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You and your action research project September 7, 2005

Posted by Andy Roberts in : learning , add a comment

You and Your Action Research Project

by McNiff, Lomax and Whitehead

is recommended by Eve in preference to Robson.
0415318858.02.LZZZZZZZ.jpg

available from Amazon both new and second hand

Spambot nailed September 6, 2005

Posted by Andy Roberts in : Wiki , 5comments

spambot.png

Spambots are evil nasty things at the best of times, but the one which kept attacking my ukcider wiki was particularly vexing. Not only did it edit a range of useful pages and replace them with a long list of links to all the usual gambling, pron and medicines pay-per-click sites but it also started creating new pages and editing them as well.
It took me 20 minutes or more to revert everything after such an attack, which began happening twice per day, especially when I was away on holiday. Banning the IP address would work if I happened to catch it in teh act, but the bot was running from a DHCP server client which meant the address kept changing. This was a serious situation which threatened the viability of the wiki. Many people helped out by reverting pages and deleting the spam but there’s only so much time and patience which can be devoted to such a pastime. meanwhile the mySQL database was expanding at a ridiculous rate taking me way beyond the quota I can afford to pay for.

So my first priority was to find a way of shrinking the database back down after cleaning up a spam attack.

DELETE FROM `old` WHERE `old_user_text` REGEXP ‘69.50*’

followed by a COMMIT and OPTIMIZE TABLE ‘old’ wipes out 90% of the excess and a few more queries take care of the rest.

The biggest breakthrough was acheived by finding a Community Of Practice for mediawiki developers and implementers. After lurking for a few days and checking all through the FAQs I explained my problem, quoting version details and asked how to block a range of IP addresses, since I had a feeling this ought to be possible but when I tried I hadn’t been allowed to.

The answer I received pointed left a few things for me to find out for myself but one evening I was particularly satisfied to have cracked it.

On 9/2/05, Andy Roberts wrote:
> Thanks for the prompt reply, Mike.
>
> With your information I googled for “defaultsettings.php” and found
> it in the ‘includes’ directory. I then copied the line
>
> $wgSysopRangeBans = false; # Allow sysops to ban IP ranges
>
> to my localsettings.php file and changed false to true.
>
> This then enabled me to block 69.50.0.0/16 which I hope will get me
> over one longstanding and persistent problem.
>
> I shall remain susbscribed to this helpful mailing list in order to
> keep up with developments in the forthcoming struggles against
> spambots, particularly if some kind of shared blacklist or bot
> detection strategy evolves.

The solution I found has killed one spambot stone dead and given the ukcider wiki a much needed reprieve, but other bots wil doubtless come along and some might even be able to evade IP range blocking. The longer term solution is probably going to involve rapid edit throttling and URL detection against blacklists. Mediawiki Plugins are being developed in this direction but I will need to learn more about remote backups of the database since I’ll need to upgrade the mediawiki software already in order to take advantage of the newer stuff.

dragonfly September 5, 2005

Posted by Andy Roberts in : hi res photos , add a comment



dragonfly

Originally uploaded by Andyrob.

A female ‘Southern Hawker’ laying eggs at the edge of the garden pond, Sunday afternoon.