对于线上的生产环境，通常对其都是有很高的要求，其中，高可用是不可或缺的一部分。必须保证服务是可用的，才能保证系统更好的运行，这是业务稳定的保证。
高可用一般分为两种：客户端高可用、服务端高可用
客户端高可用
客户端高可用 主要解决当前服务端不可用哪个的情况下，客户端依然可用正常启动。从客户端触发，不是增加配置中心的高可用性，而是降低客户端对配置中心的依赖程度，从而提高整个分布式架构的健壮性。
实现
配置的自动装配
pom.xml
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-client</artifactId>
</dependency>
</dependencies>
配置文件解析
@Component
@ConfigurationProperties(prefix = ConfigSupportProperties.CONFIG_PREFIX)
public class ConfigSupportProperties {
/**
* 加载的配置文件前缀
*/
public static final String CONFIG_PREFIX = "spring.cloud.config.backup";
/**
* 默认文件名
*/
private final String DEFAULT_FILE_NAME = "fallback.properties";
/**
* 是否启用
*/
private boolean enabled = false;
/**
* 本地文件地址
*/
private String fallbackLocation;
public String getFallbackLocation() {
return fallbackLocation;
}
public void setFallbackLocation(String fallbackLocation) {
if (!fallbackLocation.contains(".")) {
// 如果只指定了文件路径，自动拼接文件名
fallbackLocation = fallbackLocation.endsWith(File.separator) ? fallbackLocation : fallbackLocation + File.separator;
fallbackLocation += DEFAULT_FILE_NAME;
}
this.fallbackLocation = fallbackLocation;
}
public boolean isEnabled() {
return enabled;
}
public void setEnabled(boolean enabled) {
this.enabled = enabled;
}
}
自动装配实现类
@Configuration
@EnableConfigurationProperties(ConfigSupportProperties.class)
public class ConfigSupportConfiguration implements ApplicationContextInitializer<ConfigurableApplicationContext>, Ordered {
private final Logger logger = LoggerFactory.getLogger(getClass());
/**
* 重中之重！！！！
* 一定要注意加载顺序！！！
*
* bootstrap.yml 加载类：org.springframework.cloud.bootstrap.config.PropertySourceBootstrapConfiguration 的加载顺序是
* HIGHEST_PRECEDENCE+10，
* 如果当前配置类再其之前加载，无法找到 bootstrap 配置文件中的信息，继而无法加载到本地
* 所以当前配置类的装配顺序一定要在 PropertySourceBootstrapConfiguration 之后！
*/
private final Integer orderNumber = Ordered.HIGHEST_PRECEDENCE + 11;
@Autowired(required = false)
private List<PropertySourceLocator> propertySourceLocators = Collections.EMPTY_LIST;
@Autowired
private ConfigSupportProperties configSupportProperties;
/**
* 初始化操作
*/
@Override
public void initialize(ConfigurableApplicationContext configurableApplicationContext) {
// 判断是否开启 config server 管理配置
if (!isHasCloudConfigLocator(this.propertySourceLocators)) {
logger.info("Config server 管理配置未启用");
return;
}
logger.info(">>>>>>>>>>>>>>> 检查 config Server 配置资源 <<<<<<<<<<<<<<<");
ConfigurableEnvironment environment = configurableApplicationContext.getEnvironment();
MutablePropertySources propertySources = environment.getPropertySources();
logger.info(">>>>>>>>>>>>> 加载 PropertySources 源：" + propertySources.size() + " 个");
// 判断配置备份功能是否启用
if (!configSupportProperties.isEnabled()) {
logger.info(">>>>>>>>>>>>> 配置备份未启用，使用：{}.enabled 打开 <<<<<<<<<<<<<<", ConfigSupportProperties.CONFIG_PREFIX);
return;
}
if (isCloudConfigLoaded(propertySources)) {
// 可以从 spring cloud 中获取配置信息
PropertySource cloudConfigSource = getLoadedCloudPropertySource(propertySources);
logger.info(">>>>>>>>>>>> 获取 config service 配置资源 <<<<<<<<<<<<<<<");
Map<String, Object> backupPropertyMap = makeBackupPropertySource(cloudConfigSource);
doBackup(backupPropertyMap, configSupportProperties.getFallbackLocation());
} else {
logger.info(">>>>>>>>>>>>>> 获取 config Server 资源配置失败 <<<<<<<<<<<<<");
