通过syslog发送log4j2堆栈跟踪

时间：2016-11-08 12:18:52

标签： java logging logstash log4j2 syslog

我正在尝试将堆栈跟踪记录到Logstash中。

日志记录堆栈是ELK（ElasticSearch，Logstash，Kibana）。

应用程序生成日志是一个Java应用程序，使用slf4j作为日志记录接口，log4j2作为日志记录实现。

log4j2.xml使用syslog格式声明此RFC5424 Appender：

<Appenders>
  <Syslog name="RFC5424" format="RFC5424" host="localhost" port="8514"
          protocol="TCP" appName="MyApp" includeMDC="true" mdcId="mdc"
          facility="LOCAL0" enterpriseNumber="18060" newLine="true"
          messageId="Audit" id="App">
    <LoggerFields>
      <KeyValuePair key="thread" value="%t"/>
      <KeyValuePair key="priority" value="%p"/>
      <KeyValuePair key="category" value="%c"/>
      <KeyValuePair key="exception" value="%ex{full}"/>
    </LoggerFields>
  </Syslog>
</Appenders>

我从Java应用程序中记录了Throwable，如下所示：

org.slf4j.LoggerFactory.getLogger("exception_test").error("Testing errors", new RuntimeException("Exception message"));

当记录异常时，Logstash会跟踪此类内容以显示它持续存在的内容：

{
   "@timestamp":"2016-11-08T11:08:10.387Z",
   "port":60397,
   "@version":"1",
   "host":"127.0.0.1",
   "message":"<131>1 2016-11-08T11:08:10.386Z MyComputer.local MyApp - Audit [mdc@18060 category=\"exception_test\" exception=\"java.lang.RuntimeException: Exception message",
   "type":"syslog",
   "tags":[
      "_grokparsefailure"
   ]
}

我确认Kibana在其中一个日志条目的_source字段中显示完全相同的JSON。

这里有一个问题：没有保存堆栈跟踪。并且消息“测试错误”丢失了。

"tags":["_grokparsefailure"]很不幸，但与此问题无关。

我尝试添加<ExceptionPattern/>以查看它是否会改变任何内容：

<Syslog name="RFC5424" format="RFC5424" host="localhost" port="8514"
        protocol="TCP" appName="MyApp" includeMDC="true" mdcId="mdc"
        facility="LOCAL0" enterpriseNumber="18060" newLine="true"
        messageId="Audit" id="App">
  <LoggerFields>
    <KeyValuePair key="thread" value="%t"/>
    <KeyValuePair key="priority" value="%p"/>
    <KeyValuePair key="category" value="%c"/>
    <KeyValuePair key="exception" value="%ex{full}"/>
  </LoggerFields>
  <ExceptionPattern>%ex{full}</ExceptionPattern>
</Syslog>

<ExceptionPattern/>替换了日志消息，而也（遗憾地）省略了所有loggerFields。但它确实给了我一个班级名称和行号：

{
   "@timestamp":"2016-11-08T11:54:03.835Z",
   "port":60397,
   "@version":"1",
   "host":"127.0.0.1",
   "message":"at com.stackoverflow.LogTest.throw(LogTest.java:149)",
   "type":"syslog",
   "tags":[
      "_grokparsefailure"
   ]
}

再次：没有堆栈跟踪。而且：消息“测试错误”丢失了。

如何使用log4j2将堆栈跟踪记录到Logstash中？我不一定要使用syslog appender。

基本上，约束是：

  • 不会被锁定到任何特定的日志记录基础结构（这就是我使用syslog的原因）
  • 需要将多行堆栈跟踪理解为单个日志条目。 “堆栈跟踪的每一行”不是“单独的日志消息”
  • 堆栈跟踪必须能够使用过滤器。我的一个典型例外可能有一个页面长的堆栈跟踪。我想过滤掉像Spring这样的框架。

1 个答案:

答案 0 :(得分：1)

Log4j 2.5的SyslogAppender 只能通过UDP 发送堆栈跟踪。

<Syslog name="RFC5424" format="RFC5424" host="localhost" port="8514"
        protocol="UDP" appName="MyApp" includeMDC="true" mdcId="mdc"
        facility="LOCAL0" enterpriseNumber="18060" newLine="true"
        messageId="LogTest" id="App">
  <LoggerFields>
    <KeyValuePair key="thread" value="%t"/>
    <KeyValuePair key="priority" value="%p"/>
    <KeyValuePair key="category" value="%c"/>
    <KeyValuePair key="exception" value="%ex{full}"/>
  </LoggerFields>
  <ExceptionPattern>%ex{full}</ExceptionPattern>
</Syslog>

