[21830] Minimum fragment size in SHM of Fast-DDS

[Employeeprojec]

When i tried setting the maxmessagesize as 123 bytes in SHM through xml file,it shows RTPSWriter error pointing towards add_data() in the log..

Why that log message is coming...

What is the minimum fragment size or maxmessagesize that can be set in SHM ?

[Employeeprojec]

When i set the maxmessage size to 123 bytes and started sending 1GB data, fast dds is showing this error..

[paxifaer]

My impression is that shm has no maximum limit.

[Employeeprojec]

My impression is that shm has no maximum limit.

Hi, I am asking what is the minimum limit for MaxMessageSize in fast dds

[JesusPoderoso]

The recommended minimum limit for MaxMessageSize is 512B @Employeeprojec.

[Employeeprojec]

The recommended minimum limit for MaxMessageSize is 512B @Employeeprojec.

But when i tried to set MaxMessageSize as 512 bytes and transferred 1 bytes of data,why it is showing this error..

[JesusPoderoso]

We will take a look at it in the following days and come back with some feedback @Employeeprojec

[JesusPoderoso]

Hi @Employeeprojec, thanks for using Fast DDS.
The shared memory transport segment size close to or smaller than the data size poses a high risk of data loss, since the write operation will overwrite the buffer during a single send operation.
Ensure you configure the segment size to be big enough to allocate your data type.

[EugenioCollado]

I am closing this conversation as it has already been answered and the corresponding code improvements are described here and here.