Redis cache settings for Drupal 7 on Pantheon.

settings.php

<?php
/**
 * Redis cache settings for Pantheon.
 *
 * http://helpdesk.getpantheon.com/customer/portal/articles/401317
 *
 * All Pantheon Environments.
 */
if (defined('PANTHEON_ENVIRONMENT')) {
  // Use Redis for caching. (mandatory).
  $conf['redis_client_interface'] = 'PhpRedis';
  $conf['cache_backends'][] = 'sites/all/modules/contrib/redis/redis.autoload.inc';
  $conf['cache_default_class'] = 'Redis_Cache';
  $conf['cache_prefix'] = array(
    'default' => 'pantheon-redis-' . $_SERVER['PANTHEON_ENVIRONMENT'],
  );
  // Do not use Redis for cache_form (no performance difference).
  $conf['cache_class_cache_form'] = 'DrupalDatabaseCache';

  // Only enable one of the options below:

  // Option A:
  // High performance - no hook_boot(), no hook_exit(), ignores Drupal IP blacklists.
  // $conf['page_cache_without_database'] = TRUE;
  // $conf['page_cache_invoke_hooks'] = FALSE;
  // // Explicitly set page_cache_maximum_age as database won't be available.
  // $conf['page_cache_maximum_age'] = 900;

  // Option B:
  // Use the database for cached HTML.
  $conf['cache_class_cache_page'] = 'DrupalDatabaseCache';
}