Java tutorial
/* * Copyright 2015-2017 Red Hat, Inc. and/or its affiliates * and other contributors as indicated by the @author tags. * * 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.hawkular.alerter.elasticsearch; import static org.hawkular.alerts.api.util.Util.isEmpty; import java.util.Collection; import java.util.HashMap; import java.util.HashSet; import java.util.Map; import java.util.Set; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ExecutorService; import java.util.concurrent.ScheduledFuture; import java.util.concurrent.ScheduledThreadPoolExecutor; import java.util.concurrent.TimeUnit; import org.hawkular.alerts.alerters.api.Alerter; import org.hawkular.alerts.alerters.api.AlerterPlugin; import org.hawkular.alerts.api.model.trigger.Trigger; import org.hawkular.alerts.api.model.trigger.TriggerKey; import org.hawkular.alerts.api.services.AlertsService; import org.hawkular.alerts.api.services.DefinitionsService; import org.hawkular.alerts.api.services.DistributedEvent; import org.hawkular.commons.log.MsgLogger; import org.hawkular.commons.log.MsgLogging; import org.hawkular.commons.properties.HawkularProperties; /** * This is the main class of the Elasticsearch Alerter. * * The Elasticsearch Alerter will listen for triggers tagged with "Elasticsearch" tag. The Alerter will schedule a * periodic query to an Elasticsearch system with the info provided from the tagged trigger context. The Alerter * will convert Elasticsearch documents into Hawkular Alerting Events and send them into the Alerting engine. * * The Elasticsearch Alerter uses the following conventions for trigger tags and context: * * <pre> * * - [Required] trigger.tags["Elasticsearch"] = "<value reserved for future uses>" * * An "Elasticsearch" tag is required for the alerter to detect this trigger will query to an Elasticsearch system. * Value is not necessary, it can be used as a description, it is reserved for future uses. * * i.e. trigger.tags["Elasticsearch"] = "" // Empty value is valid * trigger.tags["Elasticsearch"] = "OpenShift Logging System" // It can be used as description * * - [Required] trigger.context["timestamp"] = "<timestamp field>" * * Documents fetched from Elasticsearch need a date field to indicate the timestamp. * This timestamp will be used in the queries to fetch documents in interval basis. * * If there is not defined a specific pattern under the trigger.context["timestamp_pattern"] it will follow the * default patterns: * * "yyyy-MM-dd'T'HH:mm:ss.SSSSSSZ" * "yyyy-MM-dd'T'HH:mm:ssZ" * * - [Required] trigger.context["mapping"] = "<mapping_expression>" * * A mapping expressions defines how to convert an Elasticsearch document into a Hawkular Event: * * <mapping_expression> ::= <mapping> | <mapping> "," <mapping_expression> * <mapping> ::= <elasticsearch_field> [ "|" "'" <DEFAULT_VALUE> "'" ] ":" <hawkular_event_field> * <elasticsearch_field> ::= "index" | "id" | <SOURCE_FIELD> * <hawkular_event_field> ::= "id" | "ctime" | "dataSource" | "dataId" | "category" | "text" | "context" | "tags" * * A minimum mapping for the "dataId" is required. * If a mapping is not present in an Elasticsearch document it will return an empty value. * It is possible to define a default value for cases when the Elasticsearch field is not present. * Special Elasticsearch metafields "_index" and "_id" are supported under "index" and "id" labels. * * i.e. trigger.context["mapping"] = "level|'INFO':category,@timestamp:ctime,message:text,hostname:dataId,index:tags" * * - [Optional] trigger.context["interval"] = "[0-9]+[smh]" (i.e. 30s, 2h, 10m) * * Defines the periodic interval when a query will be performed against an Elasticsearch system. * If not value provided, default one is "2m" (two minutes). * * i.e. trigger.context["interval"] = "30s" will perform queries each 30 seconds fetching new documents generated * on the last 30 seconds, using the timestamp field provided in the Alerter tag. * * - [Optional] trigger.context["timestamp_pattern"] = "<date and time pattern>" * * Defines a new time pattern for the trigger.context["timestamp"]. It must follow supported formats of * {@link java.time.format.DateTimeFormatter}. If