redis replication scheduled to be closed ASAP for overcoming of output buffer limits.

redis-client-ouput-buffer-limit

If you redis initial replication fails with error like 
"5101:M 20 Feb 18:14:29.130 # Client id=4500196 addr=71.459.815.760:43872 fd=533 name= age=127 idle=127 flags=S db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=13997 oll=1227 omem=192281275 events=rw cmd=psync scheduled to be closed ASAP for overcoming of output buffer limits.

means that slave buffer is not enough and you should increase it (at master!) with command like
redis-cli config set client-output-buffer-limit "slave 836870912 836870912 0"

more info: https://redis.io/topics/clients

@jberends

Thanks for the help!
These manipulations require AUTH password to submit changes.

redis-cli config -a "$REDIS_PASSWORD" set client-output-buffer-limit "pubsub 64mb 32mb 120"

It must return OK if a request is successful.

I can't use "mb" in redis-cli command for server version 4.0.9.
I must specify pure numbers in the command:

redis-cli config set client-output-buffer-limit "pubsub 268435456 67108864 120"

TO THE MOON

Thank you. Helpful hint.
I knew there is some buffer but official documentation was missing that info.

Thanks this is helpful!

Me too :) Thanks a lot

too bad I got here after the crash loop. Still, very helpful, thanks!

you saved my life as well 🙏