docker service scale [servicename]=0
will remove all running instances but still keep the service object alive.
eg.
[node1] (local) [email protected] ~
$ docker service create --name test-service nginx
cjvbwuhjhwpixwg01nh22cqbq
overall progress: 1 out of 1 tasks
1/1: running [==================================================>]
verify: Service converged
[node1] (local) [email protected] ~
$ docker service scale test-service=0
test-service scaled to 0
overall progress: 0 out of 0 tasks
verify: Service converged
[node1] (local) [email protected] ~
$ docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
cjvbwuhjhwpi test-service replicated 0/0 nginx:latest
[node1] (local) [email protected] ~
$