[Spread-users] sublinear movement
piotoru at zodiac.mimuw.edu.pl
Thu Feb 5 03:49:52 EST 2004
Jonathan Stanton wrote:
>The token will continue to rotate while waiting for new
>messages to be generated. To prevent too much wasted bandwith with tokens
>doing now work, Spread stops rotating the token after 100 rotations that
>accomplish nothing and then switches to only sending the token if a daemon
>asks for it, or once a second or so. So the extra 45 tokens were valid
>tokens, but no real messages were sent during their cycle (the tokens do
>not carry any message content themselves).
>We are actually going to switch this in the next version so the token goes
>in to 'idle' mode faster as people are often surprised that the token
>rotates even when no messages are being sent.
>I'm not sure about the exact packet counts you provide, but there is
>definitly some fixed overhead per spread message, and some extra traffic
>"per second" that will become less noticable the more messages you are
>sending per second.
I my aplication I use 6 spread groups (now it is only 2 clients in each
group one publisher one subscriber).
A, B, C - 3 aplications one per each host
p - publisher
s - subscriber
A p1 --> B s1
A p2 --> C s1
B p1 --> A s2
B p2 --> C s2
C p1 --> A s1
C p2 --> B s2
each publisher sends 30 packet/ s (each packet 250B). each aplication
(A,B and C) includes 2 publisher and 2 subscriber (A includes Ap1, Ap2,
As1 and As2 ; B include Bp1, Bp2, ... etc). So each genarate proces (A,
B and C) generate 30 * 2 * 250 B/s = 15000B/s.
But in fact the trafic was about 160kB OUT and ~200kB IN.
But after that I test it with 300 packet /s (each publisher).
I found something strange: on host with proces A trafic was something
about ~170kB - ~200kB OUT and ~400kB. Isn't to much?
After about one client (A xor B xor C) fall dawn with -8 error.
>On Wed, Feb 04, 2004 at 12:42:29PM +0100, Piotr Kozieradzki wrote:
>>I test spread on 3 host (Linux debian, CPU: Pentium II, network 100Mb)
>>in one segment (LAN, ethernet)
>>On each host is one spread demon and one spread client . Each client
>>has 2 publisher and two subscriber. So each program sends his messeges
>>to other program (one publisher from host A sends messeges to
>>subscriber from B and one to subscriber from C, etc. )
>>In first test I send 30 packet per second (200B each packet) from each
>>publisher. But avarage trafific is about 160B / s (it is about 10 times
>>more than it shuold be).
>>After that I change my program so each generate 300 pac sekond (200B
>>each packet) from each publisher , it generate trafic about 290B/s. Is
>>The other test was I run One demon on host A and one client (spuser) on
>>the same host. ther was no other spread demon in network. On spuser i
>>create group MY_GROUP and send to this group one message "Hello". I saw
>>about 45 annoucment from spread demon "Received token". Does it meen
>>that he received 45 packet?
>>Spread-users mailing list
>>Spread-users at lists.spread.org
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