io autoconfigure and cluexit

[Hoff]

This looks reversed. I think the dropped CLUEXIT hosts and the dropped DECnet connections and such all point to one host that's got something odd going on, and that this one host is getting bogged down in kernel mode and the electronic catatonia is then causing all of the faults shown so far.

Memory errors and wonky hardware (flaky disks, flaky buses, incomplete or errant hardware configurations, down-revision firmware) can sometimes do this, though errant kernel-mode software another common trigger.

I'd look in the error logs, and I'd look in the batch job logs for that AUTOGEN job.

Look at the storage controllers, and at differences and specific configurations of all the devices. Any devices here that are incompletely connected or left unconfigured?

Do patch firmware in controllers and disks and such, patch OpenVMS, and patch anything else here with kernel-mode code to current.

Do shut off that AUTOGEN job. (If you're not seeing the load vary and you have the box already reasonably dialed in, there's probably not a big need to run it.)

Stephen Hoffman
HoffmanLabs LLC

[MarkOfAus]

Volker,

" as a first and simple workaround, try to increase RECNXINTERVAL on both nodes to exceed the time the other node seems to 'hang' during AUTOGEN."

I changed it to 180 seconds.

" You can calculate the time from the start of the AUTOGEN command (from batch .LOG file) until the crash time of the other node (from the crash). This should at least allow the node to survive a temporary loss of connection. "

The batch job log, while not showing anything useful, shows it is taking around 5 minutes to complete. Older logs showed it takes around 3 minutes.

A solution seems to have been found. I have replied to Hoff regarding this.

Regards
Mark

[MarkOfAus]

Hoff,

" This looks reversed. I think the dropped CLUEXIT hosts and the dropped DECnet connections and such all point to one host that's got something odd going on, and that this one host is getting bogged down in kernel mode and the electronic catatonia is then causing all of the faults shown so far. "

Yes, quite correct, one server, and only one, when io autoconfigure is run during autogen's getdata phase causes the other member of the cluster to cluexit.

" Memory errors and wonky hardware (flaky disks, flaky buses, incomplete or errant hardware configurations, down-revision firmware) can sometimes do this, though errant kernel-mode software another common trigger."

It seems it was a "wonky" Compaq 5300 raid controller that was the cause. Once this was replaced, the problem disappeared.

" Do shut off that AUTOGEN job. (If you're not seeing the load vary and you have the box already reasonably dialed in, there's probably not a big need to run it.)"

I agree I will do that immediately. But, hey, without it we might not have found the wonky card until something more serious had occurred.

Regards,
Mark

[MarkOfAus]

Firstly, thank you to Jur, Kalle, volker and Hoff.

The main problem stems from an inadequate RECNXINTERVAL setting which cannot cope with extended "hanging" on the other server.

As a corollary to this, the hanging was the result of bad hardware causing sysman's io autoconfigure to become stuck for a lengthy period.

The solution was to remove/replace the bad card and increase the RECNXINTERVAL value to 180.

I never realised that autogen getdata runs sysman's io autoconfigure.

Thanks once again to all those who put their time into helping.

Regards,
Mark.