forked from nathanmarz/storm-kestrel
-
Notifications
You must be signed in to change notification settings - Fork 0
/
KestrelThriftSpout.java
277 lines (228 loc) · 9.13 KB
/
KestrelThriftSpout.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
package backtype.storm.spout;
import backtype.storm.Config;
import backtype.storm.task.TopologyContext;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.topology.base.BaseRichSpout;
import java.util.HashSet;
import java.util.Map;
import java.util.List;
import java.util.Iterator;
import java.util.Queue;
import java.util.LinkedList;
import backtype.storm.tuple.Fields;
import backtype.storm.utils.Utils;
import java.util.ArrayList;
import java.util.Arrays;
import org.apache.log4j.Logger;
import net.lag.kestrel.thrift.Item;
import org.apache.thrift7.TException;
/**
* This spout can be used to consume messages in a reliable way from a cluster
* of Kestrel servers. It is recommended that you set the parallelism hint to a
* multiple of the number of Kestrel servers, otherwise the read load will be
* higher on some Kestrel servers than others.
*/
public class KestrelThriftSpout extends BaseRichSpout {
public static Logger LOG = Logger.getLogger(KestrelThriftSpout.class);
public static final long BLACKLIST_TIME_MS = 1000 * 60;
public static final int BATCH_SIZE = 4000;
private List<String> _hosts = null;
private int _port = -1;
private String _queueName = null;
private SpoutOutputCollector _collector;
private Scheme _scheme;
private List<KestrelClientInfo> _kestrels;
private int _emitIndex;
private Queue<EmitItem> _emitBuffer = new LinkedList<EmitItem>();
private class EmitItem {
public KestrelSourceId sourceId;
public List<Object> tuple;
public EmitItem(List<Object> tuple, KestrelSourceId sourceId) {
this.tuple = tuple;
this.sourceId = sourceId;
}
}
private static class KestrelSourceId {
public KestrelSourceId(int index, long id) {
this.index = index;
this.id = id;
}
int index;
long id;
}
private static class KestrelClientInfo {
public Long blacklistTillTimeMs;
public String host;
public int port;
private KestrelThriftClient client;
public KestrelClientInfo(String host, int port) {
this.host = host;
this.port = port;
this.blacklistTillTimeMs = 0L;
this.client = null;
}
public KestrelThriftClient getValidClient() throws TException {
if(this.client==null) { // If client was blacklisted, remake it.
LOG.info("Attempting reconnect to kestrel " + this.host + ":" + this.port);
this.client = new KestrelThriftClient(this.host, this.port);
}
return this.client;
}
public void closeClient() {
if(this.client != null) {
this.client.close();
this.client = null;
}
}
}
public KestrelThriftSpout(List<String> hosts, int port, String queueName, Scheme scheme) {
if(hosts.isEmpty()) {
throw new IllegalArgumentException("Must configure at least one host");
}
_port = port;
_hosts = hosts;
_queueName = queueName;
_scheme = scheme;
}
public KestrelThriftSpout(String hostname, int port, String queueName, Scheme scheme) {
this(Arrays.asList(hostname), port, queueName, scheme);
}
public KestrelThriftSpout(String hostname, int port, String queueName) {
this(hostname, port, queueName, new RawScheme());
}
public KestrelThriftSpout(List<String> hosts, int port, String queueName) {
this(hosts, port, queueName, new RawScheme());
}
public Fields getOutputFields() {
return _scheme.getOutputFields();
}
int _messageTimeoutMillis;
public void open(Map conf, TopologyContext context, SpoutOutputCollector collector) {
//TODO: should switch this to maxTopologyMessageTimeout
Number timeout = (Number) conf.get(Config.TOPOLOGY_MESSAGE_TIMEOUT_SECS);
_messageTimeoutMillis = 1000 * timeout.intValue();
_collector = collector;
_emitIndex = 0;
_kestrels = new ArrayList<KestrelClientInfo>();
int numTasks = context.getComponentTasks(context.getThisComponentId()).size();
int myIndex = context.getThisTaskIndex();
int numHosts = _hosts.size();
if(numTasks < numHosts) {
for(String host: _hosts) {
_kestrels.add(new KestrelClientInfo(host, _port));
}
} else {
String host = _hosts.get(myIndex % numHosts);
_kestrels.add(new KestrelClientInfo(host, _port));
}
}
public void close() {
for(KestrelClientInfo info: _kestrels) info.closeClient();
// Closing the client connection causes all the open reliable reads to be aborted.
