Cluster Alias..

[Muthuvel.B]

Hi,

Is there any way to find out the Cluster_Alias name, Cluster IP_address and the patches installed on a system using command procedures?

Muthuvel.B

[Mobeen_1]

Muthu,
Yes its possible.


Could you elaborate what you are referring to by this. Normally in DNS round robin, you actually have a cluster alias name defined and that name alternates between different IP addresses for each of the nodes in the cluster
For example
I have a cluster called SUN and this cluster consists of the nodes SUN1, SUN2 and SUN3.
Assuming that SUN is defined as DNS round robin, the first hit to SUN resolves the IP for SUN1, 2nd to SUN2, 3rd to SUN3, 4th to SUN1 and so on. Do note that there is no IP for SUN.
So could you now clarify what you are asking for ?

As for the patches applied...you could get that from SYS$UPDATE:VMSINSTAL.HISTORY
If you would like to search for patches installed in a particular month then you could do something like
$pipe type sys$update:VMSINSTAL.HISTORY | search sys$input "FEB-2005"

regards
Mobeen

[Joseph Huber_1]

First of all, as a system-manager, You should know it :-)

TCPIP alias: depends on the TCP/IP stack , for TCPIP services (UCX):
TCPIP SHOW INTERFACE xxx /FULL
Cluster alias under the heading "Cluster Impersonator".

Decnet (Phase V):
NCL show all

Under "Identifiers" You will see the address towers (like NSP or Ositransport) twice, the second one is the cluster alias.
It is defined in SYS$SPECIFIC:[SYSMGR]NET$ALIAS_STARTUP.NCL
Example:
DNA_OSInetwork , 47:20:00-0D:AA-00-04-00-69-35:20
69-35
Hex 3569 = decimal 13673 = Decnet IV addresse
13.361
If You know the cluster alias name, then use
decnet_register to look up the name.

Decnet (Phase IV): NCP SHOW EXECUTOR should give similar info.

Installed patches:

PRODUCT SHOW HISTORY
lists all installed products including patches.


From inside a DCL procedure, I know no other way than to analyze the output of the commands above.

[Muthuvel.B]

Hi Mobeen,

What I was asking for is something like this... If you want to get a node_name you can use f$getsyi("nodename". The same way is there any way to find the cluster alias. Its true that you can find it from UCX SHOW INTERFACE/FULL. I think the other solution for patches was good. Thanks really.

Joseph,

Thanks for your efforts. I just wanted to know if there any possiblities other than extracting the data from a text file after directing the output of DCL commands to it. Because, I wanted to create a command procedure wherein I just wanted to reduce the coding.

I knew the stuffs you provided me. Hope you agree that I am a SysAdmin.:-) :-).

Muthuvel.B

[Mobeen_1]

Muthu,
In your environment does the following theory hold good

Is the cluster alias the first 5 characters of any node name in the cluster ?

Illustration :-
Lets assume we have a cluster with 3 nodes named VMSND1, VMSND2 and VMSND3, then the cluster alias is the first 5 chars of any node name .. i.e VMSND in this case

If the above theory holds good in your case, let me know, i will post something :)

regards
Mobeen

[Muthuvel.B]

Hi Mobeen,

In my environment, no such terminology is being used. The cluster alias for many of the clusters is entirely different than the node names. On some nodes, I find some logicals like SYS$CLUSTER_NAME or like that. But on the others I dont find it which means that its not a default one.

For the cluster Ip address, i think as Joseph said, we can use the SH INTER/FULL.
But once again we will have to direct it to some files and extract it.

Anyway pls send me the stuffs which you have right now.

Muthuvel.B

[Mobeen_1]

Muthuvel,
Now i understand what you are looking for. But the way to accomplish depends on the TCPIP component you are running... HP TCPIP or TCPware from Process Software and so on.

What is the goal that you are trying to achieve.. ?

Are you trying to write a command file that is generic enough and can run on any system and get the following details

1. Determine if a node is part of cluster
or stand alone
2. Then determine what patches are installed
on that system and
3. Only if that system is part of the
cluster then find out the IP alias ?

