:original_name: ddm_05_0007.html

.. _ddm_05_0007:

Editing a Parameter Template
============================

To improve performance of a DDM instance, you can modify parameters in custom parameter templates based on service requirements.

You cannot change parameter values in default parameter templates. When you change parameter values in a custom parameter template, the changes take effect for all instances to which the parameter template applies.

The following are the key points you should know when using parameters from a parameter template:

-  When you modify a custom parameter template, the modifications take effect only after you apply the parameter template to DDM instances. For details, see :ref:`Applying a Parameter Template <ddm_05_0013>`.
-  The time when the modification takes effect is determined by the type of the parameter.
-  Parameters in default parameter templates cannot be modified. You can view these parameters by clicking template names. If a custom parameter template is set incorrectly and causes an instance restart to fail, you can re-configure the custom parameter template according to configurations of the default parameter template.

Procedure
---------

#. Log in to the management console.

#. Click |image1| in the upper left corner and select a region and a project.

#. Click |image2| in the upper left corner of the page and choose **Databases** > **Distributed Database Middleware**.

#. Choose **Parameter Templates**, click the **Custom Templates** tab, locate the required parameter template, and click its name.

#. On the **Parameter Details** page, modify parameters as needed.

   Available operations are as follows:

   -  To save the modifications, click **Save**.
   -  To cancel the modifications, click **Cancel**.

#. After the parameter values are modified, click **Template History** to view details.

   .. important::

      -  The modifications take effect only after you apply the parameter template to DDM instances. For details, see :ref:`Applying a Parameter Template <ddm_05_0013>`.
      -  The instance restart caused by node class changes will not put parameter modifications into effect.

.. |image1| image:: /_static/images/en-us_image_0000001685307326.png
.. |image2| image:: /_static/images/en-us_image_0000001733146397.png