I’ll be speaking at Surge again this year. This time, unlike last year’s talk, I’m tackling a very concrete topic: extracting scalability and performance metrics from TCP network traffic. It turns out that most things that communicate over TCP can be analyzed very elegantly just by capturing arrival and departure timestamps of packets, nothing more. I’ll show examples where different views on the same data pull out completely different insights about the application, even though we have no information about the application itself (okay, I actually know that it’s a MySQL database, and a lot about the actual database and workload, but I don’t need that in order to do what I’ll show you). It’s an amazingly powerful technique that I continue to find new ways to apply to real systems.

Take a …

There are several parameters to set a timeout on MySQL :

But I would like to focus on wait_timeout (or interactive_timeout depending on how you connect)

This timeout allows MySQL to automatically close a connection in case of non-activity during the time defined by this parameter (default value is 28000 seconds).

The problem I wish to explain here may happen when this timeout is set to a low value (about 10 to 30 seconds).

Indeed, in this case, this timeout may have serious consequences, look at that :
[The wait_timeout parameter is set to 10 seconds in this case]

You are connected through the standard MySQL client and you need to run a delete query (bypass autocommit) :

• mysql> start transaction;
• [ You …

I prefer to say right now, the answer is no !
However, mpstat can provide a minimum service to show essentials information about your CPU usage :

Show usage for all CPU (every 1s) : mpstat 1

Show usage for CPU number 2 (every 1s) : mpstat -P 2 1

It’s possible to retrieve CPU load (user/sys) and IO waits via a simple interface.
And I like the opportunity to focus on a single CPU. It can be a usefull tool for monitoring and scripting.

But there isn’t any information about the run queue processes and this is the bad news here !

So, let me know if you’ve used this tool, all comments are welcome.

…

Even if you think you know everything about LEFT JOIN, I bet you will learn something or two in this post! The difference between the ON clause and the WHERE clause. A simple way to better understand a complex Matching-Condition with WHERE … IS NULL clause. The difference between the Matching-Conditions and the Where-conditions. A […]

This is cross-posted from http://www.ssdperformanceblog.com/2011/07/fusionio-720gb-write-performance/

I’ve got a FusionIO card with 720GB capacity on my hands.

It came with a HP ProLiant DL380 G6 server. Interesting that this card is not listed on FusionIO’s products page, and neither I see such card in the list of available configurations on HP’s site. I guess this card comes as some customization option.

It seems to be a MLC card (I did not hear about FusionIO SLC cards with a capacity greater than 320GB) and cost is always an interesting question. On HP.com I can find a HP IO Accelerator (which is a re-branded FusionIO card) …

I’m speaking at the great multi-speaker MySQL Meetup event taking place in London, 18th of July.
I’ll talk about approaches to application scalability which is one of my favorite topics and would be a good fit both for MySQL DBAs and Developers. Make sure you register on meetup page as otherwise you will not be able to get into the building.

As an extra bonus I will give away couple of tickets to the Percona Live, London scheduled for late October. Must to attend conference if you’re serious about MySQL.

Hope to see you there !

Virtualizing all parts of today’s software infrastructure has become a priority for many. Creating a more flexible and dynamic environment with improved availability enables organizations to accelerate innovation, reduce time to market, cut costs and deliver higher uptime.

Databases have rarely been the first candidates for virtualization – mainly as a result of fears in consolidating such critical resources, and in I/O overhead that may have degraded service levels. However with improvements in hypervisor designs coupled with more powerful commodity server hardware and repeatable best practices, many of these concerns are rapidly diminishing.

It was in this context that we began development of the Oracle VM Template for MySQL Enterprise Edition, making the world’s leading web database radically simpler to deploy, manage, and support in a virtualized environment.

Along with the development team, we will be hosting a …

I’ve just sent an email to the Maatkit discussion list to announce a planned change to how Maatkit (and Aspersa) are developed. In short, Percona plans to create a Percona Toolkit of MySQL-related utilities, as a fork of Maatkit and Aspersa. I’m very happy about this change, and I welcome your responses to that thread on the discussion list.

I’ll be speaking at Surge again this year. This time, unlike last year’s talk, I’m tackling a very concrete topic: extracting scalability and performance metrics from TCP network traffic. It turns out that most things that communicate over TCP can be analyzed very elegantly just by capturing arrival and departure timestamps of packets, nothing more. I’ll show examples where different views on the same data pull out completely different insights about the application, even though we have no information about the application itself (okay, I actually know that it’s a MySQL database, and a lot about the actual database and workload, but I don’t need that in order to do what I’ll show you).

I prefer to say right now, the answer is no !
However, mpstat can provide a minimum service to show essentials information about your CPU usage :

Show usage for all CPU (every 1s) : mpstat 1

Show usage for CPU number 2 (every 1s) : mpstat -P 2 1

It’s possible to retrieve CPU load (user/sys) and IO waits via a simple interface.
And I like the opportunity to focus on a single CPU. It can be a usefull tool for monitoring and scripting.

But there isn’t any information about the run queue processes and this is the bad news here !

So, let me know if you’ve used this tool, all comments are welcome.

Related Posts :

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