Welcome to a whole new chapter in our Spark and Scylla series! This post will introduce the Scylla Migrator project – a Spark-based application that will easily and efficiently migrate existing Cassandra tables into Scylla. Over the last few years, ScyllaDB has helped many customers migrate from existing Cassandra installations to a Scylla deployment. The migration approach is detailed in this document. Briefly, the process is comprised of several phases: Create an identical schema in Scylla to hold the data; Configure the application to perform dual writes; Snapshot the historical data from Cassandra and load it into Scylla; Configure the […]
The Internet is not just connecting people around the world. Through the Internet of Things (IoT), it is also connecting humans to the machines all around us and directly connecting machines to other machines. In this blog post we’ll share an emerging machine-to-machine (M2M) architecture pattern in which MQTT, Apache Kafka and Scylla all work together to provide an end-to-end IoT solution. We’ll also provide demo code so you can try it out for yourself. IoT Scale IoT is a fast-growing market, already known to be over $1.2 trillion in 2017 and anticipated to grow to over $6.5 trillion […]
This blog post is based on a talk I gave last month at the third annual Scylla Summit in San Francisco. It explains how Scylla ensures that ingestion of data proceeds as quickly as possible, but not quicker. It looks into the existing flow-control mechanism for tables without materialized views, and into the new mechanism for tables with materialized views, which is introduced in Scylla Open Source 3.0. Introduction In this post we look into ingestion of data into a Scylla cluster. What happens when we make a large volume of update (write) requests? We would like the ingestion to […]
Spark Structured Streaming with Scylla Hello again! Following up on our previous post on saving data to Scylla, this time, we’ll discuss using Spark Structured Streaming with Scylla and see how streaming workloads can be written in to ScyllaDB. This is the fourth part of our four part series. Make sure you check out all the prior blogs! Our code samples repository for this post contains an example project along with a docker-compose.yaml file with the necessary infrastructure for running the it. We’re going to use the infrastructure to run the code samples throughout the post and run the project itself, […]
In a previous blog post we examined how Scylla’s paging works, explained the problems with it and introduced the new stateful paging in Scylla 2.2 that solves these problems for singular partition queries by making paging stateful. In this second blog post we are going to look into how stateful paging was extended to support range-scans as well in Scylla Open Source 3.0. We were able to increase the throughput of range scans by 30% and how we also significantly reduced the amount of data read from the disk by 39% and the amount of disk operations by 73%. A […]
Spark and Scylla: Spark DataFrames in Scylla Welcome back! Last time, we discussed how Spark executes our queries and how Spark’s DataFrame and SQL APIs can be used to read data from Scylla. That concluded the querying data segment of the series; in this post, we will see how data from DataFrames can be written back to Scylla. As always, we have a code sample repository with a docker-compose.yaml file with all the necessary services we’ll need. After you’ve cloned it, start up the services with docker-compose: After that is done, launch the Spark shell as in the previous posts […]
In this blog post, we will take a closer look at how Scylla streaming works in detail and how Scylla 2.4’s new streaming improves streaming bandwidth by 240% and reduces the time it takes to perform a “rebuild” operation by 70%.
In this post, we will explore how the Scylla data cache works and will compare the performance results to Cassandra and earlier Scylla releases.
In this blog post, we will look into Scylla’s paging, address some of the earlier problems with it, and describe how we solved those issues in our recently released Scylla 2.2.
Learn how Scylla leverages control theory to keep compactions under control. We’ll discuss the approach ScyllaDB prescribes for solving this problem.