Remove ConnectionIdlePingTime behaviour. Fixes #1042

- 'Connection Reset = True' will perform a server roundtrip to reset the connection.
- 'Connection Reset = False' will return a connection from the pool (if one exists); the client should use appropriate retry logic to reopen the connection if the first communication with the server fails.

Signed-off-by: Bradley Grainger <[email protected]>

Author: bgrainger

docs/content/api/MySqlConnector/MySqlConnectionStringBuilder/ConnectionIdlePingTime.md

@@ -28,7 +28,6 @@ public sealed class MySqlConnectionStringBuilder : DbConnectionStringBuilder
 | [CertificateStoreLocation](../MySqlConnectionStringBuilder/CertificateStoreLocation/) { get; set; } | Uses a certificate from the specified Certificate Store on the machine. The default value of None means the certificate store is not used; a value of CurrentUser or LocalMachine uses the specified store. |
 | [CertificateThumbprint](../MySqlConnectionStringBuilder/CertificateThumbprint/) { get; set; } | Specifies which certificate should be used from the Certificate Store specified in [`CertificateStoreLocation`](../MySqlConnectionStringBuilder/CertificateStoreLocation/). This option must be used to indicate which certificate in the store should be used for authentication. |
 | [CharacterSet](../MySqlConnectionStringBuilder/CharacterSet/) { get; set; } | Supported for backwards compatibility; MySqlConnector always uses `utf8mb4`. |
-| [ConnectionIdlePingTime](../MySqlConnectionStringBuilder/ConnectionIdlePingTime/) { get; set; } | The delay (in seconds) before idle connections are pinged (to determine liveness) when being retrieved from the pool. |
 | [ConnectionIdleTimeout](../MySqlConnectionStringBuilder/ConnectionIdleTimeout/) { get; set; } | The amount of time (in seconds) that a connection can remain idle in the pool. |
 | [ConnectionLifeTime](../MySqlConnectionStringBuilder/ConnectionLifeTime/) { get; set; } | The maximum lifetime (in seconds) for any connection, or `0` for no lifetime limit. |
 | [ConnectionProtocol](../MySqlConnectionStringBuilder/ConnectionProtocol/) { get; set; } | The protocol to use to connect to the MySQL Server. |

docs/content/api/MySqlConnector/MySqlConnectionStringBuilderType.md

@@ -169,20 +169,7 @@ Connection pooling is enabled by default. These options are used to configure it
   <tr id="ConnectionReset">
     <td>Connection Reset, ConnectionReset</td>
     <td><code>true</code></td>
-    <td>If <code>true</code>, all connections retrieved from the pool will have been reset. The default value of <code>true</code> ensures that the connection is in the same state whether it’s newly created or retrieved from the pool. A value of <code>false</code> avoids making an additional server round trip to reset the connection, but the connection state is not reset, meaning that session variables and other session state changes from any previous use of the connection are carried over.</td>
-  </tr>
-  <tr id="ConnectionIdlePingTime">
-    <td>Connection Idle Ping Time, ConnectionIdlePingTime <em>(Experimental)</em></td>
-    <td>0</td>
-    <td>When a connection is retrieved from the pool, and <code>ConnectionReset</code> is <code>false</code>, the server
-      will be pinged if the connection has been idle in the pool for longer than <code>ConnectionIdlePingTime</code> seconds.
-      If pinging the server fails, a new connection will be opened automatically by the connection pool. This ensures that the
-      <code>MySqlConnection</code> is in a valid, open state after the call to <code>Open</code>/<code>OpenAsync</code>,
-      at the cost of an extra server roundtrip. For high-performance scenarios, you may wish to set <code>ConnectionIdlePingTime</code>
-      to a non-zero value to make the connection pool assume that recently-returned connections are still open. If the
-      connection is broken, it will throw from the first call to <code>ExecuteNonQuery</code>, <code>ExecuteReader</code>,
-      etc.; your code should handle that failure and retry the connection. This option has no effect if <code>ConnectionReset</code>
-      is <code>true</code>, as that will cause a connection reset packet to be sent to the server, making ping redundant.
+    <td>If <code>true</code>, all connections retrieved from the pool will have been reset. The default value of <code>true</code> ensures that the connection is in the same state whether it’s newly created or retrieved from the pool. A value of <code>false</code> avoids making an additional server round trip to reset the connection, but the connection state is not reset, meaning that session variables and other session state changes from any previous use of the connection are carried over. Additionally (if <code>Connection Reset</code> is <code>false</false>), when <code>MySqlConnection.Open</code> returns a connection from the pool (instead of opening a new one), the connection may be invalid (and throw an exception on first use) if the server has closed the connection.</td>
   </tr>
   <tr id="ConnectionIdleTimeout">
     <td>Connection Idle Timeout, ConnectionIdleTimeout</td>

docs/content/connection-options.md

@@ -67,17 +67,9 @@ public async ValueTask<ServerSession> GetSessionAsync(MySqlConnection connection
 				else
 				{
 					if (ConnectionSettings.ConnectionReset || session.DatabaseOverride is not null)
-					{
 						reuseSession = await session.TryResetConnectionAsync(ConnectionSettings, null, false, ioBehavior, cancellationToken).ConfigureAwait(false);
-					}
-					else if ((unchecked((uint) Environment.TickCount) - session.LastReturnedTicks) >= ConnectionSettings.ConnectionIdlePingTime)
-					{
-						reuseSession = await session.TryPingAsync(logInfo: false, ioBehavior, cancellationToken).ConfigureAwait(false);
-					}
 					else
-					{
 						reuseSession = true;
-					}
 				}
 
