/// <summary>
/// Handles the shardlet move request from tje request queue.
/// </summary>
/// <param name="request">The request.</param>
/// <param name="queue">The queue.</param>
/// <param name="uniqueProcessID">A unique process identifier that can be set to maintain state between moves.</param>
public static void HandleShardletMoveRequest(ShardletMoveRequest request, IShardSetActionQueue queue,
Guid uniqueProcessID)
{
Action <ShardletMoveRequest> process =
x =>
{
var shardlet = Load(x.ShardSetName, x.ShardingKey);
var destinationShard =
new RangeShard
{
Catalog = x.DestinationCatalog,
ServerInstanceName = x.DestinationServerInstanceName
};
shardlet.MoveToShard(destinationShard, x.Pin, x.DeleteOnMove, uniqueProcessID);
};
Action <ShardletMoveRequest> complete =
x =>
{
var message = GetCompletionMessage("ShardletMoveRequest", x);
queue.SendQueueProcessingEvent(message);
};
Action <ShardletMoveRequest> error =
x =>
{
var message = GetErrorMessage("ShardletMoveRequest", x);
queue.SendQueueProcessingEvent(message);
};
request.Process(process, complete, error);
}
private static void ProcessShardMapPublishingRequest(ShardMapPublishingRequest shardMapPublishingRequest,
ShardSetConfig shardSetConfig)
{
var shardSetName = shardMapPublishingRequest.ShardSetName;
var shardSetConnectionDriver = GetShardSetConnectionDriver(shardSetName);
// to do - may need to page
var shardlets = shardSetConnectionDriver.GetShardlets(shardSetName);
foreach (var shardlet in shardlets)
{
// skip if shardlet is pinned
if (shardlet.Pinned)
{
continue;
}
// get the matching range shard for this shardlet based on the range map
var rangeShard =
shardSetConfig.ShardMap.Shards
.FirstOrDefault(rs => rs.HighDistributionKey > shardlet.DistributionKey);
// skip if we cannot find a range.
if (rangeShard == null)
{
continue;
}
// determine if the shardlet needs to be moved
if (rangeShard.ServerInstanceName == shardlet.ServerInstanceName &&
rangeShard.Catalog == shardlet.Catalog)
{
continue;
}
var request =
new ShardletMoveRequest
{
DestinationCatalog = rangeShard.Catalog,
DestinationServerInstanceName = shardlet.ServerInstanceName,
SourceCatalog = shardlet.Catalog,
SourceServerInstanceName = shardlet.ServerInstanceName,
DistributionKey = shardlet.DistributionKey,
ShardingKey = shardlet.ShardingKey,
ShardSetName = shardlet.ShardSetName,
DeleteOnMove = true,
Pin = false
};
request.Save();
}
// todo: do this save in parallel
//var parallelOptions = GetParallelOptions();
//Parallel.ForEach(shardletMoveRequests, parallelOptions,
// shardletMoveRequest => shardletMoveRequest.Save());
}
/// <summary>
/// Moves to shard.
/// </summary>
/// <param name="shard">The shard to move the ShardLet data to.</param>
/// <param name="pin">if set to <c>true</c> add the shard to the pinned shard list.</param>
/// <param name="deleteOnMove">if set to <c>true</c> delete the Shardlet data from the existing Shard after move.</param>
/// <param name="uniqueProcessID">A unique process identifier that can be set to maintain state between moves.</param>
/// <param name="queueRequest">if set to <c>true</c> queue the shard move rather than executing it immediately.</param>
public void MoveToShard(ShardBase shard, bool pin, bool deleteOnMove, Guid uniqueProcessID,
bool queueRequest = false)
{
if (queueRequest)
{
var request =
new ShardletMoveRequest
{
DestinationCatalog = shard.Catalog,
DestinationServerInstanceName = shard.ServerInstanceName,
SourceCatalog = Catalog,
SourceServerInstanceName = ServerInstanceName,
DistributionKey = DistributionKey,
ShardingKey = ShardingKey,
ShardSetName = ShardSetName,
DeleteOnMove = deleteOnMove,
UniqueProcessID = uniqueProcessID,
Pin = pin
};
request.Save();
return;
}
var shardSetConnectionDriver = ScaleOutShardletManager.GetManager().GetShardletConnectionDriver(ShardSetName);
try
{
// change the state to read only in the map and update th epin status
Status = ShardletStatus.Moving;
Pinned = pin;
shardSetConnectionDriver.PublishShardlet(this);
// terminate all existing connections
shardSetConnectionDriver.TerminateConnections(this);
// copy the shardlet data
var shardSetConfig = ShardSetConfig.LoadCurrent(ShardSetName);
var currentShard =
new RangeShard
{
Catalog = Catalog,
ServerInstanceName = ServerInstanceName,
};
shardSetConfig.CopyShardlet(currentShard, shard, ShardingKey, uniqueProcessID);
// update the status and set the new catalog and instance in the shard map
Catalog = shard.Catalog;
ServerInstanceName = shard.ServerInstanceName;
Status = ShardletStatus.Active;
shardSetConnectionDriver.PublishShardlet(this);
if (deleteOnMove)
{
shardSetConfig.DeleteShardlet(currentShard, ShardingKey);
}
}
catch (Exception)
{
Status = ShardletStatus.Active;
shardSetConnectionDriver.PublishShardlet(this);
throw;
}
}
