Microsoft.Data.SqlClient.LocalAppContextSwitches

static class LocalAppContextSwitches

This class provides immutable access to the app context switches used throughout the codebase. Each switch value is read once (on first access) and cached for future access. Most switch values are obtained solely from the AppContext, but some switches may use other mechanisms to determine their values as well (e.g. environment variables).

public static bool DisableTnirByDefault { get; }

Transparent Network IP Resolution (TNIR) is a revision of the existing MultiSubnetFailover feature. TNIR affects the connection sequence of the driver in the case where the first resolved IP of the hostname doesn't respond and there are multiple IPs associated with the hostname. TNIR interacts with MultiSubnetFailover to provide the following three connection sequences: 0: One IP is attempted, followed by all IPs in parallel 1: All IPs are attempted in parallel 2: All IPs are attempted one after another TransparentNetworkIPResolution is enabled by default. MultiSubnetFailover is disabled by default. To disable TNIR, you can enable the app context switch. The default value of this switch is false.

public static bool EnableMultiSubnetFailoverByDefault { get; }

When set to true, the default value for MultiSubnetFailover connection string property will be true instead of false. This enables parallel IP connection attempts for improved connection times in multi-subnet environments. The default value of this switch is false.

public static bool GlobalizationInvariantMode { get; }

.NET Framework does not support Globalization Invariant mode, so this will always be false.

public static bool IgnoreServerProvidedFailoverPartner { get; }

When set to true, the failover partner provided by the server during connection will be ignored. This is useful in scenarios where the application wants to control the failover behavior explicitly (e.g. using a custom port). The application must be kept up to date with the failover configuration of the server. The application will not automatically discover a newly configured failover partner. The default value of this switch is false.

public static bool LegacyRowVersionNullBehavior { get; }

In System.Data.SqlClient and Microsoft.Data.SqlClient prior to 3.0.0 a field with type Timestamp/RowVersion would return an empty byte array. This switch controls whether to preserve that behaviour on newer versions of Microsoft.Data.SqlClient, if this switch returns false an appropriate null value will be returned. The default value of this switch is false.

public static bool LegacyVarTimeZeroScaleBehaviour { get; }

When set to 'true' this will output a scale value of 7 (DEFAULT_VARTIME_SCALE) when the scale is explicitly set to zero for VarTime data types ('datetime2', 'datetimeoffset' and 'time') If no scale is set explicitly it will continue to output scale of 7 (DEFAULT_VARTIME_SCALE) regardless of switch value. The default value of this switch is true.

public static bool MakeReadAsyncBlocking { get; }

When enabled, ReadAsync runs asynchronously and does not block the calling thread. The default value of this switch is false.

public static bool SuppressInsecureTlsWarning { get; }

When using Encrypt=false in the connection string, a security warning is output to the console if the TLS version is 1.2 or lower. This warning can be suppressed by enabling this AppContext switch. The default value of this switch is false.

public static bool TruncateScaledDecimal { get; }

When set to true, TdsParser will truncate (rather than round) decimal and SqlDecimal values when scaling them. The default value of this switch is false.

public static bool UseCompatibilityAsyncBehaviour { get; }

In TdsParser, the async multi-packet column value fetch behavior can use a continue snapshot state for improved efficiency. When this switch is enabled (the default), the driver preserves the legacy compatibility behavior, which does not use the continue snapshot state. When disabled, the new behavior using the continue snapshot state is enabled. This switch will always return true if UseCompatibilityProcessSni is enabled, because the continue state is not stable without the multiplexer. The default value of this switch is true.

public static bool UseCompatibilityProcessSni { get; }

In TdsParser, the ProcessSni function changed significantly when the packet multiplexing code needed for high speed multi-packet column values was added. When this switch is set to true (the default), the old ProcessSni design is used. When this switch is set to false, the new experimental ProcessSni behavior using the packet multiplexer is enabled. The default value of this switch is true.

public static bool UseConnectionPoolV2 { get; }

When set to true, the connection pool will use the new V2 connection pool implementation. When set to false, the connection pool will use the legacy V1 implementation. The default value of this switch is false.

public static bool UseManagedNetworking { get; }

.NET Framework does not support the managed SNI, so this will always be false.

public static bool UseMinimumLoginTimeout { get; }

Specifies minimum login timeout to be set to 1 second instead of 0 seconds, to prevent a login attempt from waiting indefinitely. The default value of this switch is true.