The RocketMQ console allows you to check the consumer status for troubleshooting message consumption exceptions. This function allows you to view comprehensive information about consumer instances of a group ID, as well as information about a single consumer instance. The information includes online status, subscription relationship, consumption TPS, message accumulation amount, and JStack. You can use the information to locate the causes for message consumption exceptions.
Generally, the cause of a message consumption exception is complicated. Consumer status information in the console is usually not enough to troubleshoot the problem. In this case, you need to perform further troubleshooting through log analysis and business scenario analysis.
For more information about typical troubleshooting scenarios related to consumer status query, see Typical scenarios.
Consumer status queries are often used in the following two troubleshooting scenarios:
Confirmation: On the Consumer Status page, the value of Subscription Consistency is No.
Solution: For more information about how to handle subscription inconsistency, see What should I do after receiving a subscription inconsistency alarm.
Message accumulation alarm
Confirmation: On the Consumer Status page, the value of Real-time Message Accumulation is large.
Solution: For more information about how to handle message accumulation alarms, see What should I do if I receive a message accumulation alarm.
To view the comprehensive information about the consumer instances of a specific group ID, perform the following steps:
Log on to the RocketMQ console.
In the left-side navigation pane, choose Groups.
On the Groups page, locate the row that contains the target group ID and click Consumer Status in the Actions column.
The following table describes the main fields on the Consumer Status page:
|Online||The value is Yes once the group ID has one consumer instance online. In such case, you can view the information about all online consumer instances in the Connection Information area. If none of the consumer instances of the group ID is online, the value is No.|
|Subscription Consistency||Indicates whether the subscription information of all consumer instances of the group ID are consistent. For more information about subscription consistency, see Subscription consistency.|
|Real-Time Consumption Rate||The total transactions per second (TPS) at which messages are received by the consumer instance group under the group ID. Unit: messages/s.|
|Real-Time Message Accumulation||The total number of messages not consumed by the consumer instance group under the group ID.|
|Latest Consumption Time||The time when the consumer instance group under the group ID last consumed a message.|
|Latency||The difference between the production time of the earliest unconsumed message and the current time.|
If the online status of the group ID is Yes, you can view information about each online consumer instance under the group ID in the Connection Information area, including the client ID, host/public IP address, current process ID, and message accumulation amount.
If you want to view more information about a specific consumer instance, click Detailed Information in the Detailed Information column.
A page shown in the following figure appears, showing the number of consumption threads, consumption start time, subscription, and message consumption statistics.
If you want to view the JStack information of the current process for a specific consumer instance, locate the row that contains the target consumer instance and click JStack in the JStack column. The following figure shows the displayed information: