Methods and systems for quickly serving documents are provided. Documents may be served to users, for example, in response to search query inputs. Documents may be individually communicated to a document server individually prior to batching the documents. In such a real-time serving system, serving components may fail. To ensure real-time serving despite the failure, spares are utilized to replace the failing serving components such that the spare can immediately begin receiving documents. The spare can also be synchronized with other serving components to obtain the memory of the failing serving component prior to the failure.