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Wayfair Case Study

· 7 min read


Development on Tremor started in the autumn of 2018 as a point solution for introducing a configurable traffic-shaping mechanism for our infrastructure platform engineering organization.

There were two use cases being considered at the time- the traffic-shaping use case, which had the highest priority; and a distributed data replication use case for our Kafka-based environments.

The Origin of Tremor

The Traffic Shaping use case required that log information streaming from various systems be categorized and classified in-flight, so that temporally bound rate limits could be applied when our production estate has a working set that is in excess of our current capacity. As a 24x7x365 eCommerce environment with year-on-year higher peaks, higher volumetrics and higher loads on our systems, this is a frequent occurrence. Tremor was designed to remove the burden of scaling these systems from our system reliability and network operations center engineers.

This use case saw the birth of Tremor, which was delivered in 6 weeks, just in time for Cyber 5 (the long bank-holiday weekend in the US centered around Thanksgiving, where US folk go peak shopping!). At the time, Tremor was inflexible; only supported connectivity to Kafka for Ingres and Elasticsearch downstream; and, the classification and rate-limiting logic was more or less hardwired- but it worked flawlessly!

Although designed with our logging systems in mind, our metrics systems team saw that Tremor would work for their environment (InfluxDB downstream rather than Elasticsearch, but the logic was basically the same). Tremor was designed to detect backpressure on downstream systems, and to intelligently- based on user defined logic- react by adaptively tuning the data distribution to selectively discard or forward data based on a classification system and rate limits.

The Rise of Event Processing

The user-defined logic required by our logging and metrics teams very quickly became sophisticated. A fairly quick succession of releases saw the logic change from fairly simple filtering, classification (enrichment) and rate limiting (selective dropping due to backpressure) to richer needs to slice and dice nested JSON-like data, to normalize these datasets. This rising need for sophistication in processing along with the adoption of Tremor to replace Logstash and other log shipping frameworks in our source nodes, and to replace Telegraf in our metrics environments, gave birth to Tremor as an event processing engine in its own right.

With richer programming primitives, Tremor advanced from traffic shaping, and log and metrics shipping to log and metrics cleansing, normalisation, enrichment and transformation, to impose a common symbology and structure on logs and metrics generated from many different programming languages, platforms and tools across our production estate- from system logs originated via Syslog, to those via GELF, or Prometheus.

The YAML-based configuration of the query pipelines quickly became error-prone and cumbersome as the sophistication, complexity and size of application logic grew. In addition, the success of our scripting language, tremor-script, and its hygienic set of tooling and IDE integration encouraged the addition a query language, thus enabling data flow processing with Tremor.

Cloud Native Migration

At the same time, our technology organisation was preparing for migration from on-premise data centres to cloud-based systems. Our legacy VM-based systems were now being containerised and deployed via Kubernetes in our on-premise environments. Simultaneously, our Cloud-native infrastructure, configuration as code, secrets management, developer scaling and many other infrastructure and development platform teams were building out the services that would allow our line of business service engineers to migrate to the cloud.

Tremor was already battle-hardened as a sidecar deployment, and this was extended to Cloud-native deployments by our kubernetes team who packaged Tremor for kubernetes as a set of helm charts.

As a relatively fast-paced technology organisation, our logging and metrics teams weren’t stalled- the scripting and query languages enabled rapid development. However, lack of native support in Tremor to modularise and reuse logic became a limiting factor. Thus, over the span of approximately a year, most of the modularity mechanisms, now standard in Tremor, were developed.

Tremor was now battle-tested, battle-hardened and widely adopted, having gone through many enhancements and replacing many disparate tools and frameworks with a single, easy-to-operate solution.

Tremor is the first major component of in-house critical infrastructure that was open-sourced by Wayfair and contributed to the Linux Foundation under the Cloud Native Computing Foundation.

The Tremor team then selected a panel of experts and friends, who had early access to Tremor, to assist with the open-sourcing process.

Tremor Today

Today, Tremor is planned and progresses in the open. Anyone can contribute, and with contribution comes maintainership. Tremor is now a CNCF community (sandbox) project, and maintainership has grown beyond Wayfair.

At Wayfair, Tremor has been adopted for our search environments. Our search domain has some complex use cases for audited document elementisation and indexing that are multi-participant and that need to occur transactionally.

Tremor’s QoS mechanisms were extended to support transaction orchestration to enable this and similar use cases. Our search teams are also leveraging Tremor for its traditional areas of strength in traffic shaping and adaptive rate limiting.

Our logging and metrics teams are now recalibrating our technology organisation's philosophy and core infrastructure that supports observability across our production estate. The rise of CNCF OpenTelemetry offers developers a consistent and stable set of primitives for logs, metrics and distributed tracing. It’s a lingua franca that offers developers consistency.

Even more important to large or extreme scale organisations is flexibility to make infrastructure and service decisions based on capacity, cost, or other concerns. Through CNCF OpenTelemetry as a core building block, now natively supported in Tremor, our observability teams can now unify our production support, operations and services around Tremor-based OpenTelemetry- preserving the key values that Tremor adds, whilst opening up the Cloud Native new possibilities that OpenTelemetry and OpenTelemetry-based services offer.

Tremor Tomorrow

As the tremor community grows, we have seen great contributions from the growing tremor community adding support for many different types of systems - ranging from the addition of AMQP support by Nokia Communications through to our ongoing collaboration with Microsoft Research on the snmalloc allocator which tremor defaults to.

The latest production solution based on tremor at Wayfair is from our Developer Platforms technology organization - who have used an extension to PHP to identify dead code in our legacy PHP monolith. This solution is based on tremor and included contributions to tremor in the form of the unix_socket connectivity. Thank you Ramona!

The Tremor maintainers also work on the Rust port of simd-json- SIMD accelerated JSON, which is a sister project to Tremor. Mentorships via the Linux Foundation are also producing some wonderful new capabilities and enhancements to the system, ranging from better support for developing gRPC-based connectors in Tremor, to GCP connectivity, or work to add a plugin development kit to Tremor.

Wayfair is already benefiting from community interest and contributions to the project - and the Tremor team has hired its newest member as a result of open-sourcing the project. We are hoping to package and open-source more components of Wayfair’s Tremor-based systems through the Tremor Project, and through other open-source projects at Wayfair through our new Open Source Program Office.

If you are interested, hop on over to our community chat server and say hello!