Start a Database

This article explains how to start a database.

Prerequisites

There are no prerequisites for this procedure.

Procedure

This procedure uses the c4 and confd_client command-line tools in a Linux terminal. For more information 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

    For more information about how to use c4 connect, 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 start the database, use the ConfD job db_start with the following parameters:

    Parameter name Data type Description
    db_name string The name of the database.
    cluster string

    The database cluster(s) that should be started. If the parameter is omitted, the database is started on all clusters.

    Accepted values are:

    • MAIN Starts the main cluster. The database name can be passed instead of MAIN.
    • <clustername> Starts a specific cluster
    • +all Starts all clusters
    Examples:

    To start the main cluster and all worker clusters:

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    confd_client db_start db_name: MY_DATABASE
    # or
    confd_client db_start db_name: MY_DATABASE cluster: +all

    To start only the main cluster:

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    confd_client db_start db_name: MY_DATABASE cluster: MAIN
    # or
    confd_client db_start db_name: MY_DATABASE cluster: MY_DATABASE

    To start a specific worker cluster (the main cluster must be running):

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    confd_client db_start db_name: MY_DATABASE cluster: WORKER1

Verification

To verify that the database is running, use the ConfD job db_state.

Example:
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confd_client db_state db_name: MY_DATABASE
...
Result:
'running'