Ronald Bradford
MySQL Expert

MySQL Expert Ronald Bradford shares valuable input in MySQL Performance Tuning, MySQL Scalability and general MySQL Help from his two decades of working with MySQL, Oracle, Ingres and development technologies.

I am available for MySQL consulting and contract opportunities.

Exciting upcoming MySQL events

January 24th, 2012

At the IOUC leaders’ summit in San Francisco this week, key leaders from Oracle, Java and MySQL user groups world wide have been meeting. This has included the key Oracle MySQL resources from the community, marketing and product teams. The Java User Groups and MySQL User Groups have been well represented and there has been very welcoming discussion with the IOUC about how we can become active within the Oracle Community.

There has been key discussions of upcoming and proposed MySQL events including the great outreach by the Oracle MySQL team with existing Open Source conferences this year including Scale, FOSDEM and South East Linuxfest just to name a few.

You can see the upcoming events at http://mysql.com/news-and-events/events/. In February alone there will be events in North Carolina, California, Texas, Frankfurt Germany and Stockholm Sweden. I will also be speaking in Denver at 2 events and Salt Lake City.

There is a much longer list then what is shown here, and we are working on getting the full list more available.

More info by Dave Stokes at SCaLE’s MySQL Day a big hit and Keith Larson More User Groups.

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Why is searching the manual so hard

January 14th, 2012

As a consultant I often use the MySQL Reference Manual to provide additional information for clients. I am very happy to recognize the quality of the content in the MySQL documentation, but why is the searching of the manual so, so bad?

While reading the General Security Issues section of the MySQL 5.5 manual, I performed a search for “CREATE USER”. I was not asking for anything abstract, this is an actual SQL command. I was rather horrified to find that the results could not even list the appropriate manual page in the first page of results.

I am not an expert in full-text search, however it does not take a rocket scientist to realize that a SQL keyword, the title of a page, in the language of the current page (English) and the current version of the Manual (5.5) should be an easy result. This is a simple weighted result right? Wrong.



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Posted in Databases, MySQL, Professional | 11 Comments »

The most important MySQL Reference Manual page

January 5th, 2012

In my opinion, The Server Option and Variable Reference at http://dev.mysql.com/doc/refman/5.5/en/mysqld-option-tables.html rates as my most important page. This is a consolidated index that enables a drill down to the Server Command Options, System Variables, Startup and replication specifics, as well as important information on default values and differences between versions including point releases.

However, there is another page not in the actual manual, but at http://dev.mysql.com/doc/mysqld-version-reference/en/mysqld-version-reference-optvar.html which is an Options/Variables reference akin to the Reference Manual, but includes a 5.x version matrix.

Recently I was asked about some options that had to be removed from an upgrade to MySQL 5.5. Some of these were obvious, however not all. This page enabled me to confirm deprecation (as expected), and also point to important reference material.

These options where:

  • default_table_type
  • log_long_format
  • master-connect-retry
  • default-character-set

The use of table_type was a 3.x/4.x relic, replaced with engine, so I was surprised this option was still even valid. The option replaced with default_storage_engine. The page defined this as deprecated in MySQL 5.0
log_long_format is also old, and definitely modified since MySQL 5.1 with the general_log_xxx options. In fact this has been deprecated since 4.1
I have never liked the master-xxx options, in favor of a CHANGE MASTER command and synchronization issues with the master.info file and master-xx options. master-connect-retry and several other options were deprecated in 5.1.17. On a side note, if you look at this option in the MySQL 5.5 Reference Manual you get Obsolete options. The following options are removed in MySQL 5.5. If you attempt to start mysqld with any of these options in MySQL 5.5, the server aborts with an unknown variable error. To set the replication parameters formerly associated with these options, you must use the CHANGE MASTER TO … statement (see Section 12.4.2.1, “CHANGE MASTER TO Syntax”).
Finally default-character-set. Initially I thought that is definitely still applicable, however the handy cross reference reminded me, this is also deprecated in MySQL 5.0 and the Reference Manual again stating default-character-set is also deprecated in 5.0 in favor of character-set-server.. The name has simply changed in newer version.

With so many options and as a consultant I work with many different versions each week, I sometimes need a refresher of the changes in the versions of the past 5 years. Definitely my second most important page.

If you have a favorite page, please let me know.

I would also like to say thank you to the Oracle/MySQL Documentation team that do a great job in providing an excellent resource to an open source product. We would all do well to appreciate this in comparison to other open source documentation in companion technologies and related tools. With every new release of a MySQL product you don’t realize that somebody reviewed, tested and wrote about features without receive the limelight.

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Posted in Databases, MySQL, Professional | 2 Comments »

Binary Log Replayer

December 22nd, 2011

When using the replication slave stream, or mysql command line client and mysqlbinlog output from a binary/relay log, all statements are executed in a single thread as quickly as possible.

I am seeking a tool to simulate the replay of the binary/relay log for a benchmark at a pace that is more representative to original statements. For a simple example, if the Binary Log has 3 transactions in the first second, 2 transactions in the second second, and 5 transactions in the third second, I am wanting to simulate the replay to take roughly 3 seconds, not as fast as possible (which would be sub-second). The tool should try to wait the remainder of a second before processing SQL statements in the incoming stream.

