Businesses around the globe are realizing the benefits of replacing legacy data silos with cloud-based enterprise data warehouses, including easier collaboration across business units and access to insights within their data that were previously unseen. However, bringing data from numerous disparate data sources into a single data warehouse requires you to develop pipelines that ingest data from these various sources into your enterprise data warehouse. Historically, this has meant that data engineering teams across the organization procure and implement various tools to do so. But this adds significant complexity to managing and maintaining all these pipelines and makes it much harder to effectively scale these efforts across the organization. Developing enterprise-grade, cloud-native pipelines to bring data into your data warehouse can alleviate many of these challenges. But, if done incorrectly, these pipelines can present new challenges that your teams will have to spend their time and energy addressing. 

Developing cloud-based data ingestion pipelines that replicate data from various sources into your cloud data warehouse can be a massive undertaking that requires significant investment of staffing resources. Such a large project can seem overwhelming and it can be difficult to identify where to begin planning such a project. We have defined the following principles for data pipeline planning to begin the process. These principles are intended to help you answer key business questions about your effort and begin to build data pipelines that address your business and technical needs. Each section below details a principle of data pipelines and certain factors your teams should consider as they begin developing their pipelines.

Principle 1: Clarify your objectives

The first principle to consider for pipeline development is clarify your objectives. This can be broadly defined as taking a holistic approach to pipeline development that encompasses requirements from several perspectives: technical teams, regulatory or policy requirements, desired outcomes, business goals, key timelines, available teams and their skill sets, and downstream data users. Clarifying your objectives clearly identifies and defines requirements from each key stakeholder at the beginning of the process and continually checks development against these requirements to ensure the pipelines built will meet these requirements.This is done by first clearly defining the desired end state for each project in a way that addresses a demonstrated business need of downstream data users. Remember that data pipelines are almost always the means to accomplish your end state, rather than the end state itself. An example of an effectively defined end-state is “enabling teams to gain a better understanding of our customers by providing access to our CRM data within our cloud data warehouse” rather than “move data from our CRM to our cloud data warehouse”. This may seem like a merely semantic difference, but framing the problem in terms of business needs helps your teams make technical decisions that will best meet these needs. 

After clearly defining the business problem you are trying to solve, you should facilitate requirement gathering from each stakeholder and use these requirements to guide the technical development and implementation of your ingestion pipelines. We recommend gathering stakeholders from each team, including downstream data users, prior to development to gather requirements for the technical implementation of the data pipeline. These will include critical timelines, uptime requirements, data update frequency, data transformation, DevOps needs, and security, policy, or regulatory requirements by which a data pipeline must meet.

Principle 2: Build your team

The second principle to consider for pipeline development is build your team. This means ensuring you have the right people with the right skills available in the right places to develop, deploy, and maintain your data pipelines. After you have gathered your pipeline requirements, you can begin to develop a summary architecture that will be used to build and deploy your data pipelines. This will help you identify the human talent you will need to successfully build, deploy, and manage these data pipelines and identify any potential shortfalls that would require additional support from either third-party partners or new team members.

Not only do you need to ensure you have the right people and skill sets available in aggregate, but these individuals need to be effectively structured to empower them to maximize their abilities. This means developing team structures that are optimized for each team’s responsibilities and their ability to support adjacent teams as needed.

This also means developing processes that prevent blockers to technical development whenever possible, such as ensuring that teams have all of the appropriate permissions they need to move data from the original source to your cloud data warehouse without violating the concept of least privilege. Developers need access to the original data source (depending on your requirements and architecture) in addition to the destination data warehouse. Examples of this are ensuring that developers have access to develop and/or connect to a Salesforce Connected App or read access to specific Search Ads 360 data fields.

Principle 3: Minimize time to value

The third principle to consider for pipeline development is minimize time to value. This means considering the long-term maintenance burden of a data pipeline prior to developing and deploying it in addition to being able to deploy a minimum viable pipeline as quickly as possible. Generally speaking, we recommend the following approach to building data pipelines to minimize their maintenance burden: Write as little code as possible. Functionally, this can be implemented by:

1. Leveraging interface-based data ingestion products whenever possible. These products minimize the amount of code that requires ongoing maintenance and empower users who aren’t software developers to build data pipelines. They can also reduce development time for data pipelines, allowing them to be deployed and updated more quickly. 

