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log4net logging error in mysql database logging

i am using log4net for logging in mysql database. log4net configuration is correct and because i have tested to log in sql server and in file but when i'm writing logs in mysql database then it prompt an error to me.
my log4net config is below
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
</configSections>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6"/>
</startup>
<log4net>
<appender name="AdoNetAppender" type="log4net.Appender.AdoNetAppender">
<bufferSize value="1" />
<connectionType value="MySql.Data.MySqlClient.MySqlConnection, MySql.Data" />
<connectionString value="Server=127.0.0.1;Database=logdb;Uid=abc;Pwd=abc;" />
<commandText value="INSERT INTO log (timestamp,Thread,Level,Logger,Message) VALUES (?log_date, ?thread, ?log_level, ?logger, ?message);" />
<parameter>
<parameterName value="?log_date" />
<dbType value="DateTime" />
<layout type="log4net.Layout.RawTimeStampLayout" />
</parameter>
<parameter>
<parameterName value="?thread" />
<dbType value="String" />
<size value="32" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%thread" />
</layout>
</parameter>
<parameter>
<parameterName value="?log_level" />
<dbType value="String" />
<size value="32" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%level" />
</layout>
</parameter>
<parameter>
<parameterName value="?logger" />
<dbType value="String" />
<size value="256" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%logger" />
</layout>
</parameter>
<parameter>
<parameterName value="?message" />
<dbType value="String" />
<size value="4000" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%message" />
</layout>
</parameter>
</appender>
<root>
<level value="ALL" />
<appender-ref ref="AdoNetAppender" />
</root>
</log4net>
<appSettings>
<add key="log4net.Internal.Debug" value="true"/>
</appSettings>
<system.diagnostics>
<trace autoflush="true">
<listeners>
<add name="textWriterTraceListener" type="System.Diagnostics.TextWriterTraceListener" initializeData="C:\Logs\log4net.txt"/>
</listeners>
</trace>
</system.diagnostics>
</configuration>
and the log consuming code is here
class Program
{
private static readonly ILog Logger = LogManager.GetLogger(System.Environment.MachineName);
static void Main(string[] args)
{
log4net.Config.XmlConfigurator.Configure();
Logger.Info("Testing information log from .Net app");
Logger.Debug("Testing Debug log from .Net app");
Logger.Fatal("Testing Fatal log from .Net app");
}
}
i also the
"[assembly: log4net.Config.XmlConfigurator(ConfigFile = "Web.config", Watch = true)]
"
this line in assembly file.
the error i'm encountering is
**
log4net:ERROR [AdoNetAppender] ErrorCode: GenericFailure. Exception while writing to database
System.InvalidOperationException: Parameter '?log_date' was not found during prepare.
at MySql.Data.MySqlClient.PreparableStatement.Prepare()
at MySql.Data.MySqlClient.MySqlCommand.Prepare(Int32 cursorPageSize)
at MySql.Data.MySqlClient.MySqlCommand.Prepare()
at log4net.Appender.AdoNetAppender.SendBuffer(IDbTransaction dbTran, LoggingEvent[] events)
at log4net.Appender.AdoNetAppender.SendBuffer(LoggingEvent[] events)
log4net: Shutdown called on Hierarchy [log4net-default-repository]
**
but actually I'm passing all required parameters dnt know why I'm getting this error.
can anyone guide.

This is a bug in MySql.Data. There isn't a bug report filed for it as far as I know, but you can see from the MySqlConnector integration tests that MySql.Data fails if you call MySqlCommand.Prepare before adding the parameters.
However, that's exactly what AdoNetAppender does. (There is a try/catch block in that code, but that's a recent change, after 2.0.12.)
There are two possible fixes:
Switch to MySqlConnector and change the <connectionType /> to use it.
Add IgnorePrepare=true to your MySql.Data connection string, which will cause Prepare to be a no-op. (Note: this option was removed in 8.0.24.)

