[Spread-users] Spread segments w/o active daemons cause delays in other segments

[Dmitry Korsun]

Hi all.
 I am relatively new to Spread and have stumbled across a problem that I 
need help with resolving. Apparently adding a second Spread segment 
without any spread daemons causes a big performance drop in the first 
segment, even when clients are connecting to a member of the first 
segment locally.

Here are the scenarios:

I was getting really good performance results when using a single 
segment configuration with spread daemons runing on BOTH machines in the 
segment:
#
Spread_Segment 172.16.202.255:4803 {
       DevLinuxPro     172.16.202.64
       StarDev1 172.16.202.77
}
#
Performance was tested by using spflooder utility and connecting to the 
spread daemon LOCALLY:
devlinuxpro$ time spflooder -u ya -m 10000 -b 100 -s 4803 at devlinuxpro
flooder: connecting to 4803 at devlinuxpro.mis.idt.net
flooder: starting  multicast of 10000 messages, 100 bytes each.
flooder: completed  10000 messages of 100 bytes
flooder: completed multicast of 10000 messages, 100 bytes each.
real    0m0.559s
user    0m0.020s
sys     0m0.240s

This yields ~20000 messages/sec

Once a second segment was configured but no daemon started on the new 
segment machine, performance dropped dramatically:
#
Spread_Segment 169.132.9.255:4803 {
       dev_1       169.132.9.113
}
#
Again, performance was tested LOCALLY on the machine that is part of the 
first segment:
devlinuxpro$ time spflooder -u ya -m 10000 -b 100 -s 
4803 at devlinuxpro.mis.idt.net
flooder: connecting to 4803 at devlinuxpro.mis.idt.net
flooder: starting  multicast of 10000 messages, 100 bytes each.
flooder: completed multicast of 10000 messages, 100 bytes each.
real    0m25.543s
user    0m0.060s
sys     0m0.960s
Now we are down to ~400 messages/sec.

I about to test performance once a spread daemon is brought up on the 
second segment.

Question - why does this addition of a segment without a daemon process 
affect performance on a entirely different segment, especially the LOCAL 
performance.  Is there a way to configure SPREAD so that different 
segments do not affect each other's performance ?

Thank you in advance,
Dmitry Korsun


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:: Dmitry Korsun
:: x4095
:: dmitry.korsun at corp.idt.net
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-- 
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:: Dmitry Korsun
:: x4095
:: dmitry.korsun at corp.idt.net
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