On Wed, 6 Mar 2002, Graham Leggett wrote: > > mod_accel is not proxy. It's accelarator. It can not work as usual proxy. > > I did not even try to implement it - Apache 1.3 is poor proxy. Squid or > > Oops are much better. > > Until recently you were not aware that the proxy had been updated - I > would look at the code again before passing this judgement ;)
The main reason why Squid is better than Apache is much lesser memory overhead per connection. And of course, Squid has many other proxing features - it's proxy, not webserver. > For example, you pointed out some problems with Squid and content > negotiation - mod_proxy doesn't have these problems. Do you mean that Squid returns cached gzipped content to client that does not send 'Accept-Encoding' ? mod_proxy 1.3.23 does the same. Would it be changed in 1.3.24 ? > > mod_accel can ignore client's 'Pragma: no-cache' and > > 'Cache-Control: no-cache'. These headers are sent if you press Reload > > button in Netscape or Mozilla. By default if mod_accel gets these headers > > then it does not look cache but send request to backend. > > Webmaster can set 'AccelIgnoreNoCache on' if he sure that > > backend did not give fresh data and such requests only overload backend. > > This design is broken. > > If the client sent a cache-control or pragma header it was because the > client specifically wanted that behaviour. If this causes grief on the > backend, then your backend needs to be redesigned so that it does not > have such a performance hit. I live in real world and many webmasters are too. It's not always possible to redesign backend. Unfortunately while Internet boom too many brain-damaged solutions were born. > Breaking the HTTP protocol isn't the fix to a broken backend. I'm considering mod_accel and backend as single entity. It does not matter for me which protocol I use for communication between them. Clients see nice HTTP protocol. > > > Everything under /blah is proxied, except for everything under > > > /blah/somewhere/else. > > > > Yes. But '!' is already implemented ? > > Yes it is. I suppose in 1.3.24 ? By the way mod_accel's syntax is more flexible - mod_accel can use regexp. > > > > *) proxy mass name-based virtual hosts with one directive on frontend: > > > > AccelPass / http://192.168.1.1/ [PH] > > > > [PH] means preserve hostname, i.e. request to backend would go with > > > > original 'Host' header. > > > > > > mod_accel does this in one directive, mod_proxy does it in two - but the > > > effect is the same. Should we consider adding a combined directive to > > > mod_proxy the same way mod_accel works...? > > > > What are two mod_proxy's directives ? > > As far as I know mod_proxy always change 'Host' header. > > Use the ProxyPreserveHost option. I suppose in 1.3.24 ? > > mod_accel can send part of answer to client even backend has not sent > > whole answer. But even in this case slow client never block backend - > > I use nonblocking operations and select(). > > Would it be possible with mod_cache ? > > The idea behind mod_cache was to separate the "send" threads from the > "receive" thread. This means that if a response is half-way downloaded, > and a new request comes in, the new request will be served from the > half-cached half-downloaded file, and not from a new request. When the > original request is finished, the backend is released, and the "receive" > threads carry on regardless. Would it be work in prefork MPM ? > > > Both busy locks and limiting concurrent connections can be useful in a > > > normal Apache server using mod_cgi, or one of the Java servlet > > > connectors. Adding this to proxy means it can only be used in proxy - > > > which is a bad idea. > > > > Probably but Apache 1.3.x has not such module and I needed it too much > > in mod_accel. > > You should have created a separate module for this, and run it alongside > mod_accel. This can still be done though. I did not use mod_cgi and Java. > > > This is the job of mod_rewrite. > > > > mod_rewrite can not do it. > > Then rewrite should be patched to do it. Your phrase is like 'mod_rewrite should be patched to do some SSI job' mod_rewrite works with URLs and filenames only. It can not change content. mod_randban changes content on the fly. Igor Sysoev
