Question

我正在尝试将Logback与SMTPAppender一起用作我的日志记录解决方案。我有一个附加到appender的评估程序，它会触发每100个记录错误的电子邮件。在大多数情况下，这是正常的，但我注意到，如果我在循环中快速创建错误，以触发多个电子邮件，只有最后一封电子邮件被发送，具有正确的内容。这似乎是一种竞争条件，其中第一封电子邮件未完成创建/发送，第二封电子邮件在创建时覆盖第一封电子邮件。有没有其他人经历过这个或找到了解决方案。我的logback配置附在下面。

<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>

这是评估员：

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;
        }
    }
}

非常感谢任何帮助。

Answer 1

问题是SMTPAppender的asynchronousSending属性默认为true。我把它设置为false并且它正常工作

Answer 2

您应该使您的Evaluator线程安全 - 例如使用AtomicInteger：

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 AtomicInteger counter = new AtomicInteger();

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

    public int getLimit() {
        return limit;
    }

    @Override
    public boolean evaluate(ILoggingEvent expr) throws NullPointerException, EvaluationException {
        int curValue = counter.incrementAndGet();
        if (curValue >= limit) {
            return counter.compareAndSet(curValue, 0);
        } else {
            return false;
        }
    }

}

Logback SMTPAppender仅发送最后一封电子邮件

2 个答案: