Java tutorial
/* * Copyright 2013-2015 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.springframework.cloud.consul.discovery; import javax.annotation.PostConstruct; import javax.validation.constraints.DecimalMax; import javax.validation.constraints.DecimalMin; import javax.validation.constraints.Min; import javax.validation.constraints.NotNull; import lombok.Data; import lombok.extern.apachecommons.CommonsLog; import org.joda.time.Period; import org.springframework.boot.context.properties.ConfigurationProperties; @ConfigurationProperties(prefix = "spring.cloud.consul.discovery.heartbeat") @Data @CommonsLog public class HeartbeatProperties { // 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; private Period heartbeatInterval; @PostConstruct public void init() { this.heartbeatInterval = computeHearbeatInterval(); log.debug("Computed heartbeatInterval: " + heartbeatInterval); } 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 = ttlValue * intervalRatio; double max = Math.max(interval, 1); int ttlMinus1 = ttlValue - 1; double min = Math.min(ttlMinus1, max); return new Period(Math.round(1000 * min)); } public String getTtl() { return ttlValue + ttlUnit; } }