Typical Scenario: Collecting Logs from Kafka and Uploading Them to HDFS

Scenario

This section describes how to use Flume client to collect logs from the Topic list (test1) of Kafka and save them to the /flume/test directory on HDFS.

By default, the cluster network environment is secure and the SSL authentication is not enabled during the data transmission process. For details about how to use the encryption mode, see Configuring the Encrypted Transmission. The configuration applies to scenarios where only the Flume is configured, for example, Kafka Source+Memory Channel+HDFS Sink.

Prerequisites

• The cluster, HDFS, Kafka, and Flume service have been installed.
• The Flume client has been installed. For details about how to install the client, see Installing the Flume Client on Clusters.
• The network environment of the cluster is secure.
• You have created user flume_hdfs and authorized the HDFS directory and data to be operated during log verification. For details, see Adding a Ranger Access Permission Policy for HDFS.

Procedure

1. On FusionInsight Manager, choose System > User and choose More > Download Authentication Credential to download the Kerberos certificate file of user flume_hdfs and save it to the local host.
2. Configure the client parameters of the Flume role.
   Use the Flume configuration tool on FusionInsight Manager to configure the Flume role client parameters and generate a configuration file.

   1. Log in to FusionInsight Manager and choose Cluster > Services. On the page that is displayed, choose Flume. On the displayed page, click the Configuration Tool tab.
   2. Set Agent Name to client. Select the source, channel, and sink to be used, drag them to the GUI on the right, and connect them.

      For example, use Kafka Source, Memory Channel, and HDFS Sink.

      Figure 1 Example for the Flume configuration tool
      
   3. Double-click the source, channel, and sink. Set corresponding configuration parameters by seeing Table 1 based on the actual environment.
      

      • If you want to continue using the properties.propretites file by modifying it, log in to FusionInsight Manager, choose Cluster > Name of the desired cluster > Services. On the page that is displayed, choose Flume. On the displayed page, click the Configuration Tool tab, click Import, import the file, and modify the configuration items related to non-encrypted transmission.
      • It is recommended that the numbers of Sources, Channels, and Sinks do not exceed 40 during configuration file import. Otherwise, the response time may be very long.
   4. Click Export to save the properties.properties configuration file to the local.

      Table 1 Parameters to be modified of the Flume role client

      Parameter	Description	Example Value
      Name	The value must be unique and cannot be left blank.	test
      kafka.topics	Specifies the subscribed Kafka topic list, in which topics are separated by commas (,). This parameter cannot be left blank.	test1
      kafka.consumer.group.id	Specifies the data group ID obtained from Kafka. This parameter cannot be left blank.	flume
      kafka.bootstrap.servers	Specifies the bootstrap IP address and port list of Kafka. The default value is all Kafka lists in a Kafka cluster. If Kafka has been installed in the cluster and its configurations have been synchronized, this parameter can be left blank.	192.168.101.10:9092
      batchSize	Specifies the number of events that Flume sends in a batch (number of data pieces).	61200
      hdfs.path	Specifies the HDFS data write directory. This parameter cannot be left blank.	hdfs://hacluster/flume/test
      hdfs.inUsePrefix	Specifies the prefix of the file that is being written to HDFS.	TMP_
      hdfs.batchSize	Specifies the maximum number of events that can be written to HDFS once.	61200
      hdfs.kerberosPrincipal	Specifies the Kerberos authentication user, which is mandatory in security versions. This configuration is required only in security clusters.	flume_hdfs
      hdfs.kerberosKeytab	Specifies the keytab file path for Kerberos authentication, which is mandatory in security versions. This configuration is required only in security clusters.	/opt/test/conf/user.keytab NOTE: Obtain the user.keytab file from the Kerberos certificate file of the user flume_hdfs. In addition, ensure that the user who installs and runs the Flume client has the read and write permissions on the user.keytab file.
      hdfs.useLocalTimeStamp	Specifies whether to use the local time. Possible values are true and false.	true

3. Upload the configuration file.

   Upload the file exported in 2.d to the Flume client installation directory/fusioninsight-flume-Flume component version number/conf directory of the cluster

4. Verify log transmission.
   1. Log in to FusionInsight Manager as a user who has the management permission on HDFS. For details, see Accessing FusionInsight Manager. Choose Cluster > Services > HDFS. On the page that is displayed, click the NameNode(Node name,Active) link next to NameNode WebUI to go to the HDFS web UI. On the displayed page, choose Utilities > Browse the file system.
   2. Check whether the data is generated in the /flume/test directory on the HDFS.
      Figure 2 Checking HDFS directories and files