If this is what you like, then may be i could quickly write one, test here and upload it :)

rgds
Mobeen

[Muthuvel.B]

Hi Mobeen,

You got exactly what I want. Also you are right that I am writing a generic procedure which I would be using on several nodes.
I can find if a node is a member of a cluster or not. And ofcourse the patches too. But the problem is with the cluster_alias and ip. I badly need it.

I want to give you an example for this. Say there are three nodes in a cluster NODEA, NODEB and NODEC. If these have ips like x.x.x.1, x.x.x.2 and x.x.x.3, we also have another ip x.x.x.4 which is meant for the cluster with Cluster_alias name. It also has an entry in TCPIP route database. Looks odd???? Me too...

Hope you got it..

Regards,
Muthuvel.B

[Jan van den Ende]

Muthuvel, Mobeen,

_IF_ you are using DNS round-robin, then technically you are _NOT_ using a cluster alias!
What you are doing is: you have defined a CNAME, which arternatingly translates into a cyclus of (names or adresses of) nodes.
Using Metric & Loadbroker, this same principle is used for Load Balancing.

IP _DOES_ have the "ability" of a cluster alias, but that is not exactly what is expected in a VMS environment:
the relevant interfaces are defined to have the cluster alias name/address.
_ONE_ interface (the first to be able to do so) becomes the "cluster impersonator", and will handle _ALL_ communication directed at the cluster. Only upon failure (or shutdown) will the impersonation be released, and another interface will assume it.
And as long as there is ANY connection using it, it cannot be failed over.

Using DNS, one way or another, the cluster might not even know it can also be addressed as a cluster via IP...
And DNS might know any number of different names for the cluster, or a subset of its nodes...

hth.

Proost.

Have one on me.

Jan

[Mobeen_1]

Muthuvel,
Here we go... i think this should help you to get started :)

Determine Cluster or Not
------------------------
$ if f$getsyi ("cluster_member") .eqs. "TRUE"
$ then nodename = f$extract(0,5,f$getsyi("nodename"))
$ else
$ nodename = f$getsyi("nodename")
$ endif

Cluster Alias
-------------
$ pipe tcpip show inter/full | search sys$input "Impersonator"

Patches
--------
For those installed using VMSINSTAL
$ pipe type sys$update:vmsinstal.history | search sys$input "Feb-2005"

For those installed using PCSI, use
$ pipe product show hist | search sys$input "Feb-2005"

Put them all together and you should be able to get started :)

All the best and let us know how it goes

rgds
Mobeen

[Muthuvel.B]

Hi Mobeen,

Happy with your results. Sorry that I am still not convinced. I tried with your suggestion.

$ pipe ucx show inter/full | search sys$input Impersonator
Cluster Impersonator
C_Addr: x.x.x.x C_NETWRK: x.x.x.x C_BRDCST: x.x.x.x

Here I could get the cluster_ip address(one of my exact requirements) but not the cluster alias. Now I have found one another way for this.

I found two logicals generally in these systems which are SYS$CLUSTER_NODE and SYS_CLUSTER_NAME. Atleast one of these are available almost on all the systems in my network. So I have made use of these for finding it out.

I have one more way of finding the Cluster_ip which is as easy as running UCX SHOW HOST CLUSTER_ALIAS /out=a.txt and extracting the third line from it.

Just let me know the way I use for finding the cluster_alias is correct or not.

Thanks,
Muthuvel.B

[Mobeen_1]

Muthu,
I am happy as long as it works for you :)
Can you post the output from the following command ....

$UCX SHOW HOST CLUSTER_ALIAS

(you can change your IP address to xxx.xxx.xxx.xxx)
:)

rgds
Mobeen

[Muthuvel.B]

Mobeen,

$ ucx show host 'Cluster_alias'

LOCAL database

Host address Host name

x.x.x.x xxxxxx, XXXXXX
$
where Cluster_alias equates the cluster's real alias name.

Muthuvel.B

Btw: Leaving rightaway. BRB later.

