Build GraalVM Native Image(Alpha)

Background

This section mainly introduces how to build the Native Image of ShardingSphere-Proxy and the corresponding Docker Image through the native-image component of GraalVM.

Notice

ShardingSphere Proxy is not yet ready to integrate with GraalVM Native Image. Proxy’s Native Image artifacts are built nightly at https://github.com/apache/shardingsphere/pkgs/container/shardingsphere-proxy-native . Assuming there is a conf folder containing global.yaml as ./custom/conf, you can test it with the following docker-compose.yml file.

version: "3.8"

services:
  apache-shardingsphere-proxy-native:
    image: ghcr.io/apache/shardingsphere-proxy-native:latest
    volumes:
      - ./custom/conf:/opt/shardingsphere-proxy-native/conf
    ports:
      - "3307:3307"

This section assumes a Linux (amd64, aarch64), MacOS (amd64) or Windows (amd64) environment. If you are on MacOS (aarch64/M1) environment, you need to follow https://github.com/oracle/graal/issues/2666 which is not closed yet.

Premise

Install and configure GraalVM Community Edition or a downstream distribution of GraalVM Community Edition for JDK 21 according to https://www.graalvm.org/downloads/. If SDKMAN! is used,

sdk install java 21.0.2-graalce

Install the local toolchain as required by https://www.graalvm.org/jdk17/reference-manual/native-image/#prerequisites.
If you need to build a Docker Image, make sure docker-ce is installed.

Steps

Get Apache ShardingSphere Git Source

Get it at the download page or https://github.com/apache/shardingsphere/tree/master.

Build the product on the command line, in two cases.

Scenario 1: No need to use JARs with SPI implementations or 3rd party dependencies
Execute the following command in the same directory of Git Source to directly complete the construction of Native Image.

./mvnw -am -pl distribution/proxy-native -T1C -Prelease.native -DskipTests clean package

Scenario 2: It is necessary to use a JAR that has an SPI implementation or a third-party dependent JAR of a LICENSE such as GPL V2.
Add SPI implementation JARs or third-party dependent JARs to dependencies in distribution/proxy-native/pom.xml. Examples are as follows


<dependencies>
    <dependency>
        <groupId>com.mysql</groupId>
        <artifactId>mysql-connector-j</artifactId>
        <version>8.1.0</version>
    </dependency>
</dependencies>

Build GraalVM Native Image via command line.

./mvnw -am -pl distribution/proxy-native -T1C -Prelease.native -DskipTests clean package

To start Native Image through the command line, you need to bring 4 parameters. The first parameter is the Port used by ShardingSphere Proxy, the second parameter is the /conf folder containing global.yaml written by you, the third parameter is the Address of the bound port, and the fourth parameter is Force Start, if it is true, it will ensure that ShardingSphere Proxy Native can start normally no matter whether it is connected or not. Assuming the folder ./custom/conf already exists, the example is

./apache-shardingsphere-proxy-native 3307 ./custom/conf "0.0.0.0" false

If you need to build a Docker Image, execute the following command on the command line after adding dependencies that exist for SPI implementation or third-party dependencies.

./mvnw -am -pl distribution/proxy-native -B -T1C -Prelease.native,docker.native -DskipTests clean package

Assuming that there is a conf folder containing global.yaml as ./custom/conf, you can start the Docker Image corresponding to GraalVM Native Image through the following docker-compose.yml file.

version: "3.8"

services:
  apache-shardingsphere-proxy-native:
    image: apache/shardingsphere-proxy-native:latest
    volumes:
      - ./custom/conf:/opt/shardingsphere-proxy-native/conf
    ports:
      - "3307:3307"

If you don’t make any changes to the Git Source, the commands mentioned above will use oraclelinux:9-slim as the Base Docker Image. But if you want to use a smaller Docker Image like busybox:glic, gcr.io/distroless/base or scratch as the Base Docker Image, you need according to https://www.graalvm.org/jdk17/reference-manual/native-image/guides/build-static-executables/, add operations such as -H:+StaticExecutableWithDynamicLibC to jvmArgs as the native profile of pom.xml. Also note that some 3rd-party dependencies will require more system libraries such as libdl to be installed in the Dockerfile. So make sure to tune distribution/proxy-native according to your usage pom.xml and Dockerfile below.

Observability

ShardingSphere for GraalVM Native Image form Proxy, which provides observability capabilities with https://shardingsphere.apache.org/document/current/cn/user-manual/shardingsphere-proxy/observability/ not consistent.

You can observe GraalVM Native Image using a series of command line tools or visualization tools available at https://www.graalvm.org/jdk17/tools/, and use VSCode to debug it according to its requirements. If you are using IntelliJ IDEA and want to debug the generated GraalVM Native Image, You can follow https://blog.jetbrains.com/idea/2022/06/intellij-idea-2022-2-eap-5/#Experimental_GraalVM_Native_Debugger_for_Java and its successors. If you are not using Linux, you cannot debug GraalVM Native Image, please pay attention to https://github.com/oracle/graal/issues/5648 which has not been closed yet.

For the use of Java Agents such as ShardingSphere Agent, GraalVM’s native-image component does not yet fully support building Native when using javaagent with Image, you need to pay attention to https://github.com/oracle/graal/issues/1065 which has not yet been closed.

If users expect to use this type of Java Agent under ShardingSphere Proxy Native, they need to pay attention to the changes involved in https://github.com/oracle/graal/pull/8077 .