.. _troubleshoot_alerts:

***************************************
Troubleshoot |c3-short| Alerts for |cp|
***************************************

**Issue:** Email alerts are prevented from being sent.

If ``sending=prevented`` appears in the response and logs, the email alerts 
feature
needs to be enabled in the properties file. The feature is not enabled by default.

``sending=prevented email to={} with subject={} from trigger={} messageId=``

``[2019-05-15 14:25:10,160] DEBUG [control-center-heartbeat-0] sending=prevented email to=recipient@email.com with subject``

**Resolution:** Ensure that the ``confluent.controlcenter.email.enabled`` is set 
to ``true`` in
the applicable ``control-center.properties`` file.

See :ref:`enable_disable_alerts_props`.

**Issue:** Webhook notifications are not being sent.

**Resolution**: Ensure that the ``confluent.controlcenter.webhook.enabled`` is 
set to ``true`` in
the applicable ``control-center.properties`` file. The option is enabled by 
default.

**Issue:** The alert body (email) shows an unreachable host for the |c3-short| 
URL to alerts history.

**Resolution:** Ensure that the ``confluent.controlcenter.rest.listeners`` 
property is set. The first
entry becomes the ``host:port`` combination
in the alert body. See :ref:`https_settings`.

.. note::
    The alerts feature checks for the presence of the ``confluent.controlcenter.rest.advertised.url``
    configuration first. If that is empty, then it checks ``confluent.controlcenter.rest.listeners``. If that
    is also empty, then the default value ``localhost:9021`` is used. 
    As a recommended best
    practice, configure
    both of these options. See :ref:`controlcenter_configuration`.

**Issue:** The cluster down action for the |c3-short| cluster was not created.

This is evident from a DEBUG log entry ``Failed to create cluster down action``.

**Resolution:** Ensure that the cluster down configuration
properties are properly configured. See :ref:`c3_cluster_offline` for
detailed instructions for each type of notification action.

**Issue:** The cluster down alert for the |c3-short| cluster did not appear.

**Reason:** Depending on the timing of how quickly the cluster for |c3-short| 
went
down, the alert
might not have had time for any entry to be logged or for its trigger to be fired
and delivered through
its configured actions.