As #Bradley Grainger mentioned, MySqlConnector does the job
I sadly cannot comment but #hashimkayani asked for an example, I did try it out and it works perfectly fine:
<?xml version="1.0"?>
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
</configSections>
<appSettings>
<add key="log4net.Internal.Debug" value="true"/>
</appSettings>
<log4net>
<appender name="dbAppender" type="log4net.Appender.AdoNetAppender">
<bufferSize value="1" />
<connectionType value="MySqlConnector.MySqlConnection, MySqlConnector" />
<connectionString value="Server=localhost;Database=dbName;Uid=dbUser;Pwd=dbPassword;persistsecurityinfo=True;SslMode=none;" />
<commandText value="INSERT INTO afmlog(date, thread, level, logger, message) VALUES (#log_date, #thread, #log_level, #logger, #message);" />
<parameter>
<parameterName value="#log_date" />
<dbType value="DateTime" />
<layout type="log4net.Layout.PatternLayout" value="%date{yyyy'-'MM'-'dd HH':'mm':'ss'.'fff}" />
</parameter>
<parameter>
<parameterName value="#thread" />
<dbType value="String" />
<size value="255" />
<layout type="log4net.Layout.PatternLayout" value="%thread" />
</parameter>
<parameter>
<parameterName value="#log_level" />
<dbType value="String" />
<size value="50" />
<layout type="log4net.Layout.PatternLayout" value="%level" />
</parameter>
<parameter>
<parameterName value="#logger" />
<dbType value="String" />
<size value="255" />
<layout type="log4net.Layout.PatternLayout" value="%logger" />
</parameter>
<parameter>
<parameterName value="#message" />
<dbType value="String" />
<size value="4000" />
<layout type="log4net.Layout.PatternLayout" value="%message" />
</parameter>
</appender>
</log4net>
<system.diagnostics>
<trace autoflush="true">
<listeners>
<add
name="textWriterTraceListener"
type="System.Diagnostics.TextWriterTraceListener"
initializeData="C:\temp\log4net.txt" />
</listeners>
</trace>
</system.diagnostics>
</configuration>

log4net fails to create log file

im trying to set up logging for a group c# project using log4net for the 1st time and while no issues seem to arise when running my code, and the lines responsible for logging are definately being executed no log file is created and nothing is logged. nither in a log file or in console.
my log4net.config:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<log4net>
<root>
<level value="ALL" />
<appender-ref ref="console" />
<appender-ref ref="file" />
</root>
<appender name="console" type="log4net.Appender.ConsoleAppender">
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %level %logger - %message%newline" />
</layout>
</appender>
<appender name="file" type="log4net.Appender.RollingFileAppender">
<file value="myapp.log" />
<appendToFile value="true" />
<rollingStyle value="Size" />
<maxSizeRollBackups value="5" />
<maximumFileSize value="10MB" />
<staticLogFileName value="true" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %level %logger - %message%newline" />
</layout>
</appender>
</log4net>
</configuration>
my app.config:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<dependentAssembly>
<assemblyIdentity name="System.Numerics.Vectors" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-4.1.4.0" newVersion="4.1.4.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Runtime.CompilerServices.Unsafe" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-4.0.6.0" newVersion="4.0.6.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Buffers" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-4.0.3.0" newVersion="4.0.3.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.ValueTuple" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-4.0.3.0" newVersion="4.0.3.0" />
</dependentAssembly>
</assemblyBinding>
</runtime>
<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" /></startup></configuration>
i also have the line [assembly: log4net.Config.XmlConfigurator(ConfigFile = "log4net.config",Watch =true)] added to my AssemblyInfo.cs
the code itself is along the lines of:
private static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
log.Debug("this is a test log.");
also it's worth noting that im executing this project from a secondary project.
i tried following a setup guide but i must have missed something, i would very much appriciate some help.

