Log4j 2的断路器

Question

Context: Java web application running in Tomcat, Log4j 2 version 2.5. Logging set up to go to one Sentry instance using the Raven connector and one ELK (ElasticSearch + Logstash + Kibana) instance.

Configuration looks like this (anonymized):

<configuration>
  <appenders>
    <Raven name="Sentry">
      <dsn>https://foo@bar.baz/1</dsn>
    </Raven>
    <Socket name="Logstash" host="1.2.3.4" port="1234">
      <SerializedLayout />
    </Socket>
  </appenders>
  <loggers>
    <root level="info">
      <appender-ref ref="Sentry" level="warn" />
      <appender-ref ref="Logstash" />
    </root>
  </loggers>
</configuration>

Problem is that if Sentry or ELK starts acting up (long response times, unreachable, ...), the application threads get blocked trying to log and the application effectively dies.

Is there a preferred solution to this problem? Some kind of circuit breaker would be ideal here: after detecting a problem with the remote logging destination Log4j 2 would disable the appender for some time.

We use another appender wrapped in an <Async/> appender , but as far as I understand that is a good solution to make the logging... well, asynchronous, but not to fix the problem of unresponsive log destination.

Answer 1

In our system we have a special component called logs-forwarder that collects all the logs by log4j and other systems and forwards them to logstash / splunk etc. what might have you. So that's one valid option.