1 files changed, 244 insertions, 0 deletions
diff --git a/rulemgt/src/main/java/org/onap/holmes/rulemgt/RuleAllocator.java b/rulemgt/src/main/java/org/onap/holmes/rulemgt/RuleAllocator.java
new file mode 100644
index 0000000..2dc05ee
--- /dev/null
+++ b/rulemgt/src/main/java/org/onap/holmes/rulemgt/RuleAllocator.java
@@ -0,0 +1,244 @@
+/**
+ * Copyright 2017-2020 ZTE Corporation.
+ * <p>
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.onap.holmes.rulemgt;
+
+import lombok.extern.slf4j.Slf4j;
+import org.jvnet.hk2.annotations.Service;
+import org.onap.holmes.common.api.entity.CorrelationRule;
+import org.onap.holmes.common.exception.CorrelationException;
+import org.onap.holmes.common.utils.DbDaoUtil;
+import org.onap.holmes.rulemgt.bolt.enginebolt.EngineWrapper;
+import org.onap.holmes.rulemgt.db.CorrelationRuleDao;
+import org.onap.holmes.rulemgt.tools.EngineTools;
+import org.onap.holmes.rulemgt.wrapper.RuleMgtWrapper;
+import org.onap.holmes.rulemgt.wrapper.RuleQueryWrapper;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.annotation.PostConstruct;
+import javax.inject.Inject;
+import java.util.*;
+
+import static java.util.concurrent.TimeUnit.SECONDS;
+
+@Slf4j
+@Service
+public class RuleAllocator {
+    private static final Logger LOGGER = LoggerFactory.getLogger(RuleAllocator.class);
+
+    public final static int ENABLE = 1;
+    private RuleMgtWrapper ruleMgtWrapper;
+    private RuleQueryWrapper ruleQueryWrapper;
+    private EngineWrapper engineWrapper;
+    private EngineTools engineTools;
+    private CorrelationRuleDao correlationRuleDao;
+
+    @Inject
+    public RuleAllocator(RuleMgtWrapper ruleMgtWrapper, RuleQueryWrapper ruleQueryWrapper,
+                         EngineWrapper engineWrapper, EngineTools engineTools, DbDaoUtil daoUtil) {
+        this.ruleMgtWrapper = ruleMgtWrapper;
+        this.ruleQueryWrapper = ruleQueryWrapper;
+        this.engineWrapper = engineWrapper;
+        this.engineTools = engineTools;
+        correlationRuleDao = daoUtil.getJdbiDaoByOnDemand(CorrelationRuleDao.class);
+    }
+
+    @PostConstruct
+    private void initialize() {
+        new Timer("RuleAllocatorTimer").schedule(new TimerTask() {
+
+            public void run() {
+                try {
+                    allocateRules();
+                } catch (Exception e) {
+                    LOGGER.error("Failed to reallocate rules.", e);
+                }
+            }
+
+        }, SECONDS.toMillis(10), SECONDS.toMillis(30));
+    }
+
+    public synchronized void allocateRules() throws Exception {
+        List<String> engines = engineTools.getInstanceList();
+
+        if (engines == null) {
+            return;
+        }
+
+        int numOfEngines = engines.size();
+        LOGGER.info(String.format("There are %d engine instance(s) running currently.", numOfEngines));
+
+        List<String> legacyEngineInstances = engineTools.getLegacyEngineInstances();
+        if (legacyEngineInstances == null) {
+            return;
+        }
+
+        if (legacyEngineInstances.size() < numOfEngines) {
+            //extend
+            List<CorrelationRule> rules2Allocate = calculateRule(legacyEngineInstances, numOfEngines);
+            List<CorrelationRule> rules2Delete = copyList(rules2Allocate);
+            List<String> newInstanceIds = sortOutNewEngineInstances(engines, legacyEngineInstances);
+            distributeRules(newInstanceIds, rules2Allocate);
+            cleanUpRulesFromEngines(rules2Delete, legacyEngineInstances);
+        } else {
+            //destroy
+            List<String> destroyed = getDestroyedEngines(engines, legacyEngineInstances);
+            distributeRules(getRemainingEngines(engines, destroyed), getRules(destroyed));
+        }
+    }
+
+    private List<CorrelationRule> copyList(List<CorrelationRule> rules) {
+        List<CorrelationRule> ret = new ArrayList<>(rules.size());
+        for (CorrelationRule r : rules) {
+            ret.add((CorrelationRule) r.clone());
+        }
+        return ret;
+    }
+
+    // When the engine is expanding, the rules that need to be allocated are calculated.
