Mesos源码分析(6): Mesos Master的初始化

 

Mesos Master的初始化在src/master/master.cpp中

 

 

在Mesos Master的log中，是能看到这一行的。

 

1.初始化role，并设置weight权重

 

 

 

2. 初始化Allocator

 

 

注意，Allocator的initialize函数中，传入的OfferCallback是Master::offer。

 

如果前面所述，没过allocation_interval，Allocator都会计算每个framework的offer，然后依次调用Master::offer，将资源offer给相应的framework。

 

 

在Master::offer函数中，生成如下的ResourceOffersMessage，并且发送给Framework

 

1.   // Create an offer for each slave and add it to the message.
2.   ResourceOffersMessage message;
3.  
4.   Framework* framework = CHECK_NOTNULL(frameworks.registered[frameworkId]);
5.   foreachpair (const SlaveID& slaveId, const Resources& offered, resources) {
6. ……
7.     Slave* slave = slaves.registered.get(slaveId);
8.     CHECK_NOTNULL(slave);
9. ……
10.     // TODO(bmahler): Set "https" if only "https" is supported.
11.     mesos::URL url;
12.     url.set_scheme("http");
13.     url.mutable_address()->set_hostname(slave->info.hostname());
14.     url.mutable_address()->set_ip(stringify(slave->pid.address.ip));
15.     url.mutable_address()->set_port(slave->pid.address.port);
16.     url.set_path("/" + slave->pid.id);
17.  
18.     Offer* offer = new Offer();
19.     offer->mutable_id()->MergeFrom(newOfferId());
20.     offer->mutable_framework_id()->MergeFrom(framework->id());
21.     offer->mutable_slave_id()->MergeFrom(slave->id);
22.     offer->set_hostname(slave->info.hostname());
23.     offer->mutable_url()->MergeFrom(url);
24.     offer->mutable_resources()->MergeFrom(offered);
25.     offer->mutable_attributes()->MergeFrom(slave->info.attributes());
26.  
27.     // Add all framework's executors running on this slave.
28.     if (slave->executors.contains(framework->id())) {
29.       const hashmap<ExecutorID, ExecutorInfo>& executors =
30.         slave->executors[framework->id()];
31.       foreachkey (const ExecutorID& executorId, executors) {
32.         offer->add_executor_ids()->MergeFrom(executorId);
33.       }
34.     }
35. ……
36.     offers[offer->id()] = offer;
37.  
38.     framework->addOffer(offer);
39.     slave->addOffer(offer);
40.  
41.     if (flags.offer_timeout.isSome()) {
42.       // Rescind the offer after the timeout elapses.
43.       offerTimers[offer->id()] =
44.         delay(flags.offer_timeout.get(),
45.               self(),
46.               &Self::offerTimeout,
47.               offer->id());
48.     }
49.  
50.     // TODO(jieyu): For now, we strip 'ephemeral_ports' resource from
51.     // offers so that frameworks do not see this resource. This is a
52.     // short term workaround. Revisit this once we resolve MESOS-1654.
53.     Offer offer_ = *offer;
54.     offer_.clear_resources();
55.  
56.     foreach (const Resource& resource, offered) {
57.       if (resource.name() != "ephemeral_ports") {
58.         offer_.add_resources()->CopyFrom(resource);
59.       }
60.     }
61.  
62.     // Add the offer *AND* the corresponding slave's PID.
63.     message.add_offers()->MergeFrom(offer_);
64.     message.add_pids(slave->pid);
65.   }
66.  
67.   if (message.offers().size() == 0) {
68.     return;
69.   }
70.  
71.   LOG(INFO) << "Sending " << message.offers().size()
72.             << " offers to framework " << *framework;
73.  
74.   framework->send(message);
75. }

 

3. 监听消息，注册处理函数

 

最后注册一些处理函数，当收到相应的消息的时候，调用相应的函数。

 

下面仅仅列举比较重要的几个函数。

 

第一个是Framework注册的时候调用的函数。

 

第二个是收到Framework发送来的运行Task的消息。

 

第三个是Slave发送来的注册时候调用的函数。

 

第四个是更新Status时候的Message

 

4. 竞争成为Master中的Leader，或者检测当前的Leader