As I know, DDS can use publisher-base filter, that will filter the data on publisher side, so that it would save bandwidth. But if subscriber that all use filter and up to 32, DDS will use subscriber-base filter. In my case, publisher will publise many instance, and many client will subscribe just subset of the topic, so I would define a keyed topic, each subscriber use a filter to filter the instance waht it wants. I want to use filter on publisher-base, but as far as I know, if subscriber up to 32, publisher-base filter can't work, and DDS would change to subsrciber-base fitler. How can I solve this problem? Or I I misunderstand something, in fact in my case I no need to use filter for instances? Thanks for reply.
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Maybe you should check your 'DDS_DataWriterResourceLimitsQosPolicy' settings. According to the manual, you should care about 'max_remote_reader_filters'. It means 'Maximum number of remote DataReaders for which this DataWriter will perform content-based filtering'.
Hello jasonhit,
There was a content-filtering limitation such that a DataWriter would do content filtering for a maximum of 32 remote DataReaders in versions up to 4.5f. This limitation has been removed in RTI Connext 5.0.0. You still have to change the default, however.
From the RTI_CoreLibrariesAndUtilities_WhatsNew.pdf document:
Increased Resource Limit: max_remote_reader_filters
The valid range of values for max_remote_reader_filters in the DataWriterResourceLimitsQo- sPolicy has been increased from 32 to 2(31-2); it may also be set to DDS_LENGTH_UNLIMITED. The default remains 32.
Thank you!
Rose
hi,
I publish the different number of instances and on another end want to subscribe the a particular instance based on Key .But i am not able to get the key based Filtering of instances.
Hi Umesh,
You should be able to do this with just standard Content-Filtered topics. The html documentation has an example, see
ndds.5.1.0/doc/html/api_cpp/group__NDDSFilterExampleModule.html
You can also read about it in Section 5.4 (Content Filtered Topics) of the RTI_CoreLibrariesAndUtilities_UsersManual.pdf.
--Howard
Principal Applications Engineer
RTI