How Do I Do If PostgreSQL or GaussDB Fails to Connect?

Question

How do I do if PostgreSQL or GaussDB fails to connect?

Answer

• Scenario 1: (import scenarios) Run the sqoop import command to extract the open source PostgreSQL to MRS HDFS or Hive.
  • Symptom

    The sqoop command can be executed to query PostgreSQL tables, but an error is reported when the sqoop import command is executed.

    • The authentication type 12 is not supported. Check that you have configured the pg_hba.conf file to include the client's IP address or subnet, and that it
    • The authentication type 5 is not supported. Check that you have configured the pg_hba.conf file to include the client's IP address or subnet, and that it
  • Root cause:
    • If the authentication type is 5, the root cause is as follows: When the sqoop import command is executed, a MapReduce job is started. The PostgreSQL driver package gsjdbc4-*.jar exists in the MRS Hadoop installation directory /opt/Bigdata/FusionInsight_HD_*/1_*_DataNode/install/hadoop/share/hadoop/common/lib, which is incompatible with the open source PostgreSQL service. As a result, an error is reported.
    • If the authentication type is 5, the root cause is as follows: The pg_hba.conf file of the database is incorrectly configured.
  • Solution:
    • If the authentication type is 5, the solution is as follows: Move the driver package gsjdbc4-*.jar to the tmp directory on each MRS core node.

      mv /opt/Bigdata/FusionInsight_HD_*/1_*_DataNode/install/hadoop/share/hadoop/common/lib/gsjdbc4-*.jar /tmp

    • If the authentication type is 12, the solution is as follows: Modify the pg_hba.conf file of the database by changing the value of ADDRESS to the IP address of the node where Sqoop resides.

      

• Scenario 2: (export scenarios) Run the sqoop export command to extract the open source PostgreSQL to MRS HDFS or Hive.
  • Symptom

    The sqoop command can be executed to query PostgreSQL tables, but the error message "The authentication type 5 is not supported." is displayed when the sqoop export command is executed. Check that you have configured the pg_hba.conf file to include the client's IP address or subnet, and that it

  • Root cause:

    When the sqoop export command is executed, a MapReduce job is started. The PostgreSQL driver package gsjdbc4-*.jar exists in the MRS Hadoop installation directory /opt/Bigdata/FusionInsight_HD_*/1_*_DataNode/install/hadoop/share/hadoop/common/lib, which is incompatible with the open-source PostgreSQL service. As a result, an error is reported.

  • Solution:

    1. Move the driver package gsjdbc4-*.jar to the tmp directory on each MRS core node.

    mv /opt/Bigdata/FusionInsight_HD_*/1_*_DataNode/install/hadoop/share/hadoop/common/lib/gsjdbc4-*.jar /tmp

    2. Delete /opt/Bigdata/client/Hive/Beeline/lib/gsjdbc4-*.jars.