PC spec for adequate performance of emoncms

Submitted by billt on Sun, 02/02/2014 - 18:45

I've just got started with 2 EmonTxs monitoring 8 AC circuits and 1 using Robins PV diverter into 2 dump loads (soon to be 3).

I'm trying out emoncms as a replacement for my current logging software. It looks as if it may do the job, but I'm wondering about its' performance and the hardware requirements for decent performance.

My first idea was to install it on a PC that's currently a WHS system serving files, and doing a few other things. That's more or less failed for various reasons, so I'm using the RaspberryPi HD version, which works, but is horribly slow to serve simple graphs with about 30 feeds. That makes me think that it will give up when logging 2-300 feeds.

What is a reasonable spec PC to use as an emoncms server logging a minimum of 200 feeds at 20 second intervals which will draw graphics reasonably snappily?

Re: PC spec for adequate performance of emoncms

Submitted by Paul Reed on Sun, 02/02/2014 - 19:37.

Are your feeds configured to use Timestore or MySQL?

MySQL was notoriously slow at rendering graphs, whilst Timestore saw a dramatic increase in performance.

I'm using a humble Raspberry Pi to render 20 feeds, whilst supporting a media & file server, as well as a continuous cloud backup/sync, and graphs are rendered pretty quickly.

Paul

Re: PC spec for adequate performance of emoncms

Submitted by Paul Reed on Sun, 02/02/2014 - 22:02.

Just uploaded a quick screen capture to youtube showing speed of rendering as per last post.

I suppose it depends what you call fast!

Paul

Re: PC spec for adequate performance of emoncms

Submitted by billt on Sun, 02/02/2014 - 22:44.

Thanks for doing that. That seems to be a similar update speed to my installation, if you are just using one multi-graph. That's acceptable though a bit slow. If you add more lines, or make a dashboard with more than one graph it becomes very slow; I've made one dashboard with 6 bargraphs - it takes 15 seconds to load over my local network. This is when it's not got much load logging data. I suspect that it'll give up if it has to do a lot more logging.

It's a mixture of feeds; the emonTXs use Timestore the ECM1240/btmon.py seems to have decided to use MySQL. The 6 bargraph dashboard uses 3 of each.

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