Test the connection to the HDFS data source server to verify
that the HDFS data source server is started correctly. Currently,
federation has done optimization for Hadoop parquet data source.
About this task
You can test the connection to the HDFS data source server
using telnet tool to verify if the HDFS data source server is started.
Procedure
- Start a terminal in the server that runs the federation
server.
- Issue the following command:
telnet <HDFS_data_source_server_name> port
Take Hadoop parquet data source for example:
telnet <hadoop_namenode_server> 8020
If the connection is successful, you will receive the
following similar output from the command.
Trying 9.30.252.5...
Connected to 9.30.252.5.
Escape character is '^]'.
If the connection is failed,
you will receive the following similar output from the terminal.
Trying 9.30.252.5...
telnet: connect to address 9.30.252.5: Connection refused
telnet: Unable to connect to remote host
If the connection
is unsuccessful, you will receive an error. Check the data source
configuration and make sure data source server is started successfully.