Java tutorial
/* * Copyright 2016 LINE Corporation * * LINE Corporation licenses this file to you 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 com.linecorp.armeria.client.endpoint.healthcheck; import static com.google.common.collect.ImmutableSet.toImmutableSet; import static java.util.Objects.requireNonNull; import java.util.Map; import java.util.Set; import com.codahale.metrics.Gauge; import com.codahale.metrics.Metric; import com.codahale.metrics.MetricSet; import com.google.common.collect.ImmutableMap; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Sets; import com.linecorp.armeria.client.Endpoint; import com.linecorp.armeria.client.endpoint.healthcheck.HealthCheckedEndpointGroup.ServerConnection; /** * {@link Metric}s for a {@link HealthCheckedEndpointGroup}. */ class EndpointHealthStateGaugeSet implements MetricSet { private static final String METRIC_NAME_PREFIX = "endpointHealth."; private final HealthCheckedEndpointGroup endpointGroup; private final String metricName; EndpointHealthStateGaugeSet(HealthCheckedEndpointGroup endpointGroup, String metricName) { this.endpointGroup = requireNonNull(endpointGroup, "endpointGroup"); this.metricName = requireNonNull(metricName, "metricName"); } @Override public Map<String, Metric> getMetrics() { return ImmutableMap.of(METRIC_NAME_PREFIX + metricName + ".all.count", (Gauge<Integer>) endpointGroup.allServers::size, METRIC_NAME_PREFIX + metricName + ".healthy.count", (Gauge<Integer>) endpointGroup.healthyEndpoints::size, METRIC_NAME_PREFIX + metricName + ".healthy.endpoints", (Gauge<Set<String>>) () -> ImmutableSet.copyOf(endpointGroup.healthyEndpoints).stream() .map(Endpoint::authority).collect(toImmutableSet()), METRIC_NAME_PREFIX + metricName + ".unhealthy.endpoints", (Gauge<Set<String>>) () -> { Set<String> all = ImmutableSet.copyOf(endpointGroup.allServers).stream() .map(ServerConnection::endpoint).map(Endpoint::authority).collect(toImmutableSet()); Set<String> healthy = ImmutableSet.copyOf(endpointGroup.healthyEndpoints).stream() .map(Endpoint::authority).collect(toImmutableSet()); return Sets.difference(all, healthy); }); } }