title: MySQL Cluster with MySQL innoDB persistent store
body: <p>We are working on a database solution for a high available (5 9s) application with high performance and data consistency needs. We are planning to use MySQL Cluster as the primary in-memory datastore backed up by a secondary innoDB MySQL datastore for persistent storage.</p>
  
  <p>The proposed approach is that the online application will only interact with the in-memory DB (MySQL cluster) and the MySQL Cluster will propagate the data to the innoDB instance through asynchronous replication / messaging for persistent storage. </p>
  
  <p>Can MySQL cluster or MySQL on its own support this requirement?</p>
  
  <p><strong>Update:</strong></p>
  
  <p>Regarding the answers provided so far:</p>
  
  <p>Is this doable using just MySQL 5.1 by using the MEMORY engine for the primary datastore and the innoDB engine for the secondary datastore? </p>
  
  <p>Can MySQL replicate the data inserted into the primary datastore to the secondary datastore asynchronously using an event based delayed insert approach? </p>