Do cache servers make sense for domestic users?

[Dave2002]

Years ago I looked into the use of web cache servers, though at the time I was thinking of commercial/business applications. That was a long time ago, and I had someone set up such a web server. It didn't seem too difficult, though it was based on Apache and I think ran on BSD. It didn't actually make too much difference to responsiveness, but that was because firstly the network it was attached to was a very high speed network (even by today's standards it was OK) - and secondly because the files weren't huge. Thus the time spent in searching the cache was only partially offset by the reduction in latency etc. whenever a cache hit was found. There was little perceived difference between running with the cache in, and not, but I believe that under the conditions that many of us experience these days with our domestic systems that there could be a significant improvement in responsiveness with suitable caches installed.

Since then the world has moved on. Whereas at that time few users consumed a lot of data and generated a lot of traffic, and even 1 Mbyte files were considered large, now I regularly (and sometimes annoyingly - because they block my inbox) receive emails containing attachments larger than 5 Mbytes, and it appears that our total download of data on a daily basis is at least 3 Gbytes, as I have to actively monitor our 40 Gbytes BT allowance to ensure that we don't incur additional charges.

It occurs to me that sometimes we repeatedly download the same material, and apart from the update/refresh problem, there could be a significant saving in downloaded data if in our household we installed a network cache.

I'm not sure if there are any easy to use ones which are cheap, and ready to go for domestic users. Otherwise, it would probably not be too difficult to set one up. This could have the effect of (a) reducing the total download data, and (b) reducing the latency - which is sometimes a significant factor when trying to access web pages.

Has anyone round here tried this recently?

[Frances_iom]

your web browser caches pages (unless you have turned this off - generally you can also control amount of free disk space it uses) - catch is that many sites seem to continually push video or large images - I browse text only + download images when I need them - the amount of Javascript used by web designers is a major culprit for slow downloads (tho video is by far the major user of bandwidth) - if practice most javscript adds no info but is to control tracking and adverts - again my preference is to use 'noscript' extension for firefox - tho if these javascript functions are in a sep file then your browser cache should prevent further downloads unless the web page has specified nocache.

If you have multiusers accessing similar pages/websites then possibly a per LAN cache might help keep within your BT budget tho I guess wouldn't make much difference to speed as the local browser still keeps a cache

[Dave2002]

I was specifically thinking of a multi user situation, where several different users may access similar pages. For example, user A sees a web page of interest, and emails user B to point this out. If the web page has photos or documents etc., this will result in both users downloading the file. It is not impossible that the same files could be downloaded 3 or 4 times - or more if some users have more than one machine.

Having a LAN cache could certainly reduce latency and increase effective download speed - with some provisos. If user B accesses a page which A has already downloaded it should be on the LAN cache, and there would be no need to fetch from the external ISP link. Things aren't quite as simple as that, though, as different users may use different browsers, and websites may send different files according to what browsers they detect.

It's not so much the budget issue - though that's relevant, but the latency and throughput issue which I'm considering. Keeping traffic off the link to the ISP should certainly improve the situation, providing the internal LAN is a high data rate network.

A more sophisticated system might also cache other files - such as files delivered by email. An issue there would be the delivery mechanisms. If by HTTP (presumably webmail would use this) then a web cache would do, but if by other protocols then different caching systems might be needed. Normally private data would not be cached, but there could be merits in caching some "private" data if it could be shared by a group with a common interest.