• Products like Google Data Transfer Service and Fivetran allow for managed data ingestion pipelines by any user to centralize data from SaaS applications, databases, file systems, and other tooling. With little to no code required, these managed services enable you to connect your data warehouse to your sources quickly and easily.
• For workloads managed by ETL developers and data engineers, tools like Google Cloud’s Data Fusion provide an easy-to-use visual interface for designing, managing and monitoring advanced pipelines with complex transformations.

2. Whenever interface-based products or data connectors are insufficient, use pre-existing code templates. Examples of this include templates available for Dataflow that allow users to define variables and run pipelines for common data ingestion use cases, and the Public Datasets pipeline architecture that our Datasets team uses for onboarding.

3. If neither of these options are sufficient, utilize managed services to deploy code for your pipelines. Managed services, such as Dataflow or Dataproc, eliminate the operational overhead of managing pipeline configuration by automatically scaling pipeline instances within predefined parameters.

Principle 4: Increase data trust and transparency

The fourth principle to consider for pipeline development is increase data trust and transparency. For the purposes of this document, we define this as the process of overseeing and managing data pipelines across all tools. Numerous data ingestion pipelines that each leverage different tools or are not developed under a coordinated management plan can result in “tech sprawl”, which significantly increases the management overhead of data ingestion pipelines as the quantity of data pipelines increases. This becomes especially cumbersome if you are subject to service-level agreements, or legal, regulatory, or policy requirements for overseeing data pipelines. Preventing tech sprawl is, by far, the best strategy for dealing with it by developing streamlined pipeline management processes that automate reporting. Although this can theoretically be achieved by building all of your data pipelines using a single cloud-based product, we do not recommend doing so because it prevents you from taking advantage of features and cost optimizations that come with choosing the best product for your use case. 

A monitoring service such as Google Cloud Monitoring Service or Splunk that automates metrics, events, and metadata collection from various products, including those hosted in on-premise and hybrid computing environments, can help you centralize reporting and monitoring of your data pipelines. A metadata management tool such as Google Cloud’s Data Catalog or Informatica’s Enterprise Data Catalog can help you better communicate the nuances of your data so users better understand which data resources are best fit for a given use case. This significantly reduces your pipeline’s governance burden by eliminating manual reporting processes that often result in inaccuracies or lagging updates.

Principle 5: Manage costs

The fifth principle to consider for pipeline development is manage costs. This encompasses both the cost of cloud resources and the staffing costs necessary to design, develop, deploy, and maintain your cloud resources. We believe that your goal should not necessarily be to minimize cost, but rather maximizing the value of your investment. This means maximizing the impact of every dollar spent by minimizing waste in cloud resource utilization and human time. There are several factors to consider when it comes to managing costs:

• Use the right tool for the job – Different data ingestion pipelines will have different requirements for latency, uptime, transformations, etc. Similarly, different data pipeline tools have different strengths and weaknesses. Choosing the right tool for each data pipeline can help your pipelines operate significantly more efficiently. This can reduce your overall cost, free up staffing time to focus on the most impactful projects, and make your pipelines much more efficient.
• Standardize resource labeling –  Implement and utilize a consistent labeling schema across all tools and platforms to have the most comprehensive view of your organization’s spending. One example is requiring all resources to be labeled by the cost center or team at time of creation. Consistent labeling allows you to monitor your spend across different teams and calculate the overall value of your cloud spending.
• Implement cost controls – If available, leverage cost controls to prevent errors that result in unexpectedly large bills. 
• Capture cloud spend – Capture your spend on all cloud resource utilization for internal analysis using a cloud data warehouse and a data visualization tool. Without it, you won’t understand the context of changes in cloud spend and how they correlate with changes in business.
• Make cost management everyone’s job – Managing costs should be part of the responsibilities of everyone who can create or utilize cloud resources. To do this well, we recommend making cloud spend reporting more transparent internally and/or implementing chargebacks to internal cost centers based on utilization.

Long-term, the increased granularity in cost reporting available within Google Cloud can help you better measure your key performance indicators. You can shift from cost-based reporting (i.e. – “We spent $X on BigQuery storage last month”) to value-based reporting (i.e. – “It costs $X to serve customers who bring in $Y revenue”). 

To learn more about managing costs, check out Google Cloud’s “Understanding the principles of cost optimization” white paper.

