Thanks to L. Clegg, O. Orgeron, T. Blinn, E. Branley, D. Goetzman and others
for the responses.
Here's a summary:
> 1. With TruCluster 5.1, when I "telnet" to the cluster alias, how the
cluster determine which node will pick up the session?
.........
* The node picked for telnet is usually by round-robin means.
* Magic. It load balances after a fashion. But it's magic, assume you
cannot predict or control it.
* Cluster alias configuration determines this. You can verify this by using
"cluamgr -s DEFAULTALIAS". Look at the values for the "memberid" lines.
Typically the "selp" (selection priority) is the same, this
determines what members get "selected" as possible end nodes to get the new
session. The "selw" (selection window if I remember correctly) is the one
that should determine how the connections are rotated. In the default case
it is "3". This should result in the first 3 connections going to the first
member, then the next 3 going to the next member. You can see this if you
test against the default alias (assuming you are the only one requesting a
new TCP connection) with telnet or rsh from a client system.
> 2. If users need to "rlogin" between systems in the TruCluster, should
they rlogin via the memory-channel connection? (e.g. rlogin node2-mc0 ) Or
should this memory-channel connection only be used
by system-type processes?
* Node to node communications in a TruCluster always goes over memory
channel.
* Telnet or rlogin to the physical node. The memory channel should not be
used for normal network
traffic.
* Use the normal node names. You can do it over the Memory Channel but
don't depend on it.
If you are not in the cluster already but are in the habit of using the
"global" node name, that will work and get you where you want to be.
* Don't burden users with knowledge of the cluster interconnect; it will get
them into trouble.
* Always use the network connection path. Use the node#-mco hostname to
test the mc interconnect.
* The cluster talks directly over the mc, not using IP. The IP over the
Memory Channel is just there for
testing and maybe to route network traffic over if needed (NIC failure,
cluster members not attached to primary LAN, etc.).
* Users shouldn't have to rlogin to different nodes, since they use a shared
Cluster File System. They're in the same /, /usr, and /var. If you
actually do have to login to a particular box (as opposed to whichever one
picked up your telnet or rlogin session from the cluster alias), do it from
its regular IP address.
## my response:
I think logging into a specific box is the only way users know how to
spread out their analysis/computation jobs. I'll have to dig into the docs
and see what other "transparent" tools they could use ##
Thank you again for your assistance!
Rob Aldridge
AT&T Solutions
Alliance, Ohio
..........................................
>
> Tru64 Managers:
>
>
> 1. With TruCluster 5.1, when I "telnet" to the
> cluster alias, how the
> cluster determine which node will pick up the
> session?
>
>
> 2. If users need to "rlogin" between systems in the
> TruCluster, should they
> rlogin via the memory-channel connection? (e.g.
> rlogin node2-mc0 ) Or
> should this memory-channel connection only be used
> by system-type processes?
>
>
> Thank you,
>
> Rob Aldridge
> AT&T Solutions
> Alliance, Ohio
Received on Mon May 07 2001 - 15:03:41 NZST