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Maximun number of socket connections



Author: anonymous
Date: Tue Feb 21 15:40:48 2006
Subject: Maximun number of socket connections


Somebody knows as it is limits of socket connections by port that allows SCO?

Whenever we arrived at the 100 sockets connections (netstat -an |grep 1526 | wc -l) hang the application server daemon



SCO OpenServer 5.0.6



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Tue Feb 21 16:16:57 2006: 1686   BigDumbDinosaur


It would be helpful if you were to provide some information about how STREAMS configuration is set up on this machine. Go to /etc/conf/cf.d and type ./configure. Select number 12 from the menu and see what you've got set up.



Tue Feb 21 16:43:33 2006: 1687   anonymous


option 12=

NSTREAM: number of stream-head structures configured.
The current value is: 4352 (normally: 64) New value is:

NSTRPAGES: maximum page count for streams buffers.
The current value is: 6128 (normally: 500) New value is:

STRSPLITFRAC: percentage of NSTRPAGES at which buffer splitting occurs.
The current value is: 80 New value is:

STRMSGSZ: maximum size of a data message on a stream.
The current value is: 16384 New value is:

STRMSGSZ: maximum size of a data message on a stream.
The current value is: 16384 New value is:

STRMAXBLK: maximum size of a streams buffer.
The current value is: 524288 New value is:

NUMSP: number of streams pipe devices supported by the system.
The current value is: 256 (normally: 64) New value is:

NUMTIM: maximum number of streams modules that can be pushed by the TLI.
The current value is: 1104 (normally: 16) New value is:

NUMTIM: maximum number of streams modules that can be pushed by the TLI.
The current value is: 1104 (normally: 16) New value is:

NUMTRW: number of TLI read/write structures to allocate in kernel data space.
The current value is: 1104 (normally: 16) New value is:






Tue Feb 21 18:44:25 2006: 1688   TonyLawrence

gravatar
Couple of things:

First, "lsof" is much more useful than "netstat" for this. You can download a SCO version from Skunkware.

Second, you want to look at streams usage (netstat -m), not configuration (well, you look at configuration after you figure out what you need)

But could it be much more basic? The default number of tcp/ip connections is 256 - look in netconfig, select tcp/ip and check that configuration.



Wed Feb 22 17:30:37 2006: 1693   BigDumbDinosaur


First, "lsof" is much more useful than "netstat" for this. You can download a SCO version from Skunkware.

I agree, although for some strange reason I didn't think of it at the time (another senior moment, I'd guess).

Second, you want to look at streams usage (netstat -m), not configuration (well, you look at configuration after you figure out what you need).

I asked for him to dump the configuration only because I suspected that the defaults had never been changed. In any case, I'd set NSTREAM to 32768, NSTRPAGES to 8000, NUMTIM to 8192 and NUMTRW to 8192, all of these values being the maximum allowed.

But could it be much more basic? The default number of tcp/ip connections is 256 - look in netconfig, select tcp/ip and check that configuration.

He said it was complaining when 100 sockets had been created. I'm inclined to think that the default of 256 concurrent TCP/IP connections is probably not causing the error he is seeing, although I'd double that setting to be on the safe side.

Something that must be considered while tinkering with STREAMS settings is that the memory allocated to them is in kernel space and is thus not swappable. He didn't indicate how much memory is in the machine. I'd recommend at least 512 MB to assure that the system doesn't start paging during periods of intense network activity. If this were to happen the system would drastically slow down. Memory is like money and good sex: there's no such thing as too much!

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