Does anybody know of a tool that currently provides this type of functionality? Any input appreciated before I create my own.

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Posted in Databases, MySQL, Professional | 8 Comments »

Speaking in Denver

November 22nd, 2011

Following a heavy schedule in the last month speaking in Tokyo, Beijing, Manila and Auckland it is nice to be on home soil for upcoming speaking. I will be in Denver, Colorado for RMOUG 2012 from February 14-16, 2012 where I will be speaking about the essentials of MySQL security.

I hope to also organize another presentation in the area for the local MySQL users group. More to follow.

And a friendly reminder, the annual MySQL conference is on again, same place (Santa Clara), same dates (April 10-12), same great speakers (too many to say), just a new primary sponsor. Why not submit a paper to present. Call for papers is still open, closing on December 5. More information at Percona Live MySQL Conference & Expo 2012.

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Do you have a MySQL horror story to share?

October 11th, 2011

I am looking for a few more unique examples to add to the final chapter of my upcoming book on MySQL Backup & Recovery. If you would like to share your fun experience, receive a mention and a free copy please let me know via comment. If you would like to share but not have your comment published, please note at top of your feedback.

Thanks for helping to contribute to a detailed list of what could go wrong and how to be prepared for a MySQL disaster.

Posted in Databases, MySQL | 1 Comment »

NoSQL from a RDBMS company

October 4th, 2011

Oracle has announced an open source product for the NoSQL space, the Oracle NoSQL Database. Unlike other popular products including Redis, MongoDB, Cassandra, Voldermort and many others, Oracle has set a benchmark on the features that are truly necessary for highly available data systems.

Many products in the NoSQL space have told you that consistency is not needed, eventual consistency is good enough, that transactions are not performant enough to include as a feature. No standards exists, there is no common interface for communication, or key features that products aim to meet or better. With this product, features including transactions, replicated data and failover which are built in, are features other open source NoSQL products will need to match.

Oracle NoSQL Database is a key value store, supporting a major/minor key for co-locating regularly accessed information for more consistent data retrieval. The API (built in Java) supports GET, PUT, and DEL operators. The system is designed to not have a single point of failure, and to support a node failure without impact. The replication factor is reported to enable up to 7 copies of information, which would be a feature to support cross data center management. The database driver is latency aware, so this can support load balancing operations for optimal performance.

I am excited to hear about this and looking forward to evaluating the software. I will be watching more closely how the integration of MySQL and Oracle NoSQL can be an offering for startups and Web 2.0

Posted in Databases, MySQL, Oracle NoSQL Database, Professional | 1 Comment »

Oracle Open World Presentations

October 4th, 2011

At Oracle Open World 2011 there has been a large number of MySQL presentations. You can download the slides of my two presentations at Explaining the MySQL Explain and Improving Performance with Better Indexes.

You can find additional supporting information for these presentations in the Effective MySQL: Optimizing SQL Statements book.

Posted in Databases, MySQL, MySQL Events, Professional | 1 Comment »

The Effective MySQL Book Series

October 3rd, 2011

Effective MySQL: Optimizing SQL StatementsAnnounced on Sunday at Oracle Open World 2011 is the release of the Effective MySQL book series starting with the “Optimizing SQL Statements” title. The goal of the Effective MySQL series is a highly practical, concise and topic specific reference providing applicable knowledge to use on each page. A feedback comment provided today was “no fluff” which is great comment to re-enforce the practical nature of the series.

Details on the Effective MySQL Optimizing SQL Statements page include a sample chapter, code downloads and purchase links for print and e-books at Amazon, McGraw-Hill and Barnes & Noble.

Posted in Databases, EffectiveMySQL, MySQL, Professional | No Comments »

Visualizing reqstat

September 28th, 2011

The reqstat tool was written to provide a vmstat like output of total web requests happening in real time. This really lightweight monitoring leverages memcached and has a trivial impact for immediate benefit. 

  $ ./reqstat 5 5
  epoch,time,rps,avg_req,last,%comp,---,threshold,exceed,last_excess
  1307723122,162522,25,125.92,75.25,48,---,150,9,175.55
  1307723127,162527,24,107.33,6.97,48,---,150,6,188.45
  1307723132,162532,25,118.39,97.63,50,---,150,8,151.37
  1307723137,162537,22,120.51,88.62,42,---,150,5,168.56
  1307723142,162542,26,106.62,6.12,51,---,150,6,167.81

While this is useful, I can see 22-26 requests per second, averaging 106-120 ms, visualizing this gives more information immediately available like:

It is easy to look at an average and lose site of the larger picture. What are the outliers, how many are there? Visualizing of larger samples (a later example which will show 10,000 rps across multiple servers) shows that the granularity is also critical.

This graphic is produced with Flot. A very simply javascript library. You can also use gnuplot, an example script is included in github.

This output is the result of benchmarking, this being generated from reqstat output with a script in my monitor git repository.

Posted in Data, Professional, Visualization | No Comments »

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