i am sure a vendor like f5 will help you to overcome your applications limitations On Tue, Jul 14, 2009 at 4:26 PM, David Miller <[email protected]> wrote:
> Hi All; > > I've got a situation that I'm not sure of the best way to handle. > > I have a pair of servers that are able to run the same application. > Caching issues make it weird though. The application writes to the > database when updates come in, and (of course) updates its own internal > cache. The servers don't update each other, however, nor do they get > updates from the database any time other than at startup. "startup" in this > case is defined as the first query that hits tomcat. > > What this means is that I want to run off S1 as long as its running. And > if S1 becomes unavailable I want to run off S2 until I come back and fix > things. lb-pri-servers takes care of that part. > > Here's the complicated part. The servers accept SSL as well for user > authentication. I need http and ssl to fail to S2 as a pair - both or > neither. We recently had application response issues where S1 was very slow > to respond, and http failed over but ssl did not. This broke the customers > ability to authenticate. We're terminating ssl on the ServerIron 4G's and > talking plaintext on port 443 to the server. Apache is listening on 80 and > 443 expecting plaintext. > > We've played with boolean health checks, but I haven't implemented them. > I'm concerned about separate health checks because nothing different is > being tested. It seems like a race condition would still exist where http > would fail over, but a second later the ssl check would pass. What we need > is for a single failed health check to down the server and fail all services > over to the backup. > > If it makes things easier, we can just skip the ssl test. A single test > for http is adequate for making sure apache is responding on the server. > > > Suggestions very welcome. > > --- David > > > > > _______________________________________________ > foundry-nsp mailing list > [email protected] > http://puck.nether.net/mailman/listinfo/foundry-nsp >
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