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Stewart Smith: MySQL Cluster on POWER8

Tue, 2014-11-11 23:26

So, I’ve written previously on MySQL on POWER, and today is a quick bit of news about MySQL Cluster on POWER – specifically MySQL Cluster 7.3.7.

I ran into three main issues in getting some flexAsync benchmark results. One of them was the fact that I wanted to do this in the middle of all the POWER8 machines I usually use moving buildings (hard to run benchmarks when computers are packed up in boxes on a truck).

The next issue was that ndbmtd (the multi-threaded data node) needs memory barriers for the magic message passing stuff between threads. So, that’s pretty easy (about an eight line patch).

The next issue was in the results from flexAsync, it turns out 32bit math is a bad idea with results from my POWER8 box.

My preliminary performance numbers are fairly promising (actually… what is the world record for a single machine and NDB these days? Single data node?). I think there’s a bit more low hanging fruit and a couple more things that are a bit more involved.

Bugs with patches:

  • Bug 74782 – compile fix (memory barriers for POWER)
  • Bug 74781 – flexAsync uses 32bit math, leading to incorrect summary on POWER8

Andrew Pollock: [life] Day 286: Kindergarten, startup stuff, uniform shopping

Tue, 2014-11-11 18:25

This morning was a bit cooler on account of it being overcast, so I managed to leap out of bed and go for a run. I realised afterwards that it's been quite a while since I've gone for one. I mustered 7 km this morning before blowing up, mostly due to a lack of willpower to keep slogging on in the heat. I was happy I lasted that long.

I made up for last week's lost progress on my real estate licence course and knocked over a unit and put it in the mail. I managed to get through the first two parts of another unit, and hopefully I can finish off the third part and get it into the mail tomorrow.

I also did some productive procrastinating and may actually have a successful backup of daedalus currently getting written out to virtual "tape". Who would have thought the TCP keepalive interval would be the cause of all the problems?

I biked to Kindergarten to pick Zoe up, and then we went to the post office. I thought we should get Zoe's school uniform shopping out of the way, so under protest, we headed to the uniform shop on the way home from the post office.

For some reason, Zoe hadn't been excited about the prospect of going uniform shopping. Every time I'd asked her if she wanted to do it, she'd declined. Once we got into the store and were trying on uniforms though, she wanted to wear one home on the bike. So that's the uniform shopping out of the way, we just have to get some shoes, which I'll leave until the last minute in case her feet grow.

After we got home, Zoe watched some TV and I had a crack at making a herb and garlic pull-apart that I've been wanting to try and make for a while. It's smelling delicious in the oven as I write.

I'm looking forward to closing out the day with a yoga class.

Glen Turner: USB Vendor ID for documentation

Tue, 2014-11-11 16:36

If you are writing documentation then you don't want to use an assigned magic number, like a real IP address or a real DNS name. That can readily lead to: misunderstandings; operational difficulties for the vendor's equipment if the number escapes from documentation into production; and difficulties for the author because of the risk of defamation and trademark infringement.

For these reasons standards associations commonly issue a range of their magic numbers for documentation purposes. For example, the IETF issued magic numbers for documentation in RFC2606 for DNS names, in RFC5737 for IPv4 addresses and in RFC3849 for IPv6 addresses.

I was writing some documentation for using udev, and rather than defame some vendor by suggesting that their product may need a workaround, I asked the USB Implementors' Forum if there is a USB Vendor ID for documentation purposes.

Sadly, there is not:

From: USB-IF Administration <redacted>

Subject: RE: Vendor-ID for use in documentation

Date: 11 November 2014 2:34:21 PM ACDT

To: Glen Turner <redacted>

Dear Glen,

Thank you for your message. Vendor IDs (VIDs) are owned by the vendor company and are assigned and maintained by the USB-IF only. We do not have a generic VID for documentation.

Regards, redacted

David Rowe: OpenRadio – a one day Software Defined Radio project

Tue, 2014-11-11 11:29

For the 2015 Linux Conference, I am working with Kim Hawtin and Mark Jessop on a 1 day Open Radio Mini-conference.

In this mini-conf a classroom of people will solder together their very own software defined radio (SDR) transceivers in just a few hours. It will be capable of receiving signals on the HF radio bands (3 to 30 MHz), and short range transmission of FSK/PSK data on the 13.5 and 27 MHz ISM bands (no license required).

The project is being documented on our OpenRadio Wiki. It’s completely open source and we have published the PCB CAD files, and the parts list with Digikey/Element14 catalogue part numbers. It’s based on the soft-rock radio designs.

We have put a lot of effort into making the radio easy to build. For example a minimum of (large footprint) surface mount parts, and a simple, fast to assemble design. We have intentionally included one or two inductors and transformers to wind to give people a taste of the complete radio assembly experience. With a little supervision, the project is quite suitable for radio/electronics beginners or school age children. It’s a “crystal set” for the 21st century.

Mark has done a great job designing the radio, and we have just received the prototype PCBs:

This week we will assemble and test the first prototypes, measure how long they take to build, and noting possible snags for inexperienced builders. Then our good friend Edwin from Dragino will prepare and ship kits for the mini-conf.

The resources we create for this project (wiki, CAD files, software, kits from Dragino) will remain available after LCA. So you, your radio club, hackerspace, or even school class will have access to an easy to build a Software Defined Radio (SDR).

linux.conf.au News: Speaker Feature: Fraser Tweedale, Peter Chubb

Tue, 2014-11-11 07:27
Fraser Tweedale FreeIPA: Open Source Identity Management

2:15pm Friday 16th January 2015

Fraser is a developer at Red Hat, where he works on the FreeIPA identity management solution and Dogtag Certificate System. He is passionate about security and privacy. In his spare time, Fraser writes a lot of Haskell and patiently awaits the strongly-typed functional programming revolution.

For more information on Fraser and his presentation, see here. You can follow his as @hackuador and don’t forget to mention #LCA2015.



Peter Chubb SD Cards and filesystems for Embedded Systems

2:15pm Friday 16th January 2015

Peter has been hacking on UNIX since 1979, and has never used Windows. He currently does system (kernel and low-level) programming in a Linux environment for NICTA.

Peter's research interests include operating system algorithms for scalability, including storage, scheduling, memory management, and locking. He is also interested in systems performance measurement and optimisation.

Related hobbies include music, photography and fine wines, these also occasionally lead to research.

For more information on Peter and his presentation, see here.