24. sharding-jdbc源码分析之orchestration实现
源码图解
orchestration源码结构图.png
根据源码图解可知,sharding-jdbc-orchestration模块中创建数据源有两种方式:工厂类和spring;且有两种数据源类型:OrchestrationShardingDataSource和OrchestrationMasterSlaveDataSource;
- 左边是OrchestrationShardingDataSource类型数据源创建,配置信息持久化以及监听&刷新过程;右边是OrchestrationMasterSlaveDataSource类型数据源创建,配置信息持久化以及监听&刷新过程;
- 工厂类方式通过OrchestrationShardingDataSourceFactory或者OrchestrationMasterSlaveDataSourceFactory创建;
- spring方式通过解析xml配置文件创建(可以参考OrchestrationShardingNamespaceTest测试用例);
- 得到数据源后,调用OrchestrationFacade.init()方法;在该init()方法中持久化配置信息到注册中心中;并创建监听器;
由图可知,两种类型数据源的处理大同小异,本篇文章只分析OrchestrationShardingDataSource这种类型的数据源;
源码分析
接下来通过工厂类创建OrchestrationShardingDataSource类型数据源源码剖析orchestration的实现原理;
1.创建数据源
通过测试用例YamlOrchestrationShardingIntegrateTest可知,创建数据源的代码为OrchestrationShardingDataSourceFactory.createDataSource(yamlFile);这段代码的实现如下所示:
@NoArgsConstructor(access = AccessLevel.PRIVATE)
public final class OrchestrationShardingDataSourceFactory {
public static DataSource createDataSource(
final Map<String, DataSource> dataSourceMap, final ShardingRuleConfiguration shardingRuleConfig,
final Map<String, Object> configMap, final Properties props,
final OrchestrationConfiguration orchestrationConfig) throws SQLException {
// step3.1 创建OrchestrationShardingDataSource数据源
OrchestrationShardingDataSource result = new OrchestrationShardingDataSource(dataSourceMap, shardingRuleConfig, configMap, props, orchestrationConfig);
// step3.2 初始化(这里是sharding-jdb orchestration编排治理的核心)
result.init();
return result;
}
public static DataSource createDataSource(final File yamlFile) throws SQLException, IOException {
// step1. 解析yaml文件得到YamlOrchestrationShardingRuleConfiguration
YamlOrchestrationShardingRuleConfiguration config = unmarshal(yamlFile);
// step2. 得到分库分表规则配置,即根据yaml文件中shardingRule节点信息得到的分库分表规则配置
YamlShardingRuleConfiguration shardingRuleConfig = config.getShardingRule();
// step3. 调用上面的方法创建数据源
return createDataSource(config.getDataSources(), shardingRuleConfig.getShardingRuleConfiguration(),
shardingRuleConfig.getConfigMap(), shardingRuleConfig.getProps(), config.getOrchestration().getOrchestrationConfiguration());
}
// 一些其他创建数据源的方式,大同小异,暂时省略
... ...
}
OrchestrationShardingDataSource.init()方法会调用OrchestrationFacade.init()方法,所以分析后者即可;
2.持久化
OrchestrationFacade.init()核心源码如下:
public void init(
final Map<String, DataSource> dataSourceMap,
final ShardingRuleConfiguration shardingRuleConfig,
final Map<String, Object> configMap,
final Properties props,
final ShardingDataSource shardingDataSource) throws SQLException {
// step1. 持久化sharding规则配置,且为PERSISTENT类型节点
configService.persistShardingConfiguration(getActualDataSourceMapForMasterSlave(dataSourceMap), shardingRuleConfig, configMap, props, isOverwrite);
// step2. 持久化sharding实例信息,且为EPHEMERAL类型节点
instanceStateService.persistShardingInstanceOnline();
// step3. 持久化数据源节点信息,且为PERSISTENT类型节点
dataSourceService.persistDataSourcesNode();
// step4. 注册监听器
listenerManager.initShardingListeners(shardingDataSource);
}
所以说,这里就是sharding-jdbc编排治理的核心–配置信息持久化,注册监听器;接下来先分析编排治理的配置信息持久化;
2.1持久化sharding规则配置
持久化sharding规则配置的核心实现如下,我们接下来一一分析其持久化的内容;
public void persistShardingConfiguration(
final Map<String, DataSource> dataSourceMap,
final ShardingRuleConfiguration shardingRuleConfig,
final Map<String, Object> configMap,
final Properties props, final boolean isOverwrite) {
persistDataSourceConfiguration(dataSourceMap, isOverwrite);
persistShardingRuleConfiguration(shardingRuleConfig, isOverwrite);
persistShardingConfigMap(configMap, isOverwrite);
persistShardingProperties(props, isOverwrite);
}
- 持久化数据源配置
对应源码为persistDataSourceConfiguration(dataSourceMap, isOverwrite);核心实现源码如下:
