class Aws::CloudWatch::Alarm
Public Class Methods
@overload def initialize(name, options = {})
@param [String] name @option options [Client] :client
@overload def initialize(options = {})
@option options [required, String] :name @option options [Client] :client
# File lib/aws-sdk-cloudwatch/alarm.rb, line 22 def initialize(*args) options = Hash === args.last ? args.pop.dup : {} @name = extract_name(args, options) @data = options.delete(:data) @client = options.delete(:client) || Client.new(options) @waiter_block_warned = false end
Public Instance Methods
Indicates whether actions should be executed during any changes to the alarm state. @return [Boolean]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 59 def actions_enabled data[:actions_enabled] end
The actions to execute when this alarm transitions to the `ALARM` state from any other state. Each action is specified as an Amazon Resource
Name (ARN). @return [Array<String>]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 75 def alarm_actions data[:alarm_actions] end
The Amazon Resource
Name (ARN) of the alarm. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 40 def alarm_arn data[:alarm_arn] end
The time stamp of the last update to the alarm configuration. @return [Time]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 52 def alarm_configuration_updated_timestamp data[:alarm_configuration_updated_timestamp] end
The description of the alarm. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 46 def alarm_description data[:alarm_description] end
@return [Client]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 220 def client @client end
The arithmetic operation to use when comparing the specified statistic and threshold. The specified statistic value is used as the first operand. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 179 def comparison_operator data[:comparison_operator] end
@return [Types::MetricAlarm]
Returns the data for this {Alarm}. Calls {Client#describe_alarms} if {#data_loaded?} is `false`.
# File lib/aws-sdk-cloudwatch/alarm.rb, line 240 def data load unless @data @data end
@return [Boolean]
Returns `true` if this resource is loaded. Accessing attributes or {#data} on an unloaded resource will trigger a call to {#load}.
# File lib/aws-sdk-cloudwatch/alarm.rb, line 248 def data_loaded? !!@data end
The number of data points that must be breaching to trigger the alarm. @return [Integer]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 165 def datapoints_to_alarm data[:datapoints_to_alarm] end
@example Request syntax with placeholder values
alarm.delete()
@param [Hash] options ({}) @return [EmptyStructure]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 387 def delete(options = {}) options = Aws::Util.deep_merge(options, alarm_names: [@name]) resp = @client.delete_alarms(options) resp.data end
@example Request syntax with placeholder values
alarm.describe_history({ alarm_types: ["CompositeAlarm"], # accepts CompositeAlarm, MetricAlarm history_item_type: "ConfigurationUpdate", # accepts ConfigurationUpdate, StateUpdate, Action start_date: Time.now, end_date: Time.now, max_records: 1, next_token: "NextToken", scan_by: "TimestampDescending", # accepts TimestampDescending, TimestampAscending })
@param [Hash] options ({}) @option options [Array<String>] :alarm_types
Use this parameter to specify whether you want the operation to return metric alarms or composite alarms. If you omit this parameter, only metric alarms are returned.
@option options [String] :history_item_type
The type of alarm histories to retrieve.
@option options [Time,DateTime,Date,Integer,String] :start_date
The starting date to retrieve alarm history.
@option options [Time,DateTime,Date,Integer,String] :end_date
The ending date to retrieve alarm history.
@option options [Integer] :max_records
The maximum number of alarm history records to retrieve.
@option options [String] :next_token
The token returned by a previous call to indicate that there is more data available.
@option options [String] :scan_by
Specified whether to return the newest or oldest alarm history first. Specify `TimestampDescending` to have the newest event history returned first, and specify `TimestampAscending` to have the oldest history returned first.
@return [Types::DescribeAlarmHistoryOutput]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 426 def describe_history(options = {}) options = options.merge(alarm_name: @name) resp = @client.describe_alarm_history(options) resp.data end
The dimensions for the metric associated with the alarm. @return [Array<Types::Dimension>]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 140 def dimensions data[:dimensions] end
@example Request syntax with placeholder values
alarm.disable_actions()
@param [Hash] options ({}) @return [EmptyStructure]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 437 def disable_actions(options = {}) options = Aws::Util.deep_merge(options, alarm_names: [@name]) resp = @client.disable_alarm_actions(options) resp.data end
@example Request syntax with placeholder values
alarm.enable_actions()
@param [Hash] options ({}) @return [EmptyStructure]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 448 def enable_actions(options = {}) options = Aws::Util.deep_merge(options, alarm_names: [@name]) resp = @client.enable_alarm_actions(options) resp.data end
Used only for alarms based on percentiles. If `ignore`, the alarm state does not change during periods with too few data points to be statistically significant. If `evaluate` or this parameter is not used, the alarm is always evaluated and possibly changes state no matter how many data points are available. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 196 def evaluate_low_sample_count_percentile data[:evaluate_low_sample_count_percentile] end
The number of periods over which data is compared to the specified threshold. @return [Integer]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 159 def evaluation_periods data[:evaluation_periods] end
@param [Hash] options ({}) @return [Boolean]
Returns `true` if the Alarm exists.