it is not present, it will expect default patterns: * * "yyyy-MM-dd'T'HH:mm:ss.SSSSSSZ" * "yyyy-MM-dd'T'HH:mm:ssZ" * * - [Optional] trigger.context["index"] = "<elastic_search_index>" * * Defines the index where the documents will be queried. If not index defined, query will search under all indexes * defined. * * - [Optional] trigger.context["filter"] = "<elastic_search_query_filter>" * * By default the Elasticsearch Alerter performs a range query over the timestamp field provided in the alerter tag. * This query accepts additional filter in Elasticsearch format. The final query should be built from: * * { * "query":{ * "constant_score":{ * "filter":{ * "bool":{ * "must": [<range_query_on_timestamp>, <elastic_search_query_filter>] * } * } * } * } * } * * - [Optional] trigger.context["url"] * * Elasticsearch url can be defined in several ways in the alerter. * If can be defined globally as system properties: * * hawkular-alerts.elasticsearch-url * * It can be defined globally from system env variables: * * ELASTICSEARCH_URL * * Or it can be overwritten per trigger using * * trigger.context["url"] * * Url can be a list of valid {@link org.apache.http.HttpHost} urls. By default it will point to * * trigger.context["url"] = "http://localhost:9200" * * i.e. * * trigger.context["url"] = "http://host1:9200,http://host2:9200,http://host3:9200" * * </pre> * * @author Jay Shaughnessy * @author Lucas Ponce */ @Alerter(name = "elasticsearch") public class ElasticsearchAlerter implements AlerterPlugin { private static final MsgLogger log = MsgLogging.getMsgLogger(ElasticsearchAlerter.class); private static final String ELASTICSEARCH_ALERTER = "hawkular-alerts.elasticsearch-alerter"; private static final String ELASTICSEARCH_ALERTER_ENV = "ELASTICSEARCH_ALERTER"; private static final String ELASTICSEARCH_ALERTER_DEFAULT = "true"; private boolean elasticSearchAlerter; private static final String ELASTICSEARCH_URL = "hawkular-alerts.elasticsearch-url"; private static final String ELASTICSEARCH_URL_ENV = "ELASTICSEARCH_URL"; private static final String ELASTICSEARCH_URL_DEFAULT = "http://localhost:9200"; private static final String ELASTICSEARCH_FORWARDED_FOR = "hawkular-alerts.elasticsearch-forwarded-for"; private static final String ELASTICSEARCH_FORWARDED_FOR_ENV = "ELASTICSEARCH_FORWARDED_FOR"; private static final String ELASTICSEARCH_FORWARDED_FOR_DEFAULT = ""; private static final String ELASTICSEARCH_TOKEN = "hawkular-alerts.elasticsearch-token"; private static final String ELASTICSEARCH_TOKEN_ENV = "ELASTICSEARCH_TOKEN"; private static final String ELASTICSEARCH_TOKEN_DEFAULT = ""; private static final String ELASTICSEARCH_PROXY_REMOTE_USER = "hawkular-alerts.elasticsearch-proxy-remote-user"; private static final String ELASTICSEARCH_PROXY_REMOTE_USER_ENV = "ELASTICSEARCH_PROXY_REMOTE_USER"; private static final String ELASTICSEARCH_PROXY_REMOTE_USER_DEFAULT = ""; private static final String ALERTER_NAME = "Elasticsearch"; private Map<TriggerKey, Trigger> activeTriggers = new ConcurrentHashMap<>(); private static final Integer THREAD_POOL_SIZE = 20; private static final String INTERVAL = "interval"; private static final String INTERVAL_DEFAULT = "2m"; private static final String URL = "url"; private static final String FORWARDED_FOR = "forwarded-for"; private static final String PROXY_REMOTE_USER = "proxy-remote-user"; private static final String TOKEN = "token"; private ScheduledThreadPoolExecutor scheduledExecutor; private Map<TriggerKey, ScheduledFuture<?>> queryFutures = new HashMap<>(); private Map<String, String> defaultProperties; private DefinitionsService definitions; private AlertsService alerts; private ExecutorService executor; public void init(DefinitionsService definitions, AlertsService alerts, ExecutorService executor) { if (definitions == null || alerts == null || executor == null) { throw new IllegalStateException("Elasticsearch Alerter cannot connect with Hawkular Alerting"); } this.definitions = definitions; this.alerts = alerts; this.executor = executor; elasticSearchAlerter = Boolean.parseBoolean(HawkularProperties.getProperty(ELASTICSEARCH_ALERTER, ELASTICSEARCH_ALERTER_ENV, ELASTICSEARCH_ALERTER_DEFAULT)); defaultProperties = new HashMap(); defaultProperties.put(URL, HawkularProperties.getProperty(ELASTICSEARCH_URL, ELASTICSEARCH_URL_ENV, ELASTICSEARCH_URL_DEFAULT)); defaultProperties.put(TOKEN, HawkularProperties.getProperty(ELASTICSEARCH_TOKEN, ELASTICSEARCH_TOKEN_ENV, ELASTICSEARCH_TOKEN_DEFAULT)); defaultProperties.put(FORWARDED_FOR, HawkularProperties.getProperty(ELASTICSEARCH_FORWARDED_FOR, ELASTICSEARCH_FORWARDED_FOR_ENV, ELASTICSEARCH_FORWARDED_FOR_DEFAULT)); defaultProperties.put(PROXY_REMOTE_USER, HawkularProperties.getProperty(ELASTICSEARCH_PROXY_REMOTE_USER, ELASTICSEARCH_PROXY_REMOTE_USER_ENV, ELASTICSEARCH_PROXY_REMOTE_USER_DEFAULT)); if (elasticSearchAlerter) { this.definitions.registerDistributedListener(events -> refresh(events)); initialRefresh(); } } public void stop() { if (scheduledExecutor != null) { scheduledExecutor.shutdown(); scheduledExecutor = null; } } private void refresh(Set<DistributedEvent> distEvents) { log.debugf("Events received %s", distEvents); executor.submit(() -> { try { for (DistributedEvent distEvent : distEvents) { TriggerKey triggerKey = new TriggerKey(distEvent.getTenantId(), distEvent.getTriggerId()); switch (distEvent.getOperation()) { case REMOVE: activeTriggers.remove(triggerKey); break; case ADD: if (activeTriggers.containsKey(triggerKey)) { break; } case UPDATE: Trigger trigger = definitions.getTrigger(distEvent.getTenantId(), distEvent.getTriggerId()); if (trigger != null && trigger.getTags().containsKey(ALERTER_NAME)) { if (!trigger.isLoadable()) { activeTriggers.remove(triggerKey); break; } else { activeTriggers.put(triggerKey, trigger); } } } } } catch (Exception e) { log.error("Failed to fetch Triggers for external conditions.", e); } update(); }); } private void initialRefresh() { try { Collection<Trigger> triggers = definitions.getAllTriggersByTag(ALERTER_NAME, "*"); triggers.stream().forEach( trigger -> activeTriggers.put(new TriggerKey(trigger.getTenantId(), trigger.getId()), trigger)); update(); } catch (Exception e) { log.error("Failed to fetch Triggers for external conditions.", e); } } private synchronized void update() { final Set<TriggerKey> existingKeys = queryFutures.keySet(); final Set<TriggerKey> activeKeys = activeTriggers.keySet(); Set<TriggerKey> newKeys = new HashSet<>(); Set<TriggerKey> canceledKeys = new HashSet<>(); Set<TriggerKey> updatedKeys = new HashSet<>(activeKeys); updatedKeys.retainAll(activeKeys); activeKeys.stream().filter(key -> !existingKeys.contains(key)).forEach(key -> newKeys.add(key)); existingKeys.stream().filter(key -> !activeKeys.contains(key)).forEach(key -> canceledKeys.add(key)); log.debugf("newKeys %s", newKeys); log.debugf("updatedKeys %s", updatedKeys); log.debugf("canceledKeys %s", canceledKeys); canceledKeys.stream().forEach(key -> { ScheduledFuture canceled = queryFutures.remove(key); if (canceled != null) { canceled.cancel(false); } }); updatedKeys.stream().forEach(key -> { ScheduledFuture updated = queryFutures.remove(key); if (updated != null) { updated.cancel(false); } }); if (scheduledExecutor == null) { scheduledExecutor = new ScheduledThreadPoolExecutor(THREAD_POOL_SIZE); } newKeys.addAll(updatedKeys); for (TriggerKey key : newKeys) { Trigger t = activeTriggers.get(key); String interval = t.getContext().get(INTERVAL) == null ? INTERVAL_DEFAULT : t.getContext().get(INTERVAL); queryFutures.put(key, scheduledExecutor.scheduleAtFixedRate(new ElasticsearchQuery(t, defaultProperties, alerts), 0L, getIntervalValue(interval), getIntervalUnit(interval))); } } public static int getIntervalValue(String interval) { if (isEmpty(interval)) { interval = INTERVAL_DEFAULT; } try { return new Integer(interval.substring(0, interval.length() - 1)).intValue(); } catch (Exception e) { return new Integer(INTERVAL_DEFAULT.substring(0, interval.length() - 1)).intValue(); } } public static TimeUnit getIntervalUnit(String interval) { if (interval == null || interval.isEmpty()) { interval = INTERVAL_DEFAULT; } char unit = interval.charAt(interval.length() - 1); switch (unit) { case 'h': return TimeUnit.HOURS; case 's': return TimeUnit.SECONDS; case 'm': default: return TimeUnit.MINUTES; } } }