Installing a Client

Scenario

Install the clients of all services (except Flume). MRS provides shell scripts for different services for maintenance personnel to log in to related maintenance clients and implement maintenance operations.

Reinstall the client after server configuration is modified on the Manager portal or after the system is upgraded. Otherwise, the versions of the client and server will be inconsistent.

Prerequisites

The client installation directory is automatically created if it does not exist. If it already exists, it must be empty. The directory cannot contain any space.
If the node where the client is to be installed is a server outside the cluster, it must be able to communicate with the service plane. Otherwise, the client will fail to be installed.
The client must be enabled with the NTP service and synchronize time with the server. Otherwise, the client will fail to be installed.
The HDFS and MapReduce components are stored in the same directory (client directory/HDFS/) after being downloaded.
You can install or use the client as any user. Obtain the username and password from the administrator. This section uses user user_client as an example. User user_client is the owner of the server file directory (such as /opt/Bigdata/client) and the client installation directory (such as /opt/Bigdata/hadoopclient) with the permissions of 755.
You have obtained the component service user (default user or new user) and password.
If the /var/tmp/patch directory already exists when you install the client as non-root or non-omm user, change the permission on the directory to 777 and the permission on the logs in the directory to 666.

Procedure

Obtain the software package.
Log in to FusionInsight Manager. For details, see Accessing FusionInsight Manager (MRS 3.x or Later). Click the wanted cluster from the Cluster drop-down list.

Choose More > Download Client. The Download Cluster Client window is displayed.

In a single-client scenario, choose Cluster > Name of the desired cluster > Services > Service name > More > Download Client. The Download Client dialog box is displayed.
Set Select Client type to Complete Client.
Configuration Files Only is to download client configuration files in the following scenario: After all clients are downloaded and installed and administrators modify server configuration on the Manager portal, development personnel need to update the configuration files during application development.

There are two client software packages:
- x86_64: client software package that can be deployed on the x86 platform.
- aarch64: client software package that can be deployed on the TaiShan platform.
The cluster supports x86_64 and aarch64 clients. However, the client type must match the architecture of the target node. Otherwise, the client installation will fail.
Determine whether to generate a client file on the cluster node?
- If yes, select Save to Path, and click OK to generate the client file. By default, the client file is generated in /tmp/FusionInsight-Client on the active management node. The directory can be customized and user omm has the read, write, and execute permission on the directory. Click OK, copy the software package to the file directory, for example, /opt/Bigdata/client, on the server where the client is to be installed as user omm or root. Then, go to 5.
  
  If you cannot obtain permissions of user root, use the omm user.
- If no, click OK, specify a local save path, and download the complete client. Wait until the download is complete, and go to 4.
Upload the software package. Use WinSCP to upload the software package to the server file directory where the client is to be installed (such as /opt/Bigdata/client) as the user who is to install the client (any user, such as user user_client).
The format of the client software package name is as follows: FusionInsight_Cluster_<Cluster ID>_Services_Client.tar. The following steps and sections use FusionInsight_Cluster_1_Services_Client.tar as an example.
- The host where the client is to be installed can be a node in the cluster or outside the cluster. If the node is a server outside the cluster, it must be able to communicate with the cluster, and the NTP service must be enabled to ensure that the time is the same as that on the server.
- For example, you can configure NTP clock sources for external client servers as well as clusters. Then you can execute the ntpq -np command to check whether the time is synchronized.
  - If there is a * before the result of the NTP clock source IP address, it means time synchronization is normal, as follows:
    remote refid st t when poll reach delay offset jitter ============================================================================== *10.10.10.162 .LOCL. 1 u 1 16 377 0.270 -1.562 0.014
  - If there is no * before the result of the NTP clock source IP address, and the result of refid is .INIT., or the results showed abnormal, it means synchronization is exception, please contact technical support.
    remote refid st t when poll reach delay offset jitter ============================================================================== 10.10.10.162 .INIT. 1 u 1 16 377 0.270 -1.562 0.014
- You can also configure the same chrony clock source for external servers as that for the cluster. After the configuration, run the chronyc sources command to check whether the time is synchronized.
  - In the command output, if an asterisk (*) exists before the IP address of the chrony service on the active OMS node, the synchronization is in normal state. For example:
    MS Name/IP address Stratum Poll Reach LastRx Last sample =============================================================================== ^* 10.10.10.162 10 10 377 626 +16us[ +15us] +/- 308us
  - If there is no asterisk (*) before the IP address of the NTP service on the active OMS node and Reach is "0", the synchronization is abnormal.
    MS Name/IP address Stratum Poll Reach LastRx Last sample =============================================================================== ^? 10.1.1.1 0 10 0 - +0ns[ +0ns] +/- 0ns
Log in to the server where the client software package is located as user user_client.
Decompress the package.
Go to the directory where the package is stored, for example, /opt/Bigdata/client. Run the following command to decompress the package to a local directory:

tar -xvf FusionInsight_Cluster_1_Services_Client.tar
Verify the software package.
Run the sha256sum to verify the retrieved file, for example,