# File lib/aws-sdk-cloudwatch/alarm.rb, line 255 def exists?(options = {}) begin wait_until_exists(options.merge(max_attempts: 1)) true rescue Aws::Waiters::Errors::UnexpectedError => e raise e.error rescue Aws::Waiters::Errors::WaiterFailed false end end
The percentile statistic for the metric associated with the alarm. Specify a value between p0.0 and p100. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 134 def extended_statistic data[:extended_statistic] end
@deprecated @api private
# File lib/aws-sdk-cloudwatch/alarm.rb, line 499 def identifiers { name: @name } end
The actions to execute when this alarm transitions to the `INSUFFICIENT_DATA` state from any other state. Each action is specified as an Amazon Resource
Name (ARN). @return [Array<String>]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 83 def insufficient_data_actions data[:insufficient_data_actions] end
Loads, or reloads {#data} for the current {Alarm}. Returns `self` making it possible to chain methods.
alarm.reload.data
@return [self]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 230 def load resp = @client.describe_alarms(alarm_names: [@name]) @data = resp.metric_alarms[0] self end
@return [Metric, nil]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 485 def metric if data[:namespace] && data[:metric_name] Metric.new( namespace: data[:namespace], name: data[:metric_name], client: @client ) else nil end end
The name of the metric associated with the alarm, if this is an alarm based on a single metric. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 114 def metric_name data[:metric_name] end
An array of MetricDataQuery structures, used in an alarm based on a metric math expression. Each structure either retrieves a metric or performs a math expression. One item in the Metrics array is the math expression that the alarm watches. This expression by designated by having `ReturnData` set to true. @return [Array<Types::MetricDataQuery>]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 206 def metrics data[:metrics] end
@return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 33 def name @name end
The namespace of the metric associated with the alarm. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 120 def namespace data[:namespace] end
The actions to execute when this alarm transitions to the `OK` state from any other state. Each action is specified as an Amazon Resource
Name (ARN). @return [Array<String>]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 67 def ok_actions data[:ok_actions] end
The period, in seconds, over which the statistic is applied. @return [Integer]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 146 def period data[:period] end
@example Request syntax with placeholder values
alarm.set_state({ state_value: "OK", # required, accepts OK, ALARM, INSUFFICIENT_DATA state_reason: "StateReason", # required state_reason_data: "StateReasonData", })
@param [Hash] options ({}) @option options [required, String] :state_value
The value of the state.
@option options [required, String] :state_reason
The reason that this alarm is set to this specific state, in text format.
@option options [String] :state_reason_data
The reason that this alarm is set to this specific state, in JSON format. For SNS or EC2 alarm actions, this is just informational. But for EC2 Auto Scaling or application Auto Scaling alarm actions, the Auto Scaling policy uses the information in this field to take the correct action.
@return [EmptyStructure]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 476 def set_state(options = {}) options = options.merge(alarm_name: @name) resp = @client.set_alarm_state(options) resp.data end
An explanation for the alarm state, in text format. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 95 def state_reason data[:state_reason] end
An explanation for the alarm state, in JSON format. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 101 def state_reason_data data[:state_reason_data] end
The time stamp of the last update to the alarm state. @return [Time]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 107 def state_updated_timestamp data[:state_updated_timestamp] end
The state value for the alarm. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 89 def state_value data[:state_value] end
The statistic for the metric associated with the alarm, other than percentile. For percentile statistics, use `ExtendedStatistic`. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 127 def statistic data[:statistic] end
The value to compare with the specified statistic. @return [Float]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 171 def threshold data[:threshold] end
In an alarm based on an anomaly detection model, this is the ID of the `ANOMALY_DETECTION_BAND` function used as the threshold for the alarm. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 213 def threshold_metric_id data[:threshold_metric_id] end
Sets how this alarm is to handle missing data points. If this parameter is omitted, the default behavior of `missing` is used. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 186 def treat_missing_data data[:treat_missing_data] end
The unit of the metric associated with the alarm. @return [String]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 152 def unit data[:unit] end
@deprecated Use [Aws::CloudWatch::Client] wait_until
instead
Waiter polls an API operation until a resource enters a desired state.