Principle 6: Leverage continually improving services

The sixth principle is leverage continually improving services. Cloud services are consistently improving their performance and stability, even if some of these improvements are not obvious to users. These improvements can help your pipelines run faster, cheaper, and more consistently over time. You can take advantage of the benefits of these improvements by:

• Automating both your pipelines and pipeline management: Not only should data pipelines be automated, but almost all aspects of managing your pipelines can also be automated. This includes pipeline/data lineage tracking, monitoring, cost management, scheduling, access management and more. This helps reduce long-term operational costs of each data pipeline that can significantly alter your value proposition and prevent any manual configurations from negating the benefits of later product improvements.
• Minimizing pipeline complexity whenever possible: While ingestion pipelines are relatively easy to develop using UI-based or managed services, they also require continued maintenance as long as they are in use. The most easily maintained data ingestion pipelines are typically the ones that minimize complexity and leverage automatic optimization capabilities. Any transformation in a data ingestion pipeline is a manual optimization of the pipeline that may struggle to adapt or scale as the underlying services improve. You can minimize the need for such transformations by building ELT (extract, load, transform) pipelines rather than ETL (extract, transform, load) pipelines. This pushes transformations down to the data warehouse that is use a specifically optimized query engine to transform your data rather than manually configured pipelines.

Next steps

If you’re looking for more information about developing your cloud-based data platform, check out our Build a modern, unified analytics data platform whitepaper. You can also visit our data integration site to learn more and find ways to get started with your data integration journey.

Once you’re ready to begin building your data ingestion pipelines, learn more about how Cloud Data Fusion and Fivetran can help you make sure your pipelines address these principles.

Editor’s note: Home-goods and furniture giant Wayfair first partnered up with Google Cloud to transform and scale its storefront—work that proved its value many times over during the unprecedented surge in ecommerce traffic during 2020. Today, we hear how BigQuery’s performance and cost optimization have transformed the company’s internal analytics to create an environment of “yes”. 

At Wayfair, we have several unique challenges relating to the scale of our product catalog, our global delivery network, and our position in a multi-sided marketplace that supports both our customers and suppliers. To give you a sense of our scale we have a team of more than 3,000 engineers with tens of millions of customers.  We supply more than 20 Million items using more than 16,000 supplier partners.

Serving those constituents generates a lot of analytics work.  Wayfair runs over a billion ‘analytic’ database queries a year, from both humans and systems, against multi-petabyte datasets. Scaling our previous environment to meet these challenges required us to maintain dozens of copies of data for different use cases and manage complex data synchronization routines to move trillions of records each day, resulting in long development times and high support costs for our analytics projects. 

Centralizing our data using Cloud Storage and BigQuery enabled us to break down existing silos and build unified pipelines for our batch and real-time operations. BigQuery shines by letting us decouple our compute and storage resources and flexibly ingest structured data in streaming and batch modes. We also benefit from the same decoupling for more complicated machine learning (ML) workflows in Dataproc and Cloud Storage. In particular, BigQuery is extremely low maintenance. From ML and easy data integrations to the integrated query cache, many out-of-the-box features have proven valuable for multiple use cases.

Beyond storage and compute, Google Cloud offers multiple tools to maximize the value of our data. For example, we can easily connect Data Studio to BigQuery for lightning-fast dashboarding of enterprise KPI reporting. When we need to dive deeper into a metric, Looker provides an interface and semantic model that empowers more business users to answer important questions — without understanding SQL or our vast dataset and table structure. 

The combination of all of Google Cloud’s tools enables every Wayfairian the opportunity to self-serve their data visualization and analysis needs. We are able to support all of the requirements of our internal and external users, from descriptive analytics to alerting and ML, in a platform that blends Google’s proprietary technology with open-source standards.we have seen a greater than 90% reduction in the number of analytic queries in production that take more than one minute to run

As a result, we have seen a greater than 90% reduction in the number of analytic queries in production that take more than one minute to run, which delights our users and increases adoption of our analytics tools across the business.

Higher performance means saying “Yes” more often

We went into the BigQuery experience expecting very strong performance on large, aggregate queries and excellent scalability — the kind of performance that could enable consistent 5-15 minute processing queries and 5-10 second response times for large analytics queries. 

We weren’t disappointed — we saw slightly better than linear performance profiles as record counts went up from millions to trillions for a flat resource allocation. BigQuery had the expected high performance for aggregate queries. This made our large data processing pipelines predictable and straightforward to maintain and optimize. 

Below is a plot of gigabytes processed by a query against query run time in seconds; outliers are filtered and the axes are pruned to ranges where we had a large sample size. This focuses on longer-duration queries. As an example of the linear performance, a 2 terabyte query averages 5 minutes — 2.5min/terabyte — and an 18 terabyte query (9 times as much data) averages 25s — only 1.4min/terabyte. This is despite the fact that complex queries [sorting and analytic functions are particularly problematic] are more common with large data sizes. We do see increasing variability at large sizes as slot limits and other resource constraints come into play, but these factors are controllable and ultimately a business optimization decision.

