10 KiB
Events
An Event
is a
record generated during engine execution. Such an event captures what
has happened inside the senlin-engine. The senlin-engine service
generates event records when it is performing some actions or checking
policies.
An event has a level
property which can be interpreted
as the severity level value of the event:
- 10: interpreted as
DEBUG
level. Events at this level can be ignored safely by users. For developers they may provide some useful information for debugging the code. - 20: interpreted as
INFO
level. Events at this level are mostly about notifying that some operations have been successfully performed. - 30: interpreted as
WARNING
level. Events at this level are used to signal some unhealthy status or anomalies detected by the engine. These events should be monitored and checked when operating a cluster. - 40: interpreted as
ERROR
level. Events at this level signifies some failures in engine operations. These event should be monitored and checked when operating a cluster. Usually some user intervention is expected to recover a cluster from this status. - 50: interpreted as
CRITICAL
level. Events at this level are about serious problems encountered by the engine. The engine service may have run into some bugs. User intervention is required to do a recovery.
Event Dispatcher Configuration
Senlin provides an open architecture for event dispatching. Two of
the built-in dispatchers are database
and
message
.
1. The database
dispatcher dumps the events into
database tables and it is enabled by default.
2. The message
dispatcher converts the event objects
into versioned event notifications and published on the global message
queue. This dispatcher is by default disabled. To enable it, you can add
the following line to the [DEFAULT]
section of the
senlin.conf
file and then restart the service engine:
[default]
event_dispatchers = message
Based on your deployment settings, you have to add the following
lines to the senlin.conf
file as well when using
message
dispatcher. This lines set messaging
as the default driver used by the oslo.messaging
package:
[oslo_messaging_notifications]
driver = messaging
With this configuration, the database dispatcher will be disabled, which means you can only access to the events by the message queue.
3. The event_dispatchers
field is
MultiString
, you can enable both the database
and message
dispatchers if needed by the following
configuration:
[default]
event_dispatchers = database
event_dispatchers = message
[oslo_messaging_notifications]
driver = messaging
Note that unprocessed event notifications which are not associated
with a TTL (time to live) value by default will remain queued at the
message bus, please make sure the Senlin event notifications will be
subscribed and processed by some services before enabling the
message
dispatcher.
By default, we use the senlin
exchange which type is
TOPIC
to route the notifications to queues with different
routing_key
. The queues name could be
versioned_notifications.debug
,
versioned_notifications.info
,
versioned_notifications.warn
and
versioned_notifications.error
that depends on the log level
you are using in senlin.conf
. The corresponding
routing_key
are the same as the queues' name.
There are two options to consume the notifications:
- Consume the notifications from the default queues directlly.
- Declare your own queues, then bind them to
senlin
exchange with correspondingrouting_key
to customize the flow.
Since the event dispatchers are designed as plug-ins, you can develop
your own event dispatchers and have senlin engine load them on startup.
For more details on developing and plugging in your own event
dispatchers, please refer to the ../contributor/plugin_guide
document.
The following sections are about examining events when using the
database
dispatcher which creates database records when
events happen.
