
Show HN: Raspberry Pi3 cluster with Docker/Kubernetes - nergal
http://www.sweclockers.com/galleri/13818-raspberry-pi-cluster
======
luxpir
Translation for those who care:

\-------------------

This time round I got into carpentry for my project. Something that became
both expensive and trickier than I had thought when I started. My carpentry
knowledge is limited to (high-)school lessons, so take it easy on the results.

The project became more expensive than expected. Some 6000 SEK [~$740]
including a whole bunch of tools (mill, jig saw, circular saw). Made do with
'Biltema' tools [the IKEA of tools] and returned the first mill after 1 hour
of use. The other stopped after around 2 hours so then I fixed that one myself
(took apart the start-button and modified it a bit).

The project consists of:

\- 10/100 Mbps switch

\- Nexus 7

\- 10A 6 port USB charger

\- 4 x Raspberry pi 3

\- 4 x 8GB SD card

\- TP cables + USB cables

\- Oak

\- Plexiglass

Anyway, you'd all probably rather see pictures than words.

\- Nexus 7 with realtime data for all nodes.

\- 'Economically' bought 8GB, not class 10, but thinking of running a 2.5" HDD
for the controller node.

\- Sleeved all the cables, then realised that they didn't fit with the
sleeving. Could only strip them and do again.

\- First test with 2 x USB hubs that didn't deliver enough current at start-
up.

\- Flip-up "chassis"

\- My modified netdata page showing real-time data for all nodes, including
the temperature.

\- Running Docker with Kubernetes on the cluster.

\-------------------

[Any errors/omissions are my own]

~~~
nergal
Thanks for translation!

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metakermit
Looks like it could also act as a radiator :) Especially with the RPi 3
heating issues:

[https://www.youtube.com/watch?v=e6okZKRwnTQ](https://www.youtube.com/watch?v=e6okZKRwnTQ)

~~~
nergal
Currently waiting for heatsinks that I've ordered. But so far it hasn't
reached over 50 C.

------
chx
Check [http://www.pidramble.com/](http://www.pidramble.com/) for a more
compact RasPi cluster. Jeff's uSD benchmarks made it to Hacker News front page
previously.

~~~
geerlingguy
Thanks for posting! I'm actually updating the cluster right now, and I have a
Pi2 version, a Pi3 version (still in testing, not live yet), and a Pi Zero
version (very slow, but same thing is the size of a plum!).

I'll be presenting on it at this year's php[tek], and will also post a few
YouTube videos and blog posts about it separately.

Of course it's not as fast as my 5-year-old used Lenovo... But it's great for
educational purposes (before anyone starts asking why you'd buy a bunch of Pis
when one small laptop beats them performance-wise many times over).

~~~
daveguy
I definitely get the educational appeal. Not just in construction and
configuration. This should make a great platform for distributed computing
development/testing/experimentation. What is the total build cost of a 6 unit
system?

~~~
chx
Hrm, if you'd clicked the Wiki in the top header of the link I gave you :)
[http://www.pidramble.com/wiki/hardware/pis](http://www.pidramble.com/wiki/hardware/pis)

------
audleman
It looks very cool; what does it do? All I'm seeing in the photos is a cluster
of 4 PI's that report their statistics to a dashboard.

~~~
nergal
Will run my game servers for ([http://qake.se](http://qake.se)) in docker
containers.

------
Matt3o12_
I've long thought about a similar project to test my applications when scaling
out and how well concurrency works.

One big advantage is that raspberry pies are also so you don't need to send
100MBs to your servers to max out the CPUs (and thus don't need such a quick
connection and powerful machine to generate all those requests).

------
Already__Taken
Might the HDD be attached to one Pi this way? It would be interesting if a
ghetto SAN could be arrange. Do only the enterprise people get to HDD's with
ethernet interfaces directly?

[http://www.seagate.com/files/www-content/product-
content/hdd...](http://www.seagate.com/files/www-content/product-content/hdd-
fam/kinetic-hdd/en-us/docs/kinetic-ds1835-1-1110us.pdf)

~~~
coredog64
WD has a customized-for-RPi product.

[http://wdlabs.wd.com/products/wd-
pidrive-314gb/](http://wdlabs.wd.com/products/wd-pidrive-314gb/)

~~~
johnchristopher
Do you know if the Pi2/3 alone (with only a standard smartphone USB charger)
can power the WD PiDrive without a USB hub ? It seems like it could but I
haven't found any confirmation yet (apart from so SO posts).

------
Negative1
RPI's have been shown not to scale from a power/heat to $ ratio (I believe Mac
Mini clusters are way more efficient), so this is not a practical project by
any means.

Even so, very fun looking project. It says something when a geek like me is
impressed at an electronics project for the (very nice) woodworking.

------
Already__Taken
Might want to consider sealing the plexiglass in some fashion as the gentle
air current under it will collect dust on the side you can't so easily clean.

~~~
nergal
I've considered some solution with a small steel-net used for regular computer
chassis.

~~~
Already__Taken
You can get a gauze fabric at like 60p/m. You could make a nice recessed frame
to hold it and hide the edge. There's tables online of particle size so you
can pick a mesh size.

Got some to use over windows and air vents. Works great and so cheap it's just
replaced instead of cleaned. Airflow on the finer sizes would be interesting.
Mines a spider guard.

------
rasz_pl
nice woodworking project/nightstand clock.

If you double the rpi number you will get close to used $300 laptop level of
performance.

~~~
nergal
Thanks. I know, but a $300 laptop wouldn't be that much fun to put together
like this project was ;)

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Sam--------
Very very cool. I love the enclosure!

