Is there any handy way to follow multiple piped commands' status output

Question

Let's say I have serverA with a block device, the contents of which I want to move to serverB's block device via the computer I am working on as a relay. This is very handy with pipes, buffers, dd and similar tools.

In order to monitor the progress and identify any bottlenecks, I like to follow the progress of the individual status output of each command.

Aside from complicating this one-liner by running multiple terminals, backgrounding (&), looping the outputs through FIFOs or the like, is there any way to handily sort the status outputs?

ssh serverA "sudo dd if=/dev/sdc status=progress | mbuffer" | mbuffer | ssh serverB "mbuffer | sudo dd of=/dev/sdc status=progress"

This gives me a single row that rapidly switches between the five different commands' status and also does not clean the row in between. For example alternating between the following (note the '00% full' on the alternate output):

in @ 6137 kiB/s, out @ 6137 kiB/s, 26.3 GiB total, buffer 100% full
30353129472 bytes (30 GB, 28 GiB) copied, 1158 s, 26.2 MB/s00% full

A neat output would keep each command's output consistently on a separate row.

Answer 1

pv can be used to show you the current throughput in a pipeline and can also to the same as mbuffer with its -B option (and can also report live how full the buffer is).

It also has a rate-limited mode (-qL) which you can use to simulate slow readers for testing.

ssh srchost 'sudo pv -cB1G -F "from device:%t: [%b] %r (buffer: %T)" /dev/sdc' |
 pv -WcB1G -F "through pipe:%t: [%b] %r (buffer: %T)" |
 ssh dsthost 'sudo sh -c '\''
 pv -WcB1G -F "received by dst:%t: [%b] %r (buffer: %T)" > /dev/sdc'\'

Using dd here doesn't make much sense.