APART (A Posteriori Active ReplicaTion) is a recently proposed active replication protocol specifically tailored for multi-tier data acquisition systems. It ensures consistency of middle-tier sink replicas by means of an a-posteriori synchronization phase based on reconciliation, which is activated only in case replicas react to an input message from the sensors by generating an output event destined to the back-end tier. This paper enhances APART via a novel non-blocking synchronization scheme which prevents replicas from stalling while waiting for the outcome of an on-going synchronization phase. Contrarily, replicas are allowed to optimistically process data from the sensors, and to immediately propagate any output event towards the back-end tier. The removal of the blocking synchronization phase from the critical path gives rise to striking performance gains via an effective overlapping of event processing and synchronization. On the other hand, system consistency is ensured by enhancing the back-end tier synchronization logic in order to filter out optimistically produced output events that are incompatible with the reconciled state trajectory. © 2009 IEEE.
APART+: Boosting APART performance via optimistic pipelining of output events / ROMANO, Paolo; QUAGLIA, Francesco; CICIANI, Bruno. - (2009). (Intervento presentato al convegno 23rd IEEE International Parallel and Distributed Processing Symposium, IPDPS 2009 tenutosi a Rome; Italy nel 23 May 2009 through 29 May 2009) [10.1109/ipdps.2009.5160906].
APART+: Boosting APART performance via optimistic pipelining of output events
ROMANO, Paolo;QUAGLIA, Francesco;CICIANI, Bruno
2009
Abstract
APART (A Posteriori Active ReplicaTion) is a recently proposed active replication protocol specifically tailored for multi-tier data acquisition systems. It ensures consistency of middle-tier sink replicas by means of an a-posteriori synchronization phase based on reconciliation, which is activated only in case replicas react to an input message from the sensors by generating an output event destined to the back-end tier. This paper enhances APART via a novel non-blocking synchronization scheme which prevents replicas from stalling while waiting for the outcome of an on-going synchronization phase. Contrarily, replicas are allowed to optimistically process data from the sensors, and to immediately propagate any output event towards the back-end tier. The removal of the blocking synchronization phase from the critical path gives rise to striking performance gains via an effective overlapping of event processing and synchronization. On the other hand, system consistency is ensured by enhancing the back-end tier synchronization logic in order to filter out optimistically produced output events that are incompatible with the reconciled state trajectory. © 2009 IEEE.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.