KServe

Since Camel 4.10

Only producer is supported

The KServe component provides the ability to access various AI model servers using the KServe Open Inference Protocl V2. This allows Camel to remotely perform inference with AI models on various model servers that support the KServe V2 protocol.

Currently, this component only supports GRPC API.

To use the KServe component, Maven users will need to add the following dependency to their pom.xml:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-kserve</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

URI format

kserve:api[?options]

Where api represents one of the KServe Open Inference Protocol GRPC API.

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

At the component level, you set general and shared configurations that are, then, inherited by the endpoints. It is the highest configuration level.

For example, a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre-configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

You can configure components using:

  • the Component DSL.

  • in a configuration file (application.properties, *.yaml files, etc).

  • directly in the Java code.

Configuring Endpoint Options

You usually spend more time setting up endpoints because they have many options. These options help you customize what you want the endpoint to do. The options are also categorized into whether the endpoint is used as a consumer (from), as a producer (to), or both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java.

A good practice when configuring options is to use Property Placeholders.

Property placeholders provide a few benefits:

  • They help prevent using hardcoded urls, port numbers, sensitive information, and other settings.

  • They allow externalizing the configuration from the code.

  • They help the code to become more flexible and reusable.

The following two sections list all the options, firstly for the component followed by the endpoint.

Component Options

The KServe component supports 9 options, which are listed below.

Name Description Default Type

configuration (producer)

The configuration.

KServeConfiguration

modelName (common)

The name of the model used for inference.

String

modelVersion (common)

The version of the model used for inference.

String

target (common)

The target URI of the client. See: https://grpc.github.io/grpc-java/javadoc/io/grpc/Grpc.html#newChannelBuilder%28java.lang.String,io.grpc.ChannelCredentials%29.

localhost:8001

String

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

boolean

healthCheckConsumerEnabled (health)

Used for enabling or disabling all consumer based health checks from this component.

true

boolean

healthCheckProducerEnabled (health)

Used for enabling or disabling all producer based health checks from this component. Notice: Camel has by default disabled all producer based health-checks. You can turn on producer checks globally by setting camel.health.producersEnabled=true.

true

boolean

credentials (security)

The credentials of the client.

ChannelCredentials

Endpoint Options

The KServe endpoint is configured using URI syntax:

kserve:api

With the following path and query parameters:

Path Parameters (1 parameters)

Name Description Default Type

api (producer)

Required The KServe API.

Enum values:

  • infer

  • model/ready

  • model/metadata

  • server/ready

  • server/live

  • server/metadata

String

Query Parameters (5 parameters)

Name Description Default Type

modelName (common)

The name of the model used for inference.

String

modelVersion (common)

The version of the model used for inference.

String

target (common)

The target URI of the client. See: https://grpc.github.io/grpc-java/javadoc/io/grpc/Grpc.html#newChannelBuilder%28java.lang.String,io.grpc.ChannelCredentials%29.

localhost:8001

String

lazyStartProducer (producer (advanced))

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

credentials (security)

The credentials of the client.

ChannelCredentials

Message Headers

The KServe component supports 2 message header(s), which is/are listed below:

Name Description Default Type

CamelKServeModelName (producer)

Constant: MODEL_NAME

The name of the model used for inference.

String

CamelKServeModelVersion (producer)

Constant: MODEL_VERSION

The version of the model used for inference.

String

Usage

The component supports the following APIs.

kserve:<api>[?options]
API Description Options Input (Message Body) Result (Message Body)

infer

Performs inference using the specified model.

modelName
modelVersion

ModelInferRequest [1]

ModelInferResponse [2]

model/ready

Indicates if a specific model is ready for inferencing.

modelName
modelVersion

ModelReadyRequest [3]
(optional)

ModelReadyResponse [4]

model/metadata

Provides information about a model.

modelName
modelVersion

ModelMetadataRequest [5]
(optional)

ModelMetadataResponse [6]

server/ready

Indicates if the server is ready for inferencing.

ServerReadyResponse [7]

server/live

Indicates if the inference server is able to receive and respond to metadata and inference requests.

ServerLiveResponse [8]

server/metadata

Provides information about the server.

ServerMetadataResponse [9]

Examples

Infer (ModelInfer) API

Perform inference
from("direct:infer")
    .setBody(constant(createRequest()))
    .to("kserve:infer?modelName=simple&modelVersion=1")
    .process(this::postprocess)
    .log("Result: ${body}");

