Configuration

Seldon can be configured via various config files.

Kafka Configuration

We allow configuration of the Kafka integration. In general this configuration looks like:

{
    "topicPrefix": "seldon",
    "bootstrap.servers":"kafka:9093",
    "consumer":{
	"session.timeout.ms":6000,
	"auto.offset.reset":"earliest",
	"topic.metadata.propagation.max.ms": 300000,
	"message.max.bytes":1000000000
    },
    "producer":{
	"linger.ms":0,
	"message.max.bytes":1000000000
    },
    "streams":{
    }
}

The top level keys are:

• topicPrefix : the prefix to add to kafka topics created by Seldon

• consumerGroupIdPrefix : the prefix to add to Kafka consumer group IDs created by Seldon

• bootstrap.servers : the global bootstrap kafka servers to use

• consumer : consumer settings

• producer : producer settings

• streams : KStreams settings

For topicPrefix you can use any acceptable kafka topic characters which are a-z, A-Z, 0-9, . (dot), _ (underscore), and - (dash). We use . (dot) internally as topic naming separator so we would suggest you don’t end your topic prefix with a dot for clarity. For illustration, an example topic could be seldon.default.model.mymodel.inputs where seldon is the topic prefix.

The consumerGroupIdPrefix will ensure that all consumer groups created have a given prefix.

Kubernetes

For Kubernetes this is controlled via a ConfigMap called seldon-kafka whose default values are defined in the SeldonConfig custom resource.

      bootstrap.servers: 'seldon-kafka-bootstrap.seldon-mesh:9092'
      consumer:
        auto.offset.reset: 'earliest'
        message.max.bytes: '1000000000'
        session.timeout.ms: '6000'
        topic.metadata.propagation.max.ms: '300000'
      consumerGroupIdPrefix: ''
      debug: ''
      producer:
        linger.ms: '0'
        message.max.bytes: '1000000000'
      topicPrefix: 'seldon'

When the SeldonRuntime is installed in a namespace a configMap will be created with these settings for Kafka configuration.

To customize the settings you can add and modify the Kafka configuration via Helm, for example below is a custom Helm values file that add compression for producers:

config:
  kafkaConfig:
    producer:
      compression.type: gzip

To use this with the SeldonRuntime Helm chart:

helm install seldon-v2-runtime k8s/helm-charts/seldon-core-v2-runtime \
    --namespace seldon-mesh \
    --values k8s/samples/values-runtime-kafka-compression.yaml

Topic and consumer isolation

If you use a shared Kafka cluster with other applications you may want to isolate the topic names and consumer group IDs from other users of the cluster to ensure there is no name clash. For this we provide two settings:

• topicPrefix: set a prefix for all topics

• consumerGroupIdPrefix: set a prefix for all consumer groups

An example to set this in the configuration when using the helm installation is showm below for creating the default SeldonConfig:

helm upgrade --install seldon-v2 k8s/helm-charts/seldon-core-v2-setup/ -n seldon-mesh \
    --set controller.clusterwide=true \
    --set kafka.topicPrefix=myorg \
    --set kafka.consumerGroupIdPrefix=myorg

You can find a worked example here.

You can create alternate SeldonConfigs with different values or override values for particular SeldonRuntime installs.

Tracing Configuration

We allow configuration of tracing. This file looks like:

{
  "disable": false,
  "otelExporterEndpoint": "otel-collector:4317",
  "otelExporterProtocol": "grpc",
  "ratio": "1"
}

The top level keys are:

• enable : whether to enable tracing

• otelExporterEndpoint : The host and port for the OTEL exporter

• otelExporterProtocol : The protocol for the OTEL exporter. Currently used for jvm-based components only (such as dataflow-engine), because opentelemetry-java-instrumentation requires a http(s) URI for the endpoint but defaults to http/protobuf as a protocol. Because of this, gRPC connections (over http) can only be set up by setting this option to grpc

• ratio : The ratio of requests to trace. Takes values between 0 and 1 inclusive.

Kubernetes

For Kubernetes this is controlled via a ConfigMap call seldon-tracing whose default value is shown below:

apiVersion: v1
kind: ConfigMap
metadata:
  name: tracing
data:
  tracing.json: |-
   {
     "enable": true,
     "otelExporterEndpoint": "seldon-collector:4317",
     "otelExporterProtocol": "grpc",
     "ratio": "1"
   }
  OTEL_JAVAAGENT_ENABLED: "true"
  OTEL_EXPORTER_OTLP_ENDPOINT: "http://seldon-collector:4317"
  OTEL_EXPORTER_OTLP_PROTOCOL: "grpc"

Note, this ConfigMap is created via our Helm charts and there is usually no need to modify it manually.

At present Java instrumentation (for the dataflow engine) is duplicated via separate keys.