Planet HantsLUG

May 30, 2016

Steve Kemp

A mixed weekend

This past seven days have been a little mixed:

  • I updated documentation on my simple object store.
  • I created a simplified alerting system.
    • Heavily inspired by something we use at work.
    • My version is much much simpler, but still useful enough to alert me of outages (via hearbeats) and unread email. (Both of which are sent via pushover notifications.)
  • I bought a pair of cheap USB "game controllers"
    • And have spend several hours playing SNES games such as Bomberman 2, and Super Mario Brothers 3.
    • I'm using mednafan, as it supports cheats, fullscreen, sound, and is pretty easy to drive.

Finally I spent the tail end of the weekend being a little red, sore, and itchy. . I figured this was a surprising outbreak of Dyshidrosis on my hands, and eczema on my body. Instead I received a diagnosis of Scarlet Fever. So now I feel somewhat Dickensian!

Apparently this infection is on the rise!

May 30, 2016 03:26 AM

May 19, 2016

Steve Kemp

Accidental data-store .. is go!

A couple of days ago I wrote::

The code is perl-based, because Perl is good, and available here on github:

..

TODO: Rewrite the thing in #golang to be cool.

I might not be cool, but I did indeed rewrite it in golang. It was quite simple, and a simple benchmark of uploading two million files, balanced across 4 nodes worked perfectly.

https://github.com/skx/sos/

May 19, 2016 06:38 PM

May 18, 2016

Steve Kemp

Accidental data-store ..

A few months back I was looking over a lot of different object-storage systems, giving them mini-reviews, and trying them out in turn.

While many were overly complex, some were simple. Simplicity is always appealing, providing it works.

My review of camlistore was generally positive, because I like the design. Unfortunately it also highlighted a lack of documentation about how to use it to scale, replicate, and rebalance.

How hard could it be to write something similar, but also paying attention to keep it as simple as possible? Well perhaps it was too easy.

Blob-Storage

First of all we write a blob-storage system. We allow three operations to be carried out:

  • Retrieve a chunk of data, given an ID.
  • Store the given chunk of data, with the specified ID.
  • Return a list of all known IDs.

 

API Server

We write a second server that consumers actually use, though it is implemented in terms of the blob-storage server listed previously.

The public API is trivial:

  • Upload a new file, returning the ID which it was stored under.
  • Retrieve a previous upload, by ID.

 

Replication Support

The previous two services are sufficient to write an object storage system, but they don't necessarily provide replication. You could add immediate replication; an upload of a file could involve writing that data to N blob-servers, but in a perfect world servers don't crash, so why not replicate in the background? You save time if you only save uploaded-content to one blob-server.

Replication can be implemented purely in terms of the blob-servers:

  • For each blob server, get the list of objects stored on it.
  • Look for that object on each of the other servers. If it is found on N of them we're good.
  • If there are fewer copies than we like, then download the data, and upload to another server.
  • Repeat until each object is stored on sufficient number of blob-servers.

 

My code is reliable, the implementation is almost painfully simple, and the only difference in my design is that rather than having an API-server which allows both "uploads" and "downloads" I split it into two - that means you can leave your "download" server open to the world, so that it can be useful, and your upload-server can be firewalled to only allow a few hosts to access it.

The code is perl-based, because Perl is good, and available here on github:

TODO: Rewrite the thing in #golang to be cool.

May 18, 2016 06:49 PM

Debian Bits

Imagination accelerates Debian development for 64-bit MIPS CPUs

Imagination Technologies recently donated several high-performance SDNA-7130 appliances to the Debian Project for the development and maintenance of the MIPS ports.

The SDNA-7130 (Software Defined Network Appliance) platforms are developed by Rhino Labs, a leading provider of high-performance data security, networking, and data infrastructure solutions.

With these new devices, the Debian project will have access to a wide range of 32- and 64-bit MIPS-based platforms.

Debian MIPS ports are also possible thanks to donations from the aql hosting service provider, the Eaton remote controlled ePDU, and many other individual members of the Debian community.

The Debian project would like to thank Imagination, Rhino Labs and aql for this coordinated donation.

More details about GNU/Linux for MIPS CPUs can be found in the related press release at Imagination and their community site about MIPS.

by Laura Arjona Reina at May 18, 2016 07:30 AM

May 16, 2016

Debian Bits

New Debian Developers and Maintainers (March and April 2016)

The following contributors got their Debian Developer accounts in the last two months:

  • Sven Bartscher (kritzefitz)
  • Harlan Lieberman-Berg (hlieberman)

Congratulations!

by Ana Guerrero Lopez at May 16, 2016 10:10 PM