Though individual values vary greatly depending on query complexity [analytic functions/sorting can be computationally expensive], the overall trend line is below 1-1 for bytes versus duration, meaning our BigQuery query runtimes are increasing slower than our data volumes. We are still seeing sub 1:1 threshold runtimes, and we’re already at 100 PB of total data with single queries running on 50PB or more. Going strong!

One unexpected and pleasant surprise has been high performance for smaller queries, such as those required for development, interactive analytics, and internal applications we use for forecasting, segmentation, and other latency-sensitive data workflows. BigQuery’s resource management systems have provided smoother degradation and parallelism profiles than we initially expected for a multi-tenant platform. 

We regularly see sub-second p50 query performance for interactive use cases, with p90 performance coming in under 10 seconds for Looker, Data Studio, and AtScale — meeting the threshold we set to avoid analysts losing focus during a business investigation. The chart below shows p50, p90, and p95 timing for core workloads, as well as the number of queries in each bucket and the number of unique users. [Looker and Atscale will use small numbers of service accounts for a large number of users].

This has enabled two important shifts in the way our customers experience analytics services:

1. Delivering better user productivity. People no longer have long wait times to get results for a basic query delivering an improved overall user experience.
2. Scaling our data transformation. BigQuery has proven, effective data transformation that allows us to embrace the industry shift away towards ELT (extract, load, transform) to transform raw data right within the database. 

We no longer have to ask ourselves, “Can we meet the SLA for this data processing task?” The new conversation is, “Of course, we can meet it. What’s the associated cost based on how many resources we assign?” We can make cost and resource trade-offs clear to our users and say “yes” more often to requirements that have measurable business value. 

Supporting cost vs. performance decisions

Democratized access to internal analytics is a powerful decision-making tool. With BigQuery’s robust tooling, the decision about how to best allocate computational resources is in the hands of the analytics groups closest to the business decision being made. If they want to spend a sprint optimizing a dashboard, they can show exactly how much money it will save. If they choose not to optimize a report, they can offset the decision with concrete cost savings and other realized value. 

Wayfair teams also benefit from visibility into their committed costs by abstracting away the details of the underlying services, including BigQuery slots, the virtual CPUs used to execute SQL queries. 

Take a look at this example view consumed by our teams (the metrics for these dashboards are from the BigQuery INFORMATION_SCHEMA (jobs and reservations tables):

Suppose an organization wants to purchase capacity for a period of time. In that case, we provide an average cost for a slot during that time and charge them based on their slot usage for queries, multiplied by the average price. 

Teams can see whether their consumption matches their reservations with a consistent, high-level number. We apply the same approach to tools like Dataproc by aggregating up the costs of component services and providing an organizational cost for those services.

How we use performance signals to improve user efficiency

Instead of overcorrecting for occasional performance fluctuations by allocating excessive resources, we try to align incentives so that people make the right choices for the business. Showback doesn’t work in a vacuum — it requires context and integrated insights. Teams need to show the cost of running a dashboard as well as the ROI is in terms of end user engagement and what peer dashboards with equivalent source datasets might cost. 

We want to give users the freedom to do things the way they want and need to while also educating them on achieving their goals and using best practices to reduce their costs and improve their performance. The goal is never for all dashboards to load “less than x seconds” — we believe that any dashboard can load in x seconds when it is properly designed and resourced. 

For instance, BigQuery allocates slots for a new workload quickly and efficiently, and queries that are optimized and have dedicated resources consistently complete quickly. When users experience a slowdown, it’s typically because they are sharing resources or inefficiently using their resources. Variable performance is a useful signal to help users discover opportunities to optimize queries and work more productively. We value these signals as we like to focus on the aggregate experience of all users interacting with the tool, not individual interaction. 

A natural way to improve user efficiency is to reward ideal behaviors and discourage those that do not align with our analytics strategy. Some examples include splitting out high-demand reporting from ad-hoc exploration to reduce concurrency errors or encouraging people to use materialized tables instead of writing complex custom SQL. For instance, a dedicated reporting project might only include an organization’s Data Studio dashboard if it directly references a table or meets other optimization requirements. Using this approach, we give our users a high degree of freedom and experimentation at the entry-level while providing a well-documented path to scale. 

