Hi Xiao, Seems `backlogSize` already existed in the `SubscriptionStatsImpl`, but didn’t expose in Prometheus,
We just need to expose it in Prometheus. It should exposed in Prometheus when the configuration named `exposeTopicLevelMetricsInPrometheus` and `exposeSubscriptionBacklogSizeInPrometheus` is enabled. +1 Thanks, Tao Jiuming > 2022年12月30日 23:25，萧 易客 <km...@live.com> 写道： > > can