private void persistDataSourceConfiguration(final Map<String, DataSource> dataSourceMap, final boolean isOverwrite) {
// 如果配置了overwrite,或者/demo_ds_ms/config/datasource节点还不存在,那么就持久化数据源相关配置;
if (isOverwrite || !hasDataSourceConfiguration()) {
regCenter.persist(configNode.getFullPath(ConfigurationNode.DATA_SOURCE_NODE_PATH), DataSourceJsonConverter.toJson(dataSourceMap));
}
}
根据上面的分析得出数据源配置路径为:/orchestration-yaml-test/demo_ds_ms/config/datasource
。即完整路径表达式为:/{orchestration.zookeeper.namespace}/{orchestration.name}/config/datasource
;其他几个配置信息持久化的源码分析类似;
2.2节点配置信息与源码对应关系
config
├──datasource persistDataSourceConfiguration()
├──sharding
├ ├──rule persistShardingRuleConfiguration()
├ ├──configmap persistShardingConfigMap()
├ ├──props persistShardingProperties()
├──masterslave
├ ├──rule
├ ├──configmap
state
├──instances persistShardingInstanceOnline()
├ ├──${instance1-ip}@${pid}@${uuid}
├ ├──${instance2-ip}@${pid}@${uuid}
├──datasources persistDataSourcesNode()
说明:节点信息省略了路径前缀
/{orchestration.zookeeper.namespace}/{orchestration.name}
;例如,某instance节点的完整路径::/{orchestration.zookeeper.namespace}/{orchestration.name}/state/instances/{ip}@{pid}@${uuid}
(/demo_ds_ms/state/instances/10.0.0.189@10072@6f8f1b1e-90a4-4edd-baf9-aeb906a664bd);
3.创建监听器
OrchestrationFacade.init()中调用persist***()方法持久化各配置信息到注册中心后,再调用listenerManager.initShardingListeners(shardingDataSource)创建监听器,核心源码如下:
public void initShardingListeners(final ShardingDataSource shardingDataSource) {
// 监听三个节点(/config/datasource, /config/sharding/rule, /config/sharding/props)
configurationListenerManager.start(shardingDataSource);
// 监听节点/state/instances/${instance-ip}@${pid}@${uuid},即监听表示当前实例的节点
instanceListenerManager.start(shardingDataSource);
// 监听节点/state/datasources
dataSourceListenerManager.start(shardingDataSource);
// 监听节点/config/sharding/cofigmap
configMapListenerManager.start(shardingDataSource);
}
3.1 rule节点监听分析
核心源码如下:
private void start(final String node, final ShardingDataSource shardingDataSource) {
// 得到监听的路径/config/sharding/rule
String cachePath = configNode.getFullPath(node);
// watch该注册中心中该路径
regCenter.watch(cachePath, new EventListener() {
@Override
public void onChange(final DataChangedEvent event) {
// 只处理UPDATED类型事件
if (DataChangedEvent.Type.UPDATED == event.getEventType()) {
try {
// 调用loadShardingProperties()从配置中心中拿出/config/datasource和/config/sharding/props两个路径的数据准备刷新sharding数据源
shardingDataSource.renew(dataSourceService.getAvailableShardingRuleConfiguration().build(dataSourceService.getAvailableDataSources()), configService.loadShardingProperties());
} catch (final SQLException ex) {
throw new ShardingJdbcException(ex);
}
}
}
});
}
public class ShardingDataSource extends AbstractDataSourceAdapter implements AutoCloseable {
... ...
// 刷新ShardingContext
public void renew(final ShardingRule newShardingRule, final Properties newProps) throws SQLException {
ShardingProperties newShardingProperties = new ShardingProperties(null == newProps ? new Properties() : newProps);
// 得到更新前的executor.size的值
int originalExecutorSize = shardingProperties.getValue(ShardingPropertiesConstant.EXECUTOR_SIZE);
// 得到更新后的executor.size的值
int newExecutorSize = newShardingProperties.getValue(ShardingPropertiesConstant.EXECUTOR_SIZE);
// 如果executor.size的值有变化则重新构造ExecutorEngine
if (originalExecutorSize != newExecutorSize) {
executorEngine.close();
executorEngine = new ExecutorEngine(newExecutorSize);
}
// 得到更新后的sql.show的值
boolean newShowSQL = newShardingProperties.getValue(ShardingPropertiesConstant.SQL_SHOW);
shardingProperties = newShardingProperties;
// 重新构造ShardingContext
shardingContext = new ShardingContext(newShardingRule, getDatabaseType(), executorEngine, newShowSQL);
}
... ...
