MSCP performance.

[Art Wiens]

Thanks all...lots of good ideas for me to think about so far!

Uwe - DTSEND - somehow, I'm totally unfamiliar with this diagnostic!! I'll check into it. What protocol is it actually using to do tests? Decnet?

Regarding setting MSCP_BUFFER on the Alpha's AND the VAX's, does this setting come into play on the VAX side? The VAX's are not (actively) serving any disk, the only local storage is the system disk and a page/swap disk.

Network topology - I'm using CentreCom twisted pair transceivers on the AUI ports of the 4000-105A's which are connected into an HP switch (the network folks say they have locked the ports at 10-Half). A Gig fiber uplink to a switch, down another Gig fiber link to another HP switch to the Alpha's running 100-Full. I wanted to get the VAX's onto the same switch as the Alpha's but there's a lack of free ports currently. There's a SQE test switch on the transceivers that is in the wrong position which is why I see Collision Detect Check failures. In the past this has never really been a "problem", just a max'ed counter.

Anyways, thanks again...I hope to be able to reboot the Alpha's this weekend for new MSCP sysgen settings, hopefully also get the VAX's over to the other switch.

Cheers,
Art

[John Eerenberg]

> "Regarding setting MSCP_BUFFER on the Alpha's AND the VAX's, does this setting come into play on the VAX side? The VAX's are not (actively) serving any disk, the only local storage is the system disk and a page/swap disk."

It is handy to serve your local disks on the VAXen so other nodes can have access to them. Makes it more convenient so you don't have to login to that node, or alternatively, use sysman, etc. I happen to prefer setting up my systems this way.

[Ian Miller.]

DTSEND uses DECnet task-to-task comms.
See
http://h71000.www7.hp.com/doc/73final/documentation/pdf/DECNET_OVMS_NET_UTIL.PDF
chapter 4

[Uwe Zessin]

Hello Art,
yes it uses DECnet. I forgot to mention the /SIZE qualifier. It is a nice way to put load onto a link and test the throughput without being limited by the speed of some underlying disks or tapes.

Ian, thank you for providing a pointer.

[Art Wiens]

Thanks Ian and Uwe. Now that I look at the manual I do remember reading about it/using it ... probably back in 1993 when the book was written!

I ran it against the node doing the MSCP serving:

_Test: data/print/stat/seconds=10/node=xxxxxx/size=512/type=seq
%NET-S-NORMAL, normal successful completion

Test Parameters:
Test duration (sec) 10
Target node "xxxxxx"
Line speed (baud) 1000000
Message size (bytes) 512

Summary statistics:
Total messages XMIT 14071 RECV 0
Total bytes XMIT 7204352
Messages per second 1407.10
Bytes per second 720435
Line thruput (baud) 5763480
%Line Utilization 576.348

I wish I could utilize my paycheque at 576% !!

Art

[Uwe Zessin · Accepted solution]

Well, I would use /SPEED=10000000 if this is a 10 MBit link on the VAX.

[Art Wiens]

Ahh...that's a bit better:

_Test: data/print/stat/seconds=10/node=xxxxxx/size=512/type=seq/speed=10000000
%NET-S-NORMAL, normal successful completion

Test Parameters:
Test duration (sec) 10
Target node "xxxxxx"
Line speed (baud) 10000000
Message size (bytes) 512

Summary statistics:
Total messages XMIT 17134 RECV 0
Total bytes XMIT 8772608
Messages per second 1713.40
Bytes per second 877260
Line thruput (baud) 7018080
%Line Utilization 70.181

[Uwe Zessin]

Yes, and what do you get the other way round?

[Art Wiens]

_Test: data/print/stat/seconds=10/node=yyyyyy/size=512/type=seq/speed=100000000
%NET-S-NORMAL, normal successful completion

Test Parameters:
Test duration (sec) 10
Target node "yyyyyy"
Line speed (baud) 100000000
Message size (bytes) 512

Summary statistics:
Total messages XMIT 17957 RECV 0
Total bytes XMIT 9193984
Messages per second 1795.70
Bytes per second 919398
Line thruput (baud) 7355184
%Line Utilization 7.355

[Uwe Zessin]

So, the network looks OK to me. The 7% looks a bit silly, but of course the VAX cannot receive with 100 MBit/second.