---
title: InfluxDB 3 Core internals
description: Learn about InfluxDb 3 Core internal systems and mechanisms.
url: https://docs.influxdata.com/influxdb3/core/reference/internals/
estimated_tokens: 299
product: InfluxDB 3 Core
version: core
---

# InfluxDB 3 Core internals

Learn about InfluxDB 3 Core internal systems and architecture. Understanding these internals can help with performance optimization, troubleshooting, and advanced integrations.

## [Data retention in InfluxDB 3 Core](/influxdb3/core/reference/internals/data-retention/)

InfluxDB 3 Core enforces database retention periods at query time. Retention periods are set when creating a database and cannot be changed afterward.

## [InfluxDB 3 Core authentication and authorization](/influxdb3/core/reference/internals/authentication/)

InfluxDB 3 Core uses an Attribute-Based Access Control (ABAC) model to manage permissions for authentication (authn) and authorization (authz).

## [Data durability](/influxdb3/core/reference/internals/durability/)

Learn how InfluxDB 3 Core ensures data durability through a structured write path that balances performance, persistence, and query efficiency.