This guide describes how to configure filters when you use the Monitoring API. You use filters to specify monitored resources, metric types, group definitions, and time series. You can also use a filter to configure an alerting policy that monitors processes running on your systems. For information about those filters, see Process-health filters.
Before you begin
If you aren't familiar with metrics, time series, and monitored resources, see Metrics, time series, and resources.
If you aren't familiar with labels, see Labels for an introduction.
Using filters
You can use filters in the Monitoring API to do the following:
- Select the specific time series data that is
returned from a
list
API request. The filter can select time series based on the data's project, group, monitored resource properties, and metric properties. For more information and examples, see Retrieving time series data.
Assign resources to a
Group
based on the resources' properties and the project to which they belong. For more information and examples, see Defining group membership.Select resources within a group based on the resources' properties and the project to which they belong. For more information and examples, see Listing group members.
List particular metric types. For more information and examples, see Listing metric descriptors.
List particular monitored resource types. For more information and examples, see Listing monitored resource descriptors.
Filter selectors
A filter consists of at least one selector, which is a filter keyword. The following examples illustrate the different selectors:
-
project
: Matches when the metrics of the specified project are visible to the scoping project of a metrics scope mentioned in thename
parameter.Use the
project
selector when a Google Cloud project can view the metrics of multiple Google Cloud projects or AWS accounts and you only want metrics for single project. For example, if the metrics scope forProject-A
includesProject-B
, then a match occurs whenname
has a value ofProject-A
and you use the following filter:project = "Project-B"
-
group
: Matches resources belonging to oneGroup
.The following filter matches the group with the identifier
group-id
:group.id = "group-id"
-
resource
: Matches monitored resources of a particular type or having particular label values.-
The following filter matches all monitored resources that are Compute Engine virtual machine (VM) instances:
resource.type = "gce_instance"
-
The following filter matches all resources whose zone begins with
europe-
:resource.labels.zone = starts_with("europe-")
-
-
metric
: Matches a particular metric type or time series with with a particular label that matches a specific value.-
The following filter matches a specific metric type:
metric.type = "compute.googleapis.com/instance/cpu/usage_time"
-
The following filter matches time series with a label named
instance_name
, whose value starts withgke-hipster
orgke-nginx
:metric.labels.instance_name = monitoring.regex.full_match("gke-(hipster|nginx).*")
-
The following table shows which selectors are permitted in filters based on the Monitoring API call:
Filter purpose | project selector |
group selector |
resource selector |
metric selector |
---|---|---|---|---|
Define groups | yes | yes* | ||
List group members | yes | yes | ||
List time series | yes | yes | yes | yes † |
List metric descriptors | yes | yes | ||
List monitored resource descriptors | yes |
† When listing time series, you must specify exactly one metric type.
The following sections show examples of typical uses of monitoring filters. See Filter syntax for a complete discussion of the available filter objects and operators.
Retrieving time series data
Method:
projects.timeSeries.list
Filter objects:
project
, group.id
, resource.type
, resource.labels.[KEY]
, metric.type
,
metric.labels.[KEY]
A time series is a list of time-stamped data points of a metric type from a specific monitored resource. For details, see The metric model. The metric type is specified by a metric descriptor, and the monitored resource is specified by a monitored-resource descriptor.
The filter specified to the timeSeries.list
method must include a
metric
selector, and that selector must specify exactly one metric type:
- To return all time series for a particular metric type:
metric.type = "compute.googleapis.com/instance/cpu/usage_time"
To return all time series for a specific group. The
group
selector only works with aligned time series data; see Group selector for more information:metric.type = "compute.googleapis.com/instance/cpu/usage_time" AND group.id = "2468013579"
To return all time series from a specific Compute Engine instance, use the following filter:
metric.type = "compute.googleapis.com/instance/cpu/usage_time" AND metric.labels.instance_name = "my-instance-name"
Return all time series from Compute Engine instances whose names start with
frontend-
, use the following filter:metric.type = "compute.googleapis.com/instance/cpu/usage_time" AND metric.labels.instance_name = starts_with("frontend-")
Return all time series from Compute Engine instances whose names start with
gke-hipster
orgke-nginx
, use the following filter:metric.type = "compute.googleapis.com/instance/cpu/usage_time" AND metric.labels.instance_name = monitoring.regex.full_match("^gke-(hipster|nginx).*")
Defining group membership
Method:
projects.groups
Filter objects: project
, resource.type
, resource.labels.key
,
metadata.system_labels.[KEY]
, metadata.user_labels.[KEY]
A group can contain any number of resources, as specified by a filter. Group
membership is dynamic; more or fewer resources might match the filter every
time the filter is evaluated. The name
parameter in the
Group
object specifies the group and the
scoping project of a metrics scopemetrics-scope-concept.
