Preparing the Environment

You need to prepare the local development and commissioning environment and cloud environment.

Preparing a Local Development and Commissioning Environment

The local development and commissioning environment is used to set up a simple test environment. The options are as follows:

Download the local CSE.
Use the exclusive ServiceComb engine and open the IP address for public network access to ensure that the local environment can be accessed.

Preparing the Cloud Environment

Before deploying microservice applications on the cloud, you need to prepare the cloud environment. Perform the following procedure to prepare the environment:

Create a ServiceComb engine. For details, see Creating a ServiceComb Engine.
Create an environment. For details, see Creating an Environment. The created environment must contain resources such as CCE clusters, load balancers, and ServiceComb engines.
Create an application. For details, see Creating an Application.

Common Environment Variables

Using ServiceStage to manage environments and deploy applications simplifies user configuration. ServiceStage sets some environment variables for applications. The following table lists some common environment variables:

**Table 1** Common environment variables
Name	Description
PAAS_CSE_SC_ENDPOINT	Registry center address of a ServiceComb engine.
PAAS_CSE_CC_ENDPOINT	Configuration center address of a ServiceComb engine.
PAAS_PROJECT_NAME	Name of a project.
CAS_APPLICATION_NAME	Name of a ServiceStage application.
CAS_COMPONENT_NAME	Name of a ServiceStage component.
CAS_INSTANCE_VERSION	Version of the deployed ServiceStage.

You can use these variables based on the mechanisms of different microservice development frameworks, such as the Place Holder mechanism of Spring Cloud and the mapping.yaml mechanism of Java chassis, to reduce manual input during deployment.

When creating an application on ServiceStage, you can bind middleware, such as Distributed Cache Service (DCS) and Relational Database Service (RDS), to the application. You can obtain the configuration information about the middleware bound to applications by using the following environment variables.

Distributed session

Distributed sessions are stable and reliable session storage based on DCS, supporting automatic injection for mainstream web containers, such as tomcat context, node.js express-session, and PHP session handler.

The following table describes the environment variables of distributed sessions.

**Table 2** Environment variables of DCS sessions
Name	Description
DISTRIBUTED_SESSION_CLUSTER	Whether the instance is in cluster mode. Value: true or false.
DISTRIBUTED_SESSION_TYPE	Storage type of a distributed session instance. Currently, only Redis is supported.
DISTRIBUTED_SESSION_VERSION	Version of a distributed session instance.
DISTRIBUTED_SESSION_NAME	Name of a distributed session instance.
DISTRIBUTED_SESSION_HOST	IP address for connecting to a distributed session instance.
DISTRIBUTED_SESSION_PORT	Port for connecting to a distributed session instance.
DISTRIBUTED_SESSION_PASSWORD	Password for connecting to a distributed session instance.

Distributed cache

DCS is an online, distributed, in-memory cache service compatible with Redis and Memcached. It combines high reliability and scalability with instant availability and easy management, delivering high read/write performance and fast data access.

The following table describes the environment variables of DCS.

**Table 3** Environment variables of DCS
Name	Description
DISTRIBUTED_CACHE_CLUSTER	Whether the instance is in cluster mode. Value: true or false.
DISTRIBUTED_CACHE_TYPE	Storage type of a distributed cache instance. Currently, only Redis is supported.
DISTRIBUTED_CACHE_VERSION	Version of a DCS instance.
DISTRIBUTED_CACHE_NAME	Name of a DCS instance.
DISTRIBUTED_CACHE_HOST	IP address for connecting to a DCS instance.
DISTRIBUTED_CACHE_PORT	Port for connecting to a DCS instance.
DISTRIBUTED_CACHE_PASSWORD	Password for connecting to a DCS instance.

Cloud database

RDS for MySQL is a cloud-based web service that is reliable, scalable, easy to manage, and out of the box.

The following table describes the environment variables of RDS.

**Table 4** Environment variables of RDS
Name	Description
RELATIONAL_DATABASE_NAME	Name of an RDS instance.
RELATIONAL_DATABASE_CONNECTION_TYPE	Connection type of an RDS instance. Value: JNDI/SPRING_CLOUD_CONNECTOR.
RELATIONAL_DATABASE_JNDI_NAME	JNDI name of an RDS instance. This variable is used if the connection type is JNDI.
RELATIONAL_DATABASE_DB_NAME	Database name of an RDS instance.
RELATIONAL_DATABASE_DB_USER	Database user of an RDS instance.
RELATIONAL_DATABASE_DB_TYPE	Database type of an RDS instance. Currently, only MySQL is supported.
RELATIONAL_DATABASE_VERSION	Database version of an RDS instance.
RELATIONAL_DATABASE_HOST	Database IP address of an RDS instance.
RELATIONAL_DATABASE_PORT	Database port of an RDS instance.
RELATIONAL_DATABASE_PASSWORD	Database password of an RDS instance.