// 不能获取配置信息，从本地读取
Properties backupProperty = loadBackupProperty(configSupportProperties.getFallbackLocation());
if (backupProperty != null) {
Map backupSourceMap = new HashMap<>(backupProperty);
PropertySource backupSource = new MapPropertySource("backupSource", backupSourceMap);
propertySources.addFirst(backupSource);
}
}
}
@Override
public int getOrder() {
return orderNumber;
}
/**
* 从本地加载配置
*/
private Properties loadBackupProperty(String fallbackLocation) {
logger.info(">>>>>>>>>>>> 正在从本地加载！<<<<<<<<<<<<<<<<<");
PropertiesFactoryBean propertiesFactoryBean = new PropertiesFactoryBean();
Properties properties = new Properties();
try {
FileSystemResource fileSystemResource = new FileSystemResource(fallbackLocation);
propertiesFactoryBean.setLocation(fileSystemResource);
propertiesFactoryBean.afterPropertiesSet();
properties = propertiesFactoryBean.getObject();
if (properties != null){
logger.info(">>>>>>>>>>>>>>> 读取成功！<<<<<<<<<<<<<<<<<<<<<<<<");
}
}catch (Exception e){
e.printStackTrace();
return null;
}
return properties;
}
/**
* 备份配置信息
*/
private void doBackup(Map<String, Object> backupPropertyMap, String fallbackLocation) {
FileSystemResource fileSystemResource = new FileSystemResource(fallbackLocation);
File file = fileSystemResource.getFile();
try {
if (!file.exists()){
file.createNewFile();
}
if (!file.canWrite()){
logger.info(">>>>>>>>>>>> 文件无法写入：{} <<<<<<<<<<<<<<<", fileSystemResource.getPath());
return;
}
Properties properties = new Properties();
Iterator<String> iterator = backupPropertyMap.keySet().iterator();
while (iterator.hasNext()) {
String key = iterator.next();
properties.setProperty(key, String.valueOf(backupPropertyMap.get(key)));
}
FileOutputStream fileOutputStream = new FileOutputStream(fileSystemResource.getFile());
properties.store(fileOutputStream, "backup cloud config");
}catch (Exception e){
logger.info(">>>>>>>>>> 文件操作失败！ <<<<<<<<<<<");
e.printStackTrace();
}
}
/**
* 将配置信息转换为 map
*/
private Map<String, Object> makeBackupPropertySource(PropertySource cloudConfigSource) {
Map<String, Object> backupSourceMap = new HashMap<>();
if (cloudConfigSource instanceof CompositePropertySource) {
CompositePropertySource propertySource = (CompositePropertySource) cloudConfigSource;
for (PropertySource<?> source : propertySource.getPropertySources()) {
if (source instanceof MapPropertySource){
MapPropertySource mapPropertySource = (MapPropertySource) source;
String[] propertyNames = mapPropertySource.getPropertyNames();
for (String propertyName : propertyNames) {
if (!backupSourceMap.containsKey(propertyName)) {
backupSourceMap.put(propertyName, mapPropertySource.getProperty(propertyName));
}
}
}
}
}
return backupSourceMap;
}
/**
* config server 管理配置是否开启
*/
private boolean isHasCloudConfigLocator(List<PropertySourceLocator> propertySourceLocators) {
for (PropertySourceLocator propertySourceLocator : propertySourceLocators) {
if (propertySourceLocator instanceof ConfigServicePropertySourceLocator) {
return true;
}
}
return false;
}
/**
* 获取 config service 配置资源
*/
private PropertySource getLoadedCloudPropertySource(MutablePropertySources propertySources) {
if (!propertySources.contains(PropertySourceBootstrapConfiguration.BOOTSTRAP_PROPERTY_SOURCE_NAME)){
