Actually, I forgot by far the largest downside - 3rd party vendor support both for purchased java applications and also for extra support infrastructure (like backups or whatever). Though that really depends on who your vendors are.
We have had to push vendors to support the mainframe and many of them were reluctant to try. But we have never had anything that had errors due to it being on zLinux. It's more a vendor comfort level thing. Jon -----Original Message----- From: Veencamp, Jonathon D. Sent: Monday, April 22, 2013 10:21 AM To: LINUX-390@VM.MARIST.EDU Subject: RE: Any real world WebSphere ND guidance? I would argue that WAS ND on zLinux is much simpler than clustering across a bunch of x86 servers. We've been doing Websphere ND on zLinux for 4-5 years with WAS 6.0, 6.1, 7.0, and 8.5. The biggest advantage is scalability of each host. We run 85 Websphere instances across 5 hosts with the DMGR on it's own 6th host. And this scalability is key, because maintaining 5 Websphere installations is much easier than managing 85 Websphere installations.... For production, we cluster but do not load balance. We've found plenty of scalability with running the workload on a single instance of each prod server, and the clustering is simply for failover. This makes debugging massively easier than trying to troubleshoot on what instance a problem occurred. Just for context, our volume is about 2,000,000 servlet hits per day. I don't have as good of a count on EJB's. Because of that scalability, we will not have much of a need to use the new dynamic clustering in WAS 8.5 until a bigger load comes along. Having your Websphere logs in the same place makes it easy to give your developers access via a simple common interface. Automated change control is simpler in our case, as that single DMGR can push code to any of the 85 servers. And we just have to put the prod application property & configuration files in a single (plus the failover) location that prod server instances share. There's more, but I don't want to write a book. Downsides The biggest downside is that wsadmin installation is CPU expensive! zVM is extremely simple, but not intuitive and as easy to find answers on the internet as other OS's. Mainframe memory is expensive I'll send you a note to your email address with my contact info. Feel free to call me with any questions. Jonathan Veencamp Federated Mutual Insurance ________________________________ The information contained in this e-mail message is intended only for the personal and confidential use of the designated recipient(s) named above. This message may be an attorney-client or work product communication which is privileged and confidential. It may also contain protected health information that is protected by federal law. If you have received this communication in error, please notify us immediately by telephone and destroy (shred) the original message and all attachments. Any review, dissemination, distribution or copying of this message by any person other than the intended recipient(s) or their authorized agents is strictly prohibited. Thank you. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/