Hi there. That heap sizing is not so easy. We have a number of WAS in zLinux servers. The std procedure is to use the WAS default size 512MB to start with and use the WAS admin console to monitor how the appl performs, and increase if needed. You can also configure min and max heapsize values, in which case the size will decrease if not all used making gc runs faster.
and gc have different types of how to work, it is configurable and make a difference depending on the application behaviour. many small requests/transactions require a different type of working than applications using bigger objects. So start with 512 MB, read what you can find on the net, there are several guides in this area, read the manual and try it out :) A stresstest with the load you will have in production is needed when trying out the heap size. BR /Tore (I did ask the guys here doing this work) ___________________________________________ Tore Agblad Volvo Information Technology Infrastructure Mainframe Design & Development, Linux servers Dept 4352 DA1S SE-405 08, Gothenburg Sweden Telephone: +46-31-3233569 E-mail: [email protected] http://www.volvo.com/volvoit/global/en-gb/ -----Original Message----- From: Linux on 390 Port [mailto:[email protected]] On Behalf Of Daniel Tate Sent: den 16 september 2010 00:25 To: [email protected] Subject: Good sources of information for WAS on Z sizing? In a day or so, I will be asking for sizing advice (practical, not redbook - redbooks and other theoretical sources have not been too beneficial to us - this mailing list on the other hand has).. but I would also like to know of any good resourcesdy (message boards, mailing lists, fidonet feeds, whatever) for websphere, especially websphere on Z.. We've given up on using LDAP SSO because of the memory consumption that nobody was able to find the source of (LDAP SSO turned on = uncontrolled memory growth until OOM_KILL even without apps loaded onto the appserver.. turn LDAP off, no problems).. Now we're onto sizing. We only have a dev environment with 7 servers, the LPAR has 15GB of storage, and we know we are going to need more. We will be looking for not only a number but verbose justification for that number (executives will demand that).. so we need as much ammo - theoretical and practical experience - as we can possibly gather. Our mainframe admin was expecting 15GB to be plenty, as we run our entire primary application (z/OS) on less memory than that - and he fully expected 1-2GB per system to be MORE than enough). I have asked our WAS admin for details of the final planned environment to pass along to as many people as I can to get real world advice. So does anyone have any good resources? This is WAS 6, SLES 11 GM, z/VM 5, on a z9. ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/ ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
