class Aws::CloudWatch::Alarm

Public Class Methods

new(*args) click to toggle source

@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

actions_enabled() click to toggle source

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
alarm_actions() click to toggle source

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
alarm_arn() click to toggle source

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
alarm_configuration_updated_timestamp() click to toggle source

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
alarm_description() click to toggle source

The description of the alarm. @return [String]

# File lib/aws-sdk-cloudwatch/alarm.rb, line 46
def alarm_description
  data[:alarm_description]
end
alarm_name()
Alias for: name
client() click to toggle source

@return [Client]

# File lib/aws-sdk-cloudwatch/alarm.rb, line 220
def client
  @client
end
comparison_operator() click to toggle source

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
data() click to toggle source

@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
data_loaded?() click to toggle source

@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
datapoints_to_alarm() click to toggle source

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
delete(options = {}) click to toggle source

@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
describe_history(options = {}) click to toggle source

@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
dimensions() click to toggle source

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
disable_actions(options = {}) click to toggle source

@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
enable_actions(options = {}) click to toggle source

@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
evaluate_low_sample_count_percentile() click to toggle source

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
evaluation_periods() click to toggle source

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
exists?(options = {}) click to toggle source

@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
extended_statistic() click to toggle source

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
identifiers() click to toggle source

@deprecated @api private

# File lib/aws-sdk-cloudwatch/alarm.rb, line 499
def identifiers
  { name: @name }
end
insufficient_data_actions() click to toggle source

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
load() click to toggle source

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
Also aliased as: reload
metric() click to toggle source

@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
metric_name() click to toggle source

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
metrics() click to toggle source

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
name() click to toggle source

@return [String]

# File lib/aws-sdk-cloudwatch/alarm.rb, line 33
def name
  @name
end
Also aliased as: alarm_name
namespace() click to toggle source

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
ok_actions() click to toggle source

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
period() click to toggle source

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
reload()
Alias for: load
set_state(options = {}) click to toggle source

@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
state_reason() click to toggle source

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
state_reason_data() click to toggle source

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
state_updated_timestamp() click to toggle source

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
state_value() click to toggle source

The state value for the alarm. @return [String]

# File lib/aws-sdk-cloudwatch/alarm.rb, line 89
def state_value
  data[:state_value]
end
statistic() click to toggle source

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
threshold() click to toggle source

The value to compare with the specified statistic. @return [Float]

# File lib/aws-sdk-cloudwatch/alarm.rb, line 171
def threshold
  data[:threshold]
end
threshold_metric_id() click to toggle source

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
treat_missing_data() click to toggle source

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
unit() click to toggle source

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
wait_until(options = {}, &block) click to toggle source

@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
wait_until_exists(options = {}, &block) click to toggle source

@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

extract_name(args, options) click to toggle source
# 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
separate_params_and_options(options) click to toggle source
# 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
yield_waiter_and_warn(waiter) { |waiter| ... } click to toggle source
# 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