Set Up an FE Development Environment with VSCode

This document describes how to use VSCode to set up a Doris FE development environment on a development machine, in WSL, or in Docker. Developers who prefer VSCode can use the Remote extensions for remote development and debugging.

1. Prerequisites

Component	Version Requirement	Purpose
JDK	11+ (required by the Java extension); JDK 8 can be used for compilation	Install both and switch via configuration
VSCode	Latest stable release	Editor
Extension Pack for Java	Latest version	Java language support
Remote extensions	Remote - SSH / Remote - WSL / Remote - Containers	Remote development

It is recommended to install JDK 11 and JDK 8 separately under an isolated directory such as ~/lib, used for the IDE extensions and source compilation respectively.

2. Clone and Open the Source Code

1. Download the source code from GitHub:

   git clone https://github.com/apache/doris.git

2. Open the fe directory under the source tree in VSCode (not the entire repository root).

3. Configure VSCode

Create settings.json under fe/.vscode/ and configure the Java runtime and Maven path.

Configuration item	Description
java.configuration.runtimes	Registers the list of available JDKs, used by the Java extension per project
java.jdt.ls.java.home	Points to the JDK 11+ directory used by the vscode-java extension itself
maven.executable.path	Points to the local Maven executable, used by the maven-language-server extension

Example:

{
    "java.configuration.runtimes": [
        {
            "name": "JavaSE-1.8",
            "path": "/!!!path!!!/jdk-1.8.0_191"
        },
        {
            "name": "JavaSE-11",
            "path": "/!!!path!!!/jdk-11.0.14.1+1",
            "default": true
        }
    ],
    "java.jdt.ls.java.home": "/!!!path!!!/jdk-11.0.14.1+1",
    "maven.executable.path": "/!!!path!!!/maven/bin/mvn"
}

4. Compile FE

For the full compilation procedure, refer to:

• Compile with LDB Toolchain
• Compile with Docker Development Image

5. Configure Remote Debugging

To debug FE remotely from VSCode, attach the JDWP parameters when FE starts:

-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005

To do this, edit doris/output/fe/bin/start_fe.sh and append the parameters above after $JAVA $final_java_opt.

JDWP parameter	Value	Description
transport	dt_socket	Use Socket transport
server	y	Start as the debug server and wait for a debugger to attach
suspend	n	Do not suspend at startup; run normally
address	5005	Listening port; customizable

After starting FE, use the Java Debug extension in VSCode to Attach to host:5005 for breakpoint debugging.

6. Frequently Asked Questions (FAQ)

Q1: The Java extension reports that the JDK version is too low

java.jdt.ls.java.home must point to JDK 11+. Even when JDK 8 is used for compilation, the extension itself still requires JDK 11+ to run.

Q2: Maven tasks fail / mvn is not found

Confirm that maven.executable.path points to a valid mvn executable, or add it to the system PATH.

Q3: Remote debugging cannot connect

• Confirm that the FE process has actually loaded the JDWP parameters (check the command line with ps -ef | grep java).
• Confirm that the address port is not blocked by a firewall.
• If suspend=y is used, FE will block waiting for the debugger to attach. Change it to suspend=n, or attach the debugger proactively.