public NotifyCrashReply NotifyCrashHandler(NotifyCrashRequest request)
{
lock (_syncRoot)
{
string partitionName = request.PartitionId;
string crashedMasterServerId = request.CrashedMasterServerId;
string currentMasterServerId = PartitionMapping.GetPartitionMaster(partitionName);
Console.WriteLine(">>> Received Message from the client about crashed server: PartitionName=" + partitionName + ", CrashedServerId=" + crashedMasterServerId);
// check if the crashed server has been dealt with already
string[] serversOfThePartition = PartitionMapping.partitionMapping[partitionName];
if (!serversOfThePartition.Contains(crashedMasterServerId))
{
// this means an election already happened and the crashed server was deleted. the current partition master is the election result
// another possibility is that the master detected a replica failure. In this case the partition master didn't actually change saying that it did no harm.
Console.WriteLine(">>> Election Process Has Already Happened, CurrentMasterServerId=" + currentMasterServerId);
return(new NotifyCrashReply
{
Status = "OK",
MasterId = currentMasterServerId
});
}
// confirm that server is actually crashed
SendValueToReplica svr = new SendValueToReplica(server);
return(svr.HandleServerCrash(partitionName, crashedMasterServerId));
}
}
public void createPartition(string partition_id)
{
string master_id = PartitionMapping.GetPartitionMaster(partition_id);
bool is_master = master_id.Equals(server_id);
int partition_clock = PartitionMapping.GetPartitionClock(partition_id);
Partition p = new Partition(partition_id, is_master, partition_clock);
partitions.Add(p);
}
private void write(string partition_id, string object_id, string value)
{
WriteReply reply;
if (debug_console)
{
Console.WriteLine("Get Partition Master from Partition Named: " + partition_id);
}
string partition_master_server_id = PartitionMapping.GetPartitionMaster(partition_id);
if (debug_console)
{
Console.WriteLine("Partition Master Server ID: " + partition_master_server_id);
}
reattachServer(partition_master_server_id);
var object_key = new DataStoreKeyDto
{
PartitionId = partition_id,
ObjectId = object_id
};
var object_value = new DataStoreValueDto
{
Val = value
};
Console.WriteLine(">>> Write request...");
try
{
reply = client.Write(new WriteRequest {
ObjectKey = object_key, Object = object_value
});
Console.WriteLine("Write result: " + reply);
}
catch
{
bool canRetryOperation = HandleCrashedServer(attached_server_id);
if (canRetryOperation)
{
Console.WriteLine(">>> Retrying <Write> after reattaching to new master");
write(partition_id, object_id, value);
}
return;
}
}
public string getMasterID()
{
return(PartitionMapping.GetPartitionMaster(this.id));
}