Please come and exercise my new SheevaPlug

[simonbrooke]

I've just bought myself a SheevaPlug; it arrived at lunchtime and you can play with it here. I've put a log of my setup of the beast here.

If you have a little play with the test app that's running on it, bear in mind that every page is built from data held in Postgres, is styled in real time using XSL, and is served by Tomcat, all running on a single 1.1 GHz ARM processor with 512Mb of RAM. The 'disk' is an 8Gb SD card[1]. The base operating system is Ubuntu 9.04 LTS. The test app is decidedly beta quality; it may break, and if it does I apologise.

I need to do some testing before I know whether this is an effective replacement for an Intel server, but on first impressions it really isn't bad. It's the size of a large wall wart, and it is claimed to draw 7 watts (although the temperature of the outside of the enclosure is about 25 Celsius, so I'd guess it's actually drawing a little more). It has no moving parts and is silent.

I think this - not the SheevaPlug especially, but the new generation of small ARM powered appliances and servers it foreshadows - could be game changing technology.

[1] Yes, I don't know how long an SD card will stand up to this sort of treatment - that's part of what I'm evaluating.

[chivapiano]

Hmmm ...
Looks like the server was down, can't connect   

[simonbrooke]

Hmmm ...
Looks like the server was down, can't connect   

Sorry, I messed up the DNS configuration. I've corrected it but the correction is taking a while to propagate. If you want to play, try http://217.34.156.183/

[NewIT_Marcus]

Regarding your installation / configuration log:

I usually see around 6W power consumption; I don't recall if I've ever seen 7W. Perhaps the devices one or both of us is using to read the power are inaccurate.

We like to boot from SD card, for lots of reasons, one of which you've touched upon (space limitation of internal NAND). Admittedly, using the SD card in this way will increase wear, but the NAND drive wears too; an SD card can be replaced, but the NAND drive can't (easily / cheaply).

shutdown -h should do what you want; the lights will change when the plug has powered down to the required state.

Thank you for writing up your experience, and good luck with the project.

[simonbrooke]

Regarding your installation / configuration log:

I usually see around 6W power consumption; I don't recall if I've ever seen 7W. Perhaps the devices one or both of us is using to read the power are inaccurate.

We like to boot from SD card, for lots of reasons, one of which you've touched upon (space limitation of internal NAND). Admittedly, using the SD card in this way will increase wear, but the NAND drive wears too; an SD card can be replaced, but the NAND drive can't (easily / cheaply).

shutdown -h should do what you want; the lights will change when the plug has powered down to the required state.

Thank you for writing up your experience, and good luck with the project.

I've now got near-real-time stats from the device online here. Remember, this is running a public-facing web application under Tomcat, with the database in Postgres, all on the SheevaPlug. As you can see it is not struggling at all - either on CPU (user CPU never exceeds 10%!) or on memory - although memory does seem to be creeping up slightly over time, perhaps indicating that I have a memory leak. Obviously, I'm trying to encourage people to play with the beast in order to increase the load on it, and I may move a production web app onto it soon in order to increase the load.

Marcus, I hear what you say about wearing the internal NAND. As far as I'm concerned this is very much a test device, and it is precisely that sort of question that I'm interested in evaluating. But at this moment it looks as if the answer to the question 'can a SheevaPlug replace a production web application server' seems to be a resounding 'yes'. It's possible that in a production deployment one would want to put a single database server - possibly also a SheevaPlug, but probably with a real hard disk - behind a group of SheevaPlug web application servers each running off SD card. But you could mount at least four of these in a single 1U rack chassis, probably with no fans, at below the capital cost and greatly below the running cost of equivalent Intel hardware.

In the data centre, this looks game changing.

[JustaGuy]

I'm glad to see a project going well.
I checked it out just now, it's been a couple days for your DNS to sort, & there are still some pages not loading.
==
Starting from here:
http://217.34.156.183/
These are links that work:
--
Stats:
http://www.journeyman.cc/munin/journeyman.cc/cooper.journeyman.cc.html
--
Interim start page:
http://217.34.156.183/
--
The map:
http://217.34.156.183/scenehere/
--
Sheeva's Wikipedia:
http://en.wikipedia.org/wiki/SheevaPlug
--
Ubuntu:
http://www.ubuntu.com/
--
openJDK:
http://openjdk.java.net/
--
Tomcat:
http://tomcat.apache.org/
--
Pgresql:
http://www.postgresql.org/
--
Apache:
http://httpd.apache.org/
--
Read more about the setup:
http://217.34.156.183/cooper.html
--
Join In:
http://217.34.156.183/scenehere/subscribe_verify_subscribers.jsp
--
Feedback:
http://www.surveymonkey.com/s/FTVFFZ3
--
Welcome stranger:
http://217.34.156.183/scenehere/subscriber
--
Scene Here:
http://217.34.156.183/scenehere/
==
These links aren't working:
--
From the first post in this thread:
http://cooper.journeyman.cc/
http://cooper.journeyman.cc/cooper.html
--
News:
http://cooper.journeyman.cc/scenehere/news/category_1.html
--
Help:
http://cooper.journeyman.cc/scenehere/news/category_2.html
--
Report Bug:
http://cooper.journeyman.cc/cgi-bin/bugzilla3/enter_bug.cgi?product=scenehere&version=0.0.1
==
Aside from that, it might be helpful to have a 'pin' button on the pop-ups and allow the previous baloon to fade away upon opening a new one, so that one doesn't hide another, and users can still keep some up if they want.
Maybe have them automatically tile and make room for each other somehow, that might be nice.

Anyway, good luck & have fun.

[simonbrooke]

[1] Yes, I don't know how long an SD card will stand up to this sort of treatment - that's part of what I'm evaluating.

Well, sadly it's a bust. After just a week as a public-facing server I'm seeing the SD card failing; the symptom is that things that try to write to it fail with an error message 'Read only file system', and attempts to read it fail intermittently with 'Input/output error', although mount still shows it as being mounted rw, and df returns apparently valid results. I can't tell you what's in the logs, because it seems (not unreasonably) that by the time the system detected the error it could no longer write to the log.

The SD card continues to be mostly-readable when plugged into my (Ubuntu 10.04) laptop, but it's obviously under much less strain when being read by a single process than when being read from and written to by many.

That's a disappointment. I knew it was fairly cheeky to use an SD card as a read/write drive on a public-facing server, but I'm disappointed it died so soon. You probably could use an SD card to serve static content, but not for the sort of dynamic stuff I do. It also emphasises what Marcus has said about not booting from the internal NAND (although I confess I'm still doing that for now).

[DaveH]

I'm surprised it's that bad - even MLC NAND is rated for tens or hundreds of thousands of erase cycles and there should be a decent wear-levelling algorithm in the card controller to slowly work through all the unused sectors. Or perhaps that's a distinguishing feature of different brands?

Or have you had that much usage in the past week?

[NewIT_Marcus]

I too am surprised.

The problem is, I suppose, that you don't have many variables to play with, at least not cheaply. Do you have confidence in the brand of SD card? If wear is the problem, an SLC variety would supposedly give better value for money, but obviously 1 weeks usage is impractical.

What can you say about the installed applications and the amount of I/O they would generate?

There has been discussion on the plug computer forum about using flashybrid to reduce wear. That may be another avenue worth investigating. Or maybe it was just a bad card ... I never heard of one wearing anywhere near as quickly.