[Joseph Huber_1]

>> SYS$CLUSTER_NODE and SYS_CLUSTER_NAME.

The first one is the DECNET clustername, not the IP cluster impersonation.
SYS_CLUSTER_NAME I don't think is commonly existing.

To have different DECNET and IP cluster names I
think is not so uncommon: in my case, all nodes can be reached by the DECNET cluster address. But the IP cluster alias is only defined for nodes offering services (mail,ftp,web).

[Jan van den Ende]

Muthuvel, Mobeen,


$ pipe ucx show inter/full | search sys$input Impersonator
Cluster Impersonator
C_Addr: x.x.x.x C_NETWRK: x.x.x.x C_BRDCST: x.x.x.x


Please note, that this will _ONLY_ return cluster info on the _ONE_ node that is at that moment the cluster impersonator.
On _NONE_ of the other nodes cluster info is returned!

Joseph,


in my case, all nodes can be reached by the DECNET cluster address. But the IP cluster alias is only defined for nodes offering services

Even much stronger than that: the IP cluster alias is at any moment in time _ONLY_ offered by a _SINGLE_ node, and can _NOT_ be changed while there is _ANY_ connection active on it!!

hth,

Proost.

Have one on me.

jpe

[Ian Miller.]

note that the Failsafe IP feature in TCPIP Serv ices for VMS V5.4 and later sort of superceeds the cluster alias and the ifconfig command is what you use to determine what's going on with alias addresses.

[Muthuvel.B]

Hi All,

Yeah its true that the SYS_CLUSTER_NAME is not common on all nodes. By raising some questions, I got many new concepts. Thanks to all.

Now I have got another question. How do you configure a Cluster_alias in a VMS cluster environment? I think, I was not presented an option to configure it when I ran Cluster_config.com.

Muthuvel.B

[Mobeen_1 · Accepted solution]

Muthuvel,
The command for setting cluster alias in TCPIP is as follows

$tcpip set interface/cluster=alias-name

regards
Mobeen

[Joseph Huber_1]

< How do you configure a Cluster_alias in a VMS < cluster environment? I think, I was not
The DECnet cluster alias IS asked in cluster_config when adding a node.
If You mean IP cluster alias: since it has nothing to do with VMS cluster, cluster_config is simply not aware of it (and any other TCPIP related items).

[Jan van den Ende]

Muthuvel,

Ian's answer made me realise that I have a small correction to make to my own statements:

Even much stronger than that: the IP cluster alias is at any moment in time _ONLY_ offered by a _SINGLE_ node, and can _NOT_ be changed while there is _ANY_ connection active on it!!

It is even still stronger: it should not be "_ONLY_ offered by a _SINGLE_ node", but, "_ONLY_ offered by a _SINGLE_ _INTERFACE_" This becomes VERY relevant when having multiple interfaces!
The FailSafe IP feature (IP 5.4 and after) addresses some of that.

Proost.

Have one on me.

Jan

[Michelle Popejoy]

Muthuvel.B,

Let me give you one other scenario, even though it sounds like it's not applicable to you...

We don't use actual TCPIP "alias", but rather have multiple host records for the 'cluster-alias' name in DNS. So the SHOW INTER command doesn't show an "Impersonator", but SHOW HOST 'cluster-alias' shows all IP addresses in DNS for that name.

Example:
$ tcpip show host 'cluster-alias'

BIND database

Server: xx.xx.xx.xx

Host address Host name

xx.xx.xx.xx1 'cluster-alias'.'domain'.COM
xx.xx.xx.xx2 'cluster-alias'.'domain'.COM
xx.xx.xx.xx3 'cluster-alias'.'domain'.COM

Like some of the other commands it assumes you know the "cluster alias" already.

Cheers,
Michelle

[Jan van den Ende]

Re Michelle,

YES

That is exactly what you get to se with DNS Round-robin.
The somewhat more intelligent Loadbroker/Metric setup will show a single address for one interface, but if you repeat your questions several times it will alternate, reflecting each time the system which has at that moment the most "capacity" available cf the config setup.

Proost.

Have one on me.

Jan