Logs for SQL and server processes

This article explains how to generate logs for SQL and server processes.

If you open a support case because you are experiencing transaction conflicts, you need to provide logs for the SQL and server process in the database for the time period when the problem occurred.

In on-premises deployments of Exasol 2025.1 and later you can use Exasol Admin to create an archive with logs and other information to include with your support case. For other versions of Exasol you must use EXAsupport to collect the information.

To learn more about how to use EXAsupport, see EXAsupport.

Prerequisites

You must have enough free disk space for the logs. For more information, see Check free disk space.

Procedure

This procedure uses the c4 and confd_client command-line tools in a Linux terminal. To learn more about these tools, see Exasol Deployment Tool (c4) and ConfD.

  1. Connect to the cluster operating system (COS) using c4 connect -i PLAY_ID -s cos.

    Example:
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    ./c4 connect -i c3275f84 -s cos

    To find the play ID, you can use c4 ps.

    For more information about how to use c4 commands, see How to use c4.

  2. To find the database name when you are connected to COS, use the ConfD job db_list.

    Example:
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    confd_client db_list
    - MY_DATABASE

  3. To create a SQL server process log, use exasupport -x 1.

    Specify a start date (-s) and end date (-t) using the format YYYY-MM-DD.

    Specify the database name with the option -e. If the database name is omitted, logs are collected from all databases.

    Example:
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    exasupport -x 1 -s 2022-08-11 -t 2022-08-11 -e MY_DATABASE

    If a file was successfully created, EXAsupport returns a success message with the file name.

    Example:
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    Successfully stored debug information into file /exa/tmp/support/exacluster_debuginfo_2022_08_11-23_27_20.tar.gz

  4. Use Control+D or type exit to disconnect from COS.

  5. Copy the file to your local computer by connecting to COS and using the cat command:

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    ./c4 connect -t <DEPLOYMENT>.<NODE>/cos -- "cat /exa/tmp/support/$FILENAME" > $FILENAME
    Example:
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    ./c4 connect -t 1.11/cos -- "cat /exa/tmp/support/my_log" > my_log

Verification

To verify that the file was successfully copied, use the ls command in the target folder on your local machine.

Example:
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ls -lahtr ~/mylogs | grep exacluster_debuginfo
-rwxr-xr-x  1 user group 9.8K Sep 20 17:38 exacluster_debuginfo_2022_08_11-23_27_20.tar.gz

System logs

In many cases the system logs for a specific node will also be required for troubleshooting. To collect system logs for a node, connect to the node over SSH and use sudo journalctl [filter]. If Exasol is installed with a non-root user, omit sudo.

For example, to retrieve system logs for the last 7 days and save the output to a file:

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sudo journalctl --since "7 days ago" > node11_journalctllog.txt