[23681] Content Filters not working as expected with multiple subscribers and Large Packets

[MadisonTBlake]

Is there an already existing issue for this?

• I have searched the existing issues

Expected behavior

Consider multiple subscribers with each each subscriber filtering on different parameters. different parameters. It is expected that a publisher writing a message would be filtered and delivered to none, one, or both depending on if the message satisfies the filter. Further it would be expected that the size of the message would not impact the behavior.

Current behavior

When publishing large packets (65000+) subscribers do not receive messages as expected.

Steps to reproduce

• Start with examples/cpp/content_filter
  • Remove << hello_.message() from Publisher/Subscriber prints
  • Change message to hello_.message(std::string(68000, 'A'));
• Compile example
• Run one Subscriber with -lb 0 -ub 10
• Run a second Subscriber with -lb 20 -up 20
• Run Publisher with no extra args

With message size as 65000 (works as expected):

With message size as 68000 (unexpected behavior):

Fast DDS version/commit

3.4.X
fd1bb8f

Platform/Architecture

Ubuntu Focal 20.04 amd64

Transport layer

Default configuration, UDPv4 & SHM

Additional context

No response

XML configuration file

Relevant log output

Network traffic capture

No response

[cferreiragonz]

Hello @MadisonTBlake,

We have successfully reproduced the issue and will begin working on a fix shortly. Thank you for bringing this to our attention.

[MadisonTBlake]

Thanks!

FWIW doing a similar action on older FastDDSv2.10.1 results in an error sending fragment:

Cannot add RTPS submesage to the CDRMessage. Buffer too small

Unsure if the issue in the old version is the same in latest and just manifesting differently, hopefully that knowledge helps.