Using MySQL for Pivotal Platform

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This topic provides instructions for developers using the MySQL for Pivotal Platform service for their Pivotal Platform apps.

Overview

MySQL for Pivotal Platform provides a relational database for apps and devices. To use MySQL for Pivotal Platform in an app:

  1. Check the service availability in the Marketplace, and see if there is an existing instance of MySQL for Pivotal Platform in your space.

    See Confirm the MySQL for Pivotal Platform Service Availability, below.

  2. If there is no existing instance or you want to use a different one, create an instance of the MySQL for Pivotal Platform service in the same space as the app.

    See Create a Service Instance, below.

  3. Bind the app to the MySQL for Pivotal Platform service instance, to enable the app to use MySQL.

    See Bind a Service Instance to Your App, below.

  4. Call the MySQL for Pivotal Platform service in your app code, and then re-push your app into the space.

    See Use the MySQL Service in Your App, below.

After you create a MySQL for Pivotal Platform service instance, you can manage it over the life cycle of your apps and data. See Manage Service Instances, below.

The below procedures use the Cloud Foundry Command Line Interface (cf CLI). For more information, see Managing Service Instances with the cf CLI. You can also use Apps Manager to do the same tasks using a graphical UI. For more information, see Managing Apps and Service Instances Using Apps Manager

Prerequisites

To use MySQL for Pivotal Platform with your Pivotal Platform apps, you need:

Confirm the MySQL for Pivotal Platform Service Availability

For an app to use the MySQL for Pivotal Platform service, both of the following must be true:

  • The service must be available in the Marketplace for its space.
  • An instance of the service must exist in its space.

You can confirm both of these using the cf CLI as follows.

Check Service Availability in the Marketplace

To find out if a MySQL for Pivotal Platform service is available in the Marketplace:

  1. Enter the following command:

    cf marketplace
    
  2. If the output lists p.mysql in the service column, MySQL for Pivotal Platform is available. If it is not available, ask your operator to install it.

    $ cf marketplace
    Getting services from marketplace in org my-org / space my-space as user@example.com...
    OK
    service             plans          description
    [...]
    p.mysql             db-small       Dedicated instances of MySQL service to provide a relational database
    [...]
    

Check That an Instance Is Running in the Space

To confirm that a MySQL for Pivotal Platform instance is running in the space:

  1. Use the cf CLI or Apps Manager to log in to the org and space that contains the app.
  2. Enter the following command:

    cf services
    
  3. Any p.mysql listings in the service column are service instances of MySQL for Pivotal Platform in the space.

    For example:

    $ cf services
    Getting services in org my-org / space my-space as user@example.com...
    OK
    name          service     plan        bound apps    last operation
    my-instance   p.mysql     db-small                  create succeeded
    
    You can bind your app to an existing instance or create a new instance to bind to your app.

Create a Service Instance

On-demand services are created asynchronously, not immediately. The watch command shows you when your service instance is ready to bind and use.

To create an instance of the MySQL for Pivotal Platform service:

  1. Create a service instance by running the following command:

    cf create-service p.mysql PLAN SERVICE-INSTANCE
    

    Where:

    • PLAN is the name of the MySQL for Pivotal Platform plan you want to use.
    • SERVICE-INSTANCE is a name you choose to identify the service instance. This name appears under service in output from cf services.
  2. Enter the following command and wait for the last operation for your instance to show as create succeeded.

    watch cf services
    

    For example:

    $ cf create-service p.mysql db-small my-instance
    Creating service my-instance in org my-org / space my-space as user@example.com... OK
    $ watch cf services
    Getting services in org my-org / space my-space as user@example.com... OK name service plan bound apps last operation my-instance p.mysql db-small create succeeded

    If you get an error, see Troubleshooting Instances.

Bind a Service Instance to Your App

For an app to use a service, you must bind the app to a service instance. You must do this after every time you run cf push.

To push and bind an app to a MySQL for Pivotal Platform instance run the following command:

  1. Push your app into the same space as your MySQL for Pivotal Platform service instance by running the following command:

    cf push
    
  2. Bind your app to a MySQL for Pivotal Platform instance by running the following command:

    cf bind-service APP SERVICE-INSTANCE
    

    Where:

    • APP is the app you want to use the MySQL service instance.
    • SERVICE-INSTANCE is the name you supplied when you ran cf create-service.

    For example:

    $ cf bind-service my-app my-instance
    Binding service mydb to my-app in org my-org / space test as user@example.com... OK TIP: Use 'cf push' to ensure your env variable changes take effect
  3. Restart your app by running the following command:

    cf restart APP
    

    Where APP is the app you want to use the MySQL service instance.

Use the MySQL Service in Your App

To access the MySQL service from your app:

  1. Verify that your app code (or the MySQL client library that the app uses) retries in the case of DNS timeouts.

  2. Locate the connection strings listed in the VCAP_SERVICES > credentials object for your app. For information about VCAP_SERVICES, see MySQL Environment Variables below.

  3. In your app code, call the MySQL service using the connection strings.

    See this example Node.js code.

