Preparing the Development and Operating Environment

Development Environment

Table 1 describes the environments required for developing and running an application.

**Table 1** Environment
Item	Description
OS	Development environment: Windows OS Operating environment: Linux system If the program needs to be commissioned locally, the operating environment must be able to communicate with the cluster service plane.
JDK	Basic configurations for the development and operating environments. The version requirements are as follows: If you are using the MRS server and client, only built-in OpenJDK 1.8.0_272 is supported. Other JDKs are not allowed. If the JAR packages of the SDK classes that need to be referenced by the customer applications run in the application process, the JDK requirements are as follows: x86 client: Oracle JDK 1.8; IBM JDK 1.8.5.11. TaiShan client: OpenJDK 1.8.0_272
IDEA	Tool used for developing Flink applications. The required version is 14.1.7.
Scala	Basic configuration of the development environment. The required version is 2.11.7.
Scala plug-in	Basic configuration of the development environment. The required version is 1.5.4.
Maven	Basic configuration of the development environment. This tool is used for project management throughout the lifecycle of software development.
7-zip	Tool used to decompress .zip and .rar files. 7-Zip 16.04 is supported.

Preparing the Operating Environment

During application development, prepare the environment for running and commissioning code to verify that the application can run properly.

If you use the Linux environment for commissioning, prepare the Linux node where the cluster client is to be installed and obtain related configuration files.

Install the client in a directory, for example, /opt/client, on the node.
The difference between the client time and the cluster time must be less than 5 minutes.

For details about how to use a client on a master or core node in a cluster, see Installing a Client. For details about how to use a client on a node outside a cluster, see Installing a Client.

Log in to FusionInsight Manager. Download the cluster client software package to the active management node and decompress it. Then, log in to the active management node as user root. Go to the decompression path of the cluster client and copy all configuration files in the FusionInsight_Cluster_1_Services_ClientConfig\Flink\config directory to the conf directory where the compiled JAR file is stored for subsequent commissioning, for example, /opt/client/conf.

For example, if the client software package is FusionInsight_Cluster_1_Services_Client.tar and the download path is /tmp/FusionInsight-Client on the active OMS node, run the following commands:

cd /tmp/FusionInsight-Client

tar -xvf FusionInsight_Cluster_1_Services_Client.tar

tar -xvf FusionInsight_Cluster_1_Services_ClientConfig.tar

cd FusionInsight_Cluster_1_Services_ClientConfig

scp Flink/config/* root@IP address of the client node:/opt/client/conf

Table 2 describes the main configuration files.

**Table 2** Configuration files
File	Description
core-site.xml	Flink parameters
hdfs-site.xml	HDFS parameters
yarn-site.xml	YARN parameters
flink-conf.yaml	Flink client configuration

Check the network connection of the client node.
During the client installation, the system automatically configures the hosts file on the client node. You are advised to check whether the /etc/hosts file contains the host names of the nodes in the cluster. If there is no required information, copy the content of the hosts file in the decompression directory to the hosts file on the node where the client is deployed, to ensure that the local host can communicate with each host in the cluster.