Convert metric_group_by setting

Author: sirainen

data/settings.js

@@ -8607,7 +8607,8 @@ setting.`
 		tags: [ 'metrics' ],
 		values: setting_types.STRING,
 		text: `
-Name of the metric. It is visible in statistics outputs.`
+Name of the metric. It is visible in statistics outputs. The [[setting,metric]]
+filter name refers to this setting.`
 	},
 
 	metric_fields: {
@@ -8624,10 +8625,141 @@ field that does not need to be listed explicitly.`
 
 	metric_group_by: {
 		tags: [ 'metrics' ],
-		values: setting_types.BOOLLIST,
+		values: setting_types.NAMED_LIST_FILTER,
+		seealso: [ '[[link,stats_group_by]]' ],
+		text: `
+Creates a new [[link,stats_group_by,group_by]] for dynamically generating
+sub-metrics based on the specified field's values. The filter name refers to
+the [[setting,metric_group_by_field]].`
+	},
+
+	metric_group_by_field: {
+		tags: [ 'metrics' ],
+		values: setting_types.STRING,
+		seealso: [ '[[link,stats_group_by]]' ],
+		text: `
+Generate sub-metrics based on this event field name. The
+[[setting,metric_group_by]] filter name refers to this setting.`
+	},
+
+	metric_group_by_method: {
+		tags: [ 'metrics' ],
+		values: setting_types.NAMED_LIST_FILTER,
+		seealso: [ '[[link,stats_group_by]]' ],
+		text: `
+Configures [[setting,metric_group_by_method_method,the aggregation method]] for
+the [[setting,metric_group_by]]. Only a single method can be specified for
+a group_by. The filter name refers to the
+[[setting,metric_group_by_method_method]].`
+	},
+
+	metric_group_by_method_method: {
+		tags: [ 'metrics' ],
+		values: setting_types.ENUM,
+		values_enum: [ 'discrete', 'exponential', 'linear' ],
+		default: 'discrete',
+		seealso: [ '[[link,stats_group_by]]' ],
+		text: `
+Configures the aggregation method for the
+[[setting,metric_group_by]]. The [[setting,metric_group_by_method]] filter name
+refers to this setting.`
+	},
+
+	metric_group_by_method_discrete_modifier: {
+		tags: [ 'metrics' ],
+		values: setting_types.STRING_NOVAR,
 		seealso: [ '[[link,stats_group_by]]' ],
 		text: `
-This can be used to dynamically generate sub-metrics based on fields' values.`
+Configures a modifier string for values grouped by the
+[[link,stats_group_by_discrete,discrete method]].
+[[link,settings_variables,%variables]] and their functions can be used:
+
+\`%{value}\`
+:   The original value.
+
+\`%{domain}\`
+:   If the value is in \`user@domain\` format, this contains the \`domain\`
+    text. Otherwise empty.`
+	},
+
+	metric_group_by_method_exponential_min_magnitude: {
+		tags: [ 'metrics' ],
+		values: setting_types.UINT,
+		seealso: [
+			'[[link,stats_group_by]]',
+			'metric_group_by_method_exponential_max_magnitude',
+			'metric_group_by_method_exponential_base'
+		],
+		text: `
+Configures the minimum magnitude for values grouped by the
+[[link,stats_group_by_exponential,exponential method]].`
+	},
+
+	metric_group_by_method_exponential_max_magnitude: {
+		tags: [ 'metrics' ],
+		values: setting_types.UINT,
+		seealso: [
+			'[[link,stats_group_by]]',
+			'metric_group_by_method_exponential_min_magnitude',
+			'metric_group_by_method_exponential_base'
+		],
+		text: `
+Configures the maximum magnitude for values grouped by the
+[[link,stats_group_by_exponential,exponential method]].`
+	},
+
+	metric_group_by_method_exponential_base: {
+		tags: [ 'metrics' ],
+		values: setting_types.UINT,
+		default: 10,
+		seealso: [
+			'[[link,stats_group_by]]',
+			'metric_group_by_method_exponential_min_magnitude',
+			'metric_group_by_method_exponential_max_magnitude'
+		],
+		text: `
+Configures the base for values grouped by the
+[[link,stats_group_by_exponential,exponential method]]. Only 2 and 10 are
+supported.`
+	},
+
+	metric_group_by_method_linear_min: {
+		tags: [ 'metrics' ],
+		values: setting_types.UINT,
+		seealso: [
+			'[[link,stats_group_by]]',
+			'metric_group_by_method_linear_max',
+			'metric_group_by_method_linear_step'
+		],
+		text: `
+Configures the minimum for values grouped by the
+[[link,stats_group_by_linear,linear method]].`
+	},
+
+	metric_group_by_method_linear_max: {
+		tags: [ 'metrics' ],
+		values: setting_types.UINT,
+		seealso: [
+			'[[link,stats_group_by]]',
+			'metric_group_by_method_linear_min',
+			'metric_group_by_method_linear_step'
+		],
+		text: `
+Configures the maximum for values grouped by the
+[[link,stats_group_by_linear,linear method]].`
+	},
+
+	metric_group_by_method_linear_step: {
+		tags: [ 'metrics' ],
+		values: setting_types.UINT,
+		seealso: [
+			'[[link,stats_group_by]]',
+			'metric_group_by_method_linear_min',
+			'metric_group_by_method_linear_max'
+		],
+		text: `
+Configures the step for values grouped by the
+[[link,stats_group_by_linear,linear method]].`
 	},
 
