Implementation:SeldonIO Seldon core Hodometer Publish

Knowledge Sources	SeldonIO_Seldon_core
Domains	Observability, Metrics_Publishing, Usage_Telemetry
Last Updated	2026-02-13 14:00 GMT

Overview

Concrete tool for publishing collected usage metrics to remote endpoints via the Mixpanel event tracking API provided by the Hodometer package.

Description

The JsonPublisher struct implements the Publisher interface and sends collected UsageMetrics to one or more remote URLs using the Mixpanel client library. It flattens the metrics struct into key-value properties using reflection, adds a unique insert ID and timestamp, and publishes concurrently to all configured endpoints. The HTTP client uses retryable-http with exponential backoff (up to 20 retries, 1-30 second wait range) for resilience.

The flattenStructToProperties helper recursively walks the UsageMetrics struct (including embedded structs) and extracts JSON-tagged fields into a flat property map for the Mixpanel event payload.

Usage

Use this publisher as the output stage of the Hodometer metrics pipeline. After the SeldonCoreCollector gathers metrics, the publisher sends them to the configured analytics endpoints.

Code Reference

Source Location

• Repository: SeldonIO_Seldon_core
• File: hodometer/pkg/hodometer/publish.go
• Lines: 1-205

Signature

type Publisher interface {
    Publish(ctx context.Context, metrics *UsageMetrics) error
}

type JsonPublisher struct {
    clients []urlAndClient
    logger  logrus.FieldLogger
    apiUrl  string
}

func NewJsonPublisher(
    logger logrus.FieldLogger,
    publishUrls []*url.URL,
) (*JsonPublisher, error)

func (jp *JsonPublisher) Publish(
    ctx context.Context,
    metrics *UsageMetrics,
) error

Import

import "github.com/seldonio/seldon-core/hodometer/pkg/hodometer"

I/O Contract

Inputs

Name	Type	Required	Description
logger	logrus.FieldLogger	Yes	Structured logger for operational output
publishUrls	[]*url.URL	Yes	One or more target URLs to publish metrics to (must not be empty)
ctx	context.Context	Yes	Context for cancellation
metrics	*UsageMetrics	Yes	The collected usage metrics to publish

Outputs

Name	Type	Description
error	error	Returned by NewJsonPublisher if no URLs provided; Publish always returns nil (errors logged)
HTTP POST	Mixpanel event	Metrics published as Mixpanel Track event to each configured URL

Usage Examples

Creating and Using a Publisher

package main

import (
    "context"
    "net/url"
    "github.com/sirupsen/logrus"
    "github.com/seldonio/seldon-core/hodometer/pkg/hodometer"
)

func main() {
    logger := logrus.New()

    targetUrl, _ := url.Parse("https://metrics.seldon.io/collect")
    publisher, err := hodometer.NewJsonPublisher(
        logger,
        []*url.URL{targetUrl},
    )
    if err != nil {
        logger.Fatalf("failed to create publisher: %v", err)
    }

    // Publish collected metrics
    metrics := &hodometer.UsageMetrics{}
    metrics.ClusterId = "abc-123"
    metrics.ModelCount = 5

    err = publisher.Publish(context.Background(), metrics)
    if err != nil {
        logger.Errorf("publish failed: %v", err)
    }
}

Related Pages

• Environment:SeldonIO_Seldon_core_Kubernetes_Cluster_Environment