/// <summary>
/// Returns a random existing Primary Key value
/// </summary>
private int GetRandomPK(Random rnd, TableMetadata table)
{
using (DataStressConnection conn = CreateConnection())
{
conn.Open();
// This technique to get a random row comes from http://www.4guysfromrolla.com/webtech/042606-1.shtml
// When you set rowcount and then select into a scalar value, then the query is optimised so that
// just the last value is selected. So if n = ROWCOUNT then the query returns the n'th row.
int rowNumber = rnd.Next(Depth);
DbCommand com = conn.CreateCommand();
string cmdText = string.Format(
@"SET ROWCOUNT {0};
DECLARE @PK INT;
SELECT @PK = PrimaryKey FROM {1} WITH(NOLOCK)
SELECT @PK", rowNumber, table.TableName);
com.CommandText = cmdText;
object result = com.ExecuteScalarSyncOrAsync(CancellationToken.None, rnd).Result;
if (result == DBNull.Value)
{
throw DataStressErrors.TestError(string.Format("Table {0} returned DBNull for primary key", table.TableName));
}
else
{
int primaryKey = (int)result;
return(primaryKey);
}
}
}
/// <summary>
/// Returns a random command object
/// </summary>
public DbCommand GetCommand(Random rnd, TableMetadata table, DataStressConnection conn, bool query, bool isXml = false)
{
if (query)
{
return(GetSelectCommand(rnd, table, conn, isXml));
}
else
{
// make sure arguments are correct
DataStressErrors.Assert(!isXml, "wrong usage of GetCommand: cannot create command with FOR XML that is not query");
int select = rnd.Next(4);
switch (select)
{
case 0:
return(GetUpdateCommand(rnd, table, conn));
case 1:
return(GetInsertCommand(rnd, table, conn));
case 2:
return(GetDeleteCommand(rnd, table, conn));
default:
return(GetSelectCommand(rnd, table, conn));
}
}
}
public virtual void GlobalTestSetup()
{
// Preconditions - ensure this setup is only called once
DataStressErrors.Assert(string.IsNullOrEmpty(s_scenario), "Scenario was already set");
DataStressErrors.Assert(s_source == null, "Source was already set");
DataStressErrors.Assert(s_factory == null, "Factory was already set");
// Set m_scenario
string userProvidedScenario;
TestMetrics.Overrides.TryGetValue("scenario", out userProvidedScenario);
// Empty means default scenario for the test group
s_scenario = (userProvidedScenario ?? string.Empty);
s_scenario = s_scenario.ToUpperInvariant();
// Set m_source
// Empty means that test group will peek the default data source from the config file based on the scenario
string userProvidedSourceName;
if (TestMetrics.Overrides.TryGetValue("source", out userProvidedSourceName))
{
s_source = DataStressSettings.Instance.GetSourceByName(userProvidedSourceName);
}
// Set m_factory
s_factory = CreateFactory(ref s_scenario, ref s_source);
s_factory.InitializeSharedData(s_source);
// Postconditions
DataStressErrors.Assert(!string.IsNullOrEmpty(s_scenario), "Scenario was not set");
DataStressErrors.Assert(s_source != null, "Source was not set");
DataStressErrors.Assert(s_factory != null, "Factory was not set");
}
private void HandleObjectDisposedException(ObjectDisposedException e, bool async)
{
// Race condition in DbConnectionFactory.TryGetConnection results in an ObjectDisposedException when calling OpenAsync on a non-pooled connection
string methodName = async ? "OpenAsync()" : "Open()";
throw DataStressErrors.ProductError(
"Hit ObjectDisposedException in SqlConnection." + methodName, e);
}
public void TestCommandTimeout()
{
Random rnd = RandomInstance;
DataStressConnection conn = null;
try
{
// Use a transaction 50% of the time
if (rnd.NextBool())
{
}
// Create a select command
conn = Factory.CreateConnection(rnd);
if (!OpenConnection(conn))
{
return;
}
DataStressFactory.TableMetadata table = Factory.GetRandomTable(rnd);
DbCommand com = Factory.GetSelectCommand(rnd, table, conn);
// Setup timeout. We want to see various possibilities of timeout happening before, after, or at the same time as when the result comes in.
