Software Development

Persistent Subscriptions Status in Event Store UI

Given that you are using Event Store Persistent Subscriptions
When your clients publish messages to streams
Then the UI shows a Red flag even if the messages are handled

The setting MinimumCheckPointCountOf https://eventstore.org/docs/dotnet-api/competing-consumers/index.html#persistent-subscription-settings can determine the ‘Status # of msgs’ on the Persistent Subscriptions UI View. The default value of this setting is 10. When a checkpoint is written the status is then set to green. In the same View also the ‘Current’ changes on every checkpoint, that is every 10 messages per default.

It’s a trade off between writing too many checkpoints degrading performance but having a perfect sync with the subscription status Vs leave this setting to the default or increase it to speed performances up but accepting the risk to replay twice some messages.

As an example, let’s imagine to have one or more subscribers connected to a category of streams called ‘$ce-domain’. The client publish an Event. The server immediately dispatch the event to one of the available subscribers. The subscriber handle and acknowledge it but the UI is still showing a red flag as in the picture below

Status # of msgs remains Red until a checkpoint is written (default every 10 msg's)
Status # of msgs remains Red until a checkpoint is written (default every 10 msg’s)

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