Typical Scenario: Collecting Logs from Kafka and Uploading Them to HDFS
Scenario
This section describes how to use Flume to collect logs from the Topic list (test1) of Kafka and save them to the /flume/test directory on HDFS.
This section applies to MRS 3.x or later.
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. This configuration can use only one Flume scenario, for example, Server:Kafka Source+File Channel+HDFS Sink.
Prerequisites
- The cluster, HDFS, Kafka, and Flume service have been installed.
- 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.
Procedure
- On FusionInsight Manager, choose and choose to download the Kerberos certificate file of user flume_hdfs and save it to the local host.
- 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.
- Log in to FusionInsight Manager and choose Cluster > Name of the desired cluster > Services > Flume > Configuration Tool.
- 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, File Channel, and Avro Sink.
- Double-click the source, channel, and sink. Set corresponding configuration parameters by seeing Table 1 based on the actual environment.
- If the client parameters of the Flume role have been configured, you can obtain the existing client parameter configuration file from client installation directory/fusioninsight-flume-1.9.0/conf/properties.properties to ensure that the configuration is in concordance with the previous. Log in to FusionInsight Manager, choose Cluster > Name of the desired cluster > Services > Flume > Configuration Tool > 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.
- 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
dataDirs
Specifies the directory for storing buffer data. The run directory is used by default. Configuring multiple directories on disks can improve transmission efficiency. Use commas (,) to separate multiple directories. If the directory is inside the cluster, the /srv/BigData/hadoop/dataX/flume/data directory can be used. dataX ranges from data1 to dataN. If the directory is outside the cluster, it needs to be independently planned.
/srv/BigData/hadoop/data1/flume/data
checkpointDir
Specifies the directory for storing the checkpoint information, which is under the run directory by default. If the directory is inside the cluster, the /srv/BigData/hadoop/dataX/flume/checkpoint directory can be used. dataX ranges from data1 to dataN. If the directory is outside the cluster, it needs to be independently planned.
/srv/BigData/hadoop/data1/flume/checkpoint
transactionCapacity
Specifies the transaction size, that is, the number of events in a transaction that can be processed by the current Channel. The size cannot be smaller than the batchSize of Source. Setting the same size as batchSize is recommended.
61200
hostname
Specifies the name or IP address of the host whose data is to be sent. This parameter cannot be left blank. Name or IP address must be configured to be the name or IP address that the Avro source associated with it.
192.168.108.11
port
Specifies the IP address to which Avro Sink is bound. This parameter cannot be left blank. It must be consistent with the port that is monitored by the connected Avro Source.
21154
ssl
Specifies whether to enable the SSL authentication. (You are advised to enable this function to ensure security.)
Only Sources of the Avro type have this configuration item.
- true indicates that the function is enabled.
- false indicates that the client authentication function is not enabled.
false
- Upload the properties.properties file to flume/conf/ under the installation directory of the Flume client.
- Use the Flume configuration tool on FusionInsight Manager to configure the Flume role client parameters and generate a configuration file.
- Configure the server parameters of the Flume role and upload the configuration file to the cluster.
- Use the Flume configuration tool on the FusionInsight Manager portal to configure the server parameters and generate the configuration file.
- Log in to FusionInsight Manager and choose Cluster > Name of the desired cluster > Services > Flume > Configuration Tool.
- Set Agent Name to server. Select the source, channel, and sink to be used, drag them to the GUI on the right, and connect them.
For example, use Avro Source, File Channel, and HDFS Sink.
- Double-click the source, channel, and sink. Refer to Table 2 to set corresponding configuration parameters based on the actual environment.
- If the server parameters of the Flume role have been configured, you can choose Cluster > Name of the desired cluster > Services > Flume > Instance on FusionInsight Manager. Then select the corresponding Flume role instance and click the Download button behind the flume.config.file parameter on the Instance Configurations page to obtain the existing server parameter configuration file. Choose Cluster > Name of the desired cluster > Services > Flume > Configurations > 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.
- A unique checkpoint directory needs to be configured for each File Channel.
- Click Export to save the properties.properties configuration file to the local.
Table 2 Parameters to be modified of the Flume role server Parameter
Description
Example Value
Name
The value must be unique and cannot be left blank.
test
bind
Specifies the IP address to which Avro Source is bound. This parameter cannot be left blank. It must be configured as the IP address that the server configuration file will upload.
192.168.108.11
port
Specifies the ID of the port that the Avro Source monitors. This parameter cannot be left blank. It must be configured as an unused port.
21154
ssl
Specifies whether to enable the SSL authentication. (You are advised to enable this function to ensure security.)
Only Sources of the Avro type have this configuration item.
- true indicates that the function is enabled.
- false indicates that the client authentication function is not enabled.
false
dataDirs
Specifies the directory for storing buffer data. The run directory is used by default. Configuring multiple directories on disks can improve transmission efficiency. Use commas (,) to separate multiple directories. If the directory is inside the cluster, the /srv/BigData/hadoop/dataX/flume/data directory can be used. dataX ranges from data1 to dataN. If the directory is outside the cluster, it needs to be independently planned.
/srv/BigData/hadoop/data1/flumeserver/data
checkpointDir
Specifies the directory for storing the checkpoint information, which is under the run directory by default. If the directory is inside the cluster, the /srv/BigData/hadoop/dataX/flume/checkpoint directory can be used. dataX ranges from data1 to dataN. If the directory is outside the cluster, it needs to be independently planned.
/srv/BigData/hadoop/data1/flumeserver/checkpoint
transactionCapacity
Specifies the transaction size, that is, the number of events in a transaction that can be processed by the current Channel. The size cannot be smaller than the batchSize of Source. Setting the same size as batchSize is recommended.
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
- Log in to FusionInsight Manager and choose Cluster > Name of the desired cluster > Services > Flume. On the displayed page, click the Flume role under Role.
- Select the Flume role of the node where the configuration file is to be uploaded, choose Instance Configurations > Import beside the flume.config.file, and select the properties.properties file.
- An independent server configuration file can be uploaded to each Flume instance.
- This step is required for updating the configuration file. Modifying the configuration file on the background is an improper operation because the modification will be overwritten after configuration synchronization.
- Click Save, and then click OK.
- Click Finish.
- Use the Flume configuration tool on the FusionInsight Manager portal to configure the server parameters and generate the configuration file.
- Verify log transmission.
- Log in to FusionInsight Manager as a user who has the management permission on HDFS. For details, see Accessing FusionInsight Manager (MRS 3.x or Later). Choose Cluster > Name of the desired cluster > Services > HDFS, click the HDFS web UI link of NameNode(Node name, Active) to go to the HDFS web UI, and choose Utilities > Browse the file system.
- Check whether the data is generated in the /flume/test directory on the HDFS.
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