Question

I am using log4net 1.2.10.0. I have extended ILog and LogManager to include a new level, ‘AUDIT’. I want to use an AdoNetAppender to log the %message to a database. I need other information logged and I tried using log4net.ThreadContext.Properties.

I get no output when I try to use a context property as a value for a SQL parameter.

<log4net>   <level>     <name value='AUDIT' />     <value value='35000' />   </level>   <appender name='AdoNetAppender.Audit' type='log4net.Appender.AdoNetAppender'>     <filter type='log4net.Filter.LevelMatchFilter'>       <levelToMatch value='AUDIT' />     </filter>     <filter type='log4net.Filter.DenyAllFilter' />     <connectionType value='System.Data.OracleClient.OracleConnection, System.Data.OracleClient, Version=1.0.3300.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' />     <connectionString value='data source=db1;User ID=user;Password=pass' />     <commandText value='INSERT INTO table1 VALUES(:custom_prop, :message)' />     <parameter>       <parameterName value=':custom_prop' />       <dbType value='String' />       <layout type='log4net.Layout.PatternLayout'>         <conversionPattern value='%property{custom_prop}' />       </layout>     </parameter>     <parameter>       <parameterName value=':message' />       <dbType value='String' />       <layout type='log4net.Layout.PatternLayout'>         <conversionPattern value='%message' />       </layout>     </parameter>   </appender>   <root>     <level value='ALL' />     <appender-ref ref='AdoNetAppender.Audit' />   </root> </log4net> 

The executing code is (assuming log4net has been init’ed and a logger, ‘log’, has been created).

log4net.ThreadContext.Properties['custom_prop'] = 'value'; log.Audit('a message'); 

The appender works with the AUDIT filter if I hard-code a value instead of using a SQL parameter.

... <commandText value='INSERT INTO table1 VALUES('value', :message)' /> ... 

The appender works with the context property if I filter on a built-in level, like INFO.

... <filter type='log4net.Filter.LevelMatchFilter'>   <levelToMatch value='INFO' /> </filter> ... 

A FileAppender works with the AUDIT filter and context property!

<appender name='FileAppender' type='log4net.Appender.FileAppender' >   <filter type='log4net.Filter.LevelMatchFilter'>     <levelToMatch value='AUDIT' />     </filter>   <filter type='log4net.Filter.DenyAllFilter' />   <file value='test.log' />   <layout type='log4net.Layout.PatternLayout' >     <conversionPattern value='%-5level [%property{custom_prop}] - %message%newline' />   </layout> </appender> 

Resulting in

AUDIT [value] - a message 

Using a global context property works with the AdoNetAppender and AUDIT filter. But, I need thread context resolution.

log4net.GlobalContext.Properties['custom_prop'] = 'value'; log.Audit('a message'); 

Resulting in

table1 custom_prop message =========== ======= value       a message 

So, I don’t know if it’s a problem with the AdoNetAppender or my extended classes or my configuration.

Answer 1

The problem was caused by early abortion of the foreground thread. I think log4net was running an async operation. Putting a sleep at the end of the test app fixed the problem

... log4net.ThreadContext.Properties['custom_prop'] = 'value'; log.Audit('a message'); ... Thread.Sleep(1000); 

or, when in a separate thread, joining on it

Thread t = new Thread(new ThreadStart(delegate {     log4net.ThreadContext.Properties['custom_prop'] = 'value';     log.Audit('a message');         })); t.Start(); ... t.Join(); 

In normal operation, log4net should have enough time between the latest AUDIT call and the end of execution.