quickfix-developers

[Quickfix-developers] Dual CPUs and Performance

[Barry M. <bar...@ya...>]

Since the QuickFIX Engine is capable of multithreaded operation, I
would expect dual CPUs to provide increased performance. Even
without multithreaded operation, it seems that one should be able to
run 2 instances of the engine, one on each CPU, to get better
performance.

Does any one have any views/experience with regard to this question?

Thanks,
Barry

Barry Marks
Logicware, Inc.
Northbrook, IL
email: barryimarks, yahoo.com
 

Re: [Quickfix-developers] Dual CPUs and Performance

[Dale W. <wil...@oc...>]

Barry Marks wrote:

>Since the QuickFIX Engine is capable of multithreaded operation, I
>would expect dual CPUs to provide increased performance. Even
>without multithreaded operation, it seems that one should be able to
>run 2 instances of the engine, one on each CPU, to get better
>performance.
>  
>
Hi Barry,

I didn't see any response to this message, so I'll give it a shot.

The multithreading in quickfix is basically thread-per-connection.  Thus 
the amount of paralellism is limited to the number of connections (plus 
1 for the main thread).  This is unlikely to have much impact on overall 
performance (throughput) bit it may help with response time.  For any 
significant real-world system I would expect he performance to be 
dominated by application level code, not by the quickfix engine itself.  
If you have performance conceerns, I suggest you start by profiling your 
application so you don't end up optimizing in all the wrong places.

You can't run two quickfix engines in one process[1], but I'm not sure 
that makes much difference because a single engine can handle an 
aribtrary number of connections. 

Dale

[1] At least you aren't supposed to be able to run two engines in one 
process.  I did manage to do that once.  The results were not pretty.

-- 
-----------------------------------------------------
  Dale Wilson, Senior Software Engineer      
  Object Computing, Inc. (OCI)
  http://www.ociweb.com/  http://www.theaceorb.com/
----------------------------------------------------

RE: [Quickfix-developers] Dual CPUs and Performance

[Steve B. <st...@te...>]

Hi Dale,

> You can't run two quickfix engines in one process[1], but I'm not sure
> that makes much difference because a single engine can handle an
> aribtrary number of connections.

What happens when you run multiple QF engines in a process? I can
see where someone might want to do that if they want to accept
connections on multiple ports (in the same process) or have both 
initiators and acceptors running in the same process (for example, 
third party routing hub).

Steve

Re: [Quickfix-developers] Dual CPUs and Performance

[Dale W. <wil...@oc...>]

Steve Bate wrote:

>What happens when you run multiple QF engines in a process? I can
>see where someone might want to do that if they want to accept
>connections on multiple ports (in the same process) or have both 
>initiators and acceptors running in the same process (for example, 
>third party routing hub).
>  
>
You should be able to run two acceptors by configuring two separate sessions in the config file.  Both acceptors will be sharing the same "engine".  (I haven't tried this but in theory...) 

What I managed to do was get two complete copies of the quickfix library -- one statically linked into a DLL and the other statically linked into the EXE.  If you look at Session.h, you'll see lots of static data items.  As one example, two session registries is **NOT** better than one.  

((I call this the Doubleton pattern -- maybe I'll publish a paper <grin>))

Dale
-- 
-----------------------------------------------------
  Dale Wilson, Senior Software Engineer      
  Object Computing, Inc. (OCI)
  http://www.ociweb.com/  http://www.theaceorb.com/
----------------------------------------------------

RE: [Quickfix-developers] Dual CPUs and Performance

[Steve B. <st...@te...>]

> You should be able to run two acceptors by configuring two separate
> sessions in the config file.  Both acceptors will be sharing the same
> "engine".  (I haven't tried this but in theory...)

It looks like the acceptor reads its port number from the default
section of the configuration file. If so, you'd be able to have
any number of sessions defined for that acceptor as long as they 
connect to the same accept port. 

> What I managed to do was get two complete copies of the quickfix library -
> - one statically linked into a DLL and the other statically linked into
> the EXE.  If you look at Session.h, you'll see lots of static data items.
> As one example, two session registries is **NOT** better than one.
> 
> ((I call this the Doubleton pattern -- maybe I'll publish a paper <grin>))

I can see how that might be a problem in C++. :-) Sometimes that's done
intentionally in Java programs. For example, applications can be isolated
from each other (including "singletons") by using separate class loaders 
for each application.

Steve