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
|
package com.orbekk.same;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.atomic.AtomicBoolean;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.protobuf.RpcCallback;
import com.google.protobuf.RpcController;
import com.orbekk.same.Services.ClientState;
import com.orbekk.same.Services.Empty;
import com.orbekk.same.Services.UpdateComponentResponse;
import com.orbekk.same.State.Component;
import com.orbekk.util.WorkQueue;
public class Master {
private Logger logger = LoggerFactory.getLogger(getClass());
private final ConnectionManager connections;
private String myUrl;
private String myLocation; // Protobuf server location, i.e., myIp:port
State state;
private Broadcaster broadcaster;
private volatile int masterId = 1;
public static Master create(ConnectionManager connections,
Broadcaster broadcaster, String myUrl, String networkName,
String myLocation) {
State state = new State(networkName);
state.update(".masterUrl", myUrl, 1);
state.update(".masterLocation", myLocation, 1);
return new Master(state, connections, broadcaster, myUrl, myLocation);
}
Master(State initialState, ConnectionManager connections,
Broadcaster broadcaster, String myUrl, String myLocation) {
this.state = initialState;
this.connections = connections;
this.broadcaster = broadcaster;
this.myUrl = myUrl;
this.myLocation = myLocation;
}
public String getNetworkName() {
return state.getDataOf(".networkName");
}
public String getLocation() {
return myLocation;
}
public String getUrl() {
return myUrl;
}
public Services.MasterState getMasterInfo() {
return Services.MasterState.newBuilder()
.setMasterUrl(getUrl())
.setMasterLocation(getLocation())
.setNetworkName(getNetworkName())
.setMasterId(masterId)
.build();
}
private Services.Master newMasterImpl = new Services.Master() {
@Override public void joinNetworkRequest(RpcController controller,
ClientState request, RpcCallback<Empty> done) {
logger.info("joinNetworkRequest({})", request);
List<String> participants = state.getList(".participants");
sendFullStateThread.add(request.getUrl());
if (!participants.contains(request.getUrl())) {
participants.add(request.getUrl());
synchronized (Master.this) {
state.updateFromObject(".participants", participants,
state.getRevision(".participants") + 1);
}
updateStateRequestThread.add(".participants");
} else {
logger.warn("Client {} joining: Already part of network");
}
done.run(Empty.getDefaultInstance());
}
@Override public void updateStateRequest(RpcController controller,
Services.Component request,
RpcCallback<Services.UpdateComponentResponse> done) {
logger.info("updateStateRequest({})", request);
boolean updated = state.update(request.getId(), request.getData(),
request.getRevision() + 1);
if (updated) {
updateStateRequestThread.add(request.getId());
}
done.run(Services.UpdateComponentResponse.newBuilder()
.setSuccess(updated).build());
}
};
private MasterService serviceImpl = new MasterService() {
@Override
public boolean updateStateRequest(String component,
String newData, long revision) {
Services.Component request = Services.Component.newBuilder()
.setId(component)
.setData(newData)
.setRevision(revision)
.build();
final AtomicBoolean result = new AtomicBoolean(false);
RpcCallback<Services.UpdateComponentResponse> done =
new RpcCallback<Services.UpdateComponentResponse>() {
@Override public void run(UpdateComponentResponse response) {
result.set(response.getSuccess());
}
};
newMasterImpl.updateStateRequest(null, request, done);
return result.get();
}
@Override
public void joinNetworkRequest(String clientUrl) {
Services.ClientState request = Services.ClientState.newBuilder()
.setUrl(clientUrl)
.build();
RpcCallback<Services.Empty> done =
new RpcCallback<Services.Empty>() {
@Override public void run(Empty response) {
}
};
newMasterImpl.joinNetworkRequest(null, request, done);
}
};
WorkQueue<String> updateStateRequestThread = new WorkQueue<String>() {
@Override protected void onChange() {
List<String> pending = getAndClear();
logger.info("updateStateRequestThread: Updated state: {}",
pending);
for (String componentName : pending) {
Component component = state.getComponent(componentName);
List<String> participants = state.getList(".participants");
broadcastNewComponents(participants,
Collections.singletonList(component));
}
}
};
WorkQueue<String> sendFullStateThread = new WorkQueue<String>() {
@Override protected void onChange() {
List<String> pending = getAndClear();
logger.info("Sending full state to {}", pending);
final List<Component> components = state.getComponents();
broadcaster.broadcast(pending, new ServiceOperation() {
@Override public void run(String url) {
ClientService client = connections.getClient(url);
try {
client.masterTakeover(
state.getDataOf(".masterUrl"),
state.getDataOf(".networkName"),
masterId,
state.getDataOf(".masterLocation"));
} catch (Exception e) {
logger.info("Client failed to acknowledge master. Remove.",
e);
removeParticipant(url);
}
}
});
broadcastNewComponents(pending, components);
}
};
void performWork() {
sendFullStateThread.performWork();
updateStateRequestThread.performWork();
}
public void start() {
sendFullStateThread.start();
updateStateRequestThread.start();
}
public void interrupt() {
sendFullStateThread.interrupt();
updateStateRequestThread.interrupt();
}
public Services.Master getNewService() {
return newMasterImpl;
}
public MasterService getService() {
return serviceImpl;
}
private synchronized void removeParticipant(String url) {
List<String> participants = state.getList(".participants");
if (participants.contains(url)) {
logger.info("removeParticipant({})", url);
participants.remove(url);
state.updateFromObject(".participants", participants,
state.getRevision(".participants") + 1);
updateStateRequestThread.add(".participants");
}
}
private void broadcastNewComponents(List<String> destinations,
final List<State.Component> components) {
broadcaster.broadcast(destinations, new ServiceOperation() {
@Override public void run(String url) {
ClientService client = connections.getClient(url);
try {
for (Component c : components) {
client.setState(c.getName(), c.getData(),
c.getRevision());
}
} catch (Exception e) {
logger.info("Client {} failed to receive state update.", url);
removeParticipant(url);
}
}
});
}
/** This master should take over from an earlier master. */
public void resumeFrom(State lastKnownState, final int masterId) {
state = lastKnownState;
state.update(".masterUrl", myUrl, state.getRevision(".masterUrl") + 100);
state.update(".masterLocation", myLocation,
state.getRevision(".masterLocation") + 100);
this.masterId = masterId;
broadcaster.broadcast(state.getList(".participants"),
new ServiceOperation() {
@Override
public void run(String url) {
ClientService client = connections.getClient(url);
try {
client.masterTakeover(myUrl,
state.getDataOf(".networkName"), masterId,
state.getDataOf(".masterLocation"));
} catch (Exception e) {
logger.info("Client {} failed to acknowledge new master. " +
"Removing {}", url);
removeParticipant(url);
}
}
});
}
}
|
