Message Browser

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.

Inspecting 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 inspect a topic and browse a live stream of messages:

  1. Select a cluster from the navigation bar.

  2. Click the Topics menu. The All Topics page appears.

    ../../_images/c3-topics-context-menu.png
  3. Click the ellipsis (...) by the topic name and click Inspect. The Messages page displays incoming streaming messages for the topic.

  4. 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.
    Browse topic messages in default tabular view

    Browse topic messages in default tabular view

    • To pause scrolling incoming messages so that you can analyze the data, hover in the messages pane. To resume scrolling, move the cursor focus outside of the messages pane.

    • To filter the results, enter the criteria in the Filter by keyword box.

      Search topic messages by keyword

      Prefix search for topic messages by keyword of key

      Note

      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. There is a known issue with column names that contain a period (MMA-4524).

    • Click the Card view or Tabular view (default) icon for the layout you prefer:

      ../../_images/c3-topic-inspect-card-tab-icons1.png
      Browse topic messages in cards view

      Browse topic messages in cards view

    • 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 0 offset in Control Center topic message browser

Jump to 0 offset in Control Center topic message browser

Jump to a timestamp

To jump to a message timestamp, click the Jump to timestamp menu and enter the timestamp and partition.

Jump to timestamp

The timestamp is displayed in microseconds. Enter your time of interest in milliseconds into the timestamp box and selected partition.

Tip

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.

Jump to a timestamp in Control Center topic message browser

Jump to a timestamp in Control Center topic message browser

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.

  1. Select one or more contiguous or non-contiguous rows. The Download button becomes available and shows the number of selected messages.

    Tip

    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.

    Select contiguous rows to download messages in Control Center message browser

    Contiguous rows selected for download

    Select non-contiguous rows to download messages in Control Center message browser

    Non-contiguous rows selected for download

  2. Click Download (n). A file named selected_data_n.json that contains the selected messages in JSON format is downloaded into your downloads directory. The n represents the number of selected messages.

    Example filename: selected_data_3.json

    Example contents:

    [{"topic":"pageviews","partition":0,"offset":238156,"timestamp":1561686540691,"timestampType":"CREATE_TIME","headers":[],"key":"2364041","value":{"viewtime":2364041,"userid":"User_3","pageid":"Page_25"}},{"topic":"pageviews","partition":0,"offset":238155,"timestamp":1561686540662,"timestampType":"CREATE_TIME","headers":[],"key":"2364031","value":{"viewtime":2364031,"userid":"User_1","pageid":"Page_12"}},{"topic":"pageviews","partition":0,"offset":238154,"timestamp":1561686540593,"timestampType":"CREATE_TIME","headers":[],"key":"2364021","value":{"viewtime":2364021,"userid":"User_4","pageid":"Page_21"}}]
    

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. The ability to inspect a topic is disabled.

To disable the inspect topic feature in Control Center:

  1. Set the confluent.controlcenter.topic.inspection.enable option in your control-center.properties file to false.

    ...
    confluent.controlcenter.topic.inspection.enable=false
    ...
    

    Note

    Make the change in the appropriate Control Center properties file or files configured for your environments, including control-center-dev.properties or control-center-production.properties. The properties files are located in /path-to-confluent/etc/confluent-control-center/.

  2. 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
    

    Tip

    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.