Module: Aws::EC2::Waiters

Defined in:

lib/aws-sdk-ec2/waiters.rb

Overview

Waiters are utility methods that poll for a particular state to occur on a client. Waiters can fail after a number of attempts at a polling interval defined for the service client.

For a list of operations that can be waited for and the client methods called for each operation, see the table below or the Client#wait_until field documentation for the Client.

# Invoking a Waiter To invoke a waiter, call #wait_until on a Client. The first parameter is the waiter name, which is specific to the service client and indicates which operation is being waited for. The second parameter is a hash of parameters that are passed to the client method called by the waiter, which varies according to the waiter name.

# Wait Failures To catch errors in a waiter, use WaiterFailed, as shown in the following example.

rescue rescue Aws::Waiters::Errors::WaiterFailed => error
  puts "failed waiting for instance running: #{error.message}
end

# Configuring a Waiter Each waiter has a default polling interval and a maximum number of attempts it will make before returning control to your program. To set these values, use the ‘max_attempts` and `delay` parameters in your `#wait_until` call. The following example waits for up to 25 seconds, polling every five seconds.

client.wait_until(...) do |w|
  w.max_attempts = 5
  w.delay = 5
end

To disable wait failures, set the value of either of these parameters to ‘nil`.

# Extending a Waiter To modify the behavior of waiters, you can register callbacks that are triggered before each polling attempt and before waiting.

The following example implements an exponential backoff in a waiter by doubling the amount of time to wait on every attempt.

client.wait_until(...) do |w|
  w.interval = 0 # disable normal sleep
  w.before_wait do |n, resp|
    sleep(n ** 2)
  end
end

# Available Waiters

The following table lists the valid waiter names, the operations they call, and the default ‘:delay` and `:max_attempts` values.

| waiter_name | params | :delay | :max_attempts | | ——————————- | —————————————– | ——– | ————- | | bundle_task_complete | Client#describe_bundle_tasks | 15 | 40 | | conversion_task_cancelled | Client#describe_conversion_tasks | 15 | 40 | | conversion_task_completed | Client#describe_conversion_tasks | 15 | 40 | | conversion_task_deleted | Client#describe_conversion_tasks | 15 | 40 | | customer_gateway_available | Client#describe_customer_gateways | 15 | 40 | | export_task_cancelled | Client#describe_export_tasks | 15 | 40 | | export_task_completed | Client#describe_export_tasks | 15 | 40 | | image_available | Client#describe_images | 15 | 40 | | image_exists | Client#describe_images | 15 | 40 | | instance_exists | Client#describe_instances | 5 | 40 | | instance_running | Client#describe_instances | 15 | 40 | | instance_status_ok | Client#describe_instance_status | 15 | 40 | | instance_stopped | Client#describe_instances | 15 | 40 | | instance_terminated | Client#describe_instances | 15 | 40 | | internet_gateway_exists | Client#describe_internet_gateways | 5 | 6 | | key_pair_exists | Client#describe_key_pairs | 5 | 6 | | nat_gateway_available | Client#describe_nat_gateways | 15 | 40 | | nat_gateway_deleted | Client#describe_nat_gateways | 15 | 40 | | network_interface_available | Client#describe_network_interfaces | 20 | 10 | | password_data_available | Client#get_password_data | 15 | 40 | | security_group_exists | Client#describe_security_groups | 5 | 6 | | snapshot_completed | Client#describe_snapshots | 15 | 40 | | snapshot_imported | Client#describe_import_snapshot_tasks | 15 | 40 | | spot_instance_request_fulfilled | Client#describe_spot_instance_requests | 15 | 40 | | store_image_task_complete | Client#describe_store_image_tasks | 5 | 40 | | subnet_available | Client#describe_subnets | 15 | 40 | | system_status_ok | Client#describe_instance_status | 15 | 40 | | volume_available | Client#describe_volumes | 15 | 40 | | volume_deleted | Client#describe_volumes | 15 | 40 | | volume_in_use | Client#describe_volumes | 15 | 40 | | vpc_available | Client#describe_vpcs | 15 | 40 | | vpc_exists | Client#describe_vpcs | 1 | 5 | | vpc_peering_connection_deleted | Client#describe_vpc_peering_connections | 15 | 40 | | vpc_peering_connection_exists | Client#describe_vpc_peering_connections | 15 | 40 | | vpn_connection_available | Client#describe_vpn_connections | 15 | 40 | | vpn_connection_deleted | Client#describe_vpn_connections | 15 | 40 |

Defined Under Namespace

Classes: BundleTaskComplete, ConversionTaskCancelled, ConversionTaskCompleted, ConversionTaskDeleted, CustomerGatewayAvailable, ExportTaskCancelled, ExportTaskCompleted, ImageAvailable, ImageExists, InstanceExists, InstanceRunning, InstanceStatusOk, InstanceStopped, InstanceTerminated, InternetGatewayExists, KeyPairExists, NatGatewayAvailable, NatGatewayDeleted, NetworkInterfaceAvailable, PasswordDataAvailable, SecurityGroupExists, SnapshotCompleted, SnapshotImported, SpotInstanceRequestFulfilled, StoreImageTaskComplete, SubnetAvailable, SystemStatusOk, VolumeAvailable, VolumeDeleted, VolumeInUse, VpcAvailable, VpcExists, VpcPeeringConnectionDeleted, VpcPeeringConnectionExists, VpnConnectionAvailable, VpnConnectionDeleted