Abstract: Aspects of the disclosure relate generally to reducing latency for consensus in geographically distributed disaster-safe persistent data-store systems. These distributed systems may include registry system having redundant storage for maintaining the system status. Each registry system may include a server and a storage component. Consensus may be achieved by querying all of other servers of the registry system. In one example, the consensus data may be sharded into independent small groups. This may allow for multiple consensus transactions to be generated and run in parallel, which, in turn may reduce the latency. In addition, or alternatively, requests to a server to write or otherwise change the data-store may be batched at the server side. Thus, for the consensus, the server need only communicate with the other servers only once per batch. This may also reduce the latency of the distributed system.

Abstract: Aspects of the disclosure relate generally to a distributed event joining system for joining primary and secondary events based on a common key. In one example, a continuous stream of primary events may be submitted by a plurality of ad serving computers for storage at a cache layer. Each primary event may be associated with a primary event key. After a time T, the stream of primary events may be sent to long term memory. The system may also receive secondary events, each associated with a primary key. The primary key may be used to identify a primary event in the cache layer. If the primary event is not available in the cache layer, the long term memory may be searched for the primary key. Paired events may then be submitted to a distributed joined event storage system.

Abstract: Aspects of the disclosure relate generally to a distributed event joining system for joining primary and secondary events based on a common key. In one example, a continuous stream of primary events may be stored at a cache layer. Each primary event may be associated with a primary event key which may be used to generate an index map for the cache layer. After a time T, the stream of primary events may be sent to long term memory. The system may also receive secondary events, each associated with a primary key. The primary key may be used to identify a primary event in the cache layer. If the primary event is not available in the cache layer, the long term memory may be searched for the primary key. Paired events may then be submitted to a distributed joined event storage system.