// Helper methods

ModelInferRequest createRequest() {
    // How to create a request differs depending on the input types of the model.
    var ints0 = IntStream.range(1, 17).boxed().collect(Collectors.toList());
    var content0 = InferTensorContents.newBuilder().addAllIntContents(ints0);
    var input0 = ModelInferRequest.InferInputTensor.newBuilder()
            .setName("INPUT0").setDatatype("INT32").addShape(1).addShape(16)
            .setContents(content0);
    var ints1 = IntStream.range(0, 16).boxed().collect(Collectors.toList());
    var content1 = InferTensorContents.newBuilder().addAllIntContents(ints1);
    var input1 = ModelInferRequest.InferInputTensor.newBuilder()
            .setName("INPUT1").setDatatype("INT32").addShape(1).addShape(16)
            .setContents(content1);
    return ModelInferRequest.newBuilder()
            .addInputs(0, input0).addInputs(1, input1)
            .build();
}

void postprocess(Exchange exchange) {
    // How to post-process the response differs depending on the output types
    // of the model.
    var response = exchange.getMessage().getBody(ModelInferResponse.class);
    var content = response.getRawOutputContents(0);
    var buffer = content.asReadOnlyByteBuffer().order(ByteOrder.LITTLE_ENDIAN).asIntBuffer();
    var ints = new ArrayList<Integer>(buffer.remaining());
    while (buffer.hasRemaining()) {
        ints.add(buffer.get());
    }
    exchange.getMessage().setBody(ints);
}
Specify the model name and version with headers
from("direct:infer-with-headers")
    .setBody(constant(createRequest()))
    .setHeader(KServeConstants.MODEL_NAME, constant("simple"))
    .setHeader(KServeConstants.MODEL_VERSION, constant("1"))
    .to("kserve:infer")
    .process(this::postprocess)
    .log("Result: ${body}");

// ... Same as the previous example

ModelReady API

Check if a model is ready
from("direct:model-ready")
    .to("kserve:model/ready?modelName=simple&modelVersion=1")
    .log("Status: ${body.ready}");
Specify the model name and version with headers
from("direct:model-ready-with-headers")
    .setHeader(KServeConstants.MODEL_NAME, constant("simple"))
    .setHeader(KServeConstants.MODEL_VERSION, constant("1"))
    .to("kserve:model/ready")
    .log("Status: ${body.ready}");

ModelMetadata API

Fetch model metadata
from("direct:model-metadata")
    .to("kserve:model/metadata?modelName=simple&modelVersion=1")
    .log("Metadata: ${body}");
Specify the model name and version with headers
from("direct:model-metadata-with-headers")
    .setHeader(KServeConstants.MODEL_NAME, constant("simple"))
    .setHeader(KServeConstants.MODEL_VERSION, constant("1"))
    .to("kserve:model/metadata")
    .log("Metadata: ${body}");

ServerReady API

Check if the server is ready
from("direct:server-ready")
    .to("kserve:server/ready")
    .log("Status: ${body.ready}");

ServerLive API

Check if the server is live
from("direct:server-live")
    .to("kserve:server/live")
    .log("Status: ${body.live}");

ServerMetadata API

Fetch server metadata
from("direct:server-metadata")
    .to("kserve:server/metadata")
    .log("Metadata: ${body}");

Spring Boot Auto-Configuration

When using kserve with Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

<dependency>
  <groupId>org.apache.camel.springboot</groupId>
  <artifactId>camel-kserve-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 10 options, which are listed below.

Name Description Default Type

camel.component.kserve.autowired-enabled

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

Boolean

camel.component.kserve.configuration

The configuration. The option is a org.apache.camel.component.kserve.KServeConfiguration type.

KServeConfiguration

camel.component.kserve.credentials

The credentials of the client. The option is a io.grpc.ChannelCredentials type.

ChannelCredentials

camel.component.kserve.enabled

Whether to enable auto configuration of the kserve component. This is enabled by default.

Boolean

camel.component.kserve.health-check-consumer-enabled

Used for enabling or disabling all consumer based health checks from this component.

true

Boolean

camel.component.kserve.health-check-producer-enabled

Used for enabling or disabling all producer based health checks from this component. Notice: Camel has by default disabled all producer based health-checks. You can turn on producer checks globally by setting camel.health.producersEnabled=true.

true

Boolean

camel.component.kserve.lazy-start-producer

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

Boolean

camel.component.kserve.model-name

The name of the model used for inference.

String

camel.component.kserve.model-version

The version of the model used for inference.

String

camel.component.kserve.target

The target URI of the client. See: https://grpc.github.io/grpc-java/javadoc/io/grpc/Grpc.html#newChannelBuilder%28java.lang.String,io.grpc.ChannelCredentials%29.

localhost:8001

String
1. inference.GrpcPredictV2.ModelInferRequest
2. inference.GrpcPredictV2.ModelInferResponse
3. inference.GrpcPredictV2.ModelReadyRequest
4. inference.GrpcPredictV2.ModelReadyResponse
5. inference.GrpcPredictV2.ModelMetadataRequest
6. inference.GrpcPredictV2.ModelMetadataResponse
7. inference.GrpcPredictV2.ServerReadyResponse
8. inference.GrpcPredictV2.ServerLiveResponse
9. inference.GrpcPredictV2.ServerMetadataResponse
Back to top