feat(googlecloudmonitoring): set minimum collection interval as 60s (#…

…37261)

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#### Description

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Fixes part of
#36898

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#### Testing

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.chloggen/feat_googlecloudmonitoring-interval.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: googlecloudmonitoringreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: set the minimum collection interval as 60s
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [36898]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

receiver/googlecloudmonitoringreceiver/README.md

@@ -33,7 +33,7 @@ receivers:
       - metric_name: "connectors.googleapis.com/flex/instance/cpu/usage_time"
 ```
 
-- `collection_interval` (Optional): The interval at which metrics are collected. Default is 300s.
+- `collection_interval` (Optional): The interval at which metrics are collected. Default is 300s, minimum is 60s. Be careful of the [costs](https://cloud.google.com/stackdriver/pricing#monitoring-costs) and [quotas](https://cloud.google.com/monitoring/quotas#api_quotas) when setting a low interval.
 - `initial_delay` (default = `1s`): defines how long this receiver waits before starting.
 - `timeout`: (default = `1m`) The timeout of running commands against the GCP Monitoring REST API.
 - `project_id` (Required): The GCP project ID.

receiver/googlecloudmonitoringreceiver/config.go

@@ -13,6 +13,7 @@ import (
 
 const (
 	defaultCollectionInterval = 300 * time.Second // Default value for collection interval
+	minCollectionInterval     = 60 * time.Second  // Minimum value for collection interval
 	defaultFetchDelay         = 60 * time.Second  // Default value for fetch delay
 )
 
@@ -28,8 +29,8 @@ type MetricConfig struct {
 }
 
 func (config *Config) Validate() error {
-	if config.CollectionInterval < defaultCollectionInterval {
-		return fmt.Errorf("\"collection_interval\" must be not lower than the collection interval: %v, current value is %v", defaultCollectionInterval, config.CollectionInterval)
+	if config.CollectionInterval < minCollectionInterval {
+		return fmt.Errorf("\"collection_interval\" must be not lower than the collection interval: %v, current value is %v", minCollectionInterval, config.CollectionInterval)
 	}
 
 	if len(config.MetricsList) == 0 {