how long do webmasters keep log files?

[Makaveli2007]

Does anybody on here have an idea how long webmasters typically keep the logfiles of their webservers?

I assume that there are certain laws in place (how long you can or must not ...keep them), which may vary by country.

But is it usually extremely unlikely that an ISP, a freemail provider, etc. would keep its logfiles for multiple years? (just wondering if I can basically rule it out, already - without asking people who understand the laws,etc.)

thank you

[tangor]

Unless there is a law saying keep them, AFAIK there's no requirement to even create them.

Personally, I dump my log files into five year batches in an external database to do tracking and trending. No one sees them but me.

[lucy24]

For comparison purposes: I'm on shared hosting. By default, raw logs are only available for three days. (I finally worked out that this really means five and a half, because what they count is .gz files, one per day, and things don't get gzipped until the third day.) Naturally I've set it for much longer, so logs are still there if I forget to download for a while, but three is the default. But you can see the built-in assumption that your ordinary site administrator doesn't particularly need logs for very long. (Or, conversely, that anyone who does care about logs will transfer them to some location other than the server.)

Now, obviously the hosts themselves keep archives of server access logs for longer than three days. But if you've got hundreds or thousands of servers you're going to run into a law of diminishing returns, needle-in-a-haystack etcetera, pretty quickly. In fact I can think of just as many reasons to get rid of raw logs as soon as possible-- such as being able to tell any passing law-enforcement body that sorry, nope, can't help you, we don't keep those. (If you physically don't have them, you don't have to spend time looking for them.)

While looking it up, I landed on a site that may take the prize for Most Consistently and Intentionally Unhelpful Answers Ever ... but never mind that. There's a remote possibility that the UK has actual laws-- presumably written by people who know nothing whatsoever about servers-- but I don't see anything for the US.

[MikeNoLastName]

Call me anal, but we have all of ours for every domain we've ever owned or managed for clients, in one form or another (some printed, some on zip drives, CD's etc.) dating back 20 years, with the exception of a few months that were irretrievably lost when a hard drive crashed just before it was to be backed up. Had to use some in court cases a couple of times dating back as much as 3 years.

[engine]

MikeNoLastName, i also keep the raw log files archived, but they are rarely left on the server longer than a few days.

They are zipped and send to cds (originally) now DVDs. I usually keep them for about ten years, although, some go back as far as 1995.

Why?
Primarily as it's real world data which, for example, shows patterns of user behaviour, keywords, web crawlers (good and bad), site problems, etc.