This is good unless your application has an SLA of <3s recovery time or even zero failover time. They are out there and not meeting an SLA cost money not just in internal chargeback's but in real $$$ to the business. Also Root prompt does not mean application availability. I would have asked more questions personally.
William 'Doug' Carroll Mainframe Systems Eng Sr I Global Technology Infrastructure ECS Core Services z/Software Group / Emerging Technologies RedHat Certified Engineer: 805008304430937 -----Original Message----- From: Linux on 390 Port [mailto:[email protected]] On Behalf Of Rob van der Heij Sent: Wednesday, August 12, 2009 10:43 AM To: [email protected] Subject: Re: How is the Linux-Heartbeat? On Wed, Aug 12, 2009 at 3:39 PM, Robert J Brenneman<[email protected]> wrote: > Generally - you use Linux HA for stuff that does not include its own > HA support in the product. You could think of it as strapping HA > capability onto the outside of an existing product. Word of caution though, and reference to the law of diminishing effects. Unlike you most x86 configurations, your Linux on z/VM installation has already invested a lot to get you a reliable platform. Ad-hoc duplication of components may not achieve anything useful, but does increase the cost in resource consumption and complexity. When the PEBKAC failures are my far the most dominant cause for an outage, then increasing complexity may not be a good thing to do. > WAS and DB2 on the other hand actually come with HA clustering support > out of the box, so Linux HA doesn't really give you anything more > above that. In some cases this support actually comes in a different box ;-) I believe with WAS it is a common configuration to combine application testing and deployment with fail-over support. The idea being that you need a hot standby anyway and can abuse that to test and deploy your application. When you're done fiddling with it, you change the roles. Such a scheme may not be the best approach in this environment. :story. Some time ago I was listening to someone selling a rather complicated framework for HA which includes automatic deployment of applications on whatever "lukewarm servers" (my words) ready to deploy an application that needed a home. These lukewarm servers were running "only" the Java-based HA framework. The customer asked what the reason was for all these in-queue idle servers eating up his resources. We were told this was because the server would be unused anyway (yeah) and it saves the Linux boot time. When the customer explained that a Linux virtual machine was typically at root prompt in 3 seconds, the presenter was pretty much done... :-) Rob -- Rob van der Heij Velocity Software http://www.velocitysoftware.com/ ---------------------------------------------------------------------- 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 This communication is for informational purposes only. It is not intended as an offer or solicitation for the purchase or sale of any financial instrument or as an official confirmation of any transaction. All market prices, data and other information are not warranted as to completeness or accuracy and are subject to change without notice. Any comments or statements made herein do not necessarily reflect those of JPMorgan Chase & Co., its subsidiaries and affiliates. This transmission may contain information that is privileged, confidential, legally privileged, and/or exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information contained herein (including any reliance thereon) is STRICTLY PROHIBITED. Although this transmission and any attachments are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibility of the recipient to ensure that it is virus free and no responsibility is accepted by JPMorgan Chase & Co., its subsidiaries and affiliates, as applicable, for any loss or damage arising in any way from its use. If you received this transmission in error, please immediately contact the sender and destroy the material in its entirety, whether in electronic or hard copy format. Thank you. Please refer to http://www.jpmorgan.com/pages/disclosures for disclosures relating to European legal entities. ---------------------------------------------------------------------- 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
