/// <summary>
/// Creates a new shard, or gets an existing empty shard (i.e. a shard that has no mappings).
/// The reason why an empty shard might exist is that it was created and initialized but we
/// failed to create a mapping to it.
/// </summary>
private static Shard CreateOrGetEmptyShard(RangeShardMap <int> shardMap)
{
// Get an empty shard if one already exists, otherwise create a new one
Shard shard = FindEmptyShard(shardMap);
if (shard == null)
{
// No empty shard exists, so create one
// Choose the shard name
string databaseName = string.Format(ShardNameFormat, shardMap.GetShards().Count());
// Only create the database if it doesn't already exist. It might already exist if
// we tried to create it previously but hit a transient fault.
if (!SqlDatabaseUtils.DatabaseExists(Configuration.ShardMapManagerServerName, databaseName))
{
SqlDatabaseUtils.CreateDatabase(Configuration.ShardMapManagerServerName, databaseName);
}
// Create schema and populate reference data on that database
// The initialize script must be idempotent, in case it was already run on this database
// and we failed to add it to the shard map previously
SqlDatabaseUtils.ExecuteSqlScript(
Configuration.ShardMapManagerServerName, databaseName, InitializeShardScriptFile);
// Add it to the shard map
ShardLocation shardLocation = new ShardLocation(Configuration.ShardMapManagerServerName, databaseName);
shard = ShardManagementUtils.CreateOrGetShard(shardMap, shardLocation);
}
return(shard);
}
/// <summary>
/// Creates a shard map manager, creates a shard map, and creates a shard
/// with a mapping for the full range of 32-bit integers.
/// </summary>
private static void CreateShardMapManagerAndShard()
{
if (MultiShardConfiguration.objShardMapManager != null)
{
ConsoleUtils.WriteWarning("Shard Map Manager already exists");
return;
}
// Create shard map manager database
if (!SqlDatabaseUtils.ExistsDatabase(MultiShardConfiguration.ShardMapManagerServerName, MultiShardConfiguration.ShardMapManagerDatabaseName))
{
SqlDatabaseUtils.CreateDatabase(MultiShardConfiguration.ShardMapManagerServerName, MultiShardConfiguration.ShardMapManagerDatabaseName);
}
// Create shard map manager
string shardMapManagerConnectionString = MultiShardConfiguration.GetConnectionString();
MultiShardConfiguration.objShardMapManager = ShardManagementUtils.CreateOrGetShardMapManager(shardMapManagerConnectionString);
// Create shard map
RangeShardMap <int> shardMap = ShardManagementUtils.CreateOrGetRangeShardMap <int>(
MultiShardConfiguration.objShardMapManager, MultiShardConfiguration.ShardMapName);
// Create schema info so that the split-merge service can be used to move data in sharded tables
// and reference tables.
CreateSchemaInfo(shardMap.Name);
// If there are no shards, add two shards: one for [0,100) and one for [100,+inf)
if (!shardMap.GetShards().Any())
{
CreateShardSample.CreateShard(shardMap, new Range <int>(0, 100));
CreateShardSample.CreateShard(shardMap, new Range <int>(100, 200));
}
}
/// <summary>
/// ExecuteMultiShardQuery method to get the database records using MultiShardConnection,
/// MultiShardCommand,multiShardDataReader class
/// </summary>
/// <param name="shardMap"></param>
/// <param name="credentialsConnectionString"></param>
public static void ExecuteMultiShardQuery(RangeShardMap <int> shardMap)
{
// Get the Shards from Shard Map manager
MultiShardConfiguration.Shards = shardMap.GetShards();
TestParameterValue testParameterValue
= new TestParameterValue(
"MultiShard", "ExecMultiShard", "SelectAll_DR",
"SqlDbWithMultiShard" + "%"
+ "individual" + "%"
+ "-",
new MyUserInfo("MultiShard", "MultiShard"));
// 分離レベルの設定
DbEnum.IsolationLevelEnum iso = DbEnum.IsolationLevelEnum.NoTransaction;
// B層を生成
LayerB myBusiness = new LayerB();
// 業務処理を実行
TestReturnValue testReturnValue =
(TestReturnValue)myBusiness.DoBusinessLogic(
(BaseParameterValue)testParameterValue, iso);
string strErrorMsg = "";
if (testReturnValue.ErrorFlag == true)
{
// 結果（業務続行可能なエラー）
strErrorMsg = "ErrorMessageID:" + testReturnValue.ErrorMessageID + "\r\n";
strErrorMsg += "ErrorMessage:" + testReturnValue.ErrorMessage + "\r\n";
strErrorMsg += "ErrorInfo:" + testReturnValue.ErrorInfo + "\r\n";
Console.WriteLine("Inserted failed for Error message : {0}", strErrorMsg);
}
else
{
//Converts Return value object to dataTable data to display the data in screen
DataTable dtTable = (DataTable)testReturnValue.Obj;
int rows = 0;
// Get the column names
TableFormatter formatter = new TableFormatter(ShardManagementUtils.GetColumnNames(dtTable).ToArray());
foreach (DataRow dr in dtTable.Rows)
{
// Extract just database name from the $ShardLocation pseudocolumn to make the output formater cleaner.
// Note that the $ShardLocation pseudocolumn is always the last column
int shardLocationOrdinal = dr.ItemArray.Length - 1;
dr.ItemArray[shardLocationOrdinal] = ShardManagementUtils.ExtractDatabaseName(dr.ItemArray[shardLocationOrdinal].ToString());
// Add values to output formatter
formatter.AddRow(dr.ItemArray);
rows++;
}
Console.WriteLine(formatter.ToString());
Console.WriteLine("({0} rows returned)", rows);
}
}
/// <summary>
/// Main program loop.
/// </summary>
private static void MenuLoop()
{
// Get the shard map manager, if it already exists.
// It is recommended that you keep only one shard map manager instance in
// memory per AppDomain so that the mapping cache is not duplicated.
MultiShardConfiguration.objShardMapManager = ShardManagementUtils.TryGetShardMapManager();
// Loop until the user chose "Exit".
bool continueLoop;
do
{
PrintShardMapState();
Console.WriteLine();
PrintMenu();
Console.WriteLine();
continueLoop = GetMenuChoiceAndExecute();
Console.WriteLine();
}while (continueLoop);
}
