A Multinational bank uses Amazon CloudWatch logs to capture logs from the Amazon EC2 instance on which a critical banking application is deployed.
The operations team has created a metric filter for filtering error messages from the logs captured.
But intermittently, they are observing no data is getting reported.
The Operation Lead has instructed us to check the setting of the metric filters. What setting can be done with metric filters to resolve this issue?
Click on the arrows to vote for the correct answer
A. B. C. D.Correct Answer: A.
Default Value is the value reported when no matching logs are found with a metric filter.
By setting Default Value as 0, metric data can always be reported, even if there are no matching metric filters with the captured logs.
Option B is incorrect as dimensions are the key value pair that defines the metric.
Option C is incorrect as this is a metric value based upon matching criteria in the log file.
Option D is incorrect as the filter pattern is the pattern that is specified to match in the log file.
For more information on metric filters with Amazon CloudWatch logs, refer to the following URL,
https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/MonitoringLogData.htmlTo resolve the issue of no data being reported in CloudWatch logs with metric filters, we need to understand the purpose of metric filters and how they work.
A metric filter is a rule that extracts a specific pattern from log data and transforms it into a CloudWatch metric. This metric can then be used to create alarms, dashboards, or automated responses to events. Metric filters are created based on a filter pattern, which is a string that matches the log event messages you want to extract.
In this case, the operations team has created a metric filter to capture error messages from the logs generated by the critical banking application deployed on an Amazon EC2 instance. However, they are intermittently observing no data being reported, which indicates that the metric filter is not capturing any matching log events.
To resolve this issue, we need to check the settings of the metric filter and make sure they are configured correctly. None of the answers provided directly address the issue of the metric filter not capturing matching log events.
Option A suggests setting the default value of the metric filter to 0, but this would not resolve the issue if there are no matching log events. Setting a default value would only apply if the metric filter does not match any log events, in which case CloudWatch would use the default value for the metric.
Option B suggests setting the dimensions value of the metric filter to 0, but this would not resolve the issue either. Dimensions are used to segment metrics by attributes such as instance ID, region, or environment. Setting the dimensions value to 0 would not affect the behavior of the metric filter.
Option C suggests setting the metric value of the metric filter to 0, but this would not resolve the issue either. The metric value is derived from the log events that match the filter pattern. If there are no matching log events, the metric value would be 0 anyway.
Option D suggests setting the filter pattern of the metric filter to 0, which is not a valid filter pattern. This option is incorrect.
Therefore, none of the answers provided would resolve the issue of no data being reported by the CloudWatch logs with the metric filter. To troubleshoot this issue, we would need to check the following: