performance cost of redirects?

How far can I go before it starts to slow...

[karmov]

I've just re-done a news section for a web site that had no plan for the file names for each news item. Now it's all dated and wonderful. However, I would like to ditch the old files (as they're not valid HTML and would take too long to convert) in favour of the new ones. So a redirect sounds great, but there's over 150 file, and I've got a few more redirects already. I'm wondering how far I can go with redirects before apache start's feeling the pressure and begins to perform badly. I realise that mileage will vary depending on hardware, but there's got to be some reasonable general estimate...

[jdMorgan]

How many requests do you get for the old pages per second or per minute?
Are you on a busy shared server with 100 other sites?
Those are the important questions.

If you get only one redirected request per second, you probably won't have a problem. If you get hundreds of redirected requests per second, you probably will have a problem.

Unless your "hit" rate is high and your server is very busy, 150 redirects is not a very big number.

Go slow... Test. :)

Jim

[karmov]

The whole apache server's only dealing out about 2 hits per second, 2% are currently being redirected and the new redirects will only double that to 4-5%, but I imagine apache has to go through the redirect rules for every single request. That's where I'm mildly concerned about the performance hit. However the go slow suggestion isn't a bad one :) Thanks for reminding me about that.