VB.NET语言 分布式系统中的数据一致性处理

Public Class RedisLock
Private _redis As IDatabase
Private _lockKey As String
Private _lockValue As String

Public Sub New(ByVal redis As IDatabase, ByVal lockKey As String, ByVal lockValue As String)
_redis = redis
_lockKey = lockKey
_lockValue = lockValue
End Sub

Public Function AcquireLock(ByVal timeout As TimeSpan) As Boolean
Dim lockResult As Boolean = False
Dim startTime As DateTime = DateTime.Now

While Not lockResult AndAlso (DateTime.Now - startTime) < timeout
lockResult = _redis.StringSetIf(_lockKey, _lockValue, TimeSpan.FromSeconds(10))
End While

Return lockResult
End Function

Public Class ZookeeperLock
Private _zk As ZooKeeper
Private _lockPath As String

Public Sub New(ByVal zk As ZooKeeper, ByVal lockPath As String)
_zk = zk
_lockPath = lockPath
End Sub

Public Function AcquireLock() As Boolean
Dim lockNode As String = _lockPath + "/lock"
Dim lockData As Byte() = Encoding.UTF8.GetBytes("lock")

Try
_zk.create(lockNode, lockData, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL)
Dim children As List(Of String) = _zk.getChildren(_lockPath, False)
Dim sequence As Integer = Convert.ToInt32(lockNode.Substring(lockNode.LastIndexOf("/") + 1))

For Each child As String In children
Dim childSequence As Integer = Convert.ToInt32(child.Substring(child.LastIndexOf("/") + 1))
If childSequence < sequence Then
_zk.exists(child, True)
End If
Next

Return True
Catch ex As KeeperException
Return False
End Try
End Function

Public Class RabbitMQDataReplication
Private _channel As IModel
Private _queueName As String

Public Sub New(ByVal queueName As String)
_queueName = queueName
Dim factory As New ConnectionFactory() With {
.Host = "localhost"
}
Dim connection As IConnection = factory.CreateConnection()
_channel = connection.CreateModel()
_channel.QueueDeclare(_queueName, False, False, False, Nothing)
End Sub

Public Sub SendData(ByVal data As String)
Dim body As Byte() = Encoding.UTF8.GetBytes(data)
_channel.BasicPublish("", _queueName, Nothing, body)
End Sub

Public Sub ConsumeData()
Dim consumer As EventingBasicConsumer = New EventingBasicConsumer(_channel)
AddHandler consumer.Received, AddressOf Consumer_Received

_channel.BasicConsume(_queueName, False, consumer)
End Sub

Public Class DatabaseReplication
Private _connectionString As String

Public Sub New(ByVal connectionString As String)
_connectionString = connectionString
End Sub

Public Sub ReplicateData()
Using connection As New SqlConnection(_connectionString)
connection.Open()