Preparing for Development and Operating Environment

Preparing Development Environment

Table 1 describes the environment required for application development.

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 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/hadoopclient.

     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.

     

     • Verify that the configuration options in the Flink client configuration file flink-conf.yaml are correctly configured. For details, see Installing the Client and Preparing for Security Authentication.
     • In security mode, appended the service IP address of the node where the client is installed and floating IP address of Manager to the jobmanager.web.allow-access-address configuration item in the flink-conf.yaml file. Use commas (,) to separate IP addresses.
  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\Flink\config directory to the conf directory where the compiled JAR package is stored for subsequent commissioning, for example, /opt/hadoopclient/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 Flink/config/* root@IP address of the client node:/opt/hadoopclient/conf

     The keytab file obtained during the Preparing MRS Application Development User is also stored in this directory. Table 2 describes the main configuration files.

     Table 2 Configuration file

     Document Name	Function
     core-site.xml	Configures Flink parameters.
     hdfs-site.xml	Configures hdfs parameters.
     yarn-site.xml	Configures yarn parameters.
     flink-conf.yaml	Configures Flink parameters.
     user.keytab	Provides user information for Kerberos security authentication.
     krb5.conf	Kerberos server configuration information

  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.

  4. (Optional) To run a Python job, perform the following additional configurations:
     1. Log in to the node where the Flink client is installed as the root user and run the following command to check whether Python 3.6 or a later has been installed:

        python3 -V

     2. Go to the python 3 installation path, for example, /srv/pyflink-example, and install the virtualenv:

        cd /srv/pyflink-example

        virtualenv venv --python=python3.x

        source venv/bin/activate

     3. Copy the Flink/flink/opt/python/apache-flink-*.tar.gz file from the client installation directory to /srv/pyflink-example:

        cp Client installation directory/Flink/flink/opt/python/apache-flink-*.tar.gz /srv/pyflink-example

     4. Install the dependency package. If the following command output is displayed, the installation is successful:

        python -m pip install apache-flink-libraries-*.tar.gz

        python -m pip install apache-flink-Version number.tar.gz

        ...
        Successfully built apache-flink
         Installing collected packages: apache-flink
          Attempting uninstall: apache-flink
           Found existing installation: apache-flink x.xx.x
           Uninstalling apache- flink-x.xx.x:
            Successfully uninstalled apache-flink-x.xx.x
        Successfully installed apache-flink-x.xx.x