序
本文主要研究一下spring cloud consul的TtlScheduler
TtlScheduler
spring-cloud-consul-discovery-2.1.2.RELEASE-sources.jar!/org/springframework/cloud/consul/discovery/TtlScheduler.java
public class TtlScheduler {
private static final Log log = LogFactory.getLog(ConsulDiscoveryClient.class);
private final Map serviceHeartbeats = new ConcurrentHashMap<>();
private final TaskScheduler scheduler = new ConcurrentTaskScheduler(
Executors.newSingleThreadScheduledExecutor());
private HeartbeatProperties configuration;
private ConsulClient client;
public TtlScheduler(HeartbeatProperties configuration, ConsulClient client) {
this.configuration = configuration;
this.client = client;
}
@Deprecated
public void add(final NewService service) {
add(service.getId());
}
/**
* Add a service to the checks loop.
* @param instanceId instance id
*/
public void add(String instanceId) {
ScheduledFuture task = this.scheduler.scheduleAtFixedRate(
new ConsulHeartbeatTask(instanceId), this.configuration
.computeHearbeatInterval().toStandardDuration().getMillis());
ScheduledFuture previousTask = this.serviceHeartbeats.put(instanceId, task);
if (previousTask != null) {
previousTask.cancel(true);
}
}
public void remove(String instanceId) {
ScheduledFuture task = this.serviceHeartbeats.get(instanceId);
if (task != null) {
task.cancel(true);
}
this.serviceHeartbeats.remove(instanceId);
}
private class ConsulHeartbeatTask implements Runnable {
private String checkId;
ConsulHeartbeatTask(String serviceId) {
this.checkId = serviceId;
if (!this.checkId.startsWith("service:")) {
this.checkId = "service:" + this.checkId;
}
}
@Override
public void run() {
TtlScheduler.this.client.agentCheckPass(this.checkId);
if (log.isDebugEnabled()) {
log.debug("Sending consul heartbeat for: " + this.checkId);
}
}
}
}
- TtlScheduler的构造器接收HeartbeatProperties、ConsulClient；add方法会往scheduler注册一个定时执行的ConsulHeartbeatTask，执行间隔由HeartbeatProperties的ttlValue及intervalRatio计算而来，同时如果previousTask不为null则对其进行cancel；remove方法则cancel调用ScheduledFuture，然后将其从serviceHeartbeats中移除；ConsulHeartbeatTask的run方法则是执行client.agentCheckPass
HeartbeatProperties
spring-cloud-consul-discovery-2.1.2.RELEASE-sources.jar!/org/springframework/cloud/consul/discovery/HeartbeatProperties.java
@ConfigurationProperties(prefix = "spring.cloud.consul.discovery.heartbeat")
@Validated
public class HeartbeatProperties {
private static final Log log = org.apache.commons.logging.LogFactory
.getLog(HeartbeatProperties.class);
// TODO: change enabled to default to true when I stop seeing messages like
// [WARN] agent: Check 'service:testConsulApp:xtest:8080' missed TTL, is now critical
boolean enabled = false;
@Min(1)
private int ttlValue = 30;
@NotNull
private String ttlUnit = "s";
@DecimalMin("0.1")
@DecimalMax("0.9")
private double intervalRatio = 2.0 / 3.0;
// TODO: did heartbeatInterval need to be a field?
