This blog was originally published in the Presto blog: https://prestodb.io/blog/2022/01/28/avoid-data-silos-in-presto-in-meta Alluxio: Rongrong Zhong Meta: James Sun, Ke Wang Raptor is a Presto connector (presto-raptor) that is used to power some critical interactive query workloads in Meta (previously Facebook). Though referred to in the ICDE 2019 paper Presto: SQL on Everything, it remains somewhat mysterious to many Presto users … Continued
Running Presto with Alluxio is gaining popularity in the community. It avoids long latency reading data from remote storage by utilizing SSD or memory to cache hot dataset close to Presto workers. Presto supports hash-based soft affinity scheduling to enforce that only one or two copies of the same data are cached in the entire cluster, which improves cache efficiency by allowing more hot data cached locally. The current hashing algorithm used, however, does not work well when cluster size changes. This article introduces a new hashing algorithm for soft affinity scheduling, consistent hashing, to address this problem.