One of my client makes sports apparel for adidas and I use J to compute for raw material requirements.
J sits on an application server that is also used as an WEB,FTP,MS-Sql and all around file server. The machine is an HP Blade Server with the following specs: * 4 Intel Xeon CPU * 6 GB RAM * Windows 2000 Advance Server 32bit First off, this is a 32bit OS and I actually kept hitting the J out of memory the first version of the J application. Eventually, I was able to work-around the memory limit by: 1. J will only get the minimum data it requires from MS-SQL server. 2. Breaking the process into smaller logical pieces and letting other J session process that. Number 2 actually is my poor man's multi/parallel processing for J. I basically made a windows service which listens to a particular TCP port. Once a valid connection is made, it spawns a full session of J.EXE which will do the logical partitioning and then in turn creates a loopback connection to the windows service. Depending on the operation needed, the first J session would make from 2 to 16 TCP connection (spawning new J session per valid connection). Of course, not all operations would require spawning but still, there is a minimum of one J session per valid TCP connection. A note though, this setup was able to bring down that server when more than 60 J sessions was running at the same time. The server did not crash but the server was unresponsive for some time until the J session went down to less than 20 session. :) r/Alex P.S. I have been doing a different alternative for some time now. Instead of running all J processing on one centralized server ... I've moved some of them to the client machines. The reasoning behind this is that all of my client desktops must have the MINIMUM specs: 1. Intel Pentium D 2.66ghz 2. 1GB RAM 3. ADSL internet connection Note though that our application is web based but for J processes, I run a lot them (not all) at the client machine. ;) This has worked out well and the user feels that the application is running faster or more responsive. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of bill lam Sent: Tuesday, January 19, 2010 10:25 AM To: [email protected] Subject: Re: [Jchat] Does anyone out there have a megapower PC to answer my 'out of memory' question lun, 18 Jan 2010, David Mitchell skribis: > Here is an example of a program that fails due to lack of memory on 32 bit > systems but will run to completion on 64 bit systems. It will run in a > reasonable length of time with 8 gigabytes of memory. With less than 4 > gigabytes of memory, it takes much longer. > > http://www.jsoftware.com/jwiki/JDB/Netflix I think the max file size under J32 is 2G because the file offset is signed. On a cursory glance, there is no garbage collection so that it cannot reuse space of deleted record. -- regards, ==================================================== GPG key 1024D/4434BAB3 2008-08-24 gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
