From the Messages page, you can view the data being produced to a topic. Browse message data, seek to a specific offset or timestamp by partition, and select messages you want to download.
Inspect a topic¶
The Topic Inspection feature in Control Center is enabled by default. With this feature, you can inspect topic details and browse live streaming messages.
To browse a live stream of messages and inspect a topic:
Select a cluster from the navigation bar and click the Topics menu. The All Topics page appears.
In the Topics table, click the topic name link.
Click the Messages tab.
To browse the messages pane:
- Click the horizontal (tabular view) and vertical scrollbars to view all of the available data. The newest data is displayed at the top of the messages pane. As you scroll vertically, or hover in the messages pane, a timeline arrow indicates when the messages were received.
To pause scrolling incoming messages so that you can analyze the data, click the pause icon. Messages may still be produced to the topic; however, the message browser does not display newly consumed data while the view is paused. Click the play icon to resume displaying incoming messages. Clicking the cards view expand icon automatically pauses the display of incoming messages.
Hovering over the messages pane also holds your place for a quick glance at data. Moving the cursor focus outside of the messages pane resumes the incoming flow of messages.
To filter the results, enter the criteria in the Filter by keyword box.
Only prefix searching is currently supported. You can search for the beginning portion of a keyword. The search keyword must be the first substring in a column item. The filter matches the search string across any of the columns.
When you are searching the audit log for user activity in the message browser, you must use the format
User:<username>. To navigate to the audit log, click Cluster > Topics >
confluent-audit-log-events> Messages tab.
Click Query in KSQL to register the topic as a stream or table.
Click Columns to select which columns you want to toggle on or off in the topic messages table. There must be populated message data for the Columns selector to appear. Narrow the view to focus on the columns of interest without resorting to horizontal scrolling. If you jump to an offset or timestamp, the table resets to show all columns again. The Columns selector is not available in the Cards view; it is only applicable to the Table view.
Click the Card view or Tabular view (default) icon for the layout you prefer:
Click the expand icon in the cards view to access the contents of the message. Click the Value, Header, or Key tab. Expanding the card view for a message automatically pauses the display of incoming data. Clicking the play icon collapses the expanded cards views and resumes displaying the incoming data.
Seek to a particular message using Jump to offset or Jump to timestamp.
Jump to an offset¶
To jump to a message offset, click the Jump to offset menu and enter the offset and partition. Messages are displayed in the message browser pane starting from the desired offset, and continue to feed in at the top of the message browser pane.
The record at the offset is highlighted and preselected for download.
Jump to a timestamp¶
To jump to a message timestamp, click the Jump to timestamp menu and enter the timestamp and partition.
The timestamp is displayed in microseconds. Enter your time of interest in milliseconds into the timestamp box and selected partition.
Use a timestamp converter to convert the timestamp into a human-readable date and time.
The timestamp jump searches for the earliest offset where the timestamp was first recorded. Even if there are multiple data points associated with a timestamp, the seek goes to the earliest offset. Messages are displayed in the message browser pane starting from the desired timestamp, and continue to feed in at the top of the message browser pane. Manually select any messages you want to download.
Download selected topic messages¶
Download selected rows of messages in a JSON format. You can download messages from the Messages browser in Topics or KSQL.
Select one or more contiguous or non-contiguous rows. The download button becomes available and shows the number of selected messages.
Press the command key + click to select non-contiguous rows. Press shift + click on a beginning and ending row to select a contiguous range of messages.
Click the download icon. A file named
selected_data_n.jsonthat contains the selected messages in JSON format is downloaded into your downloads directory. The n represents the number of selected messages.
Enable and disable topic inspection (message browsing) in Control Center¶
The topic inspection feature is enabled by default in Control Center. The feature can be disabled if an organization does not want any users to access the feature. After disabling the feature, the Inspect menu and the Inspect tab are no longer visible in the Control Center UI.
To disable the inspect topic feature in Control Center:
confluent.controlcenter.topic.inspection.enableoption in your
... confluent.controlcenter.topic.inspection.enable=false ...
Make the change in the appropriate Control Center properties file or files configured for your environments, including
control-center-production.properties. The properties files are located in
/path-to-confluent/etc/confluent-control-center/. For more informatin, see Control Center properties files.
Restart Control Center and pass in the properties file for the configuration to take effect:
./bin/control-center-stop ./bin/control-center-start ../etc/confluent-control-center/control-center.properties
If you are using a Confluent Platform development environment with a Confluent CLI, stop and start as follows:
./confluent local stop control-center ./confluent local start control-center ../etc/confluent-control-center/control-center-dev.properties
To enable the feature again, set the option back to
true and restart
Control Center with the updated properties file.
For more information about restarting Control Center and passing in its properties files, see Control Center properties files.