Here are the very simple straight steps -
1. Download the module memcache from https://drupal.org/project/memcache
2. Extract and move the memcache to /sites/all/modules/
3. Add/Push the memcache on Acquia Cloud Dev Environment via GIT.
4. If memory is not sufficient. To allocate memory go to Cloud > Server and click on configure for your environment.
5. Enable to Memcache admin module from admin - No Need to enable the mamache.
6. Put the code into settings.php
$conf['cache_backends'] = './sites/all/modules/memcache/memcache.inc';
$conf['cache_default_class'] = 'MemCacheDrupal';
$conf['cache_class_cache_form'] = 'DrupalDatabaseCache';
7. Clear the cache and check the reports at admin/reports/memcache of memcache, it works.
To find the memcache servers via drush
drush vget memcache_servers
Tuning your Memcached settings
The Memcache Admin Drupal module, which is included in the Memcache API and Integration project, provides statistics about how Memcached is behaving on your website. By analysing these statistics, you can decide whether you may need to allocate more memory to Memcached on your server.
To use the Memcache Admin module:
Enable the Memcache Admin module within the Memcache API and Integration project. There is no need to enable the Memcache module.
View the Memcache statistics on your site's Administration > Reports > Memcache statistics page.
Check the Memcache statistics page to see how the cache is behaving. This page reports:
Amount of memory the Memcached daemon is using Percentage of memcached memory used compared to the total memory allocated to it Number of evictions
The value should be 0, which means there is enough memory allocated to the memcached daemon. If the number of evictions is increasing between Memcache statistics reports, allocate more memory to Memcached. Bear in mind, however, that if you allocate more memory to Memcached on your server, you'll have less memory for other server functions, including PHP. Proper memory allocation depends on your site configuration.