Presto at Varsity Tutors: Using Federated Queries to Power External Reporting – John Cross

Presto at Varsity Tutors: Using Federated Queries to Power External Reporting – John Cross

Varsity Tutors is a learning platform that enables online academic, professional, and enrichment learning. A growing part of their offering partners with school districts to provide customized support for teachers and students. Varsity Tutors for Schools provides external reporting capabilities including student assessments, progress reports, and more. To provide these timely reports, Varsity Tutors (an AWS shop) uses Presto scripts to perform federated queries across MySQL, Postgres, and Redshift and writes data back to S3. They use Ahana Cloud as their managed service for Presto. In this session, John will discuss what technologies they evaluated, why they chose Presto, and their current data architecture including how they handle security for cross-account writes and how they perform upserts into the final reporting database.

Disaggregated Coordinator – Swapnil Tailor, Facebook

Disaggregated Coordinator – Swapnil Tailor, Facebook

In the existing Presto architecture, single coordinator has become a bottleneck in a number of ways for cluster scalability. – With an increasing number of workers, the coordinator has the potential of slow down due to a high number of tasks. – In high QPS use cases, we have found workers can become starved of splits by excessive CPU being spend on task updates in coordinator. – Also with single coordinator, we have an upper limit on the worker pool because of above-mentioned reasons. To overcome with this challenges, we are coming up with a new architecture which supports multiple coordinators in a single cluster.