scaling a service with docker compose - docker-compose

Question

I am facing issues with scaling a service using docker compose and need help.
Below is what I have:
My docker-compose.yml
web:
image: nginx
The command that I use to run:
docker-compose -f compose/nginx-docker-compose.yml scale web=3 up -d
The output of the command:
Creating and starting compose_web_1 ... done
Creating and starting compose_web_2 ... done
Creating and starting compose_web_3 ... done
ERROR: Arguments to scale should be in the form service=num
The output of docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
fead93372574 nginx "nginx -g 'daemon off" 6 seconds ago Up 4 seconds 80/tcp, 443/tcp compose_web_3
de110ae9606d nginx "nginx -g 'daemon off" 6 seconds ago Up 4 seconds 80/tcp, 443/tcp compose_web_1
4d7f8fd39ccd nginx "nginx -g 'daemon off" 6 seconds ago Up 4 seconds 80/tcp, 443/tcp compose_web_2
I should also mention that when I do not use the scale web=3 option, the service comes up just fine.
docker version
Client:
Version: 1.10.3
API version: 1.22
Go version: go1.5.3
Git commit: 20f81dd
Built: Thu Mar 10 15:51:19 2016
OS/Arch: linux/amd64
Server:
Version: 1.10.3
API version: 1.22
Go version: go1.5.3
Git commit: 20f81dd
Built: Thu Mar 10 15:51:19 2016
OS/Arch: linux/amd64
docker-compose version
docker-compose version 1.8.0, build f3628c7
docker-py version: 1.9.0
CPython version: 2.7.9
OpenSSL version: OpenSSL 1.0.1e 11 Feb 2013
Let me know if anybody else has face this and have found a solution.
Thanks.

Answer 1

You should remove the "up" if you use scale option. For ex: docker-compose scale web=3.
Let's see document from Docker site.
In your case:
docker-compose -f compose/nginx-docker-compose.yml scale web=3 up -d
The command may "think" that the up is the service name needed to be scaled (should be up=3). So it threw the warning like that