You had us going for a while....I thought you are talking about some distributed session management (accross different boxes)....
Another suggestion is to use lbnamed. lbnamed is a DNS server and Load Balancing server that listens to port 53 and resolves IPs, but on the other side of its personality it talks to bunch of agents who are running on workers. You get to set what the parameters or criteria is and assign a cost factor for a worker. lbnamed then distributes the work on the lightest/least cost worker. In this scenario, whence a box is out (or its critical piece like Oracle, or HTTP server) then no further work is routed to it . Also, be aware that using CNAME in DNS does not provide a uniform distribution of load. Imagine a web page having 20 images and another 5 images. You'll not know with good certainty that if your heavy work like database access is really being distributed. With CNAME you do have a chance of developing harmonics. CNAME (aka round robin) is totally unaware of the load on the worker. Maybe that's why your boxes are bulking.... See http://www.stanford.edu/~schemers/docs/lbnamed/lbnamed.html Andrew Ho wrote: > Hello, > > BE>Let me explain in more detail what I'm doing. > > So if the situation you explain is the only reason you want a variable > shared load balanced machines, I'd suggest a totally different way of > doing this altogether. Best would be to use an already shared persistent > storage mechanism (NFS or Oracle) but it looks like Oracle warnings are > precisely what you want distinct alerts on (why are you getting so many > Oracle errors anyway? that might be the first thing you want to check). > > I'm assuming the number of warning e-mails you get is less than 450,000 / > 5 == 90,000 each day, so that if each warning e-mail were a web request, a > single box could handle them (if more than 1/5 of your requests result in > errors, you REALLY want to just fix the problem first). So put up a single > webserver box to serve as an error reporter and logger. You could either > use distributed logging (like mod_log_spread) or simpler, just set up > another webserver that takes requests like > /record_error.pl?error_msg=foo&remote_addr=bar or whatever. > > Your error handlers on your five load-balanced boxes send an HTTP request > to this error handling box. All error e-mails can originate from this box, > and the box can internally keep a lookup table (using any of the fine > techniques discussed by the folks here) to avoid sending duplicate errors. > > In this scenario error handling is offloaded to another box, and as a > bonus you can track the aggregate number of errors each day in an > automated way and run reports and such (without having to count e-mails in > your inbox). > > Humbly, > > Andrew > > ---------------------------------------------------------------------- > Andrew Ho http://www.tellme.com/ [EMAIL PROTECTED] > Engineer [EMAIL PROTECTED] Voice 650-930-9062 > Tellme Networks, Inc. 1-800-555-TELL Fax 650-930-9101 > ---------------------------------------------------------------------- -- ------------------------------------------------------------------------- Medi Montaseri [EMAIL PROTECTED] Unix Distributed Systems Engineer HTTP://www.CyberShell.com CyberShell Engineering -------------------------------------------------------------------------
