diff --git a/vmware-event-router/README.MD b/vmware-event-router/README.MD index e7333cf5..72bd9b96 100644 --- a/vmware-event-router/README.MD +++ b/vmware-event-router/README.MD @@ -24,21 +24,24 @@ to normalize events from the supported event `providers`. See **Event Delivery Guarantees:** -- At-least-once event delivery for the [vCenter event provider](#provider-type-vcenter) (using checkpoints) -- At-most-once event delivery ("stateless" mode) +- At-least-once event delivery + - with the [vCenter event provider](#provider-type-vcenter) option `checkpoint: true` +- At-most-once event delivery + - with the [vCenter event provider](#provider-type-vcenter) option `checkpoint: false` + - with the [vcsim event provider](#provider-type-vcsim) **Current limitations:** - Only one event `provider` and one event `processor` can be configured at a - time -- At-least-once event delivery semantics cannot be guaranteed if the event - router crashes **within seconds** right after having received some events but before creating the - first valid checkpoint -- At-least-once event delivery semantics are only supported for the vCenter - event provider -- At-least-once event delivery semantics currently only guard against crashes of - the event router. If an event cannot be delivered to an event processor, - currently no retries are performed/dead letter queues are not supported + time (see note below) +- At-least-once event delivery semantics are not guaranteed if the event + router crashes **within seconds** right after startup and having received *n* events but before creating the + first valid checkpoint (current checkpoint interval is 5s) +- If an event cannot be successfully delivered (retried) by an event `processor` it is + logged and discarded, i.e. there is currently no support for dead letter queues +- Retries in the [OpenFaaS event processor](#processor-type-openfaas) are only + supported when running in synchronous mode, i.e. `async: false` (see this + OpenFaaS [issue](https://github.com/openfaas/nats-queue-worker/issues/84)) > **Note:** It is possible though to run **multiple instances** of the event > router with different configurations to address multi-vCenter scenarios @@ -525,6 +528,7 @@ the following script: - `kind` - `docker` + ## Example Event Structure The following example for a `VmPoweredOnEvent` shows the event structure and