Log4net - multiple appenders

I currently have two appenders, one is for logging in a file and the other is for logging in a database. The ado net appender is not working, it's not logging anything in the table. The rolling file appender however, works just fine. It logs in the file. If I remove the rolling file appender, the logging in the database works just fine.
Here's part of my app.config file:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<sectionGroup name="common">
<section name="logging" type="Common.Logging.ConfigurationSectionHandler, Common.Logging" />
</sectionGroup>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
</configSections>
<connectionStrings>
<add name="Log4NetDBConnection" connectionString="Data Source=localhost;Initial Catalog=DataProcessing;UID=dpp-user;PWD=dpp-user" providerName="System.Data.SqlClient" />
<common>
<logging>
<factoryAdapter type="Common.Logging.Log4Net.Log4NetLoggerFactoryAdapter, Common.Logging.Log4Net1211">
<arg key="configType" value="INLINE" />
</factoryAdapter>
</logging>
</common>
<log4net configSource="App.log4net.config" />
<dependentAssembly>
<assemblyIdentity name="Common.Logging.Core" publicKeyToken="af08829b84f0328e" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-3.3.0.0" newVersion="3.3.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Common.Logging" publicKeyToken="af08829b84f0328e" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-3.3.0.0" newVersion="3.3.0.0" />
</dependentAssembly>
</assemblyBinding>
And here is my App.Log4net.config file:
<log4net>
<!-- Needed for default logger behavior to the log table-->
<root>
<level value="ERROR" />
<level value="WARN" />
<appender-ref ref="AdoNetAppender" />
</root>
<appender name="AdoNetAppender" type="log4net.Appender.AdoNetAppender">
<bufferSize value="1" />
<connectionType value="System.Data.SqlClient.SqlConnection,System.Data, Version=1.0.3300.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
<connectionStringName value="DPPLog4NetDBConnection" />
<commandText value="INSERT INTO _Log ([Date],[Thread],[Level],[Logger],[Message],[Exception]) VALUES (#log_date, #thread, #log_level, #logger, #message, #exception)" />
<parameter>
<parameterName value="#log_date" />
<dbType value="DateTime" />
<layout type="log4net.Layout.RawTimeStampLayout" />
</parameter>
<parameter>
<parameterName value="#thread" />
<dbType value="String" />
<size value="255" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%thread" />
</layout>
</parameter>
<parameter>
<parameterName value="#log_level" />
<dbType value="String" />
<size value="50" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%level" />
</layout>
</parameter>
<parameter>
<parameterName value="#logger" />
<dbType value="String" />
<size value="255" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%logger" />
</layout>
</parameter>
<parameter>
<parameterName value="#message" />
<dbType value="String" />
<size value="4000" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%message" />
</layout>
</parameter>
<parameter>
<parameterName value="#exception" />
<dbType value="String" />
<size value="2000" />
<layout type="log4net.Layout.ExceptionLayout" />
</parameter>
<!-- <root>
<level value="DEBUG" />
<appender-ref ref="RollingFileAppender" />
</root>
<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
<level value="ALL" />
<file value="c:/logs/WorkflowEngineApp.log" />
<appendToFile value="true" />
<rollingStyle value="Size" />
<maxSizeRollBackups value="10" />
<maximumFileSize value="10MB" />
<staticLogFileName value="true" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %level %logger -
%message%newline%exception" />
</layout>
</appender> -->
</log4net>
As you can see, I have the rolling file appender commented because otherwise it only logs in a file. What am I doing wrong? Can I use these two appenders together?

I suspect your are on the right track, looks like both appenders needs to be specified in the same root see example and link below:
<root>
<level value="ERROR" />
<level value="WARN" />
<appender-ref ref="AdoNetAppender" />
<level value="DEBUG" />
<appender-ref ref="RollingFileAppender" />
</root>
File and Database multiple configuration for log4net

Log4net in web job: unrecognized configuration section log4net - but I have configSections in top

