Homo-Adminus Blog

Few days ago I’ve started migration of some of my non-critical servers to Debian Etch (from Sarge). Just after first apt-get update && apt-get dist-upgrade, when apt has been upgraded, I noticed really strange (as for me) error: when I’ve tried to do “apt-get update” it worked fine, but there was annoying message like following:

UPDATE: Thanks to Kurt Fitzner we know, that:

There is already a mechanism to do this automatically:

$ apt-key update

This will obtain the necesary keys and import them. No need to go through gpg directly.

After not so long research I figured out, that this problem was caused by change of gpg key used by ftpmaster on Debian official repository servers. Google gave me some information and I found some fix which works fine for me:

Where XXXXXXXXXXXXXXXX is your missing key (e.g A70DAF536070D3A1).

That’s it! Happy using Debian GNU/Linux!

I think nobody would argue today, that search engines are most import sites in todays Internet. There are lots of information sources in the Net today, and every day they are generating lots of useful content. One of major parts of this content is generated by forums aka bulletin boards. But Google - most popular search engine is not to efficient on this side of search - if you try to find something using Google, you can find information on some public forum, but Google SERP is designed for generic pages search and search results will be not so clear. That is why more specialized search engines are so popular. Technorati, Google and Yahoo blog search engines, etc are really popular today.

Just few days ago new search engine was released. Its name is Board Reader. IMHO, its major advantage of this search engine is specialization on search by forums. Its SERP has been designed to display search results in really convenient way which is specific for forums (message threading model). Its index is not littety by all these doorway sites, etc, etc. So, I think this site would grow really fast especially if they would keep working on their services extending. As for me, I’d like to give them a try and will use this search engine for my forums specific search requests.

Few days ago I’ve started new site which name is BestTechVideos.com. I’ve created this site because there are lots really interesting videos on the Net, but if you’d like to fine some good tech video, it is not so simple to find them because of tons of crappy “funny videos” like “funny cats” and so on.

So, If you like to attend technical conferences and watch conference sessions on video, if you like idea of screencasts, etc, then this site is for you! Welcome to Best Tech Videos you’ll be impressed by amount of hi-quality and useful videos on the Net.

P.S. If you like this site idea, support it on Digg.com, please. Great thanks in advance.

Looks like MySQL Camp 2006 was really interesting and useful for its attendees and for entire MySQL community. As the result of this meeting of many MySQL-related professionals we’ve got lots of interesting publications and I want to refer one of them in this post. Very interesting list of 84 MySQL performance tips has beed created on first day of this year MySQL Camp at Google headquarters:

1. Index stuff.
2. Don’t Index Everything
3. Use benchmarking
4. Minimize traffic by fetching only what you need.
   • Paging/chunked data retrieval to limit
   • Don’t use SELECT *
   • Be wary of lots of small quick queries if a longer query can be more efficient
5. Use EXPLAIN to profile the query execution plan
6. Use Slow Query Log (always have it on!)
7. Don’t use DISTINCT when you have or could use GROUP BY
8. Use proper data partitions (For Cluster. Start thinking about Cluster *before* you need them)
9. Insert performance
   • Batch INSERT and REPLACE
   • Use LOAD DATA instead of INSERT
10. LIMIT m,n may not be as fast as it sounds
11. …

So, I think this list can be really useful for all developers/DBAs working with MySQL and want to say “Thanks” to its authors.

Sometimes you may need to implement controlled downloads when all downloads requests being sent to your script and then this script decides what to do: to send some file to the user or to show some access denied page or, maybe, do something else. In lighttpd server it can be done by returning X-Sendfile header from script. Nginx have its own implementation of such idea using X-Accel-Redirect header. In this short post I will try to describe how to use this feature from PHP and Rails applications.

(more…)