Cloud Functions, Google Cloud’s Function as a Service (FaaS) offering, is a lightweight compute platform for creating single-purpose, standalone functions that respond to events, without needing an administrator to manage a server or runtime environment. 

Over the past year we have shipped many new important capabilities on Cloud Functions: new runtimes (Java, .NET, Ruby, PHP), new regions (now up to 22), an enhanced user and developer experience, fine-grained security, and cost and scaling controls. But as we continue to expand the capabilities of Cloud Functions, the number-one friction point of FaaS is the “startup tax,” a.k.a. cold starts: if your function has been scaled down to zero, it can take a few seconds for it to initialize and start serving requests. 

Today, we’re excited to announce minimum (“min”) instances for Cloud Functions. By specifying a minimum number of instances of your application to keep online during periods of low demand, this new feature can dramatically improve performance for your serverless applications and workflows, minimizing your cold starts.

Min instances in action

Let’s take a deeper look at min instances with a popular, real-world use case: recording, transforming and serving a podcast. When you record a podcast, you need to get the audio in the right format (mp3, wav), and then make the podcast accessible so that users can easily access, download and listen to it. It’s also important to make your podcast accessible to the widest audience possible including those with trouble hearing and those who would prefer to read the transcript of the podcast. 

In this post, we show a demo application that takes a recorded podcast, transcribes the audio, stores the text in Cloud Storage, and then emails an end user with a link to the transcribed file, both with and without min instances. 

Approach 1: Building the application with Cloud Functions and Cloud Workflows

In this approach, we use Cloud Functions and Google Cloud Workflows to chain together three individual cloud functions. The first function (transcribe) transcribes the podcast, the second function (store-transcription) consumes the result of the first function in the workflow and stores it in Cloud Storage, and the third function (send-email) is triggered by Cloud Storage when the transcribed result is stored and sends an email to the user to inform them that the workflow is complete.

Cloud Workflows executes the functions in the right order and can be extended to add additional steps in the workflow in the future. While the architecture in this approach is simple, extensible and easy to understand, the cold start problem remains, impacting end-to-end latency. 

Approach 2: Building the application with Cloud Functions, Cloud Workflows and min instances

In this approach, we follow all the same steps as in Approach 1, with a slightly modified configuration that enables a set of min instances for each of the functions in the given workflow.

This approach presents the best of both worlds. It has the simplicity and elegance of wiring up the application architecture using Cloud Workflows and Cloud Functions. Further, each of the functions in this architecture leverages a set of min instances to mitigate the cold-start problem and time to transcribe the podcast.

Comparison of cold start performance

Now consider executing the Podcast transcription workflow using Approach 1, where no min instances are set on the functions that make up the app. Here is an instance of this run with a snapshot of the log entries. The start and end timestamps are highlighted to show the execution of the run. You can see here that the total runtime in Approach 1 took 17 s. 

Approach 1: Execution Time (without Min Instances)

Now consider executing the podcast transformation workflow using Approach 2, where min instances are set on the functions. Here is an instance of this run with a snapshot of the log entries. The start and end timestamps are highlighted to show the execution of the run, for a total of 6 s. 

Approach 2: Execution Time (with Min Instances)

That’s an 11 second difference between the two approaches. The example set of functions are hardcoded with a 2 to 3 second sleep during function initialization, and when combined with average platform cold-start times, you can clearly see the cost of not using min instances.

You can reproduce the above experiment in your own environment using the tutorial here. 

Check out min instances on Cloud Functions

We are super excited to ship min instances on Cloud Functions, which will allow you to run more latency-sensitive applications such as podcast transcription workflows in the serverless model. You can also learn more about Cloud Functions and Cloud Workflows in the following Quickstarts: Cloud Functions, Cloud Workflows.

Editor’s note: Today’s post comes from Naohiko Takemura, Head of Engineering, and Kosukex Oya, Engineer, both from Japanese customer experience platform PLAID. The company runs its platform in a multicloud environment through Anthos clusters on AWS and shares more on its experiences and best practices. 

At PLAID, our mission is to maximize the value of people through data, and we are developing a range of products that focus on improving customer experience. Our core product is a customer experience platform, KARTE, that can analyze the behavior and emotions of website visitors and application users, enabling businesses to deliver relevant communications in real time. We make KARTE available as a service to functions such as human resources and industries such as real estate and finance, and run the platform in a multicloud environment to achieve high-speed response and meet availability requirements. This is where Anthos comes in.

We introduced KARTE in 2015 and updated the system configuration in line with the addition of new functions and the need to increase scale. Our multicloud configuration is optimized through Anthos clusters on AWS, which give us access to the capabilities of Google Kubernetes Engine (GKE). 

KARTE runs in two groups of server instances in each cloud; one group runs the management screens used by clients, and the other provides content for visitors to our website. In Google Cloud, the management system runs in GKE and content is delivered through Compute Engine.

