os-osf/5503: digital unix osf - open files limited, code change needed to increase

[Michael Long <ml...@questgate.net>]

>Number:         5503
>Category:       os-osf
>Synopsis:       digital unix osf - open files limited, code change needed to increase
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    apache
>State:          open
>Class:          change-request
>Submitter-Id:   apache
>Arrival-Date:   Wed Dec 22 23:40:01 PST 1999
>Last-Modified:
>Originator:     mlong@questgate.net
>Organization:
apache
>Release:        1.3.9
>Environment:
compaq truunix 5.0 patchlevel 1
OSF1 www0.webtelpro.com V5.0 910 alpha
>Description:
For large web providers with lots of sites, apache can hit the default limit of 4096 open files in digital unix, and quit.  Digital Unix 4.0d and later support up to 60,000 something, but you need to change the code to support it.  From the Compaq technical support paper:

--
The Digital Unix V4.0d release notes state that support has been
added for processes to have up to 65535 open files, where previous
versions of Digital Unix only supported up to 4096 open files.
How do you enable this feature?

ANSWER:

This is not done through changing the open-max-soft, and open-max-hard
parameters in /etc/sysconfigtab.  If you try this, the system won't
allow it to be more than 4096 and will report the following error
during booting:

 sysconfigtab: attribute open-max-soft in subsystem proc value/size
               must be <= 4096
 sysconfigtab: attribute open-max-hard in subsystem proc value/size
               must be <= 4096

To allow an application to access more than 4096 files, the
application has to use the setsysinfo() system call to enable
this feature.

By setting the SSI_FD_NEWMAX option of the setsysinfo() system call
to 1, the application will then be able exceed the 4096 open file
limit.

RESOURCES:

Digital Unix 4.0d release notes
setsysinfo(2) man page   
>How-To-Repeat:
We currently have 1041 virtual hosts running on the machine, each with their own access and error logs.
>Fix:
See above problem description
>Audit-Trail:
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