int delay = rnd.Next(0, 10); // delay is from 0 to 9 seconds inclusive
int timeout = rnd.Next(1, 10); // timeout is from 1 to 9 seconds inclusive
com.CommandText += string.Format("; WAITFOR DELAY '00:00:0{0}'", delay);
com.CommandTimeout = timeout;
// Execute command and catch timeout exception
try
{
CommandExecute(rnd, com, true);
}
catch (DbException e)
{
if (e is SqlException && ((SqlException)e).Number == 3989)
{
throw DataStressErrors.ProductError("Timing issue between OnTimeout and ReadAsyncCallback results in SqlClient's packet parsing going out of sync", e);
}
else if (!e.Message.ToLower().Contains("timeout"))
{
throw;
}
}
}
finally
{
if (conn != null)
{
conn.Dispose();
}
}
}
/// <summary>
/// Creates a new connection and initializes it with random connection string generated from the factory's source
/// Note: if rnd is null, create a connection with minimal string required to connect to the target database
/// </summary>
/// <param name="rnd">Randomizes Connection Pool enablement, the application Name to randomize connection pool</param>
/// <param name="options"></param>
/// <returns></returns>
public DataStressConnection CreateConnection(Random rnd = null, ConnectionStringOptions options = ConnectionStringOptions.Default)
{
// Determine connection options (connection string, identity, etc)
string connectionString = CreateBaseConnectionString(rnd, options);
bool clearPoolBeforeClose = false;
if (rnd != null)
{
// Connection string and/or identity are randomized
// We implement this using the Application Name field in the connection string since this field
// should not affect behaviour other than connection pooling, since all connections in a pool
// must have the exact same connection string (including Application Name)
if (rnd.NextBool(.1))
{
// Disable pooling
connectionString = connectionString + ";Pooling=false;";
}
else if (rnd.NextBool(0.001))
{
// Use a unique Application Name to get a new connection from a new pool. We do this in order to
// stress the code that creates/deletes pools.
connectionString = string.Format("{0}; Pooling=true; Application Name=\"{1}\";", connectionString, GetRandomApplicationName());
// Tell DataStressConnection to call SqlConnection.ClearPool when closing the connection. This ensures
// we do not keep a large number of connections in the pool that we will never use again.
clearPoolBeforeClose = true;
}
else
{
switch (CurrentPoolingStressMode)
{
case PoolingStressMode.RandomizeConnectionStrings:
// Use one of the pre-generated Application Names in order to get a pooled connection with a randomized connection string
connectionString = string.Format("{0}; Pooling=true; Application Name=\"{1}\";", connectionString, _applicationNames[rnd.Next(_applicationNames.Count)]);
break;
default:
throw DataStressErrors.UnhandledCaseError(CurrentPoolingStressMode);
}
}
}
// All options have been determined, now create
DbConnection con = DbFactory.CreateConnection();
con.ConnectionString = connectionString;
return(new DataStressConnection(con, clearPoolBeforeClose));
}
/// <summary>
/// Kills the given connection using "kill [spid]" if the parameter is nonzero
/// </summary>
private void KillConnection()
{
DataStressErrors.Assert(_spid != 0, "Called KillConnection with spid != 0");
using (var killerConn = DataTestGroup.Factory.CreateConnection())
{
killerConn.Open();
using (var killerCmd = killerConn.CreateCommand())
{
killerCmd.CommandText = "begin try kill " + _spid + " end try begin catch end catch";
killerCmd.ExecuteNonQuery();
}
}
}
protected virtual object GetRandomData(Random rnd, DbType dbType, int maxLength)
{
byte[] buffer;
switch (dbType)
{
case DbType.Boolean:
return(rnd.Next(2) == 0 ? false : true);
case DbType.Byte:
return(rnd.Next(byte.MinValue, byte.MaxValue + 1));
case DbType.Int16:
