To anyone with experience, We originally had three NT MQ servers that would handle MQ connections from 11 websphere app servers and then had SNA channels defined to our OS/390 environment. The 11 app servers are spread across three mainframe LPARS in 4x4x3 configuration. The NT boxes served for the most part as a protocol converter from IP to SNA. Since our OS/390 platform's tcp stack has become more robust, we have been migrating towards direct client channel connections to the 390. We have an application that runs on websphere (3.5x) that makes connections to the 390 on an as needed basis. If a request comes in, it searches for the first available connection, and if it doesn't find any it creates a new one. We maintain the state of these connections such that 30-40 per websphere app server seems to handle our needs most of the time. However, when an influx of requests occurs in a short span of time (say 3-5 seconds), and the mainframe is slightly slow in responding, we tend to spin through these connections creating many in a short time frame. We only allow 100 per app server and have 4 app servers pointed at a specific LPAR on the 390.
We seem to have issues some times where connections go inactive, then new channels are started, more connections go inactive, more are started and this goes on for a few minutes where several hundred connections seem to get started and dropped. It's basically impossible to determine if it's only old connections that are being dropped. Some of the settings such as HBINT are left at the default of 300 and the TCPKEEPALIVE settings are also at default which I think is set pretty high to reduce network traffic. Is anyone else out there trying anything similar to this? Would I be better off keeping the NT MQ servers and defining server channels as TCP between NT * the 390 thereby allowing the NT boxes to function as a concentrator? We currently have a problem where one of the OS/390 QMGRs CHIN application crashes during a cycle of intense channel creation. I'm just looking for someone who may be able to help with a relatively high volume MQ message application (approx. 3MM messages per day) who may have run into something that explains the channel starts and stops a little better (I realize it may just be the way our application is written, but the application never specifically shuts down connections unless the application itself shuts down). Thanks, David Corbett Work: 651-205-2714 Pager: 651-610-3842 Instructions for managing your mailing list subscription are provided in the Listserv General Users Guide available at http://www.lsoft.com Archive: http://vm.akh-wien.ac.at/MQSeries.archive
