A more committed quorum-based three phase commit protocol

Abstract

In the original quorum-based three phase commit (Q3PC) protocol, a quorum of sites may form after failure, yet those sites remain blocked. Recently, Keidar and Dolev introduced the Enhanced 3PC (E3PC) protocol, in which a quorum never blocks. However E3PC tends to decide to abort transactions in many of those quorate failure sequences where Q3PC would block. We use the concept of “views” to analyse protocols. This allows us to construct an improved version of E3PC which can make progress towards committing a transaction during recovery in circumstances where E3PC would abort. Our new protocol shares with E3PC the property that a quorum never blocks.