Kafka HealthChecker

This library helps to handle Kafka healthiness and readiness probes. It takes in input a list of Kafka consumers, a list of Kafka producers and a configuration object.

It configures each consumer and producer in order to assign them an internal status that is updated as a result of Kafka events. Then, it exposes two methods:

• isHealthy(): returns true if all the consumers and producers are healthy (i.e. they are live)
• isReady(): returns true if all the consumers and producers are ready (i.e. they are able to consume and produce messages)

In order to not lose any events, the library must be initialized before the consumers and the producers are connected to Kafka.

For more information about setup and initialization go to Setup page.

Consumer

It follows a table of all the status of the consumers caused by Kafka events. The starting status is { healthy: true, ready: false }.

Event	Status
CONNECT	{ healthy: true, ready: false }
GROUP_JOIN	{ healthy: true, ready: true }
STOP	{ healthy: true, ready: false }
DISCONNECT	{ healthy: false, ready: false }
CRASH	{ healthy: false, ready: false }

Producer

It follows a table of all the status of the producers caused by Kafka events. The starting status is { healthy: true, ready: false }.

Event	Status
CONNECT	{ healthy: true, ready: false }
DISCONNECT	{ healthy: false, ready: false }

Configuration

The configuration objects has the following schema:

configuration = {
  checkStatusForAll: { type: 'boolean', default: true }
}

The checkStatusForAll can be:

• true: the methods isHealthy and isReady return true if all the consumers and producers are, respectively, healthy and ready
• false: the methods isHealthy and isReady return true if exists at least one consumer or producer that is, respectively, healthy and ready.

Notes

At the moment the library exposes the health checker only for KafkaJS. It is recommended to have read its documentation in case some parameter or configuration is not clear.