Application startup acceleration: Asynchronous initialization

SOFABoot accelerates application startup in two ways:

• Module parallel startup

• Asynchronously executes the bean's initialization method

This topic describes how to use SOFABoot to asynchronously execute the initialization method of a bean to accelerate application startup.

Principle of asynchronous acceleration

In actual Spring/Spring Boot development, some beans perform some preparation operations during initialization, such as:

• Pull remote configuration

• Initialize a data source

During application startup, these beans increase the Spring context refresh time, resulting in a longer application startup duration.

To accelerate application startup, SOFABoot uses a separate thread to asynchronously execute the Bean initialization method (init-method) by configuring an option. This accelerates the Spring context loading process and improves application startup speed.

Asynchronous acceleration implementation

The principle of asynchronous bean initialization is to open a separate thread responsible for executing the bean's initialization method (init-method). An example of the implementation steps is as follows:

1. Introduce dependencies: Introduce the following starter into the pom.xml file of the project:

   <dependency>
       <groupId>com.alipay.sofa</groupId>
       <artifactId>runtime-sofa-boot-starter</artifactId>
   </dependency>

2. XML configuration: Configure the async-init="true" attribute in the XML of the bean to specify whether to execute the initialization method of the bean asynchronously. The configuration method is shown in the following example.

   <?xml version="1.0" encoding="UTF-8"?>
   <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:sofa="http://sofastack.io/schema/sofaboot"
           xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
           http://sofastack.io/schema/sofaboot   http://sofastack.io/schema/sofaboot.xsd"
   default-autowire="byName">
       <!-- async init  test -->
       <bean id="testBean" class="com.alipay.sofa.runtime.beans.TimeWasteBean" init-method="init" async-init="true"/>
   </beans>

3. Attribute configuration: specifies the size of the asynchronous initialization capability of SOFABoot. This value is reflected by configuring the size of the thread pool. The thread pool is used to asynchronously execute bean initialization methods (init-method). The property values of the thread pool can be configured by using one of the following methods.

   • is specified by two properties in the application.properties.

     • com.alipay.sofa.boot.asyncInitBeanCoreSize: the basic size of the thread pool. The default value is the number of CPU cores plus one.

     • com.alipay.sofa.boot.asyncInitBeanMaxSize: the maximum number of threads allowed in the thread pool. The default value is the number of CPU cores plus one.

   • Set by VM -D parameters.