics to the standard output.
090819 22:49:37InnoDB: Warning: difficult to find free blocks from
InnoDB: the buffer pool (1101051 search iterations)! Consider
InnoDB: increasing …