 				if (!reuseSession)

src/MySqlConnector/Core/ConnectionPool.cs

@@ -112,7 +112,6 @@ public ConnectionSettings(MySqlConnectionStringBuilder csb)
 		Pooling = csb.Pooling;
 		ConnectionLifeTime = Math.Min(csb.ConnectionLifeTime, uint.MaxValue / 1000) * 1000;
 		ConnectionReset = csb.ConnectionReset;
-		ConnectionIdlePingTime = Math.Min(csb.ConnectionIdlePingTime, uint.MaxValue / 1000) * 1000;
 		ConnectionIdleTimeout = (int) csb.ConnectionIdleTimeout;
 #pragma warning disable 618
 		if (!csb.DeferConnectionReset)
@@ -212,7 +211,6 @@ private static MySqlGuidFormat GetEffectiveGuidFormat(MySqlGuidFormat guidFormat
 	public bool Pooling { get; }
 	public uint ConnectionLifeTime { get; }
 	public bool ConnectionReset { get; }
-	public uint ConnectionIdlePingTime { get; }
 	public int ConnectionIdleTimeout { get; }
 	public int MinimumPoolSize { get; }
 	public int MaximumPoolSize { get; }
@@ -298,7 +296,6 @@ private ConnectionSettings(ConnectionSettings other, string host, int port, stri
 		Pooling = other.Pooling;
 		ConnectionLifeTime = other.ConnectionLifeTime;
 		ConnectionReset = other.ConnectionReset;
-		ConnectionIdlePingTime = other.ConnectionIdlePingTime;
 		ConnectionIdleTimeout = other.ConnectionIdleTimeout;
 		MinimumPoolSize = other.MinimumPoolSize;
 		MaximumPoolSize = other.MaximumPoolSize;

src/MySqlConnector/Core/ConnectionSettings.cs

@@ -339,12 +339,12 @@ public bool ConnectionReset
 	}
 
 	/// <summary>
-	/// The delay (in seconds) before idle connections are pinged (to determine liveness) when being retrieved from the pool.
+	/// This option is no longer supported.
 	/// </summary>
-	[Category("Pooling")]
+	[Category("Obsolete")]
 	[DefaultValue(0u)]
-	[Description("The delay (in seconds) before idle connections are pinged (to determine liveness) when being retrieved from the pool.")]
 	[DisplayName("Connection Idle Ping Time")]
+	[Obsolete("This option is no longer supported in MySqlConnector >= 1.4.0.")]
 	public uint ConnectionIdlePingTime
 	{
 		get => MySqlConnectionStringOption.ConnectionIdlePingTime.GetValue(this);
@@ -368,8 +368,8 @@ public uint ConnectionIdleTimeout
 	/// This option is no longer supported.
 	/// </summary>
 	[Category("Obsolete")]
-	[DisplayName("Defer Connection Reset")]
 	[DefaultValue(true)]
+	[DisplayName("Defer Connection Reset")]
 	[Obsolete("This option is no longer supported in MySqlConnector >= 1.4.0.")]
 	public bool DeferConnectionReset
 	{

src/MySqlConnector/MySqlConnectionStringBuilder.cs

@@ -39,6 +39,7 @@ public void Defaults()
 #else
 		Assert.True(csb.ConnectionReset);
 #pragma warning disable 618
+		Assert.Equal(0u, csb.ConnectionIdlePingTime);
 		Assert.True(csb.DeferConnectionReset);
 #pragma warning restore 618
 #endif
@@ -51,7 +52,6 @@ public void Defaults()
 		Assert.Equal(30u, csb.DefaultCommandTimeout);
 #if !BASELINE
 		Assert.Equal("", csb.ApplicationName);
-		Assert.Equal(0u, csb.ConnectionIdlePingTime);
 		Assert.Equal(180u, csb.ConnectionIdleTimeout);
 		Assert.False(csb.ForceSynchronous);
 		Assert.Equal(MySqlGuidFormat.Default, csb.GuidFormat);
@@ -127,7 +127,6 @@ public void ParseConnectionString()
 #if !BASELINE
 				"application name=My Test Application;" +
 				"cancellation timeout = -1;" +
-				"connection idle ping time=60;" +
 				"connectionidletimeout=30;" +
 				"defer connection reset=true;" +
 				"forcesynchronous=true;" +
@@ -188,7 +187,6 @@ public void ParseConnectionString()
 		Assert.Equal(123u, csb.DefaultCommandTimeout);
 #if !BASELINE
 		Assert.Equal("My Test Application", csb.ApplicationName);
-		Assert.Equal(60u, csb.ConnectionIdlePingTime);
 		Assert.Equal(30u, csb.ConnectionIdleTimeout);
 #pragma warning disable 618
 		Assert.True(csb.DeferConnectionReset);
@@ -499,7 +497,6 @@ public void ParseInvalidTlsVersion()
 	// not supported
 	[InlineData("Application Name", "MyApp")]
 	[InlineData("Cancellation Timeout", 5)]
-	[InlineData("Connection Idle Ping Time", 100u)]
 	[InlineData("Connection Idle Timeout", 10u)]
 	[InlineData("DateTime Kind", MySqlDateTimeKind.Utc)]
 	[InlineData("Force Synchronous", true)]