topic Re: OpenVMS user in Operating System - OpenVMS

OpenVMS user

Mrityunjoy Kundu — Thu, 19 Jun 2008 05:44:54 GMT

How could I segregate the no. of user in a cluster.Actually I want to know how many tcpip and decnet users are logged on in a specific server. I want to distribute the user load betwwen all servers . So I want to create a accesslist ,when tcpip user limit crosses more than 300 then no tcpip based user can logged on in that server.

Re: OpenVMS user

Joseph Huber_1 — Thu, 19 Jun 2008 06:17:31 GMT

What means "create accesslist" ?
In general the supported way to limit number of interactive users is via
SET LOGIN /INTERACTIVE=n

Specific access through a defined (TCPIP-)protocol can be limited via

TCPIP DISABLE SERVICE TELNET
TCPIP SET SERVICE TELNET/LIMIT=n
TCPIP ENABLE SERVICE TELNET

or for SSH
TCPIP SET SERVICE SSH/LIMIT=n

Re: OpenVMS user

Mrityunjoy Kundu — Thu, 19 Jun 2008 06:34:36 GMT

Joseph,

How could I segregate the total no. of tcpip abd denet user?

Re: OpenVMS user

Hoff — Thu, 19 Jun 2008 13:50:45 GMT

Clusters tend to be best operated as homogeneous.

Write some DCL. f$getjpi is the central lexical function. Embed it in SYLOGIN.COM or analogous, as part of controlling the login. This should not be more than a couple-dozen lines of DCL for a simple case, and there are examples around.

Alternatively, write some code that calls sys$getjpi et al, and embed it (via LGI or otherwise) in the login processing.

Alternatively, get a bigger (I assume) Alpha.

As for your likely next question, Google is your friend, and web pages that include counting users or such and particularly include references to SYLOGIN will be present in most of the topics you are interested in here. I've posted examples of scanning logged-in processes, as have others.

As for the likely underlying issue, do look at implementing the metric server or other such (if it's not already enabled), and balancing the load across nodes. If you start getting overloaded with the metric server or other cluster-level load balancing enabled, either start to off-load the boxes, or buy more Alpha or Itanium Integrity server boxes for your cluster.

Re: OpenVMS user

Joseph Huber_1 — Thu, 19 Jun 2008 14:38:35 GMT

>> How could I segregate the total no. of tcpip abd denet user?

You probably can't, using SET LOGINS, and DECNET lacks a set limit like TCPIP services as far I see.
But DECNET CTERM and LAT do load balancing in a cluster.
If You really want to differentiate, then the only way is through sylogin as Hoff mentioned.
(and of course using metric/load broker if available).