blob: c77b79ee1ef0fd86bc4d06bc7bd28594bf12295b (
plain) (
blame)
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
|
// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.documentapi.messagebus.protocol;
import com.yahoo.jrt.slobrok.api.Mirror;
import com.yahoo.messagebus.ErrorCode;
import com.yahoo.messagebus.Reply;
import com.yahoo.messagebus.routing.Hop;
import com.yahoo.messagebus.routing.Route;
import com.yahoo.messagebus.routing.RoutingContext;
import com.yahoo.messagebus.routing.RoutingNodeIterator;
import java.util.List;
import java.util.Map;
/**
* Routing policy to load balance between nodes in a randomly distributed cluster, such as a docproc cluster.
*
* pattern=<pattern> (mandatory, determines the pattern of nodes to send to)<br>
* slobroks=<comma-separated connectionspecs> (optional, list of slobroks to use to find the pattern)<br>
* config=<comma-separated list of config servers> (optional, list of config servers to use to find slobrok config)
*
* If both slobroks and config is specified, the list from slobroks is used.
*
* @author Haakon Humberset
*/
public class LoadBalancerPolicy extends SlobrokPolicy {
private final String session;
private final String pattern;
private final LoadBalancer loadBalancer;
LoadBalancerPolicy(String param) {
this(parse(param));
}
private LoadBalancerPolicy(Map<String, String> params) {
super();
String cluster = params.get("cluster");
session = params.get("session");
if (cluster == null) {
throw new IllegalArgumentException("Required parameter 'cluster' not set");
}
if (session == null) {
throw new IllegalArgumentException("Required parameter 'session' not set");
}
pattern = cluster + "/*/" + session;
loadBalancer = new AdaptiveLoadBalancer(cluster);
}
@Override
public void select(RoutingContext context) {
LoadBalancer.Node node = getRecipient(context);
if (node != null) {
context.setContext(node);
Route route = new Route(context.getRoute());
route.setHop(0, Hop.parse(node.entry.getSpecString() + "/" + session));
context.addChild(route);
} else {
context.setError(ErrorCode.NO_ADDRESS_FOR_SERVICE, "Could not resolve any nodes to send to in pattern " + pattern);
}
}
/**
Finds the TCP address of the target.
@return Returns a hop representing the TCP address of the target, or null if none could be found.
*/
private LoadBalancer.Node getRecipient(RoutingContext context) {
List<Mirror.Entry> lastLookup = lookup(context, pattern);
return loadBalancer.getRecipient(lastLookup);
}
public void merge(RoutingContext context) {
RoutingNodeIterator it = context.getChildIterator();
Reply reply = it.removeReply();
LoadBalancer.Node target = (LoadBalancer.Node)context.getContext();
boolean busy = false;
for (int i = 0; i < reply.getNumErrors(); i++) {
if (reply.getError(i).getCode() == ErrorCode.SESSION_BUSY) {
busy = true;
}
}
loadBalancer.received(target, busy);
context.setReply(reply);
}
@Override
public void destroy() {
}
// For testing
LoadBalancer getLoadBalancer() { return loadBalancer; }
}
|