In this Jira following things will be implemented:
- Make the necessary changes for non-HA code path to use Cache and DoubleBuffer.
- When adding to double buffer, return future. This future will be used in the non-HA path to wait for this, and when it is completed return response to the client.
- Add to double-buffer will happen inside validateAndUpdateCache. In this way, in non-HA, when multiple RPC handler threads are calling preExecute and validateAndUpdateCache, the order inserted in to double buffer will happen in the order requests are received.
In this Jira, we shall not convert non-ha code path to use this, as security and acl work is not completed to use this new model.