initial.min.cluster.size的行为

Z时代
2024-01-10
分类：问答

Hazelcast是否始终阻止以防未到达initial.min.cluster.size？如果不是，在哪种情况下不是？initial.min.cluster.size的行为

详情：我用下面的代码来初始化hazelcast：

Config cfg = new Config(); 
cfg.setProperty("hazelcast.initial.min.cluster.size",Integer. 
    toString(minimumInitialMembersInHazelCluster)); //2 in this case 
cfg.getGroupConfig().setName(clusterName); 
NetworkConfig network = cfg.getNetworkConfig(); 
JoinConfig join = network.getJoin(); 
join.getMulticastConfig().setEnabled(false); 
join.getTcpIpConfig().addMember("192.168.0.1").addMember("192.168.0.2"). 
    addMember("192.168.0.3").addMember("192.168.0.4"). 
    addMember("192.168.0.5").addMember("192.168.0.6"). 
    addMember("192.168.0.7").setRequiredMember(null).setEnabled(true); 
network.getInterfaces().setEnabled(true).addInterface("192.168.0.*"); 
join.getMulticastConfig().setMulticastTimeoutSeconds(MCSOCK_TIMEOUT/100);   
hazelInst = Hazelcast.newHazelcastInstance(cfg); 
distrDischargedTTGs = hazelInst.getList(clusterName);

，并得到日志消息像

调试：从Hazelcluster开始淡褐色pullExternal 1组的成员。

这是否意味着还有其他成员已经加入并离开了？它看起来不像其他实例的日志文件。因此，我想知道是否存在那些hazelInst = Hazelcast.newHazelcastInstance(cfg);不会阻止的情况，即使它是榛树群集中的唯一实例。

回答：

newHazelcastInstance阻塞，直到群集具有所需数量的成员。

查看下列它是如何实现的代码：

private static void awaitMinimalClusterSize(HazelcastInstanceImpl hazelcastInstance, Node node, boolean firstMember) 
     throws InterruptedException { 
    final int initialMinClusterSize = node.groupProperties.INITIAL_MIN_CLUSTER_SIZE.getInteger(); 
    while (node.getClusterService().getSize() < initialMinClusterSize) { 
     try { 
      hazelcastInstance.logger.info("HazelcastInstance waiting for cluster size of " + initialMinClusterSize); 
      //noinspection BusyWait 
      Thread.sleep(TimeUnit.SECONDS.toMillis(1)); 
     } catch (InterruptedException ignored) { 
     } 
    } 
    if (initialMinClusterSize > 1) { 
     if (firstMember) { 
      node.partitionService.firstArrangement(); 
     } else { 
      Thread.sleep(TimeUnit.SECONDS.toMillis(3)); 
     } 
     hazelcastInstance.logger.info("HazelcastInstance starting after waiting for cluster size of " 
       + initialMinClusterSize); 
    } 
}