S-Query-examples

This repo hosts some examples that query the internal state of stateful operators in S-Query. (Based on Hazelcast Jet)

S-Query is an adaptation of Hazelcast Jet which supports querying the internal state.

Structure

The most important are the dh, benchmark-getter-job and generic-query/generic-inc-query modules.

The dh module contains the Jet jobs for the Delivery Hero order tracking application in the S-Query paper.

Submodules:

• dh-job Job which contains the stateful operations happening on the stream and measures the time it takes to go from source to sink.
• dh-direct-query Job that queries the state of a given stateful operator using the direct object interface.
• dh-queries Job which queries the state with one of 4 complex SQL queries
• dh-query-benchmark Job which queries one of 4 complex SQL queries continuously and measures the latencies.

The benchmark-getter-job is a Jet job which gets the 2PC times of S-Query/Jet. Internally (in S-Query) the time it takes to complete a 2 phase commit is measured and put to a List. This job gets that list and prints the latencies to the console (in ns). Both phase 1 and phase 2 are individually measured.

generic-query Is a helper job which can query any table with any type of query with the latest snapshot ID.

generic-inc-query Is similar to generic-query except it will query incremental snapshots, again with the latest snapshot id.

The scripts folder contains several scripts for transferring the jars to a remote machine/multiple remote machines.