Logstash新手求助：用Grok提取日志中的时间戳与信号电平

Hey there! Let's work through your Grok configuration issue to successfully extract both the timestamp and signal level from your logs.

First, Let's Understand the Problem with Your Previous Attempts #

• First Configuration: Your pattern used repeated %{SPACE:ip} and %{GREEDYDATA:val} which is overly redundant and inefficient. GREEDYDATA is resource-heavy when overused, and this complexity caused the _groktimeout error as Logstash struggled to process the pattern within the time limit.
• Second Configuration: You split the match into two separate patterns for timestamp and signal level. Grok stops processing after the first successful match, so it only extracted the timestamp and ignored the second pattern entirely.

The Solution: A Clean, Efficient Grok Pattern #

Here's a simplified, optimized pattern that will reliably extract both fields without timing out:

filter {
  grok {
    match => {
      "message" => "%{TIMESTAMP_ISO8601:mytimestamp}.*?Signal level=(?<powerlevel>-?\d+) dBm.*"
    }
    timeout_millis => 60000
  }
}

Breakdown of the Pattern #

• %{TIMESTAMP_ISO8601:mytimestamp}:精准匹配日志开头的ISO8601格式时间戳，并将其存储到mytimestamp字段。
• .*?: Non-greedy match to skip all content between the timestamp and "Signal level="—this is more efficient than GREEDYDATA because it stops as soon as it finds the next target string.
• (?<powerlevel>-?\d+): Captures the numeric signal level (including the negative sign, since signal levels are typically negative values) and stores it in the powerlevel field.
• dBm.*: Matches the remaining part of the log line to ensure the entire message is processed.

Alternative (Using GREEDYDATA More Carefully) #

If you prefer using GREEDYDATA (though the non-greedy version above is better for performance), this pattern also works:

filter {
  grok {
    match => {
      "message" => "%{TIMESTAMP_ISO8601:mytimestamp} %{GREEDYDATA}Signal level=(?<powerlevel>-?\d+) dBm%{GREEDYDATA}"
    }
    timeout_millis => 60000
  }
}

Either of these patterns will resolve your timeout issue and extract both fields successfully. Test it out with your logs—you should see mytimestamp and powerlevel populated in your Elasticsearch documents!

内容的提问来源于stack exchange，提问作者bhavya