[Ryu-devel] Installing multiple flows in parrallel

Discussion:

corey ross

2017-06-17 11:47:39 UTC

Hey there,
I was wondering if it is possible to install multiple flows in parallel, if
yes how?

for e.g if I have a topology of three switches (s1, s2, s3), I want to
install flow-rules f1 on s1, f2 on s2 and f3 on s3. How can I install this
three flow rules in parallel instead of doing so in serial fashion?

I have searched around and It seems that using threads is not an effective
way.

Iwase Yusuke

2017-06-19 00:26:36 UTC

Permalink

Hi,

Post by corey ross
Hey there,
I was wondering if it is possible to install multiple flows in parallel, if yes how?
for e.g if I have a topology of three switches (s1, s2, s3), I want to install flow-rules f1 on s1, f2 on s2 and f3 on s3. How can I install this three flow rules in parallel instead of doing so in serial fashion?
I have searched around and It seems that using threads is not an effective way.

Please let me make your question more clear.
What does "in parallel" and "in serial" exactly mean?

You mean; you currently uses multi-thread (using "ryu.lib.hub" or "eventlet"),
but some post you read says "multi-thread on Python is not effective enough",
right?
If so, are you facing the performance limit, for example?

Or, you want to get "Datapath" instance for s2 and s3, when you get event from
s1?

Thanks,
Iwase

corey ross

2017-06-19 10:44:00 UTC

Permalink

Yes I am referring to the first statement "multi-thread on Python is not
effective enough"...

Please let me give another example to make my question more clear
Lets say the routing algorithm wants to update the paths on switch S1, S2,
S3. One way is to update all the switches at time 0 (in parallel), and the
other way is to update s1 at time 0, s2 at time 1, and s3 at time 3
(serial).

Because of GIL in python a thread has to finish its task before moving to
another thread; with this in mind I believe using threads will update the
switches in serial; because the first thread has to finish installing the
rules on s1, then it moves to the next thread to install the rules on s2
and so on....

So my question is in Ryu what mechanism I can use to update s1, s2, s3 at
time 0 (in one go)?
I hope my question is more clear now.

Thank you all for your time,
Corry

Post by corey ross
Hi,

Post by corey ross
Hey there,
I was wondering if it is possible to install multiple flows in parallel,

if yes how?

Post by corey ross
for e.g if I have a topology of three switches (s1, s2, s3), I want to

install flow-rules f1 on s1, f2 on s2 and f3 on s3. How can I install this
three flow rules in parallel instead of doing so in serial fashion?

Post by corey ross
I have searched around and It seems that using threads is not an

effective way.
Please let me make your question more clear.
What does "in parallel" and "in serial" exactly mean?
You mean; you currently uses multi-thread (using "ryu.lib.hub" or "eventlet"),
but some post you read says "multi-thread on Python is not effective enough",
right?
If so, are you facing the performance limit, for example?
Or, you want to get "Datapath" instance for s2 and s3, when you get event from
s1?
Thanks,
Iwase

Post by corey ross
------------------------------------------------------------

------------------

Post by corey ross
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Yi Tseng

2017-06-20 18:14:52 UTC

Permalink

Hi,

I think we have some similar thread before:
https://sourceforge.net/p/ryu/mailman/ryu-devel/thread/CAM5MNiVPXW3xWeoHPMriXvSKkUnAHbgv6LqRZ%2BrE5rOZqDKaLQ%40mail.gmail.com/#msg35801377

Basically, I would suggest using multiple Ryu instance(process) to install
flows to switch.

Post by corey ross
Yes I am referring to the first statement "multi-thread on Python is not
effective enough"...
Please let me give another example to make my question more clear
Lets say the routing algorithm wants to update the paths on switch S1, S2,
S3. One way is to update all the switches at time 0 (in parallel), and the
other way is to update s1 at time 0, s2 at time 1, and s3 at time 3
(serial).
Because of GIL in python a thread has to finish its task before moving to
another thread; with this in mind I believe using threads will update the
switches in serial; because the first thread has to finish installing the
rules on s1, then it moves to the next thread to install the rules on s2
and so on....
So my question is in Ryu what mechanism I can use to update s1, s2, s3 at
time 0 (in one go)?
I hope my question is more clear now.
Thank you all for your time,
Corry

Post by corey ross
Hi,

Post by corey ross
Hey there,
I was wondering if it is possible to install multiple flows in

parallel, if yes how?

Post by corey ross
for e.g if I have a topology of three switches (s1, s2, s3), I want to

install flow-rules f1 on s1, f2 on s2 and f3 on s3. How can I install this
three flow rules in parallel instead of doing so in serial fashion?

Post by corey ross
I have searched around and It seems that using threads is not an

Post by corey ross
------------------------------------------------------------

------------------

--
Yi Tseng (a.k.a Takeshi)
Taiwan National Chiao Tung University
Department of Computer Science
W2CNLab

https://takeshi.tw

Iwase Yusuke

2017-06-21 01:48:13 UTC

Permalink

Hi Corry and Yi,

Post by Yi Tseng
Hi,
https://sourceforge.net/p/ryu/mailman/ryu-devel/thread/CAM5MNiVPXW3xWeoHPMriXvSKkUnAHbgv6LqRZ%2BrE5rOZqDKaLQ%40mail.gmail.com/#msg35801377
Basically, I would suggest using multiple Ryu instance(process) to install flows to switch.

Thanks Yi!
Yes, I guess it is the best way to use multiple instances.
The architecture might become complex though.

Just an idea, I am wondering if we could use "multiprocessing" module...

Thanks,
Iwase

Post by Yi Tseng
Yes I am referring to the first statement "multi-thread on Python is not effective enough"...
Please let me give another example to make my question more clear
Lets say the routing algorithm wants to update the paths on switch S1, S2, S3. One way is to update all the switches at time 0 (in parallel), and the other way is to update s1 at time 0, s2 at time 1, and s3 at time 3 (serial).
Because of GIL in python a thread has to finish its task before moving to another thread; with this in mind I believe using threads will update the switches in serial; because the first thread has to finish installing the rules on s1, then it moves to the next thread to install the rules on s2 and so on....
So my question is in Ryu what mechanism I can use to update s1, s2, s3 at time 0 (in one go)?
I hope my question is more clear now.
Thank you all for your time,
Corry
Hi,

Please let me make your question more clear.
What does "in parallel" and "in serial" exactly mean?
You mean; you currently uses multi-thread (using "ryu.lib.hub" or "eventlet"),
but some post you read says "multi-thread on Python is not effective enough",
right?
If so, are you facing the performance limit, for example?
Or, you want to get "Datapath" instance for s2 and s3, when you get event from
s1?
Thanks,
Iwase

Post by corey ross
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
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------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Ryu-devel mailing list
https://lists.sourceforge.net/lists/listinfo/ryu-devel <https://lists.sourceforge.net/lists/listinfo/ryu-devel>
--
Yi Tseng (a.k.a Takeshi)
Taiwan National Chiao Tung University
Department of Computer Science
W2CNLab
https://takeshi.tw
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Ryu-devel mailing list
https://lists.sourceforge.net/lists/listinfo/ryu-devel

Yi Tseng

2017-06-21 20:18:04 UTC

Permalink

Hi Iwase,

I am not sure we can do that with multiprocessing module.

Might need to change Ryu event mechanism to do that (e.g. need to send
events to different process...)

Yi

Post by Iwase Yusuke
Hi Corry and Yi,

Post by Yi Tseng
Hi,
https://sourceforge.net/p/ryu/mailman/ryu-devel/thread/

CAM5MNiVPXW3xWeoHPMriXvSKkUnAHbgv6LqRZ%2BrE5rOZqDKaLQ%
40mail.gmail.com/#msg35801377

Post by Yi Tseng
Basically, I would suggest using multiple Ryu instance(process) to

install flows to switch.
Thanks Yi!
Yes, I guess it is the best way to use multiple instances.
The architecture might become complex though.
Just an idea, I am wondering if we could use "multiprocessing" module...
Thanks,
Iwase

Post by Yi Tseng
Yes I am referring to the first statement "multi-thread on Python is

not effective enough"...

Post by Yi Tseng
Please let me give another example to make my question more clear
Lets say the routing algorithm wants to update the paths on switch

S1, S2, S3. One way is to update all the switches at time 0 (in parallel),
and the other way is to update s1 at time 0, s2 at time 1, and s3 at time 3
(serial).

Post by Yi Tseng
Because of GIL in python a thread has to finish its task before

moving to another thread; with this in mind I believe using threads will
update the switches in serial; because the first thread has to finish
installing the rules on s1, then it moves to the next thread to install the
rules on s2 and so on....

Post by Yi Tseng
So my question is in Ryu what mechanism I can use to update s1, s2,

s3 at time 0 (in one go)?

Post by Yi Tseng
I hope my question is more clear now.
Thank you all for your time,
Corry
On Mon, Jun 19, 2017 at 5:26 AM, Iwase Yusuke <
Hi,

Post by corey ross
Hey there,
I was wondering if it is possible to install multiple flows in

parallel, if yes how?