Backups have been in the geek news recently, courtesy of thechilling tale of the online comic Penny Arcade's backup failure .Making backups is important, but there's an equally important and farless appreciated piece: checking your backups to make sure that youcan actually restore them .

You may say 'but, I'm sure my system would scream a lot if somethingwas wrong'. Let me tell you a story about that.

Once upon a time there was a young and innocent systemadministrator.

One form of blog spam is 'Referer' spam. Referer is the (optional)HTTP header included in requests from web browsers to web servers thatcontains the web page that the link to your page was on. Some blogsoftware uses this header as a lower-tech version of Trackback .

Referer spam has the attraction for the spammers that it's dirt simpleto do. All their software has to do is to make an ordinary HTTPrequest for a page or three on a web site and throw in a

Overall SMTP connections are running at twice the expected rate, at246,000 SMTP connections although only from the usual 33,000 differentIP address. The SMTP frontend hit a highwater of 18 simultaneousconnections during the week.

Kernel level IP filtering:

Host/Mask           Packets   Bytes204.50.22.50          11909    572K170.206.225.64         8186

Yesterday's entry mentioned in passingfixing a bug in DWiki . Today's entry is about the anatomy of that bug(and how I found it).

This starts with DWiki 's processing model, which involves displayingpages in a number of different formats, which are called'views'. (More about this is in ProcessingModel .) Not allviews are valid for all pages (for example, the ' history 'view isn't valid for a file without a version history).

If an

There's a large debate about static versus dynamic typing in theprogramming and language communities. (There is a classic BruceEckel article on this here , for example.)

I spent part of today fixing some 'issues' in DWiki , which iswritten in Python. This gave me the opportunity to reflect about thesort of bugs I've been finding in it. Python is dynamically typed,and I don't have any sort of formal test system for DWiki . In theory,this should lead to

Here's some interesting bits and pieces for software developers:

• bstring , a C library for safeand easy string manipulation in the style of Python. Every sooften I need to mangle strings faster than Python or Perl canmanage it; at those times, I turn to the bstring library.(I have a longer writeup on bstring here .)

• quilt , a packagethat allows one to manage a series of patches by keeping track of thechanges each patch makes. Patches can be applied, un-applied,

A great deal of system administration consists of not stubbing your toea second time.

(Unfortunately I must mar this by adding 'on the same thing' as afootnote.)

Centralized versus distributed version control is one of the bigdiscussion topics in the field. Being distributed complicatesthe software, and CVS and Subversion (the two version controlsystems most widely used for open source) are both centralized.Recently, Ian Bicking has written some interesting articles on the issue, in Centralized vs Decentralized and its part 2 .

I believe that open source development needs distributed versioncontrol. The argument why this is necessary is a bit too long fora comment on Ian Bicking's articles (and besides,

I feel like I've arrived somewhere: WanderingThoughts , this blog, hashad its first case of comment spam. It's interesting to look at thetrail of breadcrumbs and the actual spam, and to see both how much andhow little work the comment spammers seem to be putting into this.

To skip to the punchline: some machines in 69.57.150.0/24 (ev1.net)left a peculiarly crafted comment spam pushing a web page on the