docker:tldr:8ac9b

docker: Scale to a specific number of replicas for a space-separated list of services.

docker

$ docker service scale ${service_name}=${count_of_replicas}

try on your machine

The command "docker service scale ${service_name}=${count_of_replicas}" is used to scale the number of replicas (or instances) of a Docker service running in swarm mode.

Here's a breakdown of the command:

"docker service scale" is the initial part of the command that specifies that we want to scale the service.
"${service_name}" is a placeholder representing the name of the service we want to scale. You need to replace it with the actual name of the service.
"=" is used to assign the value on the right side to the left side.
"${count_of_replicas}" is another placeholder representing the desired number of replicas we want to scale the service to. You need to replace it with the actual number.

When you execute this command, Docker Swarm will update the service and adjust the number of replicas to match the specified count_of_replicas. If the new desired count is greater than the current number of replicas, additional containers will be deployed, and if it is smaller, some containers will be removed.

For example, if you have a service named "my-app" and want to scale it to 5 replicas, you would use the command:

docker service scale my-app=5

This would ensure that there are exactly 5 instances of the "my-app" service running in the Docker Swarm cluster.

This explanation was created by an AI. In most cases those are correct. But please always be careful and never run a command you are not sure if it is safe.

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