Use the Kafka Message Stream Viewer
The Message Stream Viewer displays messages from a Kafka topic in AxonOps. Use it to inspect topic data during troubleshooting, validation, and operational checks.
Before a user can stream messages, they must have stream access for the topic or cluster.
Grant stream access
Section titled “Grant stream access”Open the Kafka cluster in AxonOps, expand Topics, and select Stream Access.
Choose the topic scope
Section titled “Choose the topic scope”Use the Topic field to select the scope of the grant.
You can grant access to:
- All topics in the selected Kafka cluster.
- A specific topic.
Choose the member type
Section titled “Choose the member type”Set Member Type to either User or Group.
Enter the member name
Section titled “Enter the member name”Enter the AxonOps username or group name, then click Grant Access.
The grant appears in the access table. Use Revoke to remove access.
Open the stream viewer
Section titled “Open the stream viewer”Open Topics and select Stream.
The page shows the stream configuration at the top and the message table below it.
Select a topic
Section titled “Select a topic”Select the topic to inspect from the Topic field.
The topic is mandatory.
Choose the partition mode
Section titled “Choose the partition mode”Use Partition Mode to choose where streaming starts.
Available modes are:
| Mode | Description |
|---|---|
| Earliest | Start from the earliest retained records. |
| Latest | Start from new records produced after the stream starts. |
| Specify Partition Offsets | Select partitions and starting offsets manually. |
| Specify Partition Timestamps | Select partitions and start from records at or after a timestamp. |
Specify partition offsets
Section titled “Specify partition offsets”When using Specify Partition Offsets, click the settings button next to the partition mode field.
Enable the partitions you want to read from, review the offsets, then click Apply.
Specify partition timestamps
Section titled “Specify partition timestamps”When using Specify Partition Timestamps, click the settings button next to the partition mode field.
Choose whether to use the same timestamp for all partitions, select the partitions to include, then click Apply.
Configure optional display settings
Section titled “Configure optional display settings”Schema encoded messages
Section titled “Schema encoded messages”Select Schema encoded when the topic contains schema-encoded messages.
Regex filtering
Section titled “Regex filtering”Select Filter stream to filter returned messages with a regular expression.
Limit returned rows
Section titled “Limit returned rows”Use Limit returned rows to cap how many messages are returned to the UI.
This is useful for high-volume topics where an unrestricted stream would quickly fill the table.
Connect to an agent
Section titled “Connect to an agent”Click Connect to connect the stream viewer to an available agent.
When the connection succeeds, the page status changes to connected and the button changes to Disconnect.
Start streaming
Section titled “Start streaming”Click Start Stream.
The page status changes to started, and messages appear in the table.
The table includes:
- Time
- Partition
- Offset
- Headers
- Message
Use the filters above the table to filter by partition, offset, or message content. Use the column checkboxes to show or hide fields. Click Clear to clear the current table contents.
Stop streaming
Section titled “Stop streaming”Click Stop Stream to stop reading messages.
After streaming stops, you can adjust the stream settings and start again, or click Disconnect to close the agent connection.
Warning
Message streaming can expose sensitive application data. Use the narrowest practical topic scope, limit returned rows on high-volume topics, and revoke stream access when it is no longer required.