/// <summary>
/// Publishes the shard map for the shard set.
/// </summary>
/// <param name="queueRequest">if set to <c>true</c> queue request.</param>
public virtual void PublishShardMap(bool queueRequest = false)
{
var previousShardMap = -1;
//This could be null because it might be the first time the shard map is published.
if (CurrentPublishedShardMapID.HasValue)
{
previousShardMap = CurrentPublishedShardMapID.Value;
}
var request =
new ShardMapPublishingRequest
{
NewShardMapID = ShardMap.ShardMapID,
ShardSetName = ShardSetName,
CurrentShardMapID = previousShardMap
};
if (queueRequest)
{
request.Save();
return;
}
ProcessShardMapPublishingRequest(request, this);
}
private static void CompleteShardMapPublishingRequest(ShardSetConfig config,
ShardMapPublishingRequest shardMapPublishingRequest)
{
//todo: this is saving a whole'nother config rathr thanjust incrementing the "current" config map in force
config.CurrentPublishedShardMapID = shardMapPublishingRequest.NewShardMapID;
config.Save();
}
/// <summary>
/// Handles the shard map publishing request and processes it against the shard set driver.
/// </summary>
/// <param name="request">The shard map publishing request.</param>
/// <param name="queue">The queue.</param>
public static void HandleShardMapPublishingRequest(ShardMapPublishingRequest request,
IShardSetActionQueue queue)
{
var shardSetConfig = GetCurrentShardSetConfig(request.ShardSetName);
Action <ShardMapPublishingRequest> process =
x =>
{
ProcessShardMapPublishingRequest(x, shardSetConfig);
if (!request.ShouldUpdateShardMap)
{
return;
}
PublishRangeMap(shardSetConfig.ShardSetName, request.CurrentShardMapID, request.NewShardMapID);
};
Action <ShardMapPublishingRequest> complete =
x =>
{
CompleteShardMapPublishingRequest(shardSetConfig, x);
queue.SendQueueProcessingEvent(GetCompletionMessage("ShardMapPublishingRequest", x));
};
Action <ShardMapPublishingRequest> error =
x => queue.SendQueueProcessingEvent(GetErrorMessage("ShardMapPublishingRequest", x));
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());
}
