[omniORB] Performance Question

[Dietmar May]

Sai-Lai,

> > These figures are much better than the ones with arrays but still omniorb
> > is behind VisiBroker in the local case is this because VisiBroker uses
> > Shared Memory on Windows NT?
>
> I do not know what visibroker has done to make local case works better in
> your measurements. The remote case, it is quite obvious for the reason I've
> already given.
>
> It seems to me quite a number of people have done similar comparisons. It
> is more interesting to me to see comparisons that involves multiple
> concurrent clients doing transfers. Measurements on how much internal
> buffering an ORB is consuming, etc.

It is more interesting in our particular case to see comparisons such as Georg 
is doing, with a single client doing transfers, because that's how WE need to 
use omniORB :).

That is, the primary potential performance bottleneck in our environment is a 
single local connection to a single server transferring several megabytes of 
data per second, possibly for extended periods of time. The cost of passing 
this data via sockets for a local transfer really cuts into performance badly!

The only possible workaround is creating the server as a DLL, and loading the 
DLL so that it uses virtual function calls. But it seems that defeats one of 
the reasons we use CORBA in the first place: so that different companies can 
create different plug-in components (as executables) in a standard manner.

A possible solution has been suggested in Georg's comment: using shared memory 
for local connections.

The apparent implication that the omniORB team can't be bothered with 
performance is rather disheartening in light of the obvious pride they take in 
having the "fastest ORB" around. Here's a possible weakness that's been 
demonstrated in omniORB's handling of large data sets. Won't your team at least 
please look at it, rather than dismissing it as irrelevant? Because it isn't, 
at least for us and our customers; and I suspect for other companies as well.

Best regards,
Dietmar May
Software Architect
Object Workshops