@note The waiting operation is performed on a copy. The original resource
remains unchanged.
## Basic Usage
Waiter will polls until it is successful, it fails by entering a terminal state, or until a maximum number of attempts are made.
# polls in a loop until condition is true resource.wait_until(options) {|resource| condition}
## Example
instance.wait_until(max_attempts:10, delay:5) do |instance| instance.state.name == 'running' end
## Configuration
You can configure the maximum number of polling attempts, and the delay (in seconds) between each polling attempt. The waiting condition is set by passing a block to {#wait_until}:
# poll for ~25 seconds resource.wait_until(max_attempts:5,delay:5) {|resource|...}
## Callbacks
You can be notified before each polling attempt and before each delay. If you throw `:success` or `:failure` from these callbacks, it will terminate the waiter.
started_at = Time.now # poll for 1 hour, instead of a number of attempts proc = Proc.new do |attempts, response| throw :failure if Time.now - started_at > 3600 end # disable max attempts instance.wait_until(before_wait:proc, max_attempts:nil) {...}
## Handling Errors
When a waiter is successful, it returns the Resource
. When a waiter fails, it raises an error.
begin resource.wait_until(...) rescue Aws::Waiters::Errors::WaiterFailed # resource did not enter the desired state in time end
@yieldparam [Resource] resource to be used in the waiting condition.
@raise [Aws::Waiters::Errors::FailureStateError] Raised when the waiter
terminates because the waiter has entered a state that it will not transition out of, preventing success. yet successful.
@raise [Aws::Waiters::Errors::UnexpectedError] Raised when an error is
encountered while polling for a resource that is not expected.
@raise [NotImplementedError] Raised when the resource does not
@option options [Integer] :max_attempts (10) Maximum number of attempts @option options [Integer] :delay (10) Delay between each attempt in seconds @option options [Proc] :before_attempt (nil) Callback invoked before each attempt @option options [Proc] :before_wait (nil) Callback invoked before each wait @return [Resource] if the waiter was successful
# File lib/aws-sdk-cloudwatch/alarm.rb, line 363 def wait_until(options = {}, &block) self_copy = self.dup attempts = 0 options[:max_attempts] = 10 unless options.key?(:max_attempts) options[:delay] ||= 10 options[:poller] = Proc.new do attempts += 1 if block.call(self_copy) [:success, self_copy] else self_copy.reload unless attempts == options[:max_attempts] :retry end end Aws::Waiters::Waiter.new(options).wait({}) end
@param [Hash] options ({}) @option options [Integer] :max_attempts (40) @option options [Float] :delay (5) @option options [Proc] :before_attempt @option options [Proc] :before_wait @return [Alarm]
# File lib/aws-sdk-cloudwatch/alarm.rb, line 272 def wait_until_exists(options = {}, &block) options, params = separate_params_and_options(options) waiter = Waiters::AlarmExists.new(options) yield_waiter_and_warn(waiter, &block) if block_given? waiter.wait(params.merge(alarm_names: [@name])) Alarm.new({ name: @name, client: @client }) end
Private Instance Methods
# File lib/aws-sdk-cloudwatch/alarm.rb, line 506 def extract_name(args, options) value = args[0] || options.delete(:name) case value when String then value when nil then raise ArgumentError, "missing required option :name" else msg = "expected :name to be a String, got #{value.class}" raise ArgumentError, msg end end
# File lib/aws-sdk-cloudwatch/alarm.rb, line 527 def separate_params_and_options(options) opts = Set.new( [:client, :max_attempts, :delay, :before_attempt, :before_wait] ) waiter_opts = {} waiter_params = {} options.each_pair do |key, value| if opts.include?(key) waiter_opts[key] = value else waiter_params[key] = value end end waiter_opts[:client] ||= @client [waiter_opts, waiter_params] end
# File lib/aws-sdk-cloudwatch/alarm.rb, line 517 def yield_waiter_and_warn(waiter, &block) if !@waiter_block_warned msg = "pass options to configure the waiter; "\ "yielding the waiter is deprecated" warn(msg) @waiter_block_warned = true end yield(waiter.waiter) end