You can query the topic stats. There is a "backlog" field in topic stats. It will tell you how many messages that a subscription has not consumed. It is similar as consumer lag in Kafka.
Thanks, Sijie On Mon, Jul 22, 2019 at 6:46 PM Enrico Olivelli <[email protected]> wrote: > Hello, > > I am looking for a function in Pulsar API to get the current consumer "lag" > > I see that Pulsar recently added getLastMessageId API but this is not > useful to me > https://pulsar.apache.org/admin-rest-api/#operation/getLastMessageId > > In Pulsar if you have two message ids you cannot compute any kind of > "distance". > > I am migrating from Kafka and in Kafka the message id is an incremental > number (per partition). > > I am using the Reader API, and I am storing the last processed messageId > in an external system, this way I have full control over the portion of the > stream that I am processing. > > I think Sijie or Jia already told me something about this topic but I > can't find references > > Thanks in advance > > Enrico > > >
