SBA Gateway Kafka Producer Write to Disk Logging Function

When SBA Gateway streams charging data record (CDR) data to Kafka, the Write to Disk logging function writes each CDR to a log file in a persistent volume (PV) when the Kafka broker is not available. When access to Kafka is restored, records on disk can be replayed using the cdr-kafka-replay microservice.

Write to Disk with Logger Configuration Properties describes the available configuration properties.

Table 1. Write to Disk with Logger Configuration Properties
Property	Description
sba-5gc.events.shutdownSeconds	The duration in seconds that the CHF remains available while shutting down. This is the default used in Kubernetes. The default value is `30`.
sba-5gc.events.kafka.enabled	When set to `true`, the Kafka producer is enabled. The default value is `false`.
sba-5gc.events.kafka.logger.enabled	When set to `true`, the logger function is enabled. Records expired or rejected from the Kafka producer client are written to a log file on the configured PV. If `false`, expired or rejected records are discarded. The default value is `false`.
sba-5gc.events.kafka.logger.outputStorage.createPersistentVolumeClaim	When set to `true`, the Helm chart creates a persistent volume claim (PVC) with a default name of `release-shared-networkcdr-storage`. When set to `false`, you must pre-create the PVC. If you use a name different from the default name, set `sba-5gc.events.kafka.logger.outputStorage.pvcName` to the name of the PVC. The default value is `false`.
sba-5gc.events.kafka.logger.outputStorage.createPersistentVolume	When set to `true`, the Helm chart creates a PV used by the Logger for saving failed records. The PV has a default name of `release-networkcdr-storage`. Use this setting for testing and debugging purposes. Do not use this setting in production environments. When set to `false`, you must pre-create the PV. If you use a name different from the default name, set `sba-5gc.events.kafka.logger.outputStorage.pvName` to the name of the PVC. The default value is `false`.
sba-5gc.events.kafka.logger.outputStorage.pvcName	The name of the PVC if different from the default. The default value is `release-shared-networkcdr-storage`.
sba-5gc.events.kafka.logger.outputStorage.pvName	The name of the PVC, if different from the default. The default value is `release-shared-networkcdr-storage`.
sba-5gc.events.kafka.logger.outputStorage.annotations	A dictionary of annotations to add to the PVC. For more information, see the discussion about annotations in Kubernetes documentation at the Kubernetes website.
sba-5gc.events.kafka.logger.outputStorage.storage	The PV storage size used when `createPersistentVolume` is set to `true`. The default value is `10Gi`.
sba-5gc.events.kafka.logger.outputStorage.storageClassName	The PV storage class name used when `createPersistentVolume` is set to `true`. The default value is an empty string.
sba-5gc.events.kafka.logger.outputStorage.persistentVolume	Additional PV configuration when `createPersistentVolume` is set to `true`. For more informatio,n see PV documentation at the Kubernetes website.
sba-5gc.events.kafka.logger.outputStorage.dynamicProvisioning	When set to `true`, the PVC is used to dynamically provision a PV. In this case, the value of `sba-5gc.events.kafka.logger.outputStorage.pvName` is not used. Use this property in conjunction with `global.storage.shared.createPersistentVolume` set to `false`.

Configuration Behavior describes the effects of various configuration combinations on 5G event streaming.

Table 2. Configuration Behavior
Configuration	Behavior
`events.kafka.enabled=false`	SBA Gateway does not send any records to Kafka.
`events.kafka.enabled=true`	SBA Gateway sends records to Kafka, but records that could not be sent are not logged. A warning of the failure cause is logged and a failed record send metric is incremented.
`events.kafka.enabled=true events.kafka.logger.enabled=true`	SBA Gateway sends records to Kafka and any records that could not be sent are logged. A warning of the failure cause is logged and a failed record send metric is incremented. A PV and PVC must be manually created.
`events.kafka.enabled=true events.kafka.logger.enabled=true events.kafka.logger.outputStorage.createPersistentVolumeClaim=true`	SBA Gateway sends records to Kafka and any records that could not be sent are logged. A warning of the failure cause is logged and a failed record send metric is incremented. A PVC is created, but the PV must be manually created.
`events.kafka.enabled=true events.kafka.logger.enabled=true events.kafka.logger.outputStorage.createPersistentVolumeClaim=true events.kafka.logger.outputStorage.createPersistentVolume=true`	SBA Gateway sends records to Kafka and any records that cannot be sent are logged. A warning of the failure cause is logged and a failed record send metric is incremented. A PVC and PV are created, and the PV is created as a `hostPath` volume.

For more information about 5G event streaming Write to Disk functionality, see the discussion about Write to Disk in MATRIXX 5G Event Streaming.