.. _c3_edit_topic:

##########################################
Edit the configuration settings for topics
##########################################

View and edit the configuration settings for topics.

.. important:: Some topic configuration parameters are not configurable through this interface. These unmodifiable parameters
               display a lock symbol (|lock|) in the text entry box. They cannot be changed in either default or expert mode. See 
               :ref:`c3_config_topic_params`.

.. |lock| image:: ../../images/c3-lock.png
        :scale: 25%

.. _c3_edit_topic_basic:

Edit basic topic settings
=========================


#. Select a cluster from the navigation bar.

#. Click the **Topics** cluster submenu. The :ref:`c3_all_topics` appears.

#.  In the Topics table, click the ellipsis (``...``) next to the topic name and choose **Settings**.

    .. figure:: ../images/c3-topics-settings-context-menu.png
       :scale: 50%
       :alt: Topics context menu in Control Center

#.  The Configuration page appears for the topic. Click **Edit settings**.

    .. figure:: ../images/c3-topics-config-page.png
       :scale: 50%
       :alt: Configuration page for a topic in Control Center

    .. tip:: Click **Show/Hide full config** to toggle the view of all available 
             configurations.

#. The basic configurations become available for editing. Only the most commonly modified settings are 
   shown by default. Make any changes to the available fields. To edit additional settings 
   in expert mode, see :ref:`c3_edit_topic_expert`.

   .. figure:: ../images/c3-edit-basic-topic-settings.png
       :scale: 50%
       :alt: Basic configuration editing page for a topic in Control Center

   .. tip:: Click the information icon to view the tooltip for a setting.

       .. figure:: ../images/c3-topics-tooltip.png
          :scale: 50%
          :alt: Tooltip for a topic setting in Control Center

#. Click **Save changes**.

.. _c3_edit_topic_expert:

Edit topic settings in expert mode
==================================

.. caution:: Be careful when setting configurations in expert mode. With expert mode, you have full control 
             of every topic configuration and can potentially get your cluster into a bad state.

#. Follow the steps for :ref:`c3_edit_topic_basic`. On the basic configuration page, click
   **Switch to export mode**.

#. To leave expert mode without making any changes, click **Leave expert mode**.

#. Make your changes. Scroll down to the bottom of the page and click **Save changes**.

   .. figure:: ../images/c3-topics-expert-mode.png
       :scale: 50%
       :alt: Edit topic configuration in export mode of Control Center


.. _c3_config_topic_params:

Configurable topic parameters
=============================

The following table lists available parameters in alphabetical order 
and indicates whether they can be edited. Most can be 
edited with the exception of the topic name and number of partitions.

======================================== ============
Parameter                                Configurable
======================================== ============
cleanup.policy                           Yes
cluster                                  Yes
compression.type                         Yes
delete.retention.ms                      Yes
file.delete.delay.ms                     Yes
flush.messages                           Yes
flush.ms                                 Yes
follower.replication.throttled.replicas  Yes
index.interval.bytes                     Yes
leader.replication.throttled.replicas    Yes
max.message.bytes                        Yes
message.format.version                   Yes
message.timestamp.difference.max.ms      Yes
message.timestamp.type                   Yes
min.cleanable.dirty.ratio                Yes
min.compaction.lag.ms                    Yes
min.insync.replicas                      Yes
name (topic)                             No
partitions (number of)                   No
preallocate                              Yes
producer                                 Yes
replication.factor                       Yes
retention.bytes                          Yes
retention.ms                             Yes
segment.bytes                            Yes
segment.index.bytes                      Yes
segment.jitter.ms                        Yes
segment.ms                               Yes
unclean.leader.election.enable           Yes
======================================== ============