If the project
selector is used in the filter, then it must specify a
project whose metrics are visible to the scoping project.
resource.type = "gce_instance" AND resource.labels.zone = starts_with("europe-")
Listing group members
Method:
projects.groups.members.list
Filter objects: project
, resource.type
, resource.labels.[KEY]
Use a filter to limit which group members you retrieve. The name
parameter
specifies a scoping project of a metrics scope and a
group defined in that project. If the project
selector is used in the
filter, then it must specify a project whose metrics are visible to the
scoping project.
- To return a list of all Pub/Sub topic resources that belong to
project
my-project
, use the following filter:project = "my-project" AND resource.type = "pubsub_topic"
Listing metric descriptors
Method:
projects.metricDescriptors.list
Filter objects: project
, metric.type
Use a filter to limit which metric descriptors you retrieve:
- To return only the Compute Engine metric descriptors,
use the following filter:
metric.type = starts_with("compute.googleapis.com")
See Metrics list for a complete list of the available metric types. For an overview of how metrics are named, see Metric naming conventions.
Listing monitored resource descriptors
Method:
projects.monitoredResourceDescriptors.list
Filter objects: resource.type
Use a filter to limit which monitored resource descriptors you retrieve:
- To retrieve only the Pub/Sub monitored resource descriptors,
use the following filter:
resource.type = starts_with("pubsub")
See Monitored resource list for a complete list of the monitored resource types defined by Monitoring.
Examples
In the filtering examples, we use the following metric descriptor, monitored resource descriptor, and virtual machine instance, simplified for illustration:
# Metric descriptor: { "name": "projects/my-project-id/metricDescriptors/compute.googleapis.com%2Finstance%2Fdisk%2Fread_bytes_count" "type": "compute.googleapis.com/instance/disk/read_bytes_count", "labels": [ { "key": "device_name", "description": "The name of the disk device." } ] } # Monitored resource descriptor: { "name": "monitoredResourceDescriptors/gce_instance" "type": "gce_instance", "labels": [ { "key": "instance_id", "description": "The instance ID provide by Google Compute Engine." }, { "key": "zone", "description": "The Google Cloud Platform zone hosting the instance." } ] } # Resource descriptor for a virtual machine instance. { "type": "gce_instance", "instance_id": "1472038649266883453", "zone": "us-east-1b", "disks": [ "log_partition" ], "machine_type": "n1-standard-2", "tags": { "environment": "bleeding-edge", "role": "frobulator" }, "project_id": "my-project-id" }
Metric retrieval examples
To request the disk-read bandwidth usage for all instances and all devices, define a filter as follows. This filter returns, for each instance, a separate time series reporting the read bandwidth for each device:
metric.type = "compute.googleapis.com/instance/disk/read_bytes_count"
To refine the request to query for the read bandwidth for only the disk device known as "log_partition" on each instance, define the filter as follows. This filter returns, for each instance, at most one time series, depending on whether a device of that name exists on that instance:
metric.type = "compute.googleapis.com/instance/disk/read_bytes_count" AND metric.labels.device_name = "log_partition"
To restrict the request to a single instance, specify that instance:
resource.type = "gce_instance" AND resource.labels.instance_id = "1472038649266883453" AND metric.type = "compute.googleapis.com/instance/disk/read_bytes_count" AND metric.labels.device_name = "log_partition"
Filtering with groups
The following examples illustrate the use of the group selector in filters to restrict monitored resources to those in a specific group. See Resource selector for group definitions for information on the selectors used to define group membership.
{ "name": "projects/my-test-project/groups/024681012", "display_name": "My Redis Cluster", "filter": "metadata.user_labels.role=redis" }
In a call to the projects.timeSeries.list
method,
the following filter requests the disk-read bandwidth usage for all
Compute Engine instances in a particular group. The group must be
defined in the scoping project of a metrics scope specified in the
method's name
parameter:
resource.type = "gce_instance" AND group.id = "024681012" AND metric.type = "compute.googleapis.com/instance/disk/read_bytes_count"
Reference: filter syntax
For an overview of filters with examples, see Using filters.