Use Custom Schemas

MySQL for Pivotal Platform supports multiple custom schemas. You can use custom schemas with apps that share a MySQL service instance to isolate app data by schema. By default, service bindings use the default schema service_instance_db.

To use custom schemas in your apps:

  1. Bind your app to the custom schema by running the following command:

      cf bind-service APP SERVICE-INSTANCE -c '{"schema":"CUSTOM-SCHEMA"}'"
    

    Where:

    • APP is the app you want to use the custom schema.
    • SERVICE-INSTANCE is the name of your MySQL for PCF service instance.
    • CUSTOM-SCHEMA is the name of your custom schema.
  2. Restart your app by running the following command:

    cf restart APP
    

    Where APP is the app you want to use the custom schema.

MySQL Environment Variables

Apps running in Pivotal Platform gain access to bound service instances through an environment variable credentials hash called VCAP_SERVICES. This environment variable includes the credentials that apps use to access service instances.

For example:

{
  "p.mysql": [
    {
      "label": "p.mysql",
      "name": "my-instance",
      "plan": "db-medium",
      "provider": null,
      "syslog_drain_url": null,
      "tags": [
        "mysql"
      ],
      "credentials": {
        "hostname": "10.0.0.20",
        "jdbcUrl": "jdbc:mysql://10.0.0.20:3306/service_instance_db?user=fefcbe8360854a18a7994b870e7b0bf5\u0026password=z9z6eskdbs1rhtxt",
        "name": "service_instance_db",
        "password": "z9z6eskdbs1rhtxt",
        "port": 3306,
        "uri": "mysql://fefcbe8360854a18a7994b870e7b0bf5:z9z6eskdbs1rhtxt@10.0.0.20:3306/service_instance_db?reconnect=true",
        "username": "fefcbe8360854a18a7994b870e7b0bf5"
      },
      "volume_mounts": []
    }
  ]
}

You can search for your service by the name given when the service instance was created. You can also search using the tags or label properties. The credentials property can be used to provide access to the MySQL protocol.

VCAP_SERVICES is only modified when an app is bound to a service instance. If you modify your service instance, you must cf unbind-service, cf bind-service and cf restage your app to apply the changes to VCAP_SERVICES.

Manage a Service Instance

You can manage service instances in the following ways:

Update a Service Instance to a Larger Plan

As apps and their databases grow, it might be necessary to update the service instance to a larger plan. This does not require a rebinding of your app. However, while the instance is being migrated to a new service instance, the database is unavailable for several minutes.

Warning: You cannot update to or from a highly available (HA) cluster plan to a plan that uses a single-node or leader-follower topology using the update-service command. To update to or from HA cluster plan, you must migrate your data to a new service instance using the cf mysql-tools plugin. For more information about migrating data, see Migrating Data in MySQL for Pivotal Platform.

To update a service instance to a larger plan, run the following command:

cf update-service SERVICE-INSTANCE -p PLAN

Where PLAN is the plan you want to upgrade the service instance to.

For example:

$ cf update-service my-instance -p db-large

Share Service Instances

In MySQL for Pivotal Platform you can share service instances between different orgs and spaces using cf share-service. Service instance sharing is enabled by default.

For more information about service instance sharing, see Sharing Service Instances.

To share a service instance:

  1. Target the source org and space for the service instance you want to share by running:

    cf target -o SOURCE-ORG -s SOURCE-SPACE
    

    Where:

    • SOURCE-ORG is the source org for your service instance.
    • SOURCE-SPACE is the source space for your service instance.
  2. Share your service instance to the destination org and space by running:

    cf share-service SERVICE-INSTANCE -o DESTINATION-ORG -s DESTINATION-SPACE
    

    Where:

    • SERVICE-INSTANCE is the service instance you want to share.
    • DESTINATION-ORG is the destination org for the service instance.
    • DESTINATION-SPACE is the destination space for the service instance.
  3. Target the destination org and space by running:

    cf target -o DESTINATION-ORG -s DESTINATION-SPACE
    
  4. Confirm the service instance was shared by running:

    cf service SERVICE-INSTANCE
    

    Where SERVICE-INSTANCE is the service instance you shared.

Unbind an App from a Service Instance

To stop an app from using a service it no longer needs, run the following command to unbind the app from the service:

cf unbind-service APP SERVICE-INSTANCE

Where:

  • APP is the app you want to stop using the MySQL service instance.
  • SERVICE-INSTANCE is the name you supplied when you ran cf create-service.

For example:

$ cf unbind-service my-app my-instance
Unbinding app my-app from service my-instance in org my-org / space my-space as user@example.com... OK

Delete a Service Instance

You cannot delete a service instance that an app is bound to.

To delete a service instance:

  1. Run the following command:

    cf delete-service SERVICE-INSTANCE
    

    Where SERVICE-INSTANCE is the name of the service to delete.

    For example:

    $ cf delete-service my-instance
    Are you sure you want to delete the service my-instance ? y Deleting service my-service in org my-org / space my-space as user@example.com... OK
  2. Enter the following command and wait for a Service instance not found error indicating that the instance no longer exists:

    watch cf service SERVICE-INSTANCE