Smooth Migration of CERN Post Mortem Service to a Horizontally Scalable Service

The Post Mortem service for CERNs accelerator complex stores and analyses transient data recordings of various equipment systems following certain events, like a beam dump or magnet quenches. The main purpose of this framework is to provide fast and reliable diagnostic to the equipment experts and operation crews to decide whether accelerator operation can continue safely or whether an intervention is required. While the Post Mortem System was initially designed to serve CERNs Large Hadron Collider (LHC), the scope has been rapidly extended to include as well External Post Operational Checks and Injection Quality Checks in the LHC and its injector complex. These new use cases impose more stringent time-constraints on the storage and analysis of data, calling to migrate the system towards better scalability in terms of storage capacity as well as I/O throughput. This paper presents an overview on the current service, the ongoing investigations and plans towards a scalable data storage solution and API, as well as the proposed strategy to ensure an entirely smooth transition for the current Post Mortem users.