Azure Function timer trigger failed runs execution of stored procedure

I want to execute stored procedure on my azure function timer trigger. The function deployed successfully. But, when the function runs, I get this error stack trace messages

Microsoft.Azure.WebJobs.Host.FunctionInvocationException:
...
System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw:
...
Inner exception System.ComponentModel.Win32Exception handled at System.Data.SqlClient.SqlConnection.OnError:
...

Here is the code,

[FunctionName("DimensionFactTableUpdate")]
public static async Task Run([TimerTrigger("%CronJobSchedule%")]TimerInfo myTimer, TraceWriter log)
{
    log.Info($"C# Timer trigger UpdateFactDimensionTable function executed at: {DateTime.Now}");
    var _connectionString = Environment.GetEnvironmentVariable("DbConnectionString");
    var _storedProcedureDimension = Environment.GetEnvironmentVariable("StoredProcedureDimension");

    if (string.IsNullOrEmpty(_connectionString) || string.IsNullOrEmpty(_storedProcedureDimension))            
        return;            

    #region UPDATE DIMENSION TABLE
    try
    {
        log.Info($"[START] Update dimension table at: {DateTime.Now}");
        using (var connection = new SqlConnection(_connectionString))
        {
            connection.Open();
            using (var command = new SqlCommand(_storedProcedureDimension, connection) { CommandType = System.Data.CommandType.StoredProcedure })
            {
                var status = await command.ExecuteNonQueryAsync();
            }
        }
        log.Info($"[END] Update Dimension table at: {DateTime.Now}");
    }
    catch(Exception ex)
    {
        log.Error(ex.ToString());
    }            
    #endregion 
}

Thanks.

======

EDITED :

Here is the exception messages,

System.Data.SqlClient.SqlException (0x80131904): Execution Timeout Expired.  The timeout period elapsed prior to completion of the operation or the server is not responding.

So you received a Timeout exception:

This can mean 2 things. You are not able to login to the SQL Server. Does this exception occur on the Open() statement?
Then Investigate the login issues:

• Is your connection string correct?
• Is your database (tcp and port) accessible from azure? (this is Ok if you are using Azure SQL Databases)
• Does the login have the correct permissions?
• Check the SQL server error log sp_readerrorlog for more information why the login failed.

Otherwise if you receive the exception on ExecuteNonQueryAsync it's a timeout.

Option 1: The easy way, but not necessarily the best

Increase the timeout on the SqlCommand like

command.CommandTimeout = 60; // 60 seconds = 1 Minute

Option 2: The costly way

Scale out your SQL Server DB (assuming you are using Azure SQL)

Option 3 : The most time consuming way

Investigate why your Stored Procedure is slow, and solve this. This could have many issues, blocking, waits, poor or no indexes, cursors/whiles, ...