return(rnd.Next(short.MinValue, short.MaxValue + 1));
case DbType.Int32:
return(rnd.Next(2) == 0 ? int.MaxValue / rnd.Next(1, 3) : int.MinValue / rnd.Next(1, 3));
case DbType.Int64:
return(rnd.Next(2) == 0 ? long.MaxValue / rnd.Next(1, 3) : long.MinValue / rnd.Next(1, 3));
case DbType.Single:
return(rnd.NextDouble() * (rnd.Next(2) == 0 ? float.MaxValue : float.MinValue));
case DbType.Double:
return(rnd.NextDouble() * (rnd.Next(2) == 0 ? double.MaxValue : double.MinValue));
case DbType.Decimal:
return(rnd.Next(short.MinValue, short.MaxValue + 1));
case DbType.DateTime:
case DbType.DateTime2:
return(DateTime.Now);
case DbType.Date:
return(DateTime.Now.Date);
case DbType.Time:
return(DateTime.Now.TimeOfDay.ToString("c"));
case DbType.DateTimeOffset:
return(DateTimeOffset.Now);
case DbType.Guid:
buffer = new byte[16];
rnd.NextBytes(buffer);
return(new Guid(buffer));
case DbType.Object:
case DbType.Binary:
rnd.NextBytes(buffer = new byte[rnd.Next(1, maxLength)]);
return(buffer);
case DbType.String:
case DbType.Xml:
string openTag = "<Data>";
string closeTag = "</Data>";
int tagLength = openTag.Length + closeTag.Length;
if (tagLength > maxLength)
{
// Case (1): tagLength > maxTargetLength
return("");
}
else
{
StringBuilder builder = new StringBuilder(maxLength);
builder.Append(openTag);
// The data is just a repeat of one character because to the managed provider
// it is only really the length that matters, not the content of the data
char characterToUse = (char)rnd.Next((int)'@', (int)'~'); // Choosing random characters in this range to avoid special
// xml chars like '<' or '&'
int numRepeats = rnd.Next(0, maxLength - tagLength); // Case (2): tagLength == maxTargetLength
// Case (3): tagLength < maxTargetLength <-- most common
builder.Append(characterToUse, numRepeats);
builder.Append(closeTag);
DataStressErrors.Assert(builder.Length <= maxLength, "Incorrect length of randomly generated string");
return(builder.ToString());
}
default:
throw DataStressErrors.UnhandledCaseError(dbType);
}
}
private DbType GetDbType(TableColumn column)
{
switch (column.ColumnName)
{
case "bit_FLD": return(DbType.Boolean);
case "tinyint_FLD": return(DbType.Byte);
case "smallint_FLD": return(DbType.Int16);
case "int_FLD": return(DbType.Int32);
case "PrimaryKey": return(DbType.Int32);
case "bigint_FLD": return(DbType.Int64);
case "real_FLD": return(DbType.Single);
case "float_FLD": return(DbType.Double);
case "smallmoney_FLD": return(DbType.Decimal);
case "money_FLD": return(DbType.Decimal);
case "decimal_FLD": return(DbType.Decimal);
case "numeric_FLD": return(DbType.Decimal);
case "datetime_FLD": return(DbType.DateTime);
case "smalldatetime_FLD": return(DbType.DateTime);
case "datetime2_FLD": return(DbType.DateTime2);
case "timestamp_FLD": return(DbType.Binary);
case "date_FLD": return(DbType.Date);
case "time_FLD": return(DbType.Time);
case "datetimeoffset_FLD": return(DbType.DateTimeOffset);
case "uniqueidentifier_FLD": return(DbType.Guid);
case "sql_variant_FLD": return(DbType.Object);
case "image_FLD": return(DbType.Binary);
case "varbinary_FLD": return(DbType.Binary);
case "binary_FLD": return(DbType.Binary);
case "char_FLD": return(DbType.String);
case "varchar_FLD": return(DbType.String);
case "text_FLD": return(DbType.String);
case "ntext_FLD": return(DbType.String);
case "nvarchar_FLD": return(DbType.String);
case "nchar_FLD": return(DbType.String);
case "nvarcharmax_FLD": return(DbType.String);
case "varbinarymax_FLD": return(DbType.Binary);
case "varcharmax_FLD": return(DbType.String);
case "xml_FLD": return(DbType.Xml);
default: throw DataStressErrors.UnhandledCaseError(column.ColumnName);
}
}
protected DataStressFactory(DbProviderFactory factory)
{
DataStressErrors.Assert(factory != null, "Argument to DataStressFactory constructor is null");
this.DbFactory = factory;
}
