arcus-spring

Arcus as a caching provider for the Spring Cache Abstraction.

arcus-spring provides following functionalities.

• ArcusClientFactoryBean: Lifecycle management such as creating or deleting an ArcusClient object.
• ArcusCacheManager: AbstractCacheManager implementation of Spring Cache for managing ArcusCache.
• ArcusCacheConfiguration: Configuration class representing properties of ArcusCache
• ArcusCache: Spring Cache implementation for Arcus.
• StringKeyGenerator, SimpleStringKeyGenerator: KeyGenerator implementation of Spring Cache for generating ArcusStringKey.
• ArcusStringKey: Arcus subkey class with hash and string key without prefix.
• Spring 4.3 cache abstract support.

Getting Started

Dependency

The artifact for arcus-spring is in the central Maven repository. To use it, add the following dependency.

Maven (pom.xml)

<dependencies>
    <dependency>
        <groupId>com.jam2in.arcus</groupId>
        <artifactId>arcus-spring</artifactId>
        <version>1.14.0</version>
    </dependency>
</dependencies>

Gradle (build.gradle)

version 7.0 before

dependencies {
    compile 'com.jam2in.arcus:arcus-spring:1.14.0'
}

version 7.0 or later

dependencies {
  implementation 'com.jam2in.arcus:arcus-spring:1.14.0'
}

KeyGenerator

Arcus-spring provides two types of key generator. These two are StringKeyGenerator and SimpleStringKeyGenerator.

• StringKeyGenerator: it generate the key by combining the parameters and hashcode of the parameters. It's because the key can have invalid characters. This generator replace invalid characters to valid characters. But if the generator do that, even though the keys are different, they can be the same. So the generator adds hashcode to distinguish the keys.
• SimpleStringKeyGenerator: it generate the key simply by combining the parameters. So this generator can generate invalid keys or duplicate keys.

For example, when the parameters are 'a', 'b', 'c', StringKeyGenerator creates the key 'a,b,c317' and SimpleStringKeyGenerator creates the key 'a,b,c'.

Configuration

Spring Cache configuration is required before using arcus-spring. Create ArcusCacheManager and StringKeyGenerator with the following configuration.

XML

• Use ArcusClientFactoryBean or ArcusCacheConfigurationFactoryBean because these classes do not provide default constructor and setter.

<?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:cache="http://www.springframework.org/schema/cache"
       xmlns:util="http://www.springframework.org/schema/util"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
                           http://www.springframework.org/schema/beans/spring-beans.xsd
                           http://www.springframework.org/schema/cache
                           http://www.springframework.org/schema/cache/spring-cache.xsd
	                       http://www.springframework.org/schema/util
                           http://www.springframework.org/schema/util/spring-util.xsd">

    <cache:annotation-driven
        key-generator="arcusKeyGenerator"
        cache-manager="arcusCacheManager"/>

    <bean id="arcusKeyGenerator"
        class="com.navercorp.arcus.spring.cache.StringKeyGenerator"/>

    <bean id="arcusCacheManager" class="com.navercorp.arcus.spring.cache.ArcusCacheManager">
        <constructor-arg name="adminAddress" value="127.0.0.1:2181,127.0.0.1:2182,127.0.0.1:2183"/>
        <constructor-arg name="serviceCode" value="test"/>
        <constructor-arg name="connectionFactoryBuilder">
            <bean class="net.spy.memcached.ConnectionFactoryBuilder"/>
        </constructor-arg>
        <constructor-arg name="poolSize" value="8"/>
        <!-- default cache configuration (missing cache) -->
        <constructor-arg name="defaultConfiguration" ref="defaultCacheConfig"/>
        <!-- a map of cache configuration (key=cache name, value=cache configuration) -->
        <constructor-arg name="initialCacheConfigs">
            <map>
                <entry key="testCache">
                    <bean parent="defaultCacheConfig">
                        <property name="serviceId" value="TEST-"/>
                        <property name="prefix" value="PRODUCT"/>
                        <property name="expireSeconds" value="60"/>
                    </bean>
                </entry>
                <entry key="devCache">
                    <bean parent="defaultCacheConfig">
                        <property name="serviceId" value="DEV-">
                        <property name="prefix" value="PRODUCT"/>
                        <property name="expireSeconds" value="120"/>
                    </bean>
                </entry>
            </map>
        </constructor-arg>
    </bean>

    <bean id="defaultCacheConfig" class="com.navercorp.arcus.spring.ArcusCacheConfigurationFactoryBean">
        <property name="prefix" value="DEFAULT"/>
        <property name="expireSeconds" value="60"/>
        <property name="timeoutMilliSeconds" value="800"/>
    </bean>

</beans>

Java

@Configuration
@EnableCaching
public class ArcusConfiguration extends CachingConfigurerSupport {

    private static String ADMIN_ADDRESS = "127.0.0.1:2181,127.0.0.1:2182,127.0.0.1:2183";
    private static String SERVICE_CODE = "test";
    private static int POOL_SIZE = 8;

    @Bean
    @Override
    public KeyGenerator keyGenerator() {
        return new StringKeyGenerator();
    }

    @Bean
    @Override
    public CacheManager cacheManager() {
        return new ArcusCacheManager(
            ADMIN_ADDRESS,
            SERVICE_CODE,
            new ConnectionFactoryBuilder(),
            POOL_SIZE,
            /* default cache configuration (missing cache) */
            defaultCacheConfig(),
            /* a map of cache configuration (key=cache name, value=cache configuration) */
            initialCacheConfig()
        );
    }

    @Bean
    public ArcusCacheConfiguration defaultCacheConfig() {
        return new ArcusCacheConfiguration()
            .withPrefix("DEFAULT")
            .withExpireSeconds(60)
            .withTimeoutMilliSeconds(800);
    }

