CAVA: Exploring Memory Locality for Big Data Analytics in Virtualized Clusters

Running big data analytics frameworks in the cloud is becoming increasingly important, but their resource managers in the current form are not designed to consider virtualized environments. In this work, we investigate various levels of data locality in a virtualized environment, ranging from rack locality to memory locality. Exploiting extra fine-grained levels of data locality in a virtualized environment, our memory locality-aware scheduling algorithm effectively increases the cache hit ratio and thereby reduces network traffic and disk I/O. However, a high cache hit ratio does not necessarily imply a shorter job execution time in MapReduce applications. To resolve this issue, we develop the Cache-Affinity and Virtualization-Aware (CAVA) resource manager, which measures the cache affinity of MapReduce applications at runtime and efficiently manages distributed in-memory caches of a limited size by assigning high priority to applications that have high cache affinity. The proposed memory locality-aware scheduling algorithm is also integrated into the CAVA resource manager. Our extensive experimental study shows that CAVA exhibits overall good performance over various workloads composed of multiple big data analytics applications by considering the fine-grained data locality levels in virtualized clusters and by efficiently using scarce memory resources.