Understanding the DBLE Installation Directory Structure

In the previous lesson we covered the standard DBLE installation method; this session introduces the directory structure of a completed installation.

DBLE Installation Directory Overview

The algorithm directory stores custom algorithms. The bin directory contains startup scripts, cluster initialization scripts, and various utility commands. The conf directory is the most important, holding configuration files that will be described in detail later.

The pid files represent daemon process IDs, disappearing when the process stops, which can be used for monitoring DBLE’s health. The lib directory stores JAR packages, including dependencies and the main DBLE JAR. The logs directory contains current logs, archived logs sorted by date, a GC log (written only when garbage collection occurs), and a distributed transaction log; these are useful for diagnosing GC‑related issues.

A version.txt file includes an Easter egg that displays a QR code in Linux environments, linking to the community’s WeChat public account and showing the current DBLE version.

The viewConf file is used when working with DBLE views.

Below is a closer look at the conf directory.

The conf directory contains many files: cache‑related files on the first and fourth lines, template and non‑configuration files on the second and third lines, and the important log4j configuration for logging. It defines log levels (e.g., debug for testing, info for production) that can be changed at runtime without restarting. Additional settings include pattern definitions and several algorithm files. The myid.properties file relates to clustering.

wrapper.conf is the daemon configuration file. It includes many entries prefixed with Java. that set JVM startup parameters. Adjusting its log level can help diagnose startup problems, and the timeout setting defines how long the daemon waits before considering the process dead and attempting a restart.

Key XML configuration files such as rule.xml , schema.xml , and server.xml will be introduced in the next lesson with a practical example of their relationships.

This concludes the basic installation overview.