+    private List<CorrelationRule> calculateRule(List<String> existingEngineIps,
+                                                int latestEngineInsNum) throws CorrelationException {
+        List<CorrelationRule> enabledRules = ruleQueryWrapper.queryRuleByEnable(ENABLE);
+        int ruleCount = 0;
+        if (enabledRules != null) {
+            ruleCount = enabledRules.size();
+        }
+        // Average number of rule that's to be allocate into each instance
+        int count = ruleCount / latestEngineInsNum;
+        // The number of remaining rules (to be allocated) after each instance has been allocated with the average number of rules.
+        int remainder = ruleCount % latestEngineInsNum;
+
+        List<CorrelationRule> ret = new ArrayList<>();
+        for (String ip : existingEngineIps) {
+            List<CorrelationRule> rules = ruleQueryWrapper.queryRuleByEngineInstance(ip);
+            List<CorrelationRule> tmp = rules.subList(count + (remainder-- / existingEngineIps.size()), rules.size());
+            ret.addAll(tmp);
+        }
+        return ret;
+    }
+
+    // Rules that need to be allocated after the engine is destroyed
+    private List<CorrelationRule> getRules(List<String> destroyIpList) throws CorrelationException {
+        List<CorrelationRule> rules = new ArrayList<>();
+        try {
+            if (destroyIpList != null) {
+                for (String ip : destroyIpList) {
+                    rules.addAll(ruleQueryWrapper.queryRuleByEngineInstance(ip));
+                }
+            }
+        } catch (CorrelationException e) {
+            LOGGER.error("method getRules get data from DB failed !", e);
+        }
+        return rules;
+    }
+
+    // Extended IP
+    private List<String> sortOutNewEngineInstances(List<String> newIps, List<String> oldIps) {
+        List<String> ret = new ArrayList<>();
+
+        for (String ip : newIps) {
+            if (!oldIps.contains(ip)) {
+                ret.add(ip);
+            }
+        }
+        return ret;
+    }
+
+    // Destroyed IP
+    private List<String> getDestroyedEngines(List<String> latest, List<String> existing) {
+        List<String> ret = new ArrayList<>();
+        for (String ip : existing) {
+            if (!latest.contains(ip)) {
+                ret.add(ip);
+            }
+        }
+        return ret;
+    }
+
+    // Residual IP after destruction
+    private List<String> getRemainingEngines(List<String> all, List<String> destroyed) {
+        List<String> ret = new ArrayList<>();
+        for (String ip : all) {
+            if (!destroyed.contains(ip)) {
+                ret.add(ip);
+            }
+        }
+        return ret;
+    }
+
+    private void distributeRules(List<String> instanceIps, List<CorrelationRule> rules) throws CorrelationException {
+        List<String> sortedIps = sortIpByRuleNumDesc(instanceIps);
+
+        for (int i = 0, j = 0; j < rules.size(); i++, j++) {
+            int index = i % sortedIps.size();
+            String ip = sortedIps.get(index);
+            CorrelationRule rule = rules.get(j);
+            rule.setEngineInstance(ip);
+            allocateRule(rule, ip);
+        }
+    }
+
+    // Sorted by the number of rules each engine contains, in a descending order.
+    private List<String> sortIpByRuleNumDesc(List<String> ips) {
+        List<CorrelationRule> rules = null;
+        Map<String, Integer> ruleNumOfEngines = new HashMap();
+
+        try {
+            for (String ip : ips) {
+                rules = ruleQueryWrapper.queryRuleByEngineInstance(ip);
+                if (rules != null) {
+                    ruleNumOfEngines.put(ip, rules.size());
+                }
+            }
+        } catch (Exception e) {
+            LOGGER.error("getEngineWithLeastRules failed !", e);
+        }
+
+        List<Map.Entry<String, Integer>> sortedEntries = new ArrayList<>(ruleNumOfEngines.entrySet());
+        Collections.sort(sortedEntries, (o1, o2) -> o2.getValue() - o1.getValue());
+
+        List<String> ret = new ArrayList<>();
+        for (Map.Entry<String, Integer> entry : sortedEntries) {
+            ret.add(entry.getKey());
+        }
+        return ret;
+    }
+
+    private void allocateRule(CorrelationRule rule, String ip) throws CorrelationException {
+        try {
+            ruleMgtWrapper.deployRule2Engine(rule, ip);
+            correlationRuleDao.updateRule(rule);
+        } catch (CorrelationException e) {
+            throw new CorrelationException(String.format("Failed to allocate rule <%s> to <%s>",
+                    rule.getName(), ip), e);
+        }
+    }
+
+    private void cleanUpRulesFromEngines(List<CorrelationRule> rules, List<String> ipList) {
+        try {
+            for (String ip : ipList) {
+                for (CorrelationRule rule : rules) {
+                    if (ip.equals(rule.getEngineInstance())) {
+                        engineWrapper.deleteRuleFromEngine(rule.getPackageName(), ip);
+                    }
+                }
+            }
+        } catch (CorrelationException e) {
+            LOGGER.error("When the engine is extended, deleting rule failed", e);
+        }
+    }
+}