So I have a super weird issue. I have an Azure Web Job, where I want to have log4net added.
I have the following web.config file, which has the same elements as my web application which works. Please notice how my log4net declaration in configSections are in the top:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<connectionStrings>
<!-- The format of the connection string is "DefaultEndpointsProtocol=https;AccountName=NAME;AccountKey=KEY" -->
<!-- For local execution, the value can be set either in this config file or through environment variables -->
<add name="AzureWebJobsDashboard" connectionString="" />
<add name="AzureWebJobsStorage" connectionString="" />
<add name="DefaultConnection" connectionString="" providerName="System.Data.SqlClient" />
</connectionStrings>
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
</configSections>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2" />
</startup>
<appSettings>
<!--Azure Storage-->
<add key="StorageConnectionString" value="" />
<add key="DefaultStorageContainer" value="" />
<!-- GatawayApi SMS -->
<add key="GatewayApiServiceEnabled" value="FALSE" />
<add key="GatewayApiKey" value="" />
<add key="GatewayApiSecret" value="" />
<!-- Mandrill mail-->
<add key="MandrillApiServiceEnabled" value="TRUE" />
<add key="MandrillApiKey" value="" />
</appSettings>
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<dependentAssembly>
<assemblyIdentity name="Microsoft.WindowsAzure.Storage" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-7.0.0.0" newVersion="7.0.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-9.0.0.0" newVersion="9.0.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Data.Services.Client" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.7.0.0" newVersion="5.7.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Data.OData" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.7.0.0" newVersion="5.7.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Data.Edm" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.7.0.0" newVersion="5.7.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-1.5.2.14234" newVersion="1.5.2.14234" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Owin.Security.OAuth" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Owin.Security" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Owin.Security.Cookies" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
</dependentAssembly>
</assemblyBinding>
</runtime>
<log4net debug="true">
<appender name="AdoNetAppender" type="log4net.Appender.AdoNetAppender">
<bufferSize value="1" />
<connectionType value="System.Data.SqlClient.SqlConnection, System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
<connectionStringName value="DefaultConnection" />
<commandText value="INSERT INTO Log ([Date],[Thread],[Level],[Logger],[Message],[Exception]) VALUES (#log_date, #thread, #log_level, #logger, #message, #exception)" />
<parameter>
<parameterName value="#log_date" />
<dbType value="DateTime" />
<layout type="log4net.Layout.RawTimeStampLayout" />
</parameter>
<parameter>
<parameterName value="#thread" />
<dbType value="String" />
<size value="255" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%thread" />
</layout>
</parameter>
<parameter>
<parameterName value="#log_level" />
<dbType value="String" />
<size value="50" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%level" />
</layout>
</parameter>
<parameter>
<parameterName value="#logger" />
<dbType value="String" />
<size value="255" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%logger" />
</layout>
</parameter>
<parameter>
<parameterName value="#message" />
<dbType value="String" />
<size value="4000" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%message" />
</layout>
</parameter>
<parameter>
<parameterName value="#exception" />
<dbType value="String" />
<size value="2000" />
<layout type="log4net.Layout.ExceptionLayout" />
</parameter>
</appender>
<root>
<level value="DEBUG"/>
<appender-ref ref="AdoNetAppender" />
</root>
</log4net>
</configuration>
However, when I open the log on the Azure Web job in the dashboard:
Unhandled Exception: System.Configuration.ConfigurationErrorsException: Configuration system failed to initialize ---> System.Configuration.ConfigurationErrorsException: Unrecognized configuration section log4net. (D:\local\Temp\jobs\continuous\CommunicationSender\13a4pcai.5fk\CommunicationSender.exe.config line 70)
Anyone have any clue what is going on here? :-) What am I missing?
I initialize the log4net in the code like this, but I assume this is never hit because of configuration problem:
static void Main()
{
log4net.Config.XmlConfigurator.Configure();
ILog log = log4net.LogManager.GetLogger(typeof(Program));
log.Info("CommunicationSender STARTED! :-)");
var config = new JobHostConfiguration();
if (config.IsDevelopment)
{
config.UseDevelopmentSettings();
}
var host = new JobHost();
// The following code ensures that the WebJob will be running continuously
host.RunAndBlock();
}

The problem was solved by one of my employees. He pointed out that the configSection needs to be before the ConnectionStrings.
After switching those around, it worked!

How to track what adds a 'DefaultConnection' connection string to web.config of my MVC app

