hi Hans, Thanks again for the reply. So, are implying that the higher priority samples will physically reach faster than the lower priority samples? And for this I don't have to do anything specific in the logic or code other than setting the Transport Priority Qos and creating the Network Channels with priority bands, is it? Also, is "diffserv " a mandatory value ? What if the diffserv is not supported by the network hardware ?
On Fri, Oct 14, 2011 at 2:09 PM, Hans van't Hag <[email protected]>wrote: > Hi Rakesh, > > > > Interesting, got the same question from our partner RTTS recently, here’s > the same answer J > > > > Its not that trivial to demonstrate with ‘simple’ test-program, yet here’s > a YouTube video on benchmarking opensplice that demonstrates how this can be > done with the OpenSplice touchstone benchmarking suite. > > > > What you want to demonstrate is that having end-to-end > priority-preservation i.e. having high-priority data being ‘handled’ by > separate high-priority send-threads in networking, being transported over > the wire with a high diffserv setting if available, being received at the > destination-machine by high-priority-threads and being inserted in the > dataReader’s cache with high-priority. In order for this to become ‘visible’ > you could use for instance some very big low-priority samples and show that > they have little/limited impact on the latency of small high-priority > samples. This is what the YouTube video on benchmarking OpenSplice explains > with using the OpenSplice Touchstone benchmarking suite. > > > > Regards, > > Hans > > > > > > * * > > *Hans van 't Hag* > > OpenSplice DDS Product Manager > > PrismTech Netherlands > > Email: [email protected] > > Tel: +31742472572 > > Fax: +31742472571 > > Gsm: +31624654078 > > > > PrismTech is a global leader in standards-based, performance-critical > middleware. Our products enable our OEM, Systems Integrator, and End User > customers to build and optimize high-performance systems primarily for > Mil/Aero, Communications, Industrial, and Financial Markets. > ------------------------------ > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Rakesh pawar > *Sent:* Friday, October 14, 2011 10:31 AM > *To:* OpenSplice DDS Developer Mailing List > *Subject:* Re: [OSPL-Dev] Priority based message publishing and Receiving > > > > Hi Hans, > > > > Thanks for replying. So, if OpenSplice DDS has Transport Priority Qos, > how do we implement it and test it. Suppose I create 3 network channels with > the priority band defined in it and I have some 10 topic samples, each > belonging to any of the pre defined priority group. Now if I set the > Transport Priority Qos before publishing these samples, will it show the > difference at the reciever end ( we would also apply the Transport Priority > at Subscriber end) ? Will I get the higher priority samples first with these > configurations? Is there any way of testing it on a smaller scale for demo > purpose? > > > > > > On Fri, Oct 14, 2011 at 1:27 PM, Hans van't Hag < > [email protected]> wrote: > > Hi Rakesh, > > > > > > Yes, in OpenSplice you can. > > OpenSplice implements the notion of priority-bands implemented by what we > call ‘network-channels’ that are characterized by dedicated receive/transmit > threads per network-channel as well as traffic-shaping and > reactivity-control per network-channel. For all this no specific network > hardware is required. There is although a benefit to be gained if you > network hardware supports DIFSERV as each network-channel can be configured > with its ‘own’ DIFSERV priority. > > > > The selection of the priority-band (i.e. network-channel) is done > dynamically based on the DDS ‘TransportPriority’ QoS value of the dataWriter > that writes a sample. > > This logical DDS TransportPriority QoS value is ‘matched’ against the > configured ranges that each network-channel ‘manages’. > > So important/high-priority (i.e. high TransportPriority value) DDS-data is > sent over a network-channel (aka priority-band) that’s ‘dedicated’ for > high-priority-data and in this way will ‘pre-empt’ low-priority-traffic > (both at sending-node as well as receiving node). > > > > Also ‘within’ a priority-band OpenSplice assures that higher-priority data > is sent on the wire before lower-priority data within that priority-band. > > > > Regards, > > Hans > > > > > > * * > > *Hans van 't Hag* > > OpenSplice DDS Product Manager > > PrismTech Netherlands > > Email: [email protected] > > Tel: +31742472572 > > Fax: +31742472571 > > Gsm: +31624654078 > > > > PrismTech is a global leader in standards-based, performance-critical > middleware. Our products enable our OEM, Systems Integrator, and End User > customers to build and optimize high-performance systems primarily for > Mil/Aero, Communications, Industrial, and Financial Markets. > ------------------------------ > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Rakesh pawar > *Sent:* Friday, October 14, 2011 9:25 AM > *To:* developer > *Subject:* [OSPL-Dev] Priority based message publishing and Receiving > > > > Hi, I need to implement a priority based message publishing and receiving. > Is it possible to achieve this in DDS without any dependence on network > hardware ? > > > > -- > > > Cheers ! > Rakesh Pawar > > > > > _______________________________________________ > OpenSplice DDS Developer Mailing List > [email protected] > Subscribe / Unsubscribe > http://dev.opensplice.org/mailman/listinfo/developer > > > > > > -- > > > Cheers ! > Rakesh Pawar > > > > _______________________________________________ > OpenSplice DDS Developer Mailing List > [email protected] > Subscribe / Unsubscribe > http://dev.opensplice.org/mailman/listinfo/developer > > -- Cheers ! Rakesh Pawar
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