return null;
}
PropertySource<?> propertySource = propertySources.get(PropertySourceBootstrapConfiguration.BOOTSTRAP_PROPERTY_SOURCE_NAME);
if (propertySource instanceof CompositePropertySource) {
for (PropertySource<?> source : ((CompositePropertySource) propertySource).getPropertySources()) {
// 如果配置源是 config service，使用此配置源获取配置信息
// configService 是 bootstrapProperties 加载 spring cloud 的实现：ConfigServiceBootstrapConfiguration
if ("configService".equals(source.getName())){
return source;
}
}
}
return null;
}
/**
* 判断是否可以从 spring cloud 中获取配置信息
*/
private boolean isCloudConfigLoaded(MutablePropertySources propertySources) {
return getLoadedCloudPropertySource(propertySources) != null;
}
}
META-INF/spring.factories
org.springframework.cloud.bootstrap.BootstrapConfiguration=\
com.laiyy.gitee.confog.springcloudconfighaclientautoconfig.ConfigSupportConfiguration
客户端实现
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-client</artifactId>
</dependency>
<dependency>
<groupId>com.laiyy.gitee.confog</groupId>
<artifactId>spring-cloud-config-ha-client-autoconfig</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
</dependencies>
bootstrap.yml
spring:
cloud:
config:
label: master
uri: http://localhost:9090
name: config-simple
profile: dev
backup:
enabled: true # 自定义配置 -- 是否启用客户端高可用配置
fallbackLocation: D:/cloud # 自动备份的配置文档存放位置
application.yml
server:
port: 9015
spring:
application:
name: spring-cloud-config-ha-client-config
启动类
@SpringBootApplication
@RestController
public class SpringCloudConfigHaClientConfigApplication {
public static void main(String[] args) {
SpringApplication.run(SpringCloudConfigHaClientConfigApplication.class, args);
}
@Value("${com.laiyy.gitee.config}")
private String config;
@GetMapping(value = "/config")
public String getConfig(){
return config;
}
}
config server
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-server</artifactId>
</dependency>
</dependencies>
server:
port: 9090
spring:
cloud:
config:
server:
git:
uri: https://gitee.com/laiyy0728/config-repo.git
search-paths: config-simple
@EnableConfigServer
@SpringBootApplication
public class SpringCloudConfigHaClientConfigServerApplication {
public static void main(String[] args) {
SpringApplication.run(SpringCloudConfigHaClientConfigServerApplication.class, args);
}
}
验证
先后启动 config-server、config-client，查看config-client控制台输出：
Fetching config from server at : http://localhost:9090
Located environment: name=config-simple, profiles=[dev], label=master, version=ee39bf20c492b27c2d1b1d0ff378ad721e79a758, state=null
Located property source: CompositePropertySource {name='configService', propertySources=[MapPropertySource {name='configClient'}, MapPropertySource {name='https://gitee.com/laiyy0728/config-repo.git/config-simple/config-simple-dev.yml'}]}
>>>>>>>>>>>>>>> 检查 config Server 配置资源 <<<<<<<<<<<<<<<
>>>>>>>>>>>>> 加载 PropertySources 源：11 个
>>>>>>>>>>>> 获取 config service 配置资源 <<<<<<<<<<<<<<<
No active profile set, falling back to default profiles: default
查看 d:/cloud，可见存在 fallback.properties 文件，打开文件，可见配置信息如下：
#backup cloud config
#Wed Apr 10 14:49:36 CST 2019
config.client.version=ee39bf20c492b27c2d1b1d0ff378ad721e79a758
com.laiyy.gitee.config=dev \u73AF\u5883\uFF0Cgit \u7248 spring cloud config-----\!