Listing Events
The following command lists the events by the Senlin engine:
$ openstack cluster event list
+----------+---------------------+---------------+----------+--------------+-----------------------+-----------+-------+------------+
| id | generated_at | obj_type | obj_id | obj_name | action | status | level | cluster_id |
+----------+---------------------+---------------+----------+--------------+-----------------------+-----------+-------+------------+
| 1f72eb5e | 2015-12-17T15:41:48 | NODE | 427e64f3 | node-7171... | update | ACTIVE | 20 | |
| 20b8eb9a | 2015-12-17T15:41:49 | NODE | 6da22a49 | node-7171... | update | ACTIVE | 20 | |
| 23721815 | 2015-12-17T15:42:51 | NODEACTION | 5e9a9d3d | node_dele... | NODE_DELETE | START | 20 | |
| 54f9eae4 | 2015-12-17T15:41:36 | CLUSTERACTION | 1bffa11d | cluster_c... | CLUSTER_CREATE | SUCCEEDED | 20 | 9f1883a7 |
| 7e30df62 | 2015-12-17T15:42:51 | CLUSTERACTION | d3cef701 | cluster_d... | CLUSTER_DELETE | START | 20 | 9f1883a7 |
| bf51f23c | 2015-12-17T15:41:54 | CLUSTERACTION | d4dbbcea | cluster_s... | CLUSTER_SCALE_OUT | START | 20 | 9f1883a7 |
| c58063e9 | 2015-12-17T15:42:51 | NODEACTION | b2292bb1 | node_dele... | NODE_DELETE | START | 20 | |
| ca7d30c6 | 2015-12-17T15:41:38 | CLUSTERACTION | 0be70b0f | attach_po... | CLUSTER_ATTACH_POLICY | START | 20 | 9f1883a7 |
| cfe5d0d7 | 2015-12-17T15:42:51 | CLUSTERACTION | 42cf5baa | cluster_d... | CLUSTER_DELETE | START | 20 | 9f1883a7 |
| fe2fc810 | 2015-12-17T15:41:49 | CLUSTERACTION | 0be70b0f | attach_po... | CLUSTER_ATTACH_POLICY | SUCCEEDED | 20 | 9f1883a7 |
+----------+---------------------+---------------+----------+--------------+-----------------------+-----------+-------+------------+
The openstack cluster event list
command line supports
various options when listing the events.
Sorting the List
You can specify the sorting keys and sorting direction when list
events, using the option --sort
. The --sort
option accepts a string of format
key1[:dir1],key2[:dir2],key3[:dir3]
, where the keys used
are event properties and the dirs can be one of asc
and
desc
. When omitted, Senlin sorts a given key using
asc
as the default direction.
For example, the following command sorts the events using the
timestamp
property in descending order:
$ openstack cluster event list --sort timestamp:desc
When sorting the list of events, you can use one of
timestamp
, level
, otype
,
oname
, user
, action
and
status
.
Filtering the List
You can filter the list of events using the --filters
. For example, the following command filters the event
list by the otype` property:
$ openstack cluster event list --filters otype=NODE
The option --filters
accepts a list of key-value pairs
separated by semicolon (;
), where each pair is expected to
be of format key=val
. The valid keys for filtering include
oname
, otype
, oid
,
cluster_id
, action
, level
or any
combination of them.
Paginating the Query results
In case you have a huge collection of events (which is highly likely
the case), you can limit the number of events returned using the option
--limit <LIMIT>
. For example:
$ openstack cluster event list --limit 10
Another option you can specify is the ID of an event after which you
want to see the returned list starts. In other words, you don't want to
see those events with IDs that is or come before the one you specify.
You can use the option --marker <ID>
for this purpose. For
example:
$ openstack cluster event list --limit 20 \
--marker 2959122e-11c7-4e82-b12f-f49dc5dac270
At most 20 action records will be returned in this example and its UUID comes after the one specified from the command line.
Showing Details of an Event
You can use the senlin
command line to show the details about an
event you are interested in. When specifying the identity of the event,
you can use its name, its ID or its "short ID" . Senlin API and engine
will verify if the identifier you specified can uniquely identify an
event. An error message will be returned if there is no event matching
the identifier or if more than one event matching it.
An example is shown below:
$ openstack cluster event show 19ba155a
+---------------+--------------------------------------+
| Field | Value |
+---------------+--------------------------------------+
| action | NODE_DELETE |
| cluster_id | ce85d842-aa2a-4d83-965c-2cab5133aedc |
| generated_at | 2015-12-17T15:43:26+00:00 |
| id | 19ba155a-d327-490f-aa0f-589f67194b2c |
| level | INFO |
| location | None |
| name | None |
| obj_id | cd9f519a-5589-4cbf-8a74-03b12fd9436c |
| obj_name | node-ce85d842-003 |
| obj_type | NODE |
| project_id | 42d9e9663331431f97b75e25136307ff |
| status | end |
| status_reason | Node deleted successfully. |
| user_id | 5e5bf8027826429c96af157f68dc9072 |
+---------------+--------------------------------------+
See Also
Operating Actions <actions>