Java tutorial
/* * Copyright 2013 Jive Software, Inc * * 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 com.jivesoftware.os.amza.service; import com.google.common.base.Preconditions; import com.google.common.collect.HashMultimap; import com.google.common.collect.Iterables; import com.google.common.collect.SetMultimap; import com.jivesoftware.os.amza.api.TimestampedValue; import com.jivesoftware.os.amza.api.ring.RingHost; import com.jivesoftware.os.amza.api.ring.RingMember; import com.jivesoftware.os.amza.api.ring.RingMemberAndHost; import com.jivesoftware.os.amza.api.scan.RowChanges; import com.jivesoftware.os.amza.api.scan.RowsChanged; import com.jivesoftware.os.amza.api.wal.WALKey; import com.jivesoftware.os.amza.api.wal.WALUpdated; import com.jivesoftware.os.amza.service.ring.AmzaRingReader; import com.jivesoftware.os.amza.service.ring.AmzaRingWriter; import com.jivesoftware.os.amza.service.ring.CacheId; import com.jivesoftware.os.amza.service.ring.RingSet; import com.jivesoftware.os.amza.service.ring.RingTopology; import com.jivesoftware.os.amza.service.storage.PartitionCreator; import com.jivesoftware.os.amza.service.storage.SystemWALStorage; import com.jivesoftware.os.jive.utils.collections.bah.ConcurrentBAHash; import com.jivesoftware.os.jive.utils.ordered.id.TimestampedOrderIdProvider; import com.jivesoftware.os.mlogger.core.MetricLogger; import com.jivesoftware.os.mlogger.core.MetricLoggerFactory; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Random; import java.util.concurrent.atomic.AtomicLong; public class AmzaRingStoreWriter implements AmzaRingWriter, RowChanges { private static final MetricLogger LOG = MetricLoggerFactory.getLogger(); private final AmzaRingStoreReader ringStoreReader; private final SystemWALStorage systemWALStorage; private final TimestampedOrderIdProvider orderIdProvider; private final WALUpdated walUpdated; private final ConcurrentBAHash<CacheId<RingTopology>> ringsCache; private final ConcurrentBAHash<CacheId<RingSet>> ringMemberRingNamesCache; private final AtomicLong nodeCacheId; private final boolean rackDistributionEnabled; public AmzaRingStoreWriter(AmzaRingStoreReader ringStoreReader, SystemWALStorage systemWALStorage, TimestampedOrderIdProvider orderIdProvider, WALUpdated walUpdated, ConcurrentBAHash<CacheId<RingTopology>> ringsCache, ConcurrentBAHash<CacheId<RingSet>> ringMemberRingNamesCache, AtomicLong nodeCacheId, boolean rackDistributionEnabled) { this.ringStoreReader = ringStoreReader; this.systemWALStorage = systemWALStorage; this.orderIdProvider = orderIdProvider; this.walUpdated = walUpdated; this.ringsCache = ringsCache; this.ringMemberRingNamesCache = ringMemberRingNamesCache; this.nodeCacheId = nodeCacheId; this.rackDistributionEnabled = rackDistributionEnabled; } @Override public void changes(RowsChanged changes) throws Exception { if (PartitionCreator.RING_INDEX.equals(changes.getVersionedPartitionName())) { for (WALKey walKey : changes.getApply().keySet()) { byte[] ringBytes = ringStoreReader.keyToRingName(walKey); ringsCache.compute(ringBytes, (key, cacheIdRingTopology) -> { if (cacheIdRingTopology == null) { cacheIdRingTopology = new CacheId<>(null); } cacheIdRingTopology.currentCacheId++; /*LOG.info("Rings advanced {} to {}", Arrays.toString(ringBytes), cacheIdRingTopology.currentCacheId);*/ return cacheIdRingTopology; }); RingMember ringMember = ringStoreReader.keyToRingMember(walKey.key); ringMemberRingNamesCache.compute(ringMember.leakBytes(), (ringMember1, cacheIdRingSet) -> { if (cacheIdRingSet == null) { cacheIdRingSet = new CacheId<>(null); } cacheIdRingSet.currentCacheId++; return cacheIdRingSet; }); } } else if (PartitionCreator.NODE_INDEX.equals(changes.getVersionedPartitionName())) { if (!changes.getApply().isEmpty()) { nodeCacheId.incrementAndGet(); /*LOG.info("Node advanced to {}", nodeCacheId.get());*/ } } } @Override public void register(RingMember ringMember, RingHost ringHost, long timestampId, boolean force) throws Exception { TimestampedValue registeredHost = force ? null : systemWALStorage.getTimestampedValue(PartitionCreator.NODE_INDEX, null, ringMember.toBytes()); if (registeredHost == null || !ringHost.equals(RingHost.fromBytes(registeredHost.getValue()))) { long version = orderIdProvider.nextId(); long timestamp = (timestampId == -1) ? version : timestampId; systemWALStorage.update(PartitionCreator.NODE_INDEX, null, (highwater, scan) -> scan.row(-1, ringMember.toBytes(), ringHost.toBytes(), timestamp, false, version), walUpdated); LOG.info("register ringMember:{} as ringHost:{}", ringMember, ringHost); } addRingMember(AmzaRingReader.SYSTEM_RING, ringMember); } @Override public void deregister(RingMember ringMember) throws Exception { removeRingMember(AmzaRingReader.SYSTEM_RING, ringMember); long timestampAndVersion = orderIdProvider.nextId(); systemWALStorage.update(PartitionCreator.NODE_INDEX, null, (highwater, scan) -> scan.row(-1, ringMember.toBytes(), null, timestampAndVersion, true, timestampAndVersion), walUpdated); LOG.info("deregister ringMember:{}"); } public boolean isMemberOfRing(byte[] ringName, long timeoutInMillis) throws Exception { return ringStoreReader.isMemberOfRing(ringName, timeoutInMillis); } @Override public void ensureMaximalRing(byte[] ringName, long timeoutInMillis) throws Exception { ensureSubRing(ringName, ringStoreReader.getRingSize(AmzaRingReader.SYSTEM_RING, timeoutInMillis), timeoutInMillis); } @Override public void ensureSubRing(byte[] ringName, int desiredRingSize, long timeoutInMillis) throws Exception { if (ringName == null) { throw new IllegalArgumentException("ringName cannot be null."); } int ringSize = ringStoreReader.getRingSize(ringName, timeoutInMillis); if (ringSize < desiredRingSize) { LOG.info("Ring {} will grow, has {} desires {}", ringName, ringSize, desiredRingSize); buildRandomSubRing(ringName, desiredRingSize); } } private void buildRandomSubRing(byte[] ringName, int desiredRingSize) throws Exception { if (ringName == null) { throw new IllegalArgumentException("ringName cannot be null."); } RingTopology systemRing = ringStoreReader.getRing(AmzaRingReader.SYSTEM_RING, 0); if (systemRing.entries.size() < desiredRingSize) { throw new IllegalStateException( "Current 'system' ring is not large enough to support a ring of size:" + desiredRingSize); } SetMultimap<String, RingMemberAndHost> subRackMembers = HashMultimap.create(); RingTopology subRing = ringStoreReader.getRing(ringName, 0); for (RingMemberAndHost entry : subRing.entries) { String rack = rackDistributionEnabled ? entry.ringHost.getRack() : ""; subRackMembers.put(rack, entry); } Map<String, List<RingMemberAndHost>> systemRackMembers = new HashMap<>(); for (RingMemberAndHost entry : systemRing.entries) { String rack = rackDistributionEnabled ? entry.ringHost.getRack() : ""; systemRackMembers.computeIfAbsent(rack, (key) -> new ArrayList<>()).add(entry); } Random random = new Random(new Random(Arrays.hashCode(ringName)).nextLong()); for (List<RingMemberAndHost> rackMembers : systemRackMembers.values()) { Collections.shuffle(rackMembers, random); } List<String> racks = new ArrayList<>(systemRackMembers.keySet()); while (subRackMembers.size() < desiredRingSize) { Collections.sort(racks, (o1, o2) -> Integer.compare(subRackMembers.get(o1).size(), subRackMembers.get(o2).size())); boolean advanced = false; for (String cycleRack : racks) { List<RingMemberAndHost> rackMembers = systemRackMembers.get(cycleRack); if (!rackMembers.isEmpty()) { subRackMembers.put(cycleRack, rackMembers.remove(rackMembers.size() - 1)); advanced = true; break; } } if (!advanced) { break; } } setInternal(ringName, Iterables.transform(subRackMembers.values(), input -> input.ringMember)); } @Override public void addRingMember(byte[] ringName, RingMember ringMember) throws Exception { Preconditions.checkNotNull(ringName, "ringName cannot be null."); Preconditions.checkNotNull(ringMember, "ringMember cannot be null."); byte[] key = ringStoreReader.key(ringName, ringMember); TimestampedValue had = systemWALStorage.getTimestampedValue(PartitionCreator.RING_INDEX, null, key); if (had == null) { RingTopology ring = ringStoreReader.getRing(ringName, -1); setInternal(ringName, Iterables.concat(Iterables.transform(ring.entries, input -> input.ringMember), Collections.singleton(ringMember))); } } private void setInternal(byte[] ringName, Iterable<RingMember> members) throws Exception { /* We deliberately do a slab update of rings to ensure "all at once" ring visibility. */ systemWALStorage.update(PartitionCreator.RING_INDEX, null, (highwater, scan) -> { long timestampAndVersion = orderIdProvider.nextId(); for (RingMember member : members) { if (!scan.row(-1, ringStoreReader.key(ringName, member), new byte[0], timestampAndVersion, false, timestampAndVersion)) { return false; } } return true; }, walUpdated); ringsCache.remove(ringName); //ringsCache.remove(new IBA(ringName)); LOG.info("Ring update:{} -> {}", new String(ringName), members); } @Override public void removeRingMember(byte[] ringName, RingMember ringMember) throws Exception { Preconditions.checkNotNull(ringName, "ringName cannot be null."); Preconditions.checkNotNull(ringMember, "ringMember cannot be null."); byte[] key = ringStoreReader.key(ringName, ringMember); TimestampedValue had = systemWALStorage.getTimestampedValue(PartitionCreator.RING_INDEX, null, key); if (had != null) { long timestampAndVersion = orderIdProvider.nextId(); systemWALStorage.update(PartitionCreator.RING_INDEX, null, (highwater, scan) -> scan.row(-1, key, null, timestampAndVersion, true, timestampAndVersion), walUpdated); } } }