Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Scaling for Memcached clusters

ElastiCache for Memcached offers a fully managed, in-memory caching service that deploys, operates, and vertically scales Memcached in the Amazon cloud.

On-demand vertical scaling

With vertical scaling, ElastiCache for Memcached provides a high-performance, distributed memory caching system widely used to speed up dynamic we applications by alleviating database load. It stores data and objects in RAM, reducing the need to read from external data sources.

You can use ElastiCache for Memcached self-designed clusters for vertical scaling. You can apply vertical scaling to existing clusters as well as new ones. This can provide flexibility in resource allocation, allowing users to efficiently adapt to changing workloads without altering cluster architecture. This ability to scale improves performance by increasing cache capacity during high demand periods, and scaling down to optimize costs during low-demand periods. This simplifies operations, eliminates the need to create new clusters for shifting resource requirements, and enables quick responses to traffic fluctuations. Overall, vertical scaling for Memcached self-designed caches can help enhance cost efficiency, improve resource utilization, and even let users change their Memcached instance type. All making it easier for users to align their caching infrastructure with actual application needs.

Setting up on-demand vertical scaling for ElastiCache Memcached clusters

You can configure on-demand vertical scaling for Memcached with scale-config, which contains two parameters:

Converting an existing Memcached node type to a cache that can vertically scale via the CLI

To convert an existing Memcached self-designed cache to a cache that can vertically scale, you can use elasticache modify-cache-cluster via the CLI.

aws elasticache modify-cache-cluster \
    --cache-cluster-id <your-cluster-id> \
    --cache-node-type <new-node-type> \
    --scale-config <scale-config> \ 
    --apply-immediately

Setting up vertical scaling with the CLI

To set up vertical scaling for your Memcached self-designed cache via the CLI, use elasticache modify-cache-cluster with scale-config and its parameters ScalePercentage and ScaleIntervalMinutes.

These configuration options will enable you to fine-tune the scaling process according to your specific needs, balancing between minimizing cluster disruption and optimizing scaling speed. The scale-config parameter will only be applicable for Memcached engine types and will be ignored for other cache engines, ensuring backward compatibility with existing API usage for other clusters.

API call

aws elasticache modify-cache-cluster \
    --cache-cluster-id <your-cluster-id> \
    --cache-node-type <new-node-type> \
    --scale-config '{
            "ScalePercentage": 30,
            "ScaleIntervalMinutes": 2
          }'
    --apply-immediately

Result:

Returns the cache cluster ID and the pending change.

{
    "CacheCluster": {
        "CacheNodeType": "old_insance_type",
         ...
         ...
         "PendingModifiedValues": {
            "CacheNodeType": "new_instance_type"
         },
    }
}

List your Memcached cache vertical scaling setting

You can retrieve scaling options for your Memcached caches, and see what their current options are for vertical scaling.

API call

aws elasticache list-allowed-node-type-modifications --cache-cluster-id <your-cluster-id>

Result:

{ 
  "ScaleUpModifications": [
      "cache.x.xxxx", 
      "cache.x.xxxx"
   	  ],
   "ScaleDownModifications": [ 
      "cache.x.xxxx", 
      "cache.x.xxxx", 
      "cache.x.xxxx" 
      ] 
}

Vertical scaling for Memcached with the Amazon Web Services Management Console

To convert an existing Memcached self-designed cache to a cache that can vertically scale through the https://console.amazonaws.cn/elasticache/, follow these steps.