I have a weird problem - I have noticed that after web deployment of my MVC app, a new connection string is added to web.config file.
<add name="DefaultConnection" connectionString="DefaultConnection_ConnectionString" providerName="System.Data.SqlClient" />
I have no idea where it comes from, something adds it automatically.
Here is my web.config file after publishing
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
</configSections>
<connectionStrings>
<add name="AuditDbContext" connectionString="[An Azure connection string]" providerName="System.Data.SqlClient" />
<add name="DefaultConnection" connectionString="DefaultConnection_ConnectionString" providerName="System.Data.SqlClient" />
</connectionStrings>
<appSettings>
<add key="webpages:Version" value="3.0.0.0" />
<add key="webpages:Enabled" value="false" />
<add key="ClientValidationEnabled" value="true" />
<add key="UnobtrusiveJavaScriptEnabled" value="true" />
<add key="AuditingLevelModifier" value="0" />
<add key="AuditingMode" value="DatabaseAndLogger" />
<add key="IgnoreSslPolicyErrors" value="true" />
</appSettings>
<system.web>
<compilation targetFramework="4.6" />
<httpRuntime targetFramework="4.5.2" maxRequestLength="512000" />
<httpCookies httpOnlyCookies="true" requireSSL="true" lockItem="true" />
<httpModules>
<add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" />
</httpModules>
<customErrors mode="Off" />
</system.web>
<system.webServer>
<httpProtocol>
<customHeaders>
<add name="Strict-Transport-Security" value="max-age=16070400; includeSubDomains" />
</customHeaders>
</httpProtocol>
<security>
<requestFiltering>
<requestLimits maxAllowedContentLength="314572800" />
</requestFiltering>
</security>
<modules>
<remove name="ApplicationInsightsWebTracking" />
<add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" preCondition="managedHandler" />
</modules>
<validation validateIntegratedModeConfiguration="false" />
<handlers>
<remove name="ExtensionlessUrlHandler-Integrated-4.0" />
<remove name="OPTIONSVerbHandler" />
<remove name="TRACEVerbHandler" />
<add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
</handlers>
</system.webServer>
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<dependentAssembly>
<assemblyIdentity name="Microsoft.Owin.Security" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Owin.Security.OAuth" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Owin.Security.Cookies" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Newtonsoft.Json" culture="neutral" publicKeyToken="30ad4fe6b2a6aeed" />
<bindingRedirect oldVersion="0.0.0.0-10.0.0.0" newVersion="10.0.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Web.Optimization" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="1.1.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="0.0.0.0-1.5.2.14234" newVersion="1.5.2.14234" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Antlr3.Runtime" publicKeyToken="eb42632606e9261f" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-3.5.0.2" newVersion="3.5.0.2" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Web.Http" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Net.Http.Formatting" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="1.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.IdentityModel.Tokens" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.1.2.0" newVersion="5.1.2.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.IdentityModel.Logging" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-1.1.3.0" newVersion="1.1.3.0" />
</dependentAssembly>
</assemblyBinding>
</runtime>
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />
<providers>
<provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
</providers>
</entityFramework>
<system.codedom>
<compilers>
<compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701" />
<compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:14 /nowarn:41008 /define:_MYTYPE=\"Web\" /optionInfer+" />
</compilers>
</system.codedom>
<log4net>
<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
<file value="C:\Logs\Portal.log" />
<encoding value="utf-8" />
<appendToFile value="true" />
<rollingStyle value="Date" />
<datePattern value="dd.MM.yyyy'.log'" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %level [%thread] %type.%method - %message%n" />
</layout>
</appender>
<appender name="AuditTrailAppender" type="log4net.Appender.RollingFileAppender">
<file value="C:\Logs\AuditTrail.log" />
<encoding value="utf-8" />
<appendToFile value="true" />
<rollingStyle value="Date" />
<datePattern value="dd.MM.yyyy'.log'" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %level [%thread] %type.%method - %message%n" />
</layout>
</appender>
<appender name="TraceAppender" type="log4net.Appender.TraceAppender">
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %level [%thread] %type.%method - %message%n" />
</layout>
</appender>
<logger name="AuditTrailLogger" additivity="false">
<level value="ALL" />
<appender-ref ref="AuditTrailAppender" />
</logger>
<root>
<level value="Debug" />
<!-- If the following line is not included the log file
will not be created even if log4net is configured with this file. -->
<appender-ref ref="RollingFileAppender" />
<appender-ref ref="TraceAppender" />
</root>
</log4net>
</configuration>
I believe the only component of this web app which uses a connection string is Auditing module - EF is set to use another connection string (and it works) public AuditingContext() : base("name=AuditDbContext")
I am really puzzled where does it come from - especially that last night I had some weird errors related to this connection string.
Basically, I noticed that it gets added when I started getting this error
Format of the initialization string does not conform to specification
starting at index 0
At application startup - and when I removed the DefaultConnection, the error changed to a 'Network-related or instance-specific error occurred while establishing a connection to SQL Server.'
Anyway - how do I track where does it come from?
Cheers!

Ok, I've figured it out.
My pubxml profile adds it - look at these lines.
<ItemGroup>
<MSDeployParameterValue Include="$(DeployParameterPrefix)AuditDbContext-Web.config Connection String" />
<MSDeployParameterValue Include="$(DeployParameterPrefix)DefaultConnection-Web.config Connection String">
<UpdateDestWebConfig>False</UpdateDestWebConfig>
</MSDeployParameterValue>
</ItemGroup>
<ItemGroup>
<_ConnectionStringsToInsert Include="DefaultConnection" />
</ItemGroup>
I suppose it is being added because of the default code related to authorization, e.g.
app.CreatePerOwinContext(ApplicationDbContext.Create); in Startup
and
public ApplicationDbContext() : base("DefaultConnection", throwIfV1Schema: false) in IdentityModel class
Which leads me to more questions (why does it sometimes work!?), but that is out of scope of this question.