 	metric_filter: {

docs/core/config/statistics.md

@@ -9,6 +9,15 @@ dovecotlinks:
   stats_group_by:
     hash: group-by
     text: "Statistics: Group By"
+  stats_group_by_discrete:
+    hash: discrete
+    text: "Statistics: Group By: Discrete"
+  stats_group_by_exponential:
+    hash: exponential
+    text: "Statistics: Group By: Exponential"
+  stats_group_by_linear:
+    hash: linear
+    text: "Statistics: Group By: Linear"
 ---
 
 # Statistics
@@ -36,34 +45,34 @@ filter setting. You can also use `event=*` to match all named events.
 
 ## Group By
 
-The `group_by` metric setting allows dynamic hierarchical metric
+The [[setting,metric_group_by]] setting allows dynamic hierarchical metric
 generation based on event fields' values.
 
-Each field listed in the `group_by` generates one level of "sub-metrics".
+Each listed [[setting,metric_group_by]] generates one level of "sub-metrics".
 These automatically generated metrics are indistinguishable from those
 statically defined in the config file. "sub-metric" names can be up to
 256 bytes in total.
 
-Dovecot supports a number of aggregation functions that can be used to
-quantize a field's value before it is used to generate a metric.
-
-The format is always the same: the field name, a colon, the aggregation
-function name, and optionally a colon followed by colon delimited parameters
-to the aggregation function.
+Dovecot supports a number of aggregation methods that can be used to quantize
+a field's value before it is used to generate a metric.
 
 ### `discrete`
 
-The simplest aggregation function is to use the value as is.  Because this
-is a very common use case, not specifying an aggregation function is treated
-as an alias for discrete aggregation.  In other words, `field` and
-`field:discrete` produce the same behavior.
+The simplest aggregation method is to use the value as is.  Because this
+is a very common use case, this is the default aggregation method.
+
+The value can be further modified by
+[[setting,metric_group_by_method_discrete_modifier]].
 
 Example:
 
 ```[dovecot.conf]
 metric imap_command {
   filter = event=imap_command_finished
-  group_by = cmd_name tagged_reply_state
+  group_by cmd_name {
+  }
+  group_by tagged_reply_state {
+  }
 }
 ```
 
@@ -89,21 +98,24 @@ when first observed.
 
 The field's integer value is quantized into exponentially sized ranges.
 
-The exponential aggregation function takes three colon delimited integer
-arguments that define the set of ranges used: the minimum magnitude, the
-maximum magnitude, and the base.  The exact configuration syntax is:
-`field:exponential:min:max:base`
+The exponential aggregation method uses three settings:
 
-Note: Currently, only base 2 and base 10 are supported.
+ * [[setting,metric_group_by_method_exponential_min_magnitude]]
+ * [[setting,metric_group_by_method_exponential_max_magnitude]]
+ * [[setting,metric_group_by_method_exponential_base]]
+   Note: Currently, only base 2 and base 10 are supported.
 
-The first range starts at negative infinity and ends at `pow(base, min)`.
-The second range begins at `pow(base, min) + 1` and ends at
-`pow(base, min + 1)`, the next covers `pow(base, min + 1) + 1` to
-`pow(base, min + 2)`, and so on.  The last range covers
-`pow(base, max) + 1` to positive infinity.
+The first range starts at negative infinity and ends at
+`pow(base, min_magnitude)`. The second range begins at
+`pow(base, min_magnitude) + 1` and ends at `pow(base, min_magnitude + 1)`,
+the next covers `pow(base, min_magnitude + 1) + 1` to
+`pow(base, min_magnitude + 2)`, and so on.  The last range covers
+`pow(base, max_magnitude) + 1` to positive infinity.
 
