Preparing for Development and Operating Environment

Preparing the Development Environment

Table 1 describes the environment required for secondary development.

**Table 1** Development environment
Item	Description
OS	Development environment: Windows OS. Windows 7 or later is supported. Operating environment: Windows OS or Linux OS. If the program needs to be commissioned locally, the running environment must be able to communicate with the cluster service plane network.
JDK installation	Basic configuration for the development and operating environment. The version requirements are as follows: The server and client support only built-in OpenJDK, version: 1.8.0_272, and therefore a JDK replacement is not allowed. Customers' applications that need to reference the JAR packages of SDK to run in the application processes support Oracle JDK, IBM JDK, and OpenJDK. For x86 nodes that run clients, the following JDKs can be used: Oracle JDK versions: 1.8 IBM JDK versions: 1.8.5.11 For nodes that run TaiShan and clients, the following JDK can be used: OpenJDK: 1.8.0_272 NOTE: The server supports only TLS V1.2 or later to ensure security. By default, IBM JDK supports only TLS V1.0. If IBM JDK is used, setting com.ibm.jsse2.overrideDefaultTLS to true enables TLS V1.0, V1.1, and V1.2. For details, see https://www.ibm.com/support/knowledgecenter/en/SSYKE2_8.0.0/com.ibm.java.security.component.80.doc/security-component/jsse2Docs/matchsslcontext_tls.html#matchsslcontext_tls.
IntelliJ IDEA installation and configuration	Tool used for developing HBase applications. The version must be 2019.1 or other compatible version. NOTE: If the IBM JDK is used, ensure that the JDK configured in IntelliJ IDEA is the IBM JDK. If the Oracle JDK is used, ensure that the JDK configured in IntelliJ IDEA is the Oracle JDK. If the Open JDK is used, ensure that the JDK configured in IntelliJ IDEA is the Open JDK. Do not use the same workspace and the sample project in the same path for different IntelliJ IDEA programs.
JUnit plug-in installation	Basic configuration for the development environment.
Installation of Maven	Basic configurations of the development environment. It can be used for project management throughout the lifecycle of software development.
User development preparation	See Preparing MRS Application Development User for configuration.
7-zip	Used to decompress .zip and .rar packages. The 7-Zip 16.04 is supported.

Preparing an Operating Environment

During application development, you need to prepare the code running and commissioning environment to verify that the application is running properly.

If the local Windows development environment can communicate with the cluster service plane network, download the cluster client to the local host; obtain the cluster configuration file required by the commissioning program; configure the network connection, and commission the program in Windows.
1. Download and decompress the client.
  - Log in to the FusionInsight Manager portal and choose Cluster > Dashboard > More > Download Client. Set Select Client Type to Configuration Files Only and click OK. After the client files are packaged and generated, download the client to the local PC as prompted and decompress it.
  For example, if the client file package is FusionInsight_Cluster_1_Services_Client.tar, decompress it to obtain FusionInsight_Cluster_1_Services_ClientConfig_ConfigFiles.tar file. Then, decompress FusionInsight_Cluster_1_Services_ClientConfig_ConfigFiles.tar file to the D:\FusionInsight_Cluster_1_Services_ClientConfig_ConfigFiles directory on the local PC. The directory name cannot contain spaces.
2. Go to the client configuration file decompression path FusionInsight_Cluster_1_Services_ClientConfig_ConfigFiles\HBase\config, obtain the HBase-related configuration file. The configuration file will be imported to the configuration file directory (usually the conf folder) of the HBase sample project.
  The keytab authentication file obtained during the Preparing MRS Application Development User is also stored in this directory.
3. During application development, if you need to commission the application in the local Windows system, copy the content in the hosts file in the decompression directory to the hosts file of the node where the client is located. Ensure that the local host can communicate correctly with the hosts listed in the hosts file in the decompression directory.
  - If the host where the client is installed is not a node in the cluster, configure network connections for the client to prevent errors when you run commands on the client.
  - The local hosts file in a Windows environment is stored in, for example, C:\WINDOWS\system32\drivers\etc\hosts.
If you use the Linux environment for commissioning, you need to prepare the Linux node where the cluster client is to be installed and obtain related configuration files.
1. Install the client on the node. For example, the client installation directory is /opt/client.
  Ensure that the difference between the client time and the cluster time is less than 5 minutes.
  
  For details about how to use the client on a Master or Core node in the cluster, see Using an MRS Client on Nodes Inside a Cluster. For details about how to install the client outside the MRS cluster, see Using an MRS Client on Nodes Outside a Cluster.
2. Log in to the FusionInsight Manager portal. 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\HBase\config directory to the conf directory where the compiled JAR package 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 management node, run the following command:
  
  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 HBase/config/* root@IP address of the client node:/opt/client/conf
  
  The keytab file obtained during the Preparing MRS Application Development User is also stored in this directory.
3. 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 no, manually copy the content in the hosts file in the decompression directory to the hosts file on the node where the client resides, to ensure that the local host can communicate with each host in the cluster.