}
ShardingContext 包含如下属性–rule节点有变更时,这些属性都会得到更新;
public final class ShardingContext {
private final ShardingRule shardingRule;
private final DatabaseType databaseType;
private final ExecutorEngine executorEngine;
private final boolean showSQL;
}
3.2 props节点监听分析
props节点监听源码如下:
private void start(final String node, final ShardingDataSource shardingDataSource) {
// 监听的路径,即/${orchestration.zookeeper.namespace}/${orchestration.name}/config/sharding/props
String cachePath = configNode.getFullPath(node);
// watch该路径
regCenter.watch(cachePath, new EventListener() {
@Override
public void onChange(final DataChangedEvent event) {
// 如果有UPDATED变更事件(只考虑UPDATED事件)
if (DataChangedEvent.Type.UPDATED == event.getEventType()) {
try {
// 这里的逻辑和rule节点类型,刷新ShardingContext
shardingDataSource.renew(
dataSourceService.getAvailableShardingRuleConfiguration().build(dataSourceService.getAvailableDataSources()),
configService.loadShardingProperties()
);
} catch (final SQLException ex) {
throw new ShardingJdbcException(ex);
}
}
}
});
}
3.3 instances节点监听分析
实际监听的是instances下代表某具体实例的节点,例如/orchestration-spring-namespace-test/shardingDataSource/state/instances/10.0.0.188@13272@42533e85-9bb1-4484-baa1-2a2f9b2480a6。核心源码如下:
@Override
public void start(final ShardingDataSource shardingDataSource) {
regCenter.watch(stateNode.getInstancesNodeFullPath(OrchestrationInstance.getInstance().getInstanceId()), new EventListener() {
@Override
public void onChange(final DataChangedEvent event) {
// 当收到UPDATED类型事件
if (DataChangedEvent.Type.UPDATED == event.getEventType()) {
// 首先拿到所有数据源
Map<String, DataSource> dataSourceMap = configService.loadDataSourceMap();
// 如果具体实例的节点的value被置为disabled(大小写不敏感),那么将该实例下所有数据源置为CircuitBreakerDataSource(这是sharding-jdbc自定义的一个特殊数据源,如果SQL路由到该数据源上,那么执行时不返回任何数据,也不实际执行该SQL,相当于一个mock的数据源)
if (StateNodeStatus.DISABLED.toString().equalsIgnoreCase(regCenter.get(event.getKey()))) {
for (String each : dataSourceMap.keySet()) {
dataSourceMap.put(each, new CircuitBreakerDataSource());
}
}
try {
shardingDataSource.renew(configService.loadShardingRuleConfiguration().build(dataSourceMap), configService.loadShardingProperties());
} catch (final SQLException ex) {
throw new ShardingJdbcException(ex);
}
}
}
});
}
说明:将某个具体实例的节点的value置为disabled的命令(基于zookeeper): set /orchestration-spring-namespace-test/shardingDataSource/state/instances/10.52.16.134@13272@42533e85-9bb1-4484-baa1-2a2f9b2480a6 disabled,instances后面的10.52.16.134@13272@42533e85-9bb1-4484-baa1-2a2f9b2480a6视具体情况而定。
3.4 其他节点监听分析
其他节点监听处理和上面两个的处理逻辑几乎大同小异,监听UPDATED事件,然后从注册中心加载最新的配置后刷新数据;
作者:阿飞的博客
来源:https://www.jianshu.com/p/60440c317d95
看完两件小事
如果你觉得这篇文章对你挺有启发,我想请你帮我两个小忙:
- 把这篇文章分享给你的朋友 / 交流群,让更多的人看到,一起进步,一起成长!
- 关注公众号 「方志朋」,公众号后台回复「666」 免费领取我精心整理的进阶资源教程
![JS中文网,Javascriptc中文网是中国领先的新一代开发者社区和专业的技术媒体,一个帮助开发者成长的社区,是给开发者用的 Hacker News,技术文章由为你筛选出最优质的干货,其中包括:Android、iOS、前端、后端等方面的内容。目前已经覆盖和服务了超过 300 万开发者,你每天都可以在这里找到技术世界的头条内容。](https://static.javajike.com/img/common/wx-fzp.png)
本文著作权归作者所有,如若转载,请注明出处
转载请注明:文章转载自「 Java极客技术学习 」https://www.javajike.com