Memcached (ElastiCache)

This page contains information about using the Memcached service in Handel. This service provides a Memcached cluster via the ElastiCache service.

Service Limitations

No Scheduled Maintenance Window Configuration

This service currently doesn’t allow you to change the maintenance window for your Memcached cluster.

No Snapshot Window Configuration

This service currently doesn’t allow you to change the snapshot window for your Memcached cluster.

No Restoration From Snapshot

This service currently doesn’t allow you to launch a cluster from a previous cluster snapshot.

Parameters

Parameter Type Required Default Description
type string Yes   This must always be memcached for this service type.
instance_type string yes   The size of each Memcached instance in your cluster. See Choosing Your Node Size for more details.
memcached_version string yes   The version of Memcached to run. See Comparing Memcached Versions for a list of available versions.
description string No Parameter group for cluster. The parameter group description of your cluster.
node_count: number no 1 The number of memcached nodes you want in your cluster.
cache_parameters: Map<string,string> no   Any cache parameters you wish for your Memcached cluster. See Memcached Specific Parameters for the list of parameters you can provide.
tags Tags No   Any tags you wish to apply to this Memcached cluster.

Warning

Note that having more than 1 node in your cluster will greatly increase your cost. Each node you add to the cluster adds a full cache instance type node cost to your cluster cost.

For example, if you have a Memcached cluster of size 1, using a cache.m4.large instance, it will cost about $112/month.

If you have that same cache.m4.large type, but with a cluster size of 4, it will cost about $448/month since you are being charged for four full Memcached instances.

Be careful to calculate how much this service will cost you if you are using a cluster of more than 1 node.

Tags

The Tags element is defined by the following schema:

tags:
 <your_tag_name>: <your_tag_value>

Note

Handel automatically applies some tags for you. See Default Tags for information about these tags.

Example Handel File

version: 1

name: my-memcached-cluster

environments:
  dev:
    cache:
      type: memcached
      instance_type: cache.m3.medium
      memcached_version: 1.4.34
      node_count: 1
      cache_parameters:
        cas_disabled: 1
      tags:
        mytag: myvalue

Depending on this service

The Memcached service outputs the following environment variables:

Environment Variable Description
<ENV_PREFIX>_ADDRESS The DNS name of the Memcached configuration endpoint address.
<ENV_PREFIX>_PORT The port on which the Memcached cluster is listening.

The <ENV_PREFIX> is a consistent prefix applied to all information injected for service dependencies. See Environment Variable Prefix for information about the structure of this prefix.

Events produced by this service

The Memcached service does not produce events for other Handel services to consume.

Events consumed by this service

The Memcached service does not consume events from other Handel services.