[pca] pca-proxy.cgi questions

[Martin Paul]

Lee, Jarrett wrote:
> How does PCA handle multiple clients checking in with the local patch server
> simultaneously? What if two servers ask for the same patch before the patch
> downloads completely? Does it have a mechanism that knows the original
> request to download the patch has not yet completed?

That's no problem, PCA takes care of that. When a client asks for a patch which 
is currently being downloaded due to some other request, PCA will complete the 
download and then deliver the patch to both clients. This seems to be pretty 
robust, I can't remember any recent problem reports about such issues.

> We plan to have a few hundred servers downloading patches at one time. Will
> this be fine? Anybody else already doing this?

I don't have hundreds of clients, but I've heard from others that have. So this 
should be fine. If you do experience any trouble, let me know. Even more, tell 
us when you have your setup running and working - success stories are always 
welcome :)

If you want to spread the load to multiple servers, you might be interested to 
hear that you can even build a cascade of pca proxies - just point one proxy at 
another by setting xrefurl/patchurl on a secondary proxy to the primary proxy.

hth,
Martin.