Tuesday, March 24, 2009

Some database cleanups

Since the popularity of the site is increasing I need to do some optimizations to keep the site running smoothly.

As announced before, I ran some database restructuring batch jobs during the weekend. The last one was actually started on Monday morning and the execution was completed early Tuesday morning. I hope the slowdowns were not too noticeable, I tried to make them run slowly enough to not interfere with normal use.

I'm currently looking at ways to clean up some unused data from the aprs.fi database. There's quite a lot of automatically or erroneously generated targets stored in the database, most of which are not really looked at by anyone. They just inflate my tables and make the prefix browsing view very cluttered. The performance impact caused by the extra targets isn't really noticeable, but it's just not very nice to have them there.

If you're keeping an eye on the statistics, you might have noticed that today I deleted about 60000 targets. Those were all APRS objects, which had only a single point stored (non-moving), which were last announced over a week ago, and which were announced for less than 12 hours. Almost all of them were automatically generated earthquake and severe weather warning objects, which don't really need to be here any more.

There's also an awful lot of regular APRS targets which have a corrupted source callsign. Most usually one or two characters have been lost from the beginning of the callsign. For example: 1VAJ (J41VAJ), 3GXT-2 (W3GXT-2) and 3TVX-9 (VE3TVX-9). You can find these by looking at the prefix browsing view, picking a strange prefix starting with a number, and looking up the correct original call in the "nearby stations" list of the info page. I wonder how the callsigns get mangled like this, and how could I remove these from the database without accidentally removing some valid data.

Friday, March 20, 2009

Slowdowns caused by maintenance work

I'm doing some changes in the database structures during this Friday evening and Saturday morning, so there might be some slowdowns in the aprs.fi service. In particular, updated data might take a few minutes to be inserted in the database. No data should be lost, though, it'll just be delayed. Thank you for your patience!

Sunday, March 1, 2009

APRS in русский язык

Thanks to UZ2HZ, RA1AMW, UA3IRS and UR7IMM, aprs.fi is now available in the Russian language! The site has now been translated to 20 languages. Although there's not so much APRS activity in Russia yet, Russian is the primary language of about 164 million people living in quite a few countries. Even here in Helsinki, it's the third most common language.

There are spots of APRS coverage in (at least) St. Petersburg, Moscow and Novgorod.