A monitoring filter is a string consisting of up to four types of selectors:
<monitoring_filter> ::= <project_selector> AND <group_selector> AND <resource_selector> AND <metric_selector>
The filter matches an item if all of the included selectors match the item.
As described in the following sections, some selectors can have multiple
comparisons joined by AND
or OR
. The order of the selectors in the
filter doesn't matter, but comparisons for different selectors must not be
intermingled.
Depending on the filter's purpose, certain selectors might be required, optional, or prohibited. For example, the filter used to list time series must contain a metric selector. However, the filter that defines the resources in a group can't contain a metric selector, because groups don't contain metric types or time series.
Comparisons
Filters and their selectors are built from comparisons. Each comparison has the following form:
-
[OBJECT]: selects a value to be tested; one of the following:
project group.id metric.type metric.labels.[KEY] resource.type resource.labels.[KEY] metadata.system_labels.[KEY] metadata.user_labels.[KEYSTRING]
[KEY] is a name, such as
zone
orinstance_id
.[KEYSTRING] can be name, but if it contains special characters, then it must be quoted with quotation marks (
"
). -
[OPERATOR]: a comparison operator; one of the following:
= # equality (case-sensitive) > < >= <= # numeric ordering != # not equal : # "has" substring match and test for key (case-sensitive)
-
[VALUE]: a literal value or a built-in function call; one of the following:
<string> # "a Unicode string". Don't use apostrophes (`'`) to quote strings. <bool> # true or false <number> # 0, -2, 123456, 3.14156 <function> # operators on the right side of '=' or '!=': # starts_with(<string>) # ends_with(<string>) # has_substring(<string> [, ignore_case=false]) # one_of(<string>,...,<string>) for up to 100 strings # monitoring.regex.full_match(<RE2-string>)
Except when used in the
timeSeries.list
method, thehas_substring
filter takes an optional second argument, which specifies whether the match ignores case or not. The default value isfalse
, so the default match is case-sensitive:- Case-sensitive:
display_name=has_substring("Demo")
- Case-sensitive:
display_name=has_substring("Demo", false)
- Case-insensitive:
display_name=has_substring("Demo", true)
When used in the
timeSeries.list
method, only thehas_substring(<string>)
form is supported.The
monitoring.regex.full_match
filter takes a regular-expression string in RE2 syntax. - Case-sensitive:
You can use the following operators to group or modify comparisons. OR
has
higher precedence than AND
. The operators must be written in upper case:
(...) # grouping comparisons AND # conjunction (optional but recommended) OR # disjunction
The AND
operator can be omitted between operators, but it is clearer and
less error-prone to include it.
The comparison x = one_of("a", "b", "c")
is equivalent to the following:
(x = "a" OR x = "b" OR x = "c")Only in group definitions, you can use the unary negation operator,
NOT
,
before a comparison, but not with an exists operator (:
) or before a
parenthesized expression:
NOT # negates the following comparison
Filter selectors
Use selectors to limit the filter selections to certain items.
In the following sections, braces are used to show repetition. For example,
the notation <x> {OR <y>}
means that you can write any of the
following:
<x> <x> OR <y> <x> OR <y> OR <y> <x> OR <y> OR <y> OR <y> ...
Project selector
A project selector limits the filter selection to items belonging to a single project or to any one of a set of projects. Each project can be specified by its ID or its number:
<project_selector> ::= project '=' (<number> | <string>) {OR project '=' (<number> | <string>)}
If your project selector has more than a single comparison, enclose the entire selector in parentheses for better readability. For example:
(project=12345 OR project="my-project-id") AND resource.type="gce_instance"
Group selector
A group selector limits the filter selection to items belonging to a single group:
<group_selector> ::= group.id '=' <string>
For example, the following filter can be used to retrieve a time seriess from each of the VM instances in a group:
group.id = 12345 AND resource.type = "gce_instance" AND metric.type = "compute.googleapis.com/instance/disk/read_bytes_count"
The group selector is permitted only in filters passed to the
projects.timeSeries.list
method. In addition,
group selection requires aligned data; that is, the
projects.timeSeries.list
call must include values for the fields
perSeriesAligner
and alignmentPeriod
. This is because group membership is
itself a kind of time series that must be joined with the metric data, and
supplying alignment parameters gives you control over how that join happens.