protected Period computeHearbeatInterval() {
// heartbeat rate at ratio * ttl, but no later than ttl -1s and, (under lesser
// priority), no sooner than 1s from now
double interval = this.ttlValue * this.intervalRatio;
double max = Math.max(interval, 1);
int ttlMinus1 = this.ttlValue - 1;
double min = Math.min(ttlMinus1, max);
Period heartbeatInterval = new Period(Math.round(1000 * min));
log.debug("Computed heartbeatInterval: " + heartbeatInterval);
return heartbeatInterval;
}
public String getTtl() {
return this.ttlValue + this.ttlUnit;
}
public boolean isEnabled() {
return this.enabled;
}
public void setEnabled(boolean enabled) {
this.enabled = enabled;
}
public @Min(1) int getTtlValue() {
return this.ttlValue;
}
public void setTtlValue(@Min(1) int ttlValue) {
this.ttlValue = ttlValue;
}
public @NotNull String getTtlUnit() {
return this.ttlUnit;
}
public void setTtlUnit(@NotNull String ttlUnit) {
this.ttlUnit = ttlUnit;
}
public @DecimalMin("0.1") @DecimalMax("0.9") double getIntervalRatio() {
return this.intervalRatio;
}
public void setIntervalRatio(
@DecimalMin("0.1") @DecimalMax("0.9") double intervalRatio) {
this.intervalRatio = intervalRatio;
}
@Override
public String toString() {
return new ToStringCreator(this).append("enabled", this.enabled)
.append("ttlValue", this.ttlValue).append("ttlUnit", this.ttlUnit)
.append("intervalRatio", this.intervalRatio).toString();
}
}
- HeartbeatProperties有ttlValue、intervalRatio等属性，其computeHearbeatInterval方法会取ttlMinus1及Math.max(interval, 1)的最小值作为heartbeatInterval
ConsulDiscoveryClientConfiguration
spring-cloud-consul-discovery-2.1.2.RELEASE-sources.jar!/org/springframework/cloud/consul/discovery/ConsulDiscoveryClientConfiguration.java
@Configuration
@ConditionalOnConsulEnabled
@ConditionalOnProperty(value = "spring.cloud.consul.discovery.enabled", matchIfMissing = true)
@ConditionalOnDiscoveryEnabled
@EnableConfigurationProperties
@AutoConfigureBefore({ SimpleDiscoveryClientAutoConfiguration.class,
CommonsClientAutoConfiguration.class })
public class ConsulDiscoveryClientConfiguration {
/**
* Name of the catalog watch task scheduler bean.
*/
public static final String CATALOG_WATCH_TASK_SCHEDULER_NAME = "catalogWatchTaskScheduler";
@Autowired
private ConsulClient consulClient;
@Bean
@ConditionalOnMissingBean
@ConditionalOnProperty("spring.cloud.consul.discovery.heartbeat.enabled")
// TODO: move to service-registry for Edgware
public TtlScheduler ttlScheduler(HeartbeatProperties heartbeatProperties) {
return new TtlScheduler(heartbeatProperties, this.consulClient);
}
@Bean
@ConditionalOnMissingBean
// TODO: move to service-registry for Edgware
public HeartbeatProperties heartbeatProperties() {
return new HeartbeatProperties();
}
@Bean
@ConditionalOnMissingBean
// TODO: Split appropriate values to service-registry for Edgware
public ConsulDiscoveryProperties consulDiscoveryProperties(InetUtils inetUtils) {
return new ConsulDiscoveryProperties(inetUtils);
}
@Bean
@ConditionalOnMissingBean
public ConsulDiscoveryClient consulDiscoveryClient(
ConsulDiscoveryProperties discoveryProperties) {
return new ConsulDiscoveryClient(this.consulClient, discoveryProperties);
}
@Bean
@ConditionalOnMissingBean
@ConditionalOnProperty(name = "spring.cloud.consul.discovery.catalog-services-watch.enabled", matchIfMissing = true)
public ConsulCatalogWatch consulCatalogWatch(
ConsulDiscoveryProperties discoveryProperties,
@Qualifier(CATALOG_WATCH_TASK_SCHEDULER_NAME) TaskScheduler taskScheduler) {
return new ConsulCatalogWatch(discoveryProperties, this.consulClient,
taskScheduler);
}
@Bean(name = CATALOG_WATCH_TASK_SCHEDULER_NAME)
@ConditionalOnProperty(name = "spring.cloud.consul.discovery.catalog-services-watch.enabled", matchIfMissing = true)
public TaskScheduler catalogWatchTaskScheduler() {
return new ThreadPoolTaskScheduler();
}
}
- ConsulDiscoveryClientConfiguration在@ConditionalOnMissingBean以及@ConditionalOnProperty("spring.cloud.consul.discovery.heartbeat.enabled")的条件下会自动注册ttlScheduler
小结
TtlScheduler的构造器接收HeartbeatProperties、ConsulClient；add方法会往scheduler注册一个定时执行的ConsulHeartbeatTask，执行间隔由HeartbeatProperties的ttlValue及intervalRatio计算而来，同时如果previousTask不为null则对其进行cancel；remove方法则cancel调用ScheduledFuture，然后将其从serviceHeartbeats中移除；ConsulHeartbeatTask的run方法则是执行client.agentCheckPass
doc
- TtlScheduler