APM Metrics Handler

The APM Metrics Handler (APMMetricsHandler) is a specialized metrics handler designed to integrate with Broadcom APM (formerly CA APM). It collects application metrics and sends them to the APM EPAgent (Enterprise Performance Agent) via its RESTful interface.

Introduction

Many enterprise customers use Broadcom APM for monitoring and performance management. This handler allows light-4j services (microsrevices, gateways, sidecars) to push metrics directly to an EPAgent deployed as a sidecar or a common service in the Kubernetes cluster or on the VM host.

It extends the AbstractMetricsHandler and shares the same core logic for collecting request/response metrics, but implements a specific sender for the APM protocol.

Configuration

The handler uses the metrics.yml configuration file, which is shared by all push-based metrics handlers.

Config Field	Description	Default
`enabled`	Enable or disable the metrics handler.	`true`
`enableJVMMonitor`	Enable JVM metrics collection (CPU, Memory).	`false`
`serverProtocol`	Protocol for the EPAgent (http or https).	`http`
`serverHost`	Hostname of the EPAgent.	`localhost`
`serverPort`	Port of the EPAgent.	`8086`
`serverPath`	REST path for the EPAgent metric feed.	`/apm/metricFeed`
`productName`	The product/service name used as a category in APM.	`http-sidecar`
`reportInMinutes`	Interval in minutes to report metrics.	`1`

`metrics.yml` Example

enabled: true
enableJVMMonitor: true
serverProtocol: http
# Hostname of the Broadcom APM EPAgent service
serverHost: opentracing.ccaapm.svc.cluster.local
serverPort: 8888
# Default path for EPAgent REST interface
serverPath: /apm/metricFeed
# Name of your service/component in APM
productName: my-service-name
reportInMinutes: 1

Usage

1. Register the Handler

In handler.yml, you must register the APMMetricsHandler specifically. Since there can only be one metrics handler active in the chain usually, you should use the alias metrics.

handlers:
  - com.networknt.metrics.APMMetricsHandler@metrics

2. Configure the Chain

Add the metrics alias to your default chain. It should be placed early in the chain to capture the full duration of requests.

chains:
  default:
    - exception
    - metrics
    - header
    # ... other handlers

3. Update values.yml

In your deployment’s values.yml, override the default metrics.yml values to point to your actual EPAgent.

metrics.serverHost: epagent.monitoring.svc
metrics.serverPort: 8080
metrics.productName: payment-service

Metrics Collected

The handler collects the following metrics:

Response Time: Duration of the request.
Success Count: Number of successful requests (2xx).
Error Counts: 4xx (request errors) and 5xx (server errors).
JVM Metrics: (Optional) Heap usage, Thread count, CPU usage.

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