使用UDP：ExceptionPattern 和 LoggerFields.KeyValuePair["exception"]开始作为多行堆栈跟踪的解决方案。

当我通过syslog通过 UDP 发送异常时，这是logstash打印的内容：

{
    "@timestamp" => 2016-11-14T13:23:38.304Z,
      "@version" => "1",
          "host" => "127.0.0.1",
       "message" => "<131>1 2016-11-14T13:23:38.302Z BirchBox.local MyApp - LogTest [mdc@18060 category=\"com.stackoverflow.Deeply\" exception=\"java.lang.RuntimeException: Exception message\n\tat com.stackoverflow.Deeply.complain(Deeply.java:10)\n\tat com.stackoverflow.Nested.complain(Nested.java:8)\n\tat com.stackoverflow.Main.main(Main.java:20)\n\" priority=\"ERROR\" thread=\"main\"] Example error\njava.lang.RuntimeException: Exception message\n\tat com.stackoverflow.Deeply.complain(Deeply.java:10)\n\tat com.stackoverflow.Nested.complain(Nested.java:8)\n\tat com.stackoverflow.Main.main(Main.java:20)",
          "type" => "syslog",
          "tags" => [
        [0] "_grokparsefailure"
    ]
}

在[mdc@18060 exception=\"…\"]内，我们获得 LoggerFields.KeyValuePair["exception"] 堆栈跟踪。

除此之外：由于ExceptionPattern，堆栈跟踪将插入到已记录的消息本身中。

供参考：当我通过syslog通过 TCP 发送异常时，这是logstash打印的内容（即与上述相同的SyslogAppender，但改为使用protocol="TCP"）： 

{
    "@timestamp" => 2016-11-14T19:56:30.293Z,
          "port" => 63179,
      "@version" => "1",
          "host" => "127.0.0.1",
       "message" => "<131>1 2016-11-14T19:56:30.277Z BirchBox.local MyApp - Audit [mdc@18060 category=\"com.stackoverflow.Deeply\" exception=\"java.lang.RuntimeException: Exception message",
          "type" => "syslog",
          "tags" => [
        [0] "_grokparsefailure"
    ]
}
{
    "@timestamp" => 2016-11-14T19:56:30.296Z,
          "port" => 63179,
      "@version" => "1",
          "host" => "127.0.0.1",
       "message" => "at com.stackoverflow.Deeply.complain(Deeply.java:10)",
          "type" => "syslog",
          "tags" => [
        [0] "_grokparsefailure"
    ]
}
{
    "@timestamp" => 2016-11-14T19:56:30.296Z,
          "port" => 63179,
      "@version" => "1",
          "host" => "127.0.0.1",
       "message" => "at com.stackoverflow.Nested.complain(Nested.java:8)",
          "type" => "syslog",
          "tags" => [
        [0] "_grokparsefailure"
    ]
}
{
    "@timestamp" => 2016-11-14T19:56:30.296Z,
          "port" => 63179,
      "@version" => "1",
          "host" => "127.0.0.1",
       "message" => "at com.stackoverflow.Main.main(Main.java:20)",
          "type" => "syslog",
          "tags" => [
        [0] "_grokparsefailure"
    ]
}
{
    "@timestamp" => 2016-11-14T19:56:30.296Z,
          "port" => 63179,
      "@version" => "1",
          "host" => "127.0.0.1",
       "message" => "\" priority=\"ERROR\" thread=\"main\"] Example error",
          "type" => "syslog",
          "tags" => [
        [0] "_grokparsefailure"
    ]
}
{
    "@timestamp" => 2016-11-14T19:56:30.296Z,
          "port" => 63179,
      "@version" => "1",
          "host" => "127.0.0.1",
       "message" => "java.lang.RuntimeException: Exception message",
          "type" => "syslog",
          "tags" => [
        [0] "_grokparsefailure"
    ]
}
{
    "@timestamp" => 2016-11-14T19:56:30.297Z,
          "port" => 63179,
      "@version" => "1",
          "host" => "127.0.0.1",
       "message" => "at com.stackoverflow.Deeply.complain(Deeply.java:10)",
          "type" => "syslog",
          "tags" => [
        [0] "_grokparsefailure"
    ]
}
{
    "@timestamp" => 2016-11-14T19:56:30.298Z,
          "port" => 63179,
      "@version" => "1",
          "host" => "127.0.0.1",
       "message" => "at com.stackoverflow.Nested.complain(Nested.java:8)",
          "type" => "syslog",
          "tags" => [
        [0] "_grokparsefailure"
    ]
}
{
    "@timestamp" => 2016-11-14T19:56:30.298Z,
          "port" => 63179,
      "@version" => "1",
          "host" => "127.0.0.1",
       "message" => "at com.stackoverflow.Main.main(Main.java:20)",
          "type" => "syslog",
          "tags" => [
        [0] "_grokparsefailure"
    ]
}
{
    "@timestamp" => 2016-11-14T19:56:30.299Z,
          "port" => 63179,
      "@version" => "1",
          "host" => "127.0.0.1",
       "message" => "",
          "type" => "syslog",
          "tags" => [
        [0] "_grokparsefailure"
    ]
}

看起来TCP实际上“工作”，但将单个日志消息拆分为许多系统日志消息（例如遇到\n时）。

相关问题
最新问题