golden-yang opened a new issue, #9351: URL: https://github.com/apache/rocketmq/issues/9351
### Before Creating the Enhancement Request - [x] I have confirmed that this should be classified as an enhancement rather than a bug/feature. ### Summary In our usage scenario, we have a lot of groups and topics. This should be a scenario that RocketMQ is good at. However, as the number of groups increased to tens of thousands, we found that there was a significant performance consumption in queryTopicConsumeByWho, which accounted for 6.75% of the cluster CPU. This is just a very simple query action, but due to the data structure of org.apache.rocketmq.broker.client.ConsumerManager#consumerTable, each query needs to traverse the Map. This can be slow when there are many groups. ### Motivation Adding a simple cache to the consumerManager will reduce the query cost. This 6.67% of CPU consumption can be reduced to 0. ### Describe the Solution You'd Like Adding a simple cache to the consumerManager will reduce the query cost. This 6.67% of CPU consumption can be reduced to 0. ### Describe Alternatives You've Considered Reduce the use of this method ### Additional Context  -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@rocketmq.apache.org.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