-For example, given the specification `duration:exponential:1:5:10`, the
-ranges would be:
+For example, given the settings
+[[setting,metric_group_by_method_exponential_min_magnitude,1]],
+[[setting,metric_group_by_method_exponential_max_magnitude,5]] and
+[[setting,metric_group_by_method_exponential_base,10]], the ranges would be:
 
 * (-inf, 10]
 * [11, 100]
@@ -112,8 +124,8 @@ ranges would be:
 * [10001, 100000]
 * [100001, +inf)
 
-Much like the metric names generated with the `discrete` aggregation
-function, the ones generated by the `exponential` function include
+Much like the metric names generated with the [discrete](#discrete) aggregation
+method, the ones generated by the `exponential` method include
 information about the value of the field.  However, in this case it is the
 range the value belongs to.
 
@@ -125,7 +137,15 @@ Example:
 ```[dovecot.conf]
 metric imap_command {
   filter = event=imap_command_finished
-  group_by = cmd_name duration:exponential:1:5:10
+  group_by cmd_name {
+  }
+  group_by duration {
+    method exponential {
+      min_magnitude = 1
+      max_magnitude = 5
+      base = 10
+    }
+  }
 }
 ```
 
@@ -144,7 +164,7 @@ for a `SELECT` IMAP command, the possible generated metric names are:
 Note: Since the metric names cannot contain `-`, the string `ninf` is used
 to denote negative infinity.
 
-Note: Much like in the `discrete` case, the metrics are allocated only
+Note: Much like in the [discrete](#discrete) case, the metrics are allocated only
 when first observed.
 
 Finally, because all intermediate level metrics are generated as well.  The
@@ -157,18 +177,20 @@ above example, will also generate all of the following metrics:
 
 The field's integer value is quantized into linearly sized ranges.
 
-The linear aggregation function takes three colon delimited integer
-arguments that define the set of ranges used: the minimum value, the
-maximum value, and the range step size.  The exact configuration syntax is:
-`field:linear:min:max:step`
+The linear aggregation method uses three settings:
+
+ * [[setting,metric_group_by_method_linear_min]]
+ * [[setting,metric_group_by_method_linear_max]]
+ * [[setting,metric_group_by_method_linear_step]]
 
 The first range starts at negative infinity and ends at `min`.  The second
 range begins at `min + 1` and ends at `min + step`, the next covers
 `min + step + 1` to `min + (2 * step)`, and so on.  The last range
 covers `max + 1` to positive infinity.
 
-For example, given the specification `net_out_bytes:linear:0:5000:1000`, the
-ranges would be:
+For example, given settings [[setting,metric_group_by_method_linear_min,0]],
+[[setting,metric_group_by_method_linear_max,5000]] and
+[[setting,metric_group_by_method_linear_step,1000]], the ranges would be:
 
 * (-inf, 0]
 * [1, 1000]
@@ -178,7 +200,7 @@ ranges would be:
 * [4001, 5000]
 * [5001, +inf)
 
-See the description of the [exponential](#exponential) aggregation function
+See the description of the [exponential](#exponential) aggregation method
 for how metric names are formed from these ranges.
 
 ## Listing Statistics
@@ -285,7 +307,8 @@ metric storage_http_gets {
 # generate per-command metrics on successful commands
 metric imap_command {
   filter = event=imap_command_finished AND tagged_reply_state=OK
-  group_by = cmd_name
+  group_by cmd_name {
+  }
 }
 ```
 
@@ -364,17 +387,34 @@ metric auth_success {
 
 metric imap_command {
   filter = event=imap_command_finished
-  group_by = cmd_name tagged_reply_state
+  group_by cmd_name {
+  }
+  group_by tagged_reply_state {
+  }
 }
 
 metric smtp_command {
   filter = event=smtp_server_command_finished
-  group_by = cmd_name status_code duration:exponential:1:5:10
+  group_by cmd_name {
+  }
+  group_by status_code {
+  }
+  group_by duration {
+    method exponential {
+      min_magnitude = 1
+      max_magnitude = 5
+    }
+  }
 }
 
 metric mail_delivery {
   filter = event=mail_delivery_finished
-  group_by = duration:exponential:1:5:10
+  group_by duration {
+    method exponential {
+      min_magnitude = 1
+      max_magnitude = 5
+    }
+  }
 }
 ```