/// <summary>
/// Executes the Multi-Shard Query sample.
/// </summary>
private static void MultiShardQuery()
{
RangeShardMap <int> shardMap = MultiShardConfiguration.TryGetShardMap();
if (shardMap != null)
{
MultiShardQuerySupport.ExecuteMultiShardQuery(shardMap);
}
}
/// <summary>
/// Executes the Data-Dependent Routing sample.
/// </summary>
private static void DataDepdendentRoutingForDelete()
{
RangeShardMap <int> shardMap = MultiShardConfiguration.TryGetShardMap();
if (shardMap != null)
{
DataDependentRoutingSupport.ExecuteDataDependentRoutingQueryForDelete(shardMap);
}
}
/// <summary>
/// Writes the shard map's state to the console.
/// </summary>
private static void PrintShardMapState()
{
Console.WriteLine("Current Shard Map state:");
RangeShardMap <int> shardMap = MultiShardConfiguration.TryGetShardMap();
if (shardMap == null)
{
return;
}
// Get all shards
IEnumerable <Shard> allShards = shardMap.GetShards();
// Get all mappings, grouped by the shard that they are on. We do this all in one go to minimise round trips.
ILookup <Shard, RangeMapping <int> > mappingsGroupedByShard = shardMap.GetMappings().ToLookup(m => m.Shard);
if (allShards.Any())
{
// The shard map contains some shards, so for each shard (sorted by database name)
// write out the mappings for that shard
foreach (Shard shard in shardMap.GetShards().OrderBy(s => s.Location.Database))
{
IEnumerable <RangeMapping <int> > mappingsOnThisShard = mappingsGroupedByShard[shard];
if (mappingsOnThisShard.Any())
{
string mappingsString = string.Join(", ", mappingsOnThisShard.Select(m => m.Value));
Console.WriteLine("\t{0} contains key range {1}", shard.Location.Database, mappingsString);
}
else
{
Console.WriteLine("\t{0} contains no key ranges.", shard.Location.Database);
}
}
}
else
{
Console.WriteLine("\tShard Map contains no shards");
}
}
/// <summary>
/// Drops all shards and the shard map manager database (if it exists).
/// </summary>
private static void DropAll()
{
RangeShardMap <int> shardMap = MultiShardConfiguration.TryGetShardMap();
if (shardMap != null)
{
// Drop shards
foreach (Shard shard in shardMap.GetShards())
{
SqlDatabaseUtils.DropDatabase(shard.Location.DataSource, shard.Location.Database);
}
}
if (SqlDatabaseUtils.ExistsDatabase(MultiShardConfiguration.ShardMapManagerServerName, MultiShardConfiguration.ShardMapManagerDatabaseName))
{
// Drop shard map manager database
SqlDatabaseUtils.DropDatabase(MultiShardConfiguration.ShardMapManagerServerName, MultiShardConfiguration.ShardMapManagerDatabaseName);
}
// Since we just dropped the shard map manager database, this shardMapManager reference is now non-functional.
// So set it to null so that the program knows that the shard map manager is gone.
MultiShardConfiguration.objShardMapManager = null;
}
/// <summary>
/// Reads the user's choice of a split point, and creates a new shard with a mapping for the resulting range.
/// </summary>
private static void AddShard()
{
RangeShardMap <int> shardMap = MultiShardConfiguration.TryGetShardMap();
if (shardMap != null)
{
// Here we assume that the ranges start at 0, are contiguous,
// and are bounded (i.e. there is no range where HighIsMax == true)
int currentMaxHighKey = shardMap.GetMappings().Max(m => m.Value.High);
int defaultNewHighKey = currentMaxHighKey + 100;
Console.WriteLine("A new range with low key {0} will be mapped to the new shard.", currentMaxHighKey);
int newHighKey = ConsoleUtils.ReadIntegerInput(
string.Format("Enter the high key for the new range [default {0}]: ", defaultNewHighKey),
defaultNewHighKey,
input => input > currentMaxHighKey);
Range <int> range = new Range <int>(currentMaxHighKey, newHighKey);
Console.WriteLine();
Console.WriteLine("Creating shard for range {0}", range);
CreateShardSample.CreateShard(shardMap, range);
}
}
