Filtering metrics

Use the dsetool insights_filters command to filter metrics deemed unimportant or sensitive, and focus on specific metrics important to your organization.

Apply filters with one of these options:

--global: Filters metrics reported locally and insights data files.
--insights_only: Filters insights data files only (for diagnostic purposes).

Use a regular expression (regex) to specify which metrics to include or exclude from the filter. The regex is not anchored, so a substring match like Keyspace blocks anything with keyspace in the metric name. You can also specify a full regex such as org.apache.cassandra.metrics.Keyspace.+ to filter metrics from a specific keyspace. For details, see Example filters.

The following tables describe whitelist and blacklist combinations to grant or deny access to a metric using a regex. When evaluating a regex, the blacklist always overrides the whitelist.

Blacklist and whitelist combinations to grant access
Regex	Blacklist	Whitelist	Access
No metric indicated.	-	-	✓
Metric included in whitelist without any blacklist entries.	-	Match	✓
Metric not included in blacklist without any whitelist entries.	No match	-	✓
Metric included in whitelist without any matches in blacklist.	No match	Match	✓

Blacklist and whitelist combinations to deny access
Regex	Blacklist	Whitelist	Access
Metric not included in whitelist without any blacklist entries.	-	No match	X
Metric included in blacklist without any whitelist entries.	Match	-	X
Metric not included in whitelist.	No match	No match	X
Metric included in blacklist without a match in the whitelist.	Match	No match	X
Metric included in both blacklist and whitelist.	Match	Match	X

Example filters

Show all active filters

dsetool insights_filters --show_filters

Remove all active filters

dsetool insights_filters --remove_all_filters

Add a global filter to deny all metrics for a specific keyspace

dsetool insights_filters --add --global --deny "org\\.apache\\.cassandra\\.metrics\\.(keyspace_name|table_name).*(keyspace_name).*"

Add a global filter to deny all metrics matching KeyspaceMetrics

dsetool insights_filters --add --global --deny .+KeyspaceMetrics.+

Remove a global filter to allow metrics for a specific keyspace that has an existing deny filter

dsetool insights_filters --remove --global --deny "org\\.apache\\.cassandra\\.metrics\\.(keyspace_name|table_name).*(keyspace_name).*"

Add a filter to insights data files that deny grace period metrics

dsetool insights_filters --add --insights_only --deny .+gc.+