// Thus, clear our local buffer of these reliable reads.
_emitBuffer.clear();
_kestrels.clear();
}
public boolean bufferKestrelGet(int index) {
assert _emitBuffer.size() == 0; // JTODO
KestrelClientInfo info = _kestrels.get(index);
long now = System.currentTimeMillis();
if(now > info.blacklistTillTimeMs) {
List<Item> items = null;
try {
items = info.getValidClient().get(_queueName, BATCH_SIZE, 0, _messageTimeoutMillis);
} catch(TException e) {
blacklist(info, e);
return false;
}
assert items.size() <= BATCH_SIZE;
// LOG.info("Kestrel batch get fetched " + items.size() + " items. (batchSize= " + BATCH_SIZE +
// " queueName=" + _queueName + ", index=" + index + ", host=" + info.host + ")");
HashSet toAck = new HashSet();
for(Item item : items) {
List<Object> retItems = _scheme.deserialize(item.get_data());
if (retItems != null) {
EmitItem emitItem = new EmitItem(retItems, new KestrelSourceId(index, item.get_id()));
if(!_emitBuffer.offer(emitItem)) {
throw new RuntimeException("KestrelThriftSpout's Internal Buffer Enqeueue Failed.");
}
} else {
toAck.add(item.get_id());
}
}
if(toAck.size() > 0) {
try {
info.client.abort(_queueName, toAck);
} catch(TException e) {
blacklist(info, e);
}
}
if(items.size() > 0) return true;
}
return false;
}
public void tryEachKestrelUntilBufferFilled() {
for(int i=0; i<_kestrels.size(); i++) {
int index = (_emitIndex + i) % _kestrels.size();
if(bufferKestrelGet(index)) {
_emitIndex = index;
break;
}
}
_emitIndex = (_emitIndex + 1) % _kestrels.size();
}
public void nextTuple() {
if(_emitBuffer.isEmpty()) tryEachKestrelUntilBufferFilled();
EmitItem item = _emitBuffer.poll();
if(item != null) {
_collector.emit(item.tuple, item.sourceId);
} else { // If buffer is still empty here, then every kestrel Q is also empty.
Utils.sleep(10);
}
}
private void blacklist(KestrelClientInfo info, Throwable t) {
LOG.warn("Failed to read from Kestrel at " + info.host + ":" + info.port, t);
//this case can happen when it fails to connect to Kestrel (and so never stores the connection)
info.closeClient();
info.blacklistTillTimeMs = System.currentTimeMillis() + BLACKLIST_TIME_MS;
int index = _kestrels.indexOf(info);
// we just closed the connection, so all open reliable reads will be aborted. empty buffers.
for(Iterator<EmitItem> i = _emitBuffer.iterator(); i.hasNext();) {
EmitItem item = i.next();
if(item.sourceId.index == index) i.remove();
}
}
public void ack(Object msgId) {
KestrelSourceId sourceId = (KestrelSourceId) msgId;
KestrelClientInfo info = _kestrels.get(sourceId.index);
//if the transaction didn't exist, it just returns false. so this code works
//even if client gets blacklisted, disconnects, and kestrel puts the item
//back on the queue
try {
if(info.client!=null) {
HashSet xids = new HashSet();
xids.add(sourceId.id);
info.client.confirm(_queueName, xids);
}
} catch(TException e) {
blacklist(info, e);
}
}
public void fail(Object msgId) {
KestrelSourceId sourceId = (KestrelSourceId) msgId;
KestrelClientInfo info = _kestrels.get(sourceId.index);
// see not above about why this works with blacklisting strategy
try {
if(info.client!=null) {
HashSet xids = new HashSet();
xids.add(sourceId.id);
info.client.abort(_queueName, xids);
}
} catch(TException e) {
blacklist(info, e);
}
}
public void declareOutputFields(OutputFieldsDeclarer declarer) {
declarer.declare(getOutputFields());
}
}