// Inspiration for the leader election have been found here: https://www.sandtable.com/etcd3-leader-election-using-python/
private static async Task LeaderElectionExample(EtcdClient client, string me)
{
client.Watch(LeaderKey, SetNewElection);
while (true)
{
NewElection = false;
var(leader, lease) = await LeaderElection(client, me);
if (leader)
{
Console.WriteLine("I'm the leader!!!");
var count = 0;
while (count < 20)
{
count++;
client.LeaseKeepAlive(new LeaseKeepAliveRequest {
ID = lease.ID
}, Print, CancellationToken.None);
Thread.Sleep(500);
}
Console.WriteLine("I'm no longer the leader");
Thread.Sleep(10000);
}
else
{
Console.WriteLine("I'm a follower!!!");
while (!NewElection)
{
Thread.Sleep(500);
}
}
}
}
public void LeaseKeepAlive(long leaseid)
{
var request = new LeaseKeepAliveRequest()
{
ID = leaseid
};
var req = request.ToProto();
var rsp = client.LeaseKeepAlive(req, new Action <Etcdserverpb.LeaseKeepAliveResponse>(p =>
{
}), CancellationToken.None);
}
private static async Task LeadershipGained(long lease)
{
Console.WriteLine("Press ESC to terminate");
while (!(Console.KeyAvailable && Console.ReadKey(true).Key == ConsoleKey.Escape))
{
Console.WriteLine("Refreshing. Still a leader.");
EtcdClient.LeaseKeepAlive(lease, CancellationToken.None);
await DoWork();
}
await Revoke(lease);
}
/// <summary>
/// 发送更新
/// </summary>
/// <param name="client"></param>
/// <param name="id"></param>
private bool KeepAlive(EtcdClient client, long id)
{
try
{
CancellationToken token = new CancellationToken();
client.LeaseKeepAlive(new LeaseKeepAliveRequest()
{
ID = id
}, Watch, token);
return(true);
}
catch
{
return(false);
}
}
private void LeaseKeepAlive(object state)
{
_client.LeaseKeepAlive(new LeaseKeepAliveRequest {
ID = _leaseId
}, KeepAliveResponseHandler, CancellationToken.None);
}
/// <summary>
/// 注册服务
/// </summary>
/// <param name="client">客户端</param>
/// <param name="systemName">系统名称(默认：Agent)</param>
/// <param name="registration">注册信息</param>
/// <returns></returns>
public static async Task <bool> RegisterAsync(this EtcdClient client, AgentServiceRegistration registration, string systemName = "Agent")
{
try
{
// /系统/Services/srvname/srvid
ServiceEntry entry = new ServiceEntry()
{
Host = registration.Address,
Port = registration.Port,
Name = registration.Name,
Id = registration.ID,
Tags = registration.Tags,
Version = registration.Version
};
if (registration.Checks == null || registration.Checks.Length == 0)
{
registration.Checks = new AgentServiceCheck[1];
registration.Checks[0] = new AgentServiceCheck();
registration.Checks[0].Interval = new TimeSpan(0, 0, 5);
}
var val = JsonConvert.SerializeObject(entry);
string key = "/" + systemName + "/Services/" + entry.Name + "/" + entry.Id;
CancellationToken token = new CancellationToken();
if (!string.IsNullOrEmpty(Utiletcd.Sinlgeton.Password) || !string.IsNullOrEmpty(Utiletcd.Sinlgeton.Username))
{
await client.AuthenticateAsync(new AuthenticateRequest()
{
Name = Utiletcd.Sinlgeton.Username,
Password = Utiletcd.Sinlgeton.Password
});
}
//申请TTL的ID
var lease = await client.LeaseGrantAsync(new LeaseGrantRequest()
{
ID = 0, TTL = (long)registration.Checks[0].Interval.TotalSeconds
});
//加入节点
var rsp = await client.PutAsync(new PutRequest()
{
Key = key.ToGoogleString(), Value = val.ToGoogleString(), Lease = lease.ID
});
//保持激活
await client.LeaseKeepAlive(new LeaseKeepAliveRequest()
{
ID = lease.ID
}, Watch, token);
//添加配置
await AddConfigAsync(client, systemName, registration);
//服务加入更新列表
await Utiletcd.Sinlgeton.AddKeepAliveAsync(client, key, (long)registration.Checks[0].Interval.TotalSeconds, lease.ID);
Init(client, key);
return(true);
}catch (Exception ex)
{
return(false);
}
}