DwarfGC: A Space-Efficient and Crash-Consistent Garbage Collector in NVM for Cloud Computing

Emerging cloud computing arouses need for large-scale data processing which in turn promises vigorous developments on big data platforms running on Java Virtual Machine (JVM), such as Hadoop, Spark and Flink. Storing a large amount of data in memory allows those platforms to benefit from satisfying performance and powerful memory management and garbage collection service in Java. Non-volatile memory (NVM) provides nonvolatility, byte-addressable and fast access speed characteristics and thus becomes a superior alternative for volatile memory utilizing in future cloud system and Java world. This paper presents a recoverable garbage collector named DwarfGC to manage Java objects in NVM so as to ensure crash consistency and durability. DwarfGC persists heap-related metadata into NVM at the beginning of GC and relies on it for recovery. The metadata is stored in a space-efficient fashion but incurring little time overhead.