Metrics & JMX in Neo4j

1. Introduction

Monitoring and observability are critical in maintaining the health of Neo4j databases. This lesson covers the use of Java Management Extensions (JMX) for monitoring and metrics collection.

2. Key Concepts

• JMX (Java Management Extensions): A Java technology that provides tools for managing and monitoring applications.
• Metrics: Quantitative measures used to assess the performance and health of the database.
• Neo4j: A graph database management system that uses JMX for monitoring various metrics.

3. Setting Up JMX

To enable JMX in your Neo4j installation, follow these steps:

1. Locate the Neo4j configuration file, usually found at neo4j.conf.
2. Enable JMX by adding the following line:

dbms.jvm.additional=-Dcom.sun.management.jmxremote

3. Specify the JMX port:

dbms.jvm.additional=-Dcom.sun.management.jmxremote.port=1099

4. Set authentication options (optional but recommended):

dbms.jvm.additional=-Dcom.sun.management.jmxremote.authenticate=true

5. Restart Neo4j for the changes to take effect.

4. Metrics in Neo4j

Neo4j exposes a variety of metrics through JMX, including:

• Heap Memory: Monitors JVM heap usage.
• Garbage Collection: Tracks GC activity, important for performance tuning.
• Transaction Metrics: Provides insights on transaction rates and latencies.

To query metrics, use a JMX client such as JConsole or VisualVM.

5. Best Practices

• Limit JMX exposure to trusted networks only.
• Regularly monitor JMX metrics for early detection of performance issues.
• Use a centralized logging and monitoring system to aggregate metrics data.

6. FAQ