Map of the APRS-IS

Have you ever wondered what the APRS-IS looks like? Well, here you go (click on the link, 1.2 megabytes, 3154 x 3072 PNG image):

Map of the APRS-IS

• Servers with less than 5 clients are not shown.
• Only servers running javAPRSSrvr are shown.
• Darker colour indicates more clients connected.
• Green servers are core servers, orange ones are T2 hubs, red ones have a T2* name (most of them belong to the Tier2 network), purple ones are WXQA servers, the rest of them are blue.
• Inter-server links between hubs and core servers are blue, the rest of the links are green.

Another project I'm working on: we've got 6 ocicat kittens!  I've set up a live kitten camera. Cheap Chinese webcam (foscam) + ffmpeg + ffserver does the trick.

New map viewers record

Yesterday afternoon aprs.fi made a new record: there were well over 3000 users viewing the real-time map at the same time. Almost all of them were displaying the embedded map on the Copenhagen Suborbitals Launch Campaign June 2011 page. The guys built a rocket, capable of taking 1 man to the edge of the space, and did their first successful test flight yesterday. Awesome.



The launch campaing page's embedded APRS map shows the position of the Sputnik launch platform. The platform hosts a custom APRS tracker designed and built by OZ1EKD and OZ7HVO.

I was happy to see that aprs.fi did well with the larger amount of visitors. They were all looking at the same station, and the caching worked well - the database really didn't get any additional queries due to the amount of viewers. I was able to find some spots where additional optimization would be useful and could take down the CPU usage of the web service considerably. Here are some graphs from one of the two servers:

Statistics after the upgrade

On 31 Oct I switched from Apache to nginx. Here are some graphs from one frontend. Which would you prefer, based on these graphs?




I only added the temperature plugin yesterday (before the upgrade), but ... the CPU core temperatures did drop by 2°C. Now, does nginx reduce global warming?