---
description: Reference for JMX source usage, including wildcard ObjectName and key property extraction.
date_published: 2026-08-13
date_modified: 2026-08-13
canonical_url: https://metricshub.org/community-connectors/develop/sources/jmx.html
---

# jmx (Source)

On this Page

- [When To Use](#when-to-use)
- [Syntax](#syntax)
- [Properties](#properties)
- [Recommended Pattern](#recommended-pattern)
- [Common Mistakes](#common-mistakes)
- [Community Examples](#community-examples)

## When To Use

Use `jmx` for Java-based products exposing metrics through MBeans.

This source is central for JVM/database connectors such as Cassandra.

## Syntax

```yaml
sources:
  cacheRequests:
    type: jmx
    objectName: org.apache.cassandra.metrics:type=Cache,scope=*,name=Requests
    attributes:
    - Count
    keyProperties:
    - scope
```

## Properties

| Property | Required | Default | Description |
| --- | --- | --- | --- |
| `type` | Yes | None | `jmx`. |
| `objectName` | Yes | None | MBean ObjectName pattern. |
| `attributes` | Conditionally | `[]` | Attribute names to fetch. |
| `keyProperties` | Conditionally | `[]` | ObjectName key properties to emit as extra columns. |
| `resultContent` | No | Runtime-dependent | Compatibility property in schema snapshots; usually not needed for JMX source declarations. |
| `executeForEachEntryOf` | No | None | Fan-out execution context. |
| `computes` | No | `[]` | Post-processing pipeline. |
| `forceSerialization` | No | `false` | Serialize execution via a per-connector, per-host lock (see the Sources overview). Default `false`. |

At least one of `attributes` or `keyProperties` must be non-empty.

## Recommended Pattern

- Keep one logical metric family per source.
- Use wildcard ObjectNames (`scope=*`) plus `keyProperties` for multi-instance monitors.
- Normalize units in computes (`divide`, `multiply`) before mapping.

## Common Mistakes

- Fetching too many attributes in one source.
- Ignoring ObjectName dimensions and losing instance identity.
- Relying on unstable attribute naming across product versions without fallback.

## Community Examples

- [Cassandra](https://github.com/metricshub/community-connectors/blob/main/src/main/connector/database/Cassandra/Cassandra.yaml)