> > * z800 > > * 2 IFL's (tested using single and dual, still slow) in LPAR > > * z/VM 4.4.0 > > * guest lan networking > > * 256 meg RAM > > * 512 meg vdisk swap
That's a bit on the anemic side for Java apps. > > * Turning of hz_timer patch helps lower CPU utilization footprint of > > the java processes, but of course, then the system never sleeps. Yep. > > * When running a J2EE app, it takes often over a minute to finish > > rendering a page to a browser. Yep. Most J2EE apps are pretty inefficient in their use of resources. > > * When running a J2EE app, java consumes an entire IFL of > cpu if we let > > it. Nothing surprising here -- the same thing happens on Intel boxes; nobody notices because they're usually not shared. > > 1. Is J2EE a cpu resource hog for you? Yes. It's usually caused by careless application programs assuming resources are infinite and expecting the system deployer to add hardware until the poor app can be supported. The JVM version can make a dramatic difference in how piggy the app is (we saw significant differences from 1.3.x to 1.4.x, both up and down depending what Java features the apps used). > > 2. Are you running Linux under VM or right on the LPAR? Under VM. The cost case for LPAR is very difficult (if not impossible) to make. > > 3. Do you charge users for MIP usage? If so, how does > this high CPU > > utilization not eat your customer alive in billed costs? Not for apps involving Java. We measure it for capacity planning purposes, but don't try to bill it. > > 4. Does anyone have some advice on how to run J2EE services more > > efficiently, faster and easier on cpu? Add resources to the 390 (either additional IFLs or convert to a 890/990 CPU), or segment the app such that the computationally-intensive components are not run on the 390. 390 processors aren't designed for problems that assume that CPU is a free resource. > > 5. Which J2EE server software for mainframe Linux do you prefer and > > why? JBoss is the least piggy of the bunch, but both Websphere and BEA run fairly well given enough resources. The configuration you listed above is a little light for either one. It's usually not the server software that causes the problems; it's more likely to be the application itself if it executes on the server side. > > 6. Lastly, why would you choose to run J2EE on mainframe Linux as > > apposed to some stand-alone system (Unix, Windows, Other)? Convenience, proximity to the data, ease of creation for testing environments. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