sha256sum -c FusionInsight_Cluster_1_Services_ClientConfig.tar.sha256
```
FusionInsight_Cluster_1_Services_ClientConfig.tar: OK     
```
Run the following command to decompress the retrieved file:
tar -xvf FusionInsight_Cluster_1_Services_ClientConfig.tar
Configure network connections for the client.
1. Ensure that the host where the client is installed can communicate with the hosts listed in the hosts file stored in the directory containing the decompressed package, for example, /opt/Bigdata/client/FusionInsight_Cluster_<Cluster ID>_Services_ClientConfig/hosts.
2. If the host where the client is installed is not a host in the cluster, you need to set the mapping between the host name and the service plane IP address for each cluster node in /etc/hosts, user root rights are required to modify the file. Each host name uniquely maps an IP address. You can perform the following steps to import the domain name mapping of the cluster to the hosts file:
  1. Switch to the root user or a user who has permission to modify the hosts file.
    su - root
  2. Go to the directory where the client package is decompressed.
    cd /opt/Bigdata/client/FusionInsight_Cluster_1_Services_ClientConfig
  3. Run the cat realm.ini >> /etc/hosts command to import the domain name mapping to the hosts file.
- If the host where the client is installed is not a host in the cluster, configure network connections for the client to prevent errors from occurring when you run commands on the client.
- If the Spark task is run in yarn-client mode, add the spark.driver.host parameter in the Client installation directory/Spark/spark/conf/spark-defaults.conf file and set the parameter value to the IP address of the client.
- When yarn-client mode is used, to ensure that the Spark WebUI can properly display information, add the mappings between the client IP addresses and host names to the hosts file on the active and standby Yarn nodes, that is, the ResourceManager nodes in the cluster.
Go to the directory where the installation package is stored, and run the following command to install the client to the specified directory (an absolute path), for example, /opt/hadoopclient:
cd /opt/Bigdata/client/FusionInsight_Cluster_1_Services_ClientConfig

Run the ./install.sh /opt/hadoopclient command and wait for the client installation to complete. The client is successfully installed if information similar to the following is displayed:
```
The component client is installed successfully
```
- If the /opt/hadoopclient directory has been used by the client of all or some installed services, use another directory when another client is installed.
- Delete the client installation directory to uninstall the client.
- To ensure that the client you install can only be used by you, add the -o parameter. That is, run the ./install.sh /opt/hadoopclient -o command to install the client.
- If the NTP server is to be installed in chrony mode, ensure that the parameter chrony is added in the installation process, that is, run the command ./install.sh /opt/hadoopclient -o chrony to install the client.
- Because HBase uses the Ruby syntax, if the installed client contains the HBase client, it is recommended that the client installation directory contain only uppercase letters, lowercase letters, digits, and _-?.@+= characters.
- If the client node is a server outside the cluster and cannot communicate with the service plane IP address of the active OMS node or cannot access port 20029 of the active OMS node, the client can be successfully installed but cannot be registered with the cluster and cannot be displayed on the GUI.
Log in to the client to check whether the client is successfully installed.
1. Run the cd /opt/hadoopclient command to go to the client installation directory.
2. Run the source bigdata_env command to configure the environment variables for the client.
3. If the cluster is in security mode, run the following command to set kinit authentication and enter the password for logging in to the client, In normal mode, user authentication is not required:
  kinit admin
```
Password for admin@HADOOP.COM:          #Enter the login password of user admin (this password is the same as the user password for cluster login).
```
4. Run the klist command to view and confirm authentication details.
```
Ticket cache: FILE:/tmp/krb5cc_0 
Default principal: admin@HADOOP.COM   

Valid starting     Expires            Service principal 
04/09/2021 18:22:35  04/10/2021 18:22:29  krbtgt/HADOOP.COM@HADOOP.COM
```
  - When kinit authentication is used, the ticket is stored in the /tmp/krb5cc_uid directory by default.
    uid indicates the ID of the user who logs in to the operating system. For example, if the UID of user root is 0, the ticket generated for kinit authentication after user root logs in to the system is stored in the /tmp/krb5cc_0 directory.
    
    If the current user does not have the read and write permission on the /tmp directory, the ticket generated cache path is changed to client installation directory/tmp/krb5cc_uid. For example, the client installation directory is /opt/hadoopclient. The kinit authentication ticket is stored in /opt/hadoopclient/tmp/krb5cc_uid.
  - If kinit authentication is used and the same user is used to log in to the operating system, there is a risk that tickets are overwritten. You can set the -c cache_name parameter to specify the ticket buffer location or set the KRB5CCNAME environment variable to avoid this problem.
After the cluster is reinstalled, the client that has been installed is no longer available. Perform the following operations to reinstall the client.
1. Log in to the node where the client is located as user root.
2. Run the following command to check the directory where the client is located. (In the following example, the client is located in the /opt/hadoopclient directory.)
  ll /opt
```
drwxr-x---. 6 root root       4096 Dec 11 19:00 hadoopclient 
drwxr-xr-x. 3 root root       4096 Dec  9 02:04 godi 
drwx------. 2 root root      16384 Nov  6 01:03 lost+found 
drwxr-xr-x. 2 root root       4096 Nov  7 09:49 rh 
```
3. Run the mv command to remove the directory where the client program is located and all files in this directory. (For example, remove the /opt/hadoopclient directory and all files in it.)
  mv /opt/hadoopclient /tmp/clientbackup
4. Reinstall the client.