Случайный тайм -аут подключения NPGSQL в приложении .NET6 ⇐ C#

[Anonymous]

У меня есть этот кусок кода в программе.

Код: Выделить всё

List connections = new List();

for (int i = 0; i < 5; i++)
{

NpgsqlConnection connection = new NpgsqlConnection(connectionString);
try
{
connection.Open(); // This actually opens the connection

}
catch (Exception e)
{
continue;
}

connections.Add(connection);
}
connections.ForEach(connection => { connection.Close(); });
< /code>
Первая попытка создать соединение всегда терпит неудачу с тайм -аутом < /p>

2024-01-11T19:54:53.7699503+09:00 40000374-0003-fc00-b63f-84710c7967bb [INF] Entity Framework Core "6.0.19" initialized '"DbContextClass"' using provider '"Npgsql.EntityFrameworkCore.PostgreSQL":"6.0.8"' with options: "CommandTimeout=15 " (d2805559)
2024-01-11T19:55:09.4702152+09:00 40000374-0003-fc00-b63f-84710c7967bb [ERR] An error occurred using the connection to database '"my_db"' on server '""'. (5fc3407c)
2024-01-11T19:55:09.5272113+09:00 40000374-0003-fc00-b63f-84710c7967bb [INF] A transient exception occurred during execution.  The operation will be retried after 0ms."
""System.TimeoutException: The operation has timed out.
at Npgsql.Util.NpgsqlTimeout.Check()
at Npgsql.Util.NpgsqlTimeout.CheckAndGetTimeLeft()
at Npgsql.Util.NpgsqlTimeout.CheckAndApply(NpgsqlConnector connector)
at Npgsql.Internal.NpgsqlConnector.g__OpenCore|195_1(NpgsqlConnector conn, SslMode sslMode, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken, Boolean isFirstAttempt)
at Npgsql.Internal.NpgsqlConnector.Open(NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.ConnectorPool.OpenNewConnector(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.ConnectorPool.g__RentAsync|28_0(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.NpgsqlConnection.g__OpenAsync|45_0(Boolean async, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternalAsync(Boolean errorsExpected, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternalAsync(Boolean errorsExpected, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenAsync(CancellationToken cancellationToken, Boolean errorsExpected)
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.AsyncEnumerator.InitializeReaderAsync(AsyncEnumerator enumerator, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.c__DisplayClass33_0`2.d.MoveNext()
--- End of stack trace from previous location ---
at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.ExecuteImplementationAsync[TState,TResult](Func`4 operation, Func`4 verifySucceeded, TState state, CancellationToken cancellationToken)"  (43386701)
System.TimeoutException: The operation has timed out.
at Npgsql.Util.NpgsqlTimeout.Check()
at Npgsql.Util.NpgsqlTimeout.CheckAndGetTimeLeft()
at Npgsql.Util.NpgsqlTimeout.CheckAndApply(NpgsqlConnector connector)
at Npgsql.Internal.NpgsqlConnector.g__OpenCore|195_1(NpgsqlConnector conn, SslMode sslMode, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken, Boolean isFirstAttempt)
at Npgsql.Internal.NpgsqlConnector.Open(NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.ConnectorPool.OpenNewConnector(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.ConnectorPool.g__RentAsync|28_0(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.NpgsqlConnection.g__OpenAsync|45_0(Boolean async, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternalAsync(Boolean errorsExpected, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternalAsync(Boolean errorsExpected, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenAsync(CancellationToken cancellationToken, Boolean errorsExpected)
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.AsyncEnumerator.InitializeReaderAsync(AsyncEnumerator enumerator, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.c__DisplayClass33_0`2.d.MoveNext()
--- End of stack trace from previous location ---

< /code>
Но следующие попытки сделать то же самое достигнуто, и пул всегда создается с помощью 4 соединений < /p>
, и еще одна вещь - следовательно, созданные соединения автоматически закрываются через некоторое время, если я пытаюсь вызвать API, которые требуют некоторых данных из базы данных, первая попытка выполнить, что всегда выходит на неудачу, и это всегда выходит на неудачу, и это всегда выполняет.
builder.Services.AddDbContext(options =>
{
options.UseNpgsql(connectionString,
options =>
{
options.CommandTimeout(15);
options.EnableRetryOnFailure(2);
}
);
});

Это моя стратегия повторения.>

Подробнее здесь: https://stackoverflow.com/questions/777 ... pplication