/
DemoScheduler.java
115 lines (99 loc) · 5.76 KB
/
DemoScheduler.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
package storm;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import backtype.storm.scheduler.Cluster;
import backtype.storm.scheduler.EvenScheduler;
import backtype.storm.scheduler.ExecutorDetails;
import backtype.storm.scheduler.IScheduler;
import backtype.storm.scheduler.SchedulerAssignment;
import backtype.storm.scheduler.SupervisorDetails;
import backtype.storm.scheduler.Topologies;
import backtype.storm.scheduler.TopologyDetails;
import backtype.storm.scheduler.WorkerSlot;
/**
* This demo scheduler make sure a spout named <code>special-spout</code> in topology <code>special-topology</code> runs
* on a supervisor named <code>special-supervisor</code>. supervisor does not have name? You can configure it through
* the config: <code>supervisor.scheduler.meta</code> -- actually you can put any config you like in this config item.
*
* In our example, we need to put the following config in supervisor's <code>storm.yaml</code>:
* <pre>
* # give our supervisor a name: "special-supervisor"
* supervisor.scheduler.meta:
* name: "special-supervisor"
* </pre>
*
* Put the following config in <code>nimbus</code>'s <code>storm.yaml</code>:
* <pre>
* # tell nimbus to use this custom scheduler
* storm.scheduler: "storm.DemoScheduler"
* </pre>
* @author xumingmingv May 19, 2012 11:10:43 AM
*/
public class DemoScheduler implements IScheduler {
public void prepare(Map conf) {}
public void schedule(Topologies topologies, Cluster cluster) {
System.out.println("DemoScheduler: begin scheduling");
// Gets the topology which we want to schedule
TopologyDetails topology = topologies.getByName("special-topology");
// make sure the special topology is submitted,
if (topology != null) {
boolean needsScheduling = cluster.needsScheduling(topology);
if (!needsScheduling) {
System.out.println("Our special topology DOES NOT NEED scheduling.");
} else {
System.out.println("Our special topology needs scheduling.");
// find out all the needs-scheduling components of this topology
Map<String, List<ExecutorDetails>> componentToExecutors = cluster.getNeedsSchedulingComponentToExecutors(topology);
System.out.println("needs scheduling(component->executor): " + componentToExecutors);
System.out.println("needs scheduling(executor->compoenents): " + cluster.getNeedsSchedulingExecutorToComponents(topology));
SchedulerAssignment currentAssignment = cluster.getAssignmentById(topologies.getByName("special-topology").getId());
if (currentAssignment != null) {
System.out.println("current assignments: " + currentAssignment.getExecutorToSlot());
} else {
System.out.println("current assignments: {}");
}
if (!componentToExecutors.containsKey("special-spout")) {
System.out.println("Our special-spout DOES NOT NEED scheduling.");
} else {
System.out.println("Our special-spout needs scheduling.");
List<ExecutorDetails> executors = componentToExecutors.get("special-spout");
// find out the our "special-supervisor" from the supervisor metadata
Collection<SupervisorDetails> supervisors = cluster.getSupervisors().values();
SupervisorDetails specialSupervisor = null;
for (SupervisorDetails supervisor : supervisors) {
Map meta = (Map) supervisor.getSchedulerMeta();
if (meta.get("name").equals("special-supervisor")) {
specialSupervisor = supervisor;
break;
}
}
// found the special supervisor
if (specialSupervisor != null) {
System.out.println("Found the special-supervisor");
List<WorkerSlot> availableSlots = cluster.getAvailableSlots(specialSupervisor);
// if there is no available slots on this supervisor, free some.
// TODO for simplicity, we free all the used slots on the supervisor.
if (availableSlots.isEmpty() && !executors.isEmpty()) {
for (Integer port : cluster.getUsedPorts(specialSupervisor)) {
cluster.freeSlot(new WorkerSlot(specialSupervisor.getId(), port));
}
}
// re-get the aviableSlots
availableSlots = cluster.getAvailableSlots(specialSupervisor);
// since it is just a demo, to keep things simple, we assign all the
// executors into one slot.
cluster.assign(availableSlots.get(0), topology.getId(), executors);
System.out.println("We assigned executors:" + executors + " to slot: [" + availableSlots.get(0).getNodeId() + ", " + availableSlots.get(0).getPort() + "]");
} else {
System.out.println("There is no supervisor named special-supervisor!!!");
}
}
}
}
// let system's even scheduler handle the rest scheduling work
// you can also use your own other scheduler here, this is what
// makes storm's scheduler composable.
new EvenScheduler().schedule(topologies, cluster);
}
}