For more information on alignment parameters, see
Aggregating data.
Resource selector
A resource selector limits the filter selection to resources—or items associated with resources—that have a specific resource type or label values:
<resource_selector> ::= <resource_type_expression> | <resource_label_expression> | <resource_type_expression> AND <resource_label_expression> <resource_type_expression> ::= resource.type '=' <string> | resource.type ':' <string> | resource.type '=' starts_with '(' <string>')' | resource.type '=' ends_with '(' <string> ')' <r_label_comparison> ::= resource.labels.[KEY] '=' (<string> | <bool>) | resource.labels.[KEY] ':' <string> | resource.labels.[KEY] '=' (starts_with | ends_with) '(' <string> ')' | resource.labels.[KEY] ('=' | '>' | '<' | '>=' | '<=') <number> <resource_label_expression> ::= <r_label_comparison> {AND <r_label_comparison>} | <r_label_comparison> {OR <r_label_comparison>}
If you use more than one <r_label_comparison>
in your selector, then
enclose them all in parentheses for better readability.
For example, the following filter could be used to define a group that includes
all Compute Engine VM instances in the USA and Europe.
resource.type = "gce_instance" AND (resource.labels.zone = starts_with("us-") OR resource.labels.zone = starts_with("europe-"))
Resource selector for group definitions
Resource selectors used to define group membership use extensions to the
<resource_selector>
syntax:
You include filters based on the value of metadata system labels,
metadata.system_labels.[KEY]
, and metadata user labels,metadata.user_labels.[KEYSTRING]
. We recommend quoting the keys formetadata.user_labels
because they can contain special characters such as hyphens.When a selector contains a metadata filter and a resource filter, you must combine them with
AND
; you can't useOR
. For example, a chart with the following selector displays the CPU utilization for all VM instances with a machine type ofe2-medium
ore2-micro
:metric.type="compute.googleapis.com/instance/cpu/utilization" resource.type="gce_instance" AND (metadata.system_labels."machine_type"="e2-medium" OR metadata.system_labels."machine_type"="e2-micro")
You can use the not-equals operator (
!=
) to compare resource types, resource labels, and metadata. The operator can be used when comparing strings, numbers, Booleans, or the substring functions. For example,resource.type!=starts_with("gce")
is true if the resource type does not start with"gce"
.You can use a single
NOT
operator before a resource comparison. For example,NOT resource.labels.zone="europe"
is true if the resource's zone doesn't include"europe"
. You can't useNOT
before an exists operator (:
) or a parenthesized expression.You can use the "exists" operator (
:
) to test for the existence of keys. For example, the comparisonresource.labels:zone
is true if the label keyzone
is present in the resource.
For example, one of the platform resource metadata keys for VM instances is
spot_instance
. The following filter selector chooses instances that are
spot instances:
resource.type = "gce_instance" AND metadata.system_labels.spot_instance = true
Metric selector
A metric selector specifies certain metrics or metric descriptors by limiting
the metric type and metric labels. When used with the
projects.timeSeries.list
method,
the metric selector must specify a single metric type:
<metric_selector> ::= <metric_name_expression> [AND <metric_label_expression>] <metric_name_expression> ::= metric.type '=' <string> | metric.type ':' <string> | metric.type '=' starts_with '(' <string> ')' | metric.type '=' ends_with '(' <string> ')' <metric_label_comparison> ::= metric.labels.[KEY] '=' <string> | <bool> | metric.labels.[KEY] ':' <string> | metric.labels.[KEY] '=' starts_with '(' <string> ')' | metric.labels.[KEY] '=' ends_with '(' <string> ')' | metric.labels.[KEY] ('=' | '>' | '<' | '>=' | '<=') <number> <metric_label_expression> ::= <metric_label_comparison> {[AND] <metric_label_comparison>} | <metric_label_comparison> {OR <metric_label_comparison>}
For example, the following filter could be used to retrieve a time series for a specific database instance:
metric.type = "cloudsql.googleapis.com/database/state" AND (metric.labels.resource_type = "instance" AND metric.labels.resource_id = "abc-123456")