Synchronizing in-memory caches while being updated by a high rate data stream

Embodiments of the present invention provide methods and systems for high availability in data-stream applications using separate but synchronized nodes. Initially, a live node is designated to provide the data stream. Upon startup or restart, a standby node synchronizes its state with the live node. The initial synchronization is performed in two phases. In the first phase, the standby node connects to the same data stream (or a data stream with same content) and obtains the same symbols as the live node. In the second phase, the standby node obtains metadata from the live node for various symbols, such as symbols that are new to the standby node. Once synchronized, the live and the standby nodes then continue with separately processing the data stream.