How to control log4net.Appender.SmtpAppender email trigger

Question

I am using log4net.Appender.SmtpAppender in application. This is how it is configured.

  <appender name="FatalSmtpAppender" type="log4net.Appender.SmtpAppender">
  <to value="...." />
  <from value="......" />
  <subject value="URGENT: Error occured" />
  <smtpHost value="....." />
  <bufferSize value="1" />
  <lossy value="false" />
  <filter type="log4net.Filter.LevelRangeFilter">
    <levelMin value="FATAL" />
    <levelMax value="FATAL" />
  </filter>
  <layout type="log4net.Layout.PatternLayout">
    <conversionPattern value="%newline%date [%thread] %-5level %logger [%property{NDC}] - %message%newline%newline%newline" />
  </layout>
</appender>

It is working as expected so far.

Now there is change in business requirement. If there is an error, system will try to fix 3 times. After all attempts are failed, it should send email.

3 attempts to fix error part is coded. But the log4net sends email on first occurrence of error. I don't know how to hold email until 3 attempts.

I hope it is not confusing. Thanks!!!

If you have logic to count the number of attempts, then you should only call the log4net log command whenever it has exceeded that number. — sgmoore, May 15 '15 at 19:14

score 0 · Answer 1 · answered May 16 '15 at 18:21

The logic of sending a error after 3 attempts is best solved in the business logic not in an smtp appender.

int failurecount = 0;
while (true){   
...
  try{
  ... 
  }catch(...){
      failurecount++;
      if (failurecount == 3){
          _logger.Error(...);
           break;
      } // else log warning
  }
}

Appenders do not know how error relate to each other and you have to keep in mind that log4net is a best-effort and fail-stop logging system. You will not be informed if log4net fails to log. See https://logging.apache.org/log4net/release/faq.html for more information.

How to control log4net.Appender.SmtpAppender email trigger

1 Answers1