jln646v jln646v - 1 month ago 27
Java Question

Logback SMTPAppender only sending last email

I am attempting to use

Logback
with
SMTPAppender
as my logging solution. I have an evaluator attached to the
appender
that triggers an email to be sent every 100 errors logged. For the most part this works correctly, but I've noticed if I create errors rapidly in a loop to trigger multiple emails, only the last email gets sent, with the correct content. It seems to be a race condition where the first email is not finished being created/sent, and the second one overwrites the first on creation. Has anyone else experienced this or found a solution. My logback config is attached below.

<configuration>
<appender name="emailAppender" class="${logback.emailAppenderClass}">
<evaluator class="com.wdp.common.logging.logback.evaluators.CountingLoggerEvaulator">
<limit>100</limit>
</evaluator>
<to>${logback.emailNotificationRecipientStr}</to>
<from>${logback.emailNotificationFromStr}</from>
<smtpHost>${logback.smtpHost}</smtpHost>
<subject>Logback logs for facebook-ads-processes</subject>
<filter class="ch.qos.logback.classic.filter.LevelFilter">
<level>ERROR</level>
<onMatch>ACCEPT</onMatch>
<onMismatch>DENY</onMismatch>
</filter>
<layout class="ch.qos.logback.classic.PatternLayout">
<pattern>%d [Thread:%t] %p [%c] - %m%n</pattern>
</layout>

<cyclicBufferTracker class="ch.qos.logback.core.spi.CyclicBufferTracker">
<bufferSize>${logback.cyclicBufferSize}</bufferSize>
</cyclicBufferTracker>
</appender>
</configuration>


This is the evaluator:

public class CountingLoggerEvaulator extends EventEvaluatorBase<ILoggingEvent> implements EventEvaluator<ILoggingEvent> {
//if limit is not set in configuration, this will cause it to send one email for each message received.
private int limit = 100;
private int counter = 0;

public void setLimit(int limit) {
this.limit = limit;
}

public int getLimit() {
return limit;
}

@Override
public boolean evaluate(ILoggingEvent expr) throws NullPointerException, EvaluationException {
counter++;
if (counter == limit) {
counter = 0;
return true;
} else {
return false;
}
}
}


Any help is greatly appreciated.

Answer

The issue was the asynchronousSending attribute of the SMTPAppender defaults to true. I set it to false and it works properly