访问 http://localhost:9015/config ，可见打印信息如下：
config-client-ha-result
停止 server、client，删除 d:/cloud/fallback.properties，将 ConfigSupportConfiguration 的 orderNumber 改为 Ordered.HIGHEST_PRECEDENCE + 9，再次先后启动 config-server、config-client，查看控制 client 控制台输出如下：
>>>>>>>>>>>>>>> 检查 config Server 配置资源 <<<<<<<<<<<<<<<
>>>>>>>>>>>>> 加载 PropertySources 源：10 个
>>>>>>>>>>>>>> 获取 config Server 资源配置失败 <<<<<<<<<<<<<
Fetching config from server at : http://localhost:9090
可见，PropertySources 源从原来的 11 个，变为 10 个。原因是 bootstrap.yml 的加载顺序问题。
在源码：org.springframework.cloud.bootstrap.config.PropertySourceBootstrapConfiguration 中，其加载顺序为：Ordered.HIGHEST_PRECEDENCE + 10，而 ConfigSupportConfiguration 的加载顺序为 Ordered.HIGHEST_PRECEDENCE + 9，先于 bootstrap.yml 配置文件加载执行，所以无法获取到远程配置信息，继而无法备份配置信息。
重新进行第一步验证，然后将 config-server、config-client 停掉后，只启动 config-client，可见其控制台打印信息如下：
>>>>>>>>>>>>>>> 检查 config Server 配置资源 <<<<<<<<<<<<<<<
>>>>>>>>>>>>> 加载 PropertySources 源：10 个
>>>>>>>>>>>>>> 获取 config Server 资源配置失败 <<<<<<<<<<<<<
>>>>>>>>>>>> 正在从本地加载！<<<<<<<<<<<<<<<<<
>>>>>>>>>>>>>>> 读取成功！<<<<<<<<<<<<<<<<<<<<<<<<
访问 http://localhost:9015/config 正常返回信息。
由此验证客户端高可用成功
服务端高可用
服务端高可用，一般情况下是通过与注册中心结合实现。通过 Ribbon 的负载均衡选择 Config Server 进行连接，来获取配置信息。
eureka 选择使用 spring-cloud-eureka-server-simple
config server
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-server</artifactId>
</dependency>
</dependencies>
spring:
cloud:
config:
server:
git:
uri: https://gitee.com/laiyy0728/config-repo.git
search-paths: config-simple
application:
name: spring-cloud-config-ha-server-app
server:
port: 9090
eureka:
client:
service-url:
defaultZone: http://localhost:8761/eureka/
@SpringBootApplication
@EnableConfigServer
@EnableDiscoveryClient
public class SpringCloudConfigHaServerConfigApplication {
public static void main(String[] args) {
SpringApplication.run(SpringCloudConfigHaServerConfigApplication.class, args);
}
}
config client
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
</dependencies>
application.yml
server:
port: 9016
spring:
application:
name: spring-cloud-config-ha-server-client
bootstrap.yml
spring:
cloud:
config:
label: master
name: config-simple
profile: dev
discovery:
enabled: true # 是否从注册中心获取 config server
service-id: spring-cloud-config-ha-server-app # 注册中心 config server 的 serviceId
eureka:
client:
service-url:
defauleZone: http://localhost:8761/eureka/
@SpringBootApplication
@RestController
public class SpringCloudConfigHaServerClientApplication {
public static void main(String[] args) {
SpringApplication.run(SpringCloudConfigHaServerClientApplication.class, args);
}
@Value("${com.laiyy.gitee.config}")
private String config;
@GetMapping(value = "/config")
public String getConfig(){
return config;
}
}
启用验证：访问 http://localhost:9016/config ,返回值如下：
config-client-ha-result
