republication to another serves in rtmp (h264 codec) is not recommended?
Not "not recommended", it just should be taken into account that in the currently available version transcoding may be enabled in the case, and then there is a limit on the number of republished streams which can be processed depending on the stream parameters and hardware configuration.
There is already an open issue under development for the redundant transcoding when pushing stream as RTMP using REST request (WCS-2457). After the fix, transcoding will not be enabled in the case when stream is pushed with the same video resolution and there will not be those limits on the maximum number of streams.
Also, stream can be republished to another RTMP server not only using the push REST request but by specifying the RTMP URL when publishing WebRTC (
WebRTC as RTMP re-publishing example), and there is no video transcoding in that case.
More information on republishing as RTMP is
here.
(Currently, there is also another known issue with auto started (rtmp_push_auto_start=true) push as RTMP of WebRTC stream: no audio and video.)