Re: Run Priority -- Tomcat running on IBM Midrange boxes

James,

On 3/13/26 4:32 PM, James H. H. Lampert via users wrote:
> On 3/13/26 12:32 PM, Christopher Schultz wrote:
> . . .
>> I *am* very curious whether this priority is taking effect, as it's 
>> looking for an OS string that begins with "OS400". If you run "uname" 
>> at your command prompt, what does it print? IIRC, you were running 
>> Tomcat inside of a Linux VM because "it was easier" or something like 
>> that. If that's the case, than the OS400-related stuff won't be 
>> running at all.
> . . .
> 
> Dear Christopher:
> 
> Thanks for visiting my humble thread. Your knowledge of Tomcat is always 
> welcome (especially given that you've saved my E.asinus more than once). 
> That said, . . .
> 
> Uh, "uname" is not a native command in whatever IBM is calling OS/400 
> these days. If you were to type it on a native command line, you'd get 
> an error message, "Command UNAME in library *LIBL not found." on your 
> status line. (Note that the native file system is actually a DB2 
> database, and object names are not case-sensitive.)

This isn't surprising at all.

> If you start a QShell session, which is a *nix-like shell environment 
> where Java runs (but definitely not an actual Linux VM), and you type 
> uname, you get "OS400."

Okay, so if you launch Tomcat from a QShell session, then it *will* be 
using that OS400-specific code in the shell script, and applying that 
priority level...

But then both the change-in-priority and the JVM launch will happen in 
that same shell. So what happens when you set the priority of a process 
in this way through QShell? Does it give you an absolute priority (e.g. 
0 - 100 maps directly to 0 - 100 system priority), or a relative one 
(e.g. 0 - 100 maps to [current process priority + requested priority], 
or something else?

> And no, a Linux VM would not be easier. Short of setting up some sort of 
> Linux LPAR on the box, I couldn't imagine how one would even do that. 
> What I did to make it easier was to create a CL program (like a shell 
> script for IBM Midrange boxes, except that CL programs are compiled) 
> that looks for the most compatible JVM, sets parameters accordingly, 
> then launches Tomcat. And another one that attempts to initiate a 
> shutdown, waits for the job to go away, and if it fails to do so, abends 
> it.

Okay, forget the Linux VM thing, then. I think maybe I was remembering 
you using QShell to get a POSIX-style shell.

-chris