Monday, February 11, 2008

Second server in use! Hooray.

The new server has been taken into use just a few minutes ago. This should maintain the high speed and performance of the aprs.fi service while the amount of users keeps increasing. Please drop a comment if I broke something on the way!

The servers are currently sharing load using database replication and DNS round-robin. The setup isn't really highly available or fail-proof. If one server breaks, the service will not function properly until I do corrective actions (remove the broken server from the DNS and possibly start the master APRS data collecting processes on the secondary server, if the primary dies). But at least that'll only take a few minutes to do, instead of a lengthy hardware repairing and backup restoring process.

There's also a third online replica of the database for the purpose of taking database backup snapshots on a third server (thanks ZFS on Solaris 10). So even if erroneous data is propagated over the replication and data is corrupted on all of the running database servers, I'll be able to roll back to an older snapshot and avoid losing all of the history data.

I'll continue working on automatic fail-over - it'd be nice if a hardware problem wouldn't cause much of an outage. I've done this sort of things before at work, so the plan is quite clear, it just takes some time to do it properly.

2 comments:

Anonymous said...

Hi,

I see there are no comments as yet - I have no technical comments, but, as someone who enjoy usning aprs.fi I would like to express by thanks for keeping this up and working! Absolutely great. Maybe I should not ask, but how is this financed?

Sincerly
LA9ULA

oh7lzb said...

Thanks, I'm happy to hear people like using the service. It's fun to design and develop such a high-profile and highly used system.

Financing comes from my pocket, ad revenues and contributions (in that order). The ads easily pay for the hosting costs (which are not very expensive since not much network bandwidth is required, and the co-location site is maintained by seasoned network engineers as a hobby), but probably cannot foot the server hardware bill quickly enough (before a new server is needed). And in no way could pay for the time required to develop and maintain the site. But this is a hobby for me, so that's OK. Good hobbies usually take all of your spare time and money, right?

I wrote something about the server hardware upgrade costs in a previous post.