> I know Sessions variables can span a cluster, but am not sure > of the details/gotchas.
That's incorrect. In CF 5, Session variables are stored within the memory of an individual server, and can't span a cluster. > My experience with clusters is non-existent, but it looks > like I'm going to be getting a crash course soon. So, I need > to know some details for ensuring my sites work well over a > cluster. I'm assuming the cluster will be using CF5's clustering > capabilities. (well, I know CF4.5 did it, and assume CF5 does > as well). > > Are session variables a reasonable option on a cluster? or > should I be using Client variables with a DSN for storage? > Are there any gotcha's I need to be aware of with regards to > the Session variables? If you want to use the full benefits of clustering, such as having every incoming request sent to the least busy server, and failover, you'll want to use Client variables instead. Typically, you'd store those variables within a shared datasource, although you could use the cookie storage option. If you can live without full load-balancing and failover, you can configure your cluster to use "sticky sessions"; then, rather than having every incoming request sent to the least busy server, only the first request from a user would be sent to the least busy server, and all subsequent requests from that user would then be directed to the same server. If you're currently using Session variables heavily within the application, you may run into some problems when moving to Client variables. Client variables can only contain strings, so if you're storing recordsets or structures, you'd have to convert them to WDDX first. Also, there's more overhead with Client variables, and this overhead increases significantly with any increases in the size of the string being stored. Dave Watts, CTO, Fig Leaf Software http://www.figleaf.com/ voice: (202) 797-5496 fax: (202) 797-5444 ______________________________________________________________________ Get Your Own Dedicated Windows 2000 Server PIII 800 / 256 MB RAM / 40 GB HD / 20 GB MO/XFER Instant Activation · $99/Month · Free Setup http://www.pennyhost.com/redirect.cfm?adcode=coldfusionb FAQ: http://www.thenetprofits.co.uk/coldfusion/faq Archives: http://www.mail-archive.com/cf-talk@houseoffusion.com/ Unsubscribe: http://www.houseoffusion.com/index.cfm?sidebar=lists
