Stop/Start a Service Instance

danger

Currently a9s PostgreSQL is the only Data Service that supports the usage of the Stop/Start feature.

Trying to apply the information contained on this document to an a9s Data Service aside from the ones mentioned above can leave the Service Instances in an irrecuperable state.

note

The Stop/Start feature, which is currently in Beta, must be enabled by the Platform Operator in order to be used.

The Stop/Start feature allows for the removal of the VMs belonging to a Service Instance when necessary as well as adding them again later without losing any persistent data. This allows to save on infrastructure costs during periods when the Service Instance is not needed.

Use the Stop/Start Feature

There are two ways to use the Stop/Start feature: via the a9s Public API and via the a9s CF Plugin.

a9s Public API

The a9s Public API can be used to stop and startan a9s Service Instance. For more information on these endpoints, see API V1 Endpoints - Stop/Start documentation.

a9s CF Plugin

There is also an a9s CF Plugin available that can be used to stop and start a Service Instance via the CF CLI.

Install the a9s CF Plugin

The a9s CF Plugin can be downloaded from our public S3 bucket. The plugin is available for the following operating systems:

• Linux (sha256:68d3a24293c0b74fa2c91662beaa1c9effd215685c0709bbbf8f8be8018b799c)
• MacOS (sha256:4f69e9a55d89d8d125f56142e513d7233e7f2c25c47a430d02da60877796b568)
• Windows (sha256:38899d3e1301cfb3f0d28df72de025cd168600d215478725101bbe67263a1233)

Once downloaded, the binary file can be installed to the Cloud Foundry CLI with the following command:

cf install-plugin <source-path>/a9s-cf-plugin -f

The -f flag in the command is necessary because this plugin is not signed by Cloud Foundry. Therefore it is needed to ignore the unsigned certificate when installing the a9s CF Plugin to the CF CLI.

Execute the following command to verify that the a9s CF Plugin was successfully installed:

cf a9s-version
1.0.0

Usage

There are 3 commands available in the a9s CF Plugin which are described in more detail below.

Stop

The stop command can be used to stop a Service Instance:

cf a9s-stop-service <my-service>
Are you sure you want to stop the service instance 'my-service'? [y/N]: y
stop in progress. Operation ID: 1234

More details on the available option can be found in the help text of the command:

cf a9s-stop-service -h
NAME:
   a9s-stop-service - Stop a service instance via the a9s Public API

USAGE:
   cf a9s-stop-service SERVICE_INSTANCE [--force] [--wait]

OPTIONS:
   --force, -f      Skip confirmation prompt
   --wait, -w       Wait for the stop operation to complete

Start

The start command can be used to stop a Service Instance:

cf a9s-start-service <my-service>
start in progress. Operation ID: 1234

More details on the available option can be found in the help text of the command:

cf a9s-start-service -h
NAME:
   a9s-start-service - Start a service instance via the a9s Public API

USAGE:
   cf a9s-start-service SERVICE_INSTANCE [--wait]

OPTIONS:
   --wait, -w      Wait for the start operation to complete

Status

The status command can be used to stop a Service Instance:

cf a9s-status <my-service>
State: provisioned

More details on the available option can be found in the help text of the command:

cf a9s-status -h
NAME:
   a9s-status - Show service instance status via the a9s Public API

USAGE:
   cf a9s-status SERVICE_INSTANCE [--json] [--details]

OPTIONS:
   --details, -d      Display detailed information
   --json, -j         Display raw JSON response

Expected Behavior

• Any attempt to bind an application to a stopped Service Instance, or to create a Service Key for it, will be rejected, as a stopped Service Instance doesn’t count as provisioned.

• Any attempt to unbind an application, or to delete a Service Key, from a stopped Service Instance will be rejected, as a stopped Service Instance doesn’t count as provisioned.

• Any attempt to update a custom parameter for a stopped Service Instance will be rejected, as a stopped Service Instance doesn’t count as provisioned.

• Any attempt to update the Service Plan for a stopped Service Instance will be rejected, as a stopped Service Instance doesn’t count as provisioned.

• Only the data stored on the persistent disk is retained and available again after a restart; all data in the memory and on the ephemeral disk is lost when a Service Instance is stopped.

• Calling the start endpoint of the a9s Public API for a Service Instance in any state other than stopped will not trigger a BOSH task and instead will get the following error message:

  Service Instance is currently in the state '<Service Instance's state> and not in 'stopped'.

• Calling the stop endpoint of the a9s Public API for a Service Instance in any state other than provisioned will not trigger a BOSH task and instead will get the following error message:

  Service Instance is currently in the state <Service Instance's state> and not in 'provisioned'.

Known Limitations

• The Application Developer cannot determine via the Cloud Foundry's cf CLI whether a Service Instance has been stopped or not.
• If a binding, or a service key, for a Service Instance exists in CF, this Service Instance cannot be deleted as long as it is stopped.