Visibility into query performance improves business performance

The detailed tracking information we get from Google Cloud products is critical — Google’s robust analytics performance has enabled us to scale Data Studio to over 15,000 Wayfarians. Of course, a larger user base always comes with concerns that less sophisticated users may not appropriately optimize their queries or make the best use of the infrastructure. 

Evaluating the different Data Studio dashboards helps us identify opportunities to use better query optimization practices, such as reducing custom queries, connecting directly to permanent tables, or using the BI Engine to improve dashboard performance. Recently, our team built new billing projects specific for Data Studio reporting. We can scale up a reservation dedicated to reporting about a major sales event in minutes.

Beyond everyday reporting, holidays and sales events may require higher, guaranteed performance. BigQuery’s flexible capacity commitments allow us to decide at a business level whether an urgent need requires us to reprioritize resources immediately or whether we have the time to optimize queries and rebuild dashboards to be performant. These new billing projects let us evaluate if teams need to scale up resourcing, what areas they can optimize in BigQuery, or if a new reservation is needed to resource that team separately. 

Recommendations for achieving high performance at low cost

Are you wondering how to allocate BigQuery slots? Teams must see direct, immediate return on their investment in performance and optimization. 

Our first rule of thumb is to align resource utilization with ownership as closely as possible. This makes it easier for teams to secure dedicated resources, even if they start out small. We’re comfortable doing this because BigQuery dynamically reassigns capacity between the targeted reservation and other consumers in milliseconds. We always get the total usage of our slots — there is no wasted capacity even when we break assignments down granularly.

Once a team has a reservation, we provide reporting that consumes various BigQuery information schema views, such as query logs and reservation information, and processes it into aggregated reporting. We look for metrics like the average slots available to a query at a point in time, overall query performance, and how long queries took to execute to pinpoint the overall health of a reservation against our business objectives. Flex slots also let us experiment easily with additional capacity, and BigQuery’s performance is so consistent that we can use straightforward models to estimate return on additional slot investment. 

Other key cost optimization tips we have found helpful at Wayfair include: 

• Optimize for worst-case performance. Given BigQuery’s ability to share slots, we expect teams will often see much better performance, but we find that thinking it’s more effective when teams think about the most pessimistic case when resourcing their jobs.
• Take advantage of BI Engine reservations. We like to think critically about the data and workload. BI Engine reservations are excellent for workloads that query lots of small dimension tables or a few larger tables loaded into memory. In cases like that, such as with OLAP tools using pre-computed aggregates, we’ve seen BI engine investments drive a 25% reduction in average query time—excellent ROI.
• Leverage Looker for large, longitudinal datasets. Since Looker supports a wide range of use cases, we see a broader range of performance — p50 is still under a second, but p95 can get as high as a minute. For these cases, we recommend modeling user patterns [first of month, first day of week] and dynamically allocating more slots for these periods while deprioritizing batch workloads in the key windows. 
• Lean in heavily on the BQ cache for broad-based reporting. To avoid a Monday morning reporting lag, We use the BigQuery cache to avoid Monday morning report loading lags. Up to 30% of our Data Studio queries hit the BQ cache, ensuring our Data Studio p95 consistently stays under 10 seconds. 
• Use slots-per-job to improve experience. In our reporting, we find that the most valuable view is slots-per-job. We look for dips in slots available for jobs as this situation often correlates strongly with poor user experiences. For example, our reporting showed us that Looker has the highest volumes of queries and users on Mondays and during each month’s first two business days. We used this information to scale up slots to support these periods of highest demand, delivering on performance SLAs to support business users.

• Get a global picture of usage. We manage slots in a central tool. Teams input their requirements into a calendar to indicate when they want higher or lower capacity to inform our flex slot purchases and annual commitments. It might seem like dozens of relatively inconsistent workloads at the team level, but the picture changes when you look at demand across a week (or our entire business). Understanding global usage makes it easy for us to model baseline capacity recommendations for serving year slots versus flexible demands. 

Reaping the rewards of BigQuery

From our first initial undertaking with Google Cloud to transform our storefront, we had a lot of confidence in the underlying technology offerings and the teams that ran them and their ability to meet our unique requirements. But our experience using BigQuery for internal analytics at Wayfair has exceeded our already high expectations. 

BigQuery’s fast, dynamic allocation of resources and ability to transform data in place are important to our mission of maintaining consistently high performance for our users while closely managing costs. Moreover, our visibility into query and dashboard performance through BigQuery’s DSP views and other performance metrics have helped us make clearer connections between performance goals and the costs required to meet them — and guide our analysts across the company towards attaining high performance on every project.