    @Bean
    public Map<String, ArcusCacheConfiguration> initialCacheConfig() {
        Map<String, ArcusCacheConfiguration> initialCacheConfig = new HashMap<>();
        initialCacheConfig.put("testCache", testCacheConfig());
        initialCacheConfig.put("devCache", devCacheConfig());
        return initialCacheConfig;
    }

    @Bean
    public ArcusCacheConfiguration testCacheConfig() {
        return new ArcusCacheConfiguration()
            .withServiceId("TEST-")
            .withPrefix("PRODUCT")
            .withExpireSeconds(60)
            .withTimeoutMillisSeconds(800);
    }

    @Bean
    public ArcusCacheConfiguration devCacheConfig() {
        return new ArcusCacheConfiguration()
            .withServiceId("DEV-")
            .withPrefix("PRODUCT")
            .withExpireSeconds(120)
            .withTimeoutMillisSeconds(800);
    }

}

Example

Apply the cache using the key(cacheNames) stored in the initialCacheConfig map of ArcusCacheManager you created with XML or Java configuration.

@Service
public class ProductService {

    /*
        using the "testCache" cache with 60 expire seconds and "TEST-PRODUCT" prefix.
    */
    @Cacheable(cacheNames = "testCache", key="#id")
    public Product getProduct_TestCache(int id) {
        return new Product(id);
    }

    /*
        using the "devCache" cache with 120 expire seconds and "DEV-PRODUCT" prefix.
    */
    @Cacheable(cacheNames = "devCache", key="#id")
    public Product getProduct_DevCache(int id) {
        return new Product(id);
    }

    /*
        In ArcusCacheManger, missing cache is loaded with default cache configuration.
        so, the below code uses the default cache with 60 expire seconds and "DEFAULT" prefix.
    */
    @Cacheable(cacheNames = "missingCache", key="#id")
    public Product getProduct_DefaultCache(int id) {
        return new Product(id);
    }

}

Front Cache

You can use the front cache to provide fast responsiveness of cache requests. The front cache takes precedence over ARCUS and performs cache requests. To enable this feature, create an implementation of the ArcusFrontCache interface and set it to the ArcusCacheConfiguration.

Configuration

@Bean
public ArcusCacheConfiguration testCacheConfig() {
  return new ArcusCacheConfiguration()
      .withServiceId("TEST-")
      .withPrefix("PRODUCT")
      .withExpireSeconds(60)
      .withTimeoutMilliSeconds(800)
      /* front cache configuration */
      .withArcusFrontCache(testArcusFrontCache())
      .withFrontExpireSeconds(120)
      .enableForcingFrontCache();
      /* front cache configuration */
}

@Bean
public ArcusCacheConfiguration devCacheConfig() {
  return new ArcusCacheConfiguration()
      .withServiceId("DEV-")
      .withPrefix("PRODUCT")
      .withExpireSeconds(120)
      .withTimeoutMilliSeconds(800)
      /* front cache configuration */
      .withArcusFrontCache(devArcusFrontCache())
      .withFrontExpireSeconds(240)
      .enableForcingFrontCache();
      /* front cache configuration */
}

@Bean
public ArcusFrontCache testArcusFrontCache() {
    return new DefaultArcusFrontCache("test" /*name*/, 10000 /*maxEntries*/, false /*copyOnRead*/, false /*copyOnWrite*/);
}

@Bean
public ArcusFrontCache devArcusFrontCache() {
    return new DefaultArcusFrontCache("dev" /*name*/, 20000 /*maxEntries*/, false /*copyOnRead*/, false /*copyOnWrite*/);
}

The properties added to the ArcusCacheConfiguration class related to Front Cache are as follows.

• withArcusFrontCache(ArcusFrontCache arcusFrontCache)
  • Set the ArcusFrontCache object to enable Front Caching.
  • The DefaultArcusFrontCache class provided by Arcus Spring can be used.
  • Front caching is disabled by default and arguments cannot be set to null.
• withFrontExpireSeconds(int frontExpireSeconds)
  • Set Front Cache TTL(TimeToLive).
• enableForcingFrontCache(), disableForcingFrontCache()
  • Set whether to perform Front Cache regardless of success or failure of ARCUS change request(put, delete, clear).
  • It is prone to data consistency issues, so we recommend using it only for data that doesn't change frequently.
  • It is disabled by default.

Front Caching is not always performed. It is performed depending on the attribute of forceFrontCaching property and the result of the ARCUS request.

ArcusCache API	ARCUS Result	forceFrontCaching=false	forceFrontCaching=true
get	success	O	O
get	failure	X	X
put	success	O	O
put	failure	X	O
putIfAbsent	success	O	O
putIfAbsent	failure	X	X
evict	success	O	O
evict	failure	O	O
clear	success	O	O
clear	failure	X	X

DefaultArcusFrontCache

ArcusFrontCache consists of a simple interface for Front Cache. You can implement and use the ArcusFrontCache interface, or you can use the DefaultArcusFrontCache implementation provided by default in the library. Four options are required to use DefaultArcusFrontCache.

• name
  • Cache name. It must be unique each time an instance is created.
• maxEntries
  • The maximum number of items that can be stored in the front cache.
• copyOnRead
  • Whether the Front Cache should copy elements it returns.
• copyOnWrite
  • Whether the Front Cache should copy elements it gets.

Issues

If you find a bug, please report it via the GitHub issues page.

https://github.com/naver/arcus-spring/issues

License

Licensed under the Apache License, Version 2.0: http://www.apache.org/licenses/LICENSE-2.0