This neat one line command can be of interest when you are rebuilding a MySQL slave and replication is currently catching up.

$ watch --interval=1 --differences 'mysql -uuser -ppassword -e "show slave status\G"'

You will see the standard SHOW SLAVE STATUS output, but the watch command presents an updated view every second, and highlights differences. This can be useful in a background window to keep an eye on those ‘Seconds Behind Master’.

*************************** 1. row ***************************
             Slave_IO_State: Waiting for master to send event
                Master_Host: 10.10.10.10
                Master_User: slave
                Master_Port: 3306
              Connect_Retry: 60
            Master_Log_File: mysql-bin.000626
        Read_Master_Log_Pos: 88159239
             Relay_Log_File: slave-relay.000005
              Relay_Log_Pos: 426677632
      Relay_Master_Log_File: mysql-bin.000621 …

I had the opportunity to review a client’s production Drupal installation recently. This is a new site and traffic is just starting to pick up. Drupal is a popular LAMP stack open source CMS system using the MySQL Database.

Unfortunately I don’t always have the chance to focus on one product when consulting, sometimes the time can be minutes to a few hours. Some observations from looking at Drupal.

Disk footprint

Presently, volume and content is of a low volume, but expecting to ramp up. I do however find 90% of disk volume in one table called ‘watchdog’;

+--------------+--------------+--------------+-------------+--------+
| table_schema | total_mb     | data_mb      | index_mb    | tables |
+--------------+--------------+--------------+-------------+--------+
| xxxxx        | 812.95555878 | …

This week I was the invited speaker to give a 4 hr presentation to the Federal Government Sector in Washington DC on “Best Practices in Migrating to MySQL“. This was a followup to my day long “MySQL for the Oracle DBA Bootcamp” which I presented in Washington DC last year. It was good to see a number of attendees from my first DC presentation.

There was good attendance across various government departments and companies providing services to the government sector, as well a variety of job descriptions.

Thanks to Carahsoft and Sun/MySQL for organizing and sponsoring the event. Thanks also to Phil Hildebrand who provided fantastic support during my preparation answering all my SQL Server questions.

Thanks also …

MySQL by default is vary lax with data validation. Silent conversions is a concept that is not a common practice in other databases. In MySQL, instead of throwing an error, a warning was thrown and many applications simply did not handle warnings. With the introduction of sql_mode=STRICT_ALL_TABLES (or TRADITIONAL), in MySQL 5, a better level of validation now exists.

My understanding was that Warnings are now thrown as Errors, therefore eliminating the need to do a SHOW WARNINGS to confirm any problems after every query (this is a performance overhead on a high volume system due to the round trip latency).

However I found an instance where MySQL in STRICT Mode still throws warnings, leading to the question, are there any other areas, and does the earlier statement “Warnings are now thrown as Errors” hold true.

Here is my seeding process to showing the problem.

mysql> create table i(i tinyint, unique key( …

The current size of a MySQL 5.1.30 installation is around 420M.

$ du -sh .
426M    .

A further breakdown.

$ du -sh *
213M    bin
20K     COPYING
9.8M    docs
8.0K    EXCEPTIONS-CLIENT
436K    include
12K     INSTALL-BINARY
121M    lib
504K    man
4.0K    my.cnf
77M     mysql-test
4.0K    README
20K     scripts
2.3M    share
2.9M    sql-bench
100K    support-files

A means to reduce the footprint by 25% is to delete some unused stuff.

$ rm -rf docs/ mysql-test/ sql-bench/
$ du -sh .
337M    .

It’s no big deal, however it certainly does cut down on verbose output in the backup logs removing the mysql-test directory and files.

Few days ago we were chatting in our corporate Campfire room and one of the guys asked me what do I think about Rails developers hiring process, what questions I’d ask a candidate, etc… This question started really long and interesting discussion and I’d like to share my thoughts on this question in this post.

So, first of all I would like to explain what kind of interviews I really hate Ever since I was thinking of myself as of a developer (many years ago) and was going to “software developer position” interviews I really hated questions like “What is the name and possible values of the third parameter of the function some_freakin_weird_func() from some_weird.h” or “How to declare a virtual destructor and when it could be useful?”… All my life I had pretty practical thinking and never bothered to learn APIs or some really deep language concepts that are useful in 1% of …

These are my spoken notes from last week's earnings call - rather than recraft them, I figured I'd simply republish.

_______________________________

And thank you all for joining us this afternoon. 

I'll start with some perspective on our Q2 results and the current climate, then follow-up with commentary on our products disclosure - slides 6 and 7 in the slide deck. Then I'll turn it over to Mike Lehman (Sun's CFO) for commentary on financial metrics, and an update on the restructuring plan we announced back in November.

Overall, results for Q2 were in line with what we expected, as macro worries factored into customer discussions across all geographies. These concerns resulted in decisions related to higher end system purchases being pushed out - so billings were down year over year for SPARC Enterprise …

As Peter Gulutzan just announced - we’re opening up a “new” worklog that we’ve been working on, Worklog #2360. PERFORMANCE_SCHEMA.

In fact - it’s not “new”, it’s something that has been in the worklog system for a long time, and has had much much much discussion internally between some of the brightest engineers in the group.

The astute among you out there that read my post on the benchmark with Maria for the the tokutek challenge, may have noted this in the configure line that I used:

./configure –prefix=/usr/local/mysql –localstatedir=/data0/mysqldata \
–without-query-cache –with-extra-charsets=complex –with-pic …

A little late to post (I’ve known a while), but I thought I’d plug my talk for any interested readers out there, that are going to the conference, and use MEM!

I’m talking about Extending MySQL Enterprise Monitor with Custom Advisors, Graphs and Data Collections.

I’ve had the pleasure of working with the team that writes the MEM software (the “Enterprise Tools” team, internally and lovingly known as the “Merlin Team“, the codename that has survived various renames of the product!) for a little over 3 years now. I can’t say I was there at it’s conception, but I started working with them before the initial release of the product, and have watched (and I like to think helped shape) the product very closely whilst being the “Support Coordinator” for the Support Team for MEM. It’s …

So I saw the tokutek challenge, and wondered to myself how Maria would get along with it. I duly downloaded a 6.0 tree, and the iiBench code, tinkered with it to make it actually build, and fired things up.

I watched it closely, for about a day, then got bored and forgot about it. I remembered today that I should take a look!

CPU Usage (Quad Core)

Average rows per second inserted

Load Averages

You can …