We initially developed and operated the core of our services on another provider and from 2016 began to transition to Google Cloud due to its strong data processing capabilities. The products that handled big data, such as Cloud Bigtable and BigQuery, were attractive because they could handle data in real time and were compatible with KARTE. Now most functions, including peripheral aspects, run in Google Cloud, because we thought if we built a system centered on these products, it would become efficient to build other parts on Google Cloud.

While we considered migrating everything to Google Cloud, we decided to leverage its strengths alongside those of our existing provider, AWS. We felt a multicloud approach could create more opportunities and deliver higher growth than a mono-cloud environment.  

We completed our move to a multicloud environment in 2017 and found that by building systems with almost the same content on two cloud services to leverage the strengths of each, we could reduce costs and improve performance and availability.

However, as KARTE grew, and the content of the service increased in complexity, we began to experience new problems. The increased load on the system due to an influx of in-house engineers from 2018 onwards impacted the scalability and development speeds of our  conventional monolithic architecture running in virtual machines. We opted for an approach based on microservices and containerization, excluding the components that enabled real-time analysis as these had been modernized since initially being deployed in 2016, and the management screens, as the infrastructure running these did not require crisp tuning. Our key priority was to improve the ability of our engineers to deliver quickly.

From 2019, we turned to promoting microservices that make full use of container technology. When deciding to move from a target built on virtual machines to containerization, we evaluated the ease of use of GKE and decided to build in Google Cloud. At the same time, the number of systems with strict service level obligations was increasing, so to ensure higher availability, we considered running these in a multi cloud environment. The announcement of Anthos clusters on AWS at Google Cloud Next ‘19 in San Francisco provided an answer.

We had been wondering how to achieve the equivalent smooth operation of GKE in our AWS environment, and welcomed the Anthos clusters on AWS announcement. We consulted with a Google Cloud customer engineer through an early access program and quickly gained an opportunity to work with this version of Anthos. This allowed us to provide feedback and requests for improvement, and this paved the way for us to implement the product to take advantage of its functionality and future enhancements. With Google Cloud, we have been able to continue to interact closely with the development team to understand and provide input into the product roadmap.

We are now realizing the benefits of multicloud, including faster development speeds and higher availability. For businesses in general, we recommend they take a thoughtful approach to multicloud—while for us, multicloud is a useful mechanism that enables us to provide large-scale data analysis in real time, other businesses should consider whether multicloud is right for them and if so, the role of a technology like Anthos. They should also start small before ramping up.  Moving forward, we are keen to see what other products Google Cloud is creating that can help drive our business to a higher level.

Today’s enterprise applications are often assembled across distributed environments. This includes the integration of services across multi-cloud, multi-SaaS and on-premises environments. While the approach has the advantage of enabling enterprises to choose the best service available to support their applications, it adds the complexity of delivering services across heterogeneous environments. To solve this, Cloud Load Balancing supports an open cloud strategy, which includes:

• Supporting universal traffic management policies across heterogeneous environment by leveraging open source and open standards
• Enabling a global front-end so applications can leverage a common set of policies and security postures
• Providing tools that give your users the highest possible performance and reliability

Universal traffic management with open source and open standards

Kubernetes is a great solution for managing containers across environments. We believe that traffic management policies should also be supported across environments. Cloud Load Balancing creates homogeneous traffic policies across highly distributed heterogeneous environments by supporting standard-based traffic management in a fully managed solution, and allowing open source Envoy Proxy sidecars to be used on-premises or in a multi-cloud environment, using the same traffic management as our fully managed Cloud Load Balancers.

As enterprises start modernizing services and refactor monolithic applications, they require solutions that can provide consistent traffic management across distributed systems at scale. But organizations want to invest their time and resources innovating and building new applications — not on the infrastructure and networking required to deploy and manage these services. Envoy is an open-source high-performance proxy that runs alongside the application to deliver common platform-agnostic networking capabilities, including:

• New load balancing algorithms, (e.g. round robin, ring hash, least conns)
• Weighted traffic splitting
• Fault injection
• Request mirroring
• Outlier detection
• Additional header transformation options
• Request retries
• Additional backend session affinity options
• Cross-origin resource sharing (CORS)

Hybrid Load Balancing across multi-cloud and private clouds

Over the years Google has deployed Load Balancers across 173+ Edge Pop locations, delivering customer applications at massive-scale on Google infrastructure. And now Google Cloud has introduced Hybrid Load Balancing, extending our Load Balancing capabilities beyond Google’s network to on-premises private clouds and multi-cloud solutions. This allows our customers to migrate applications to the cloud iteratively, or build hybrid applications that are assembled from services that are running across heterogeneous environments.

Supporting modern application delivery with HTTP3/QUIC

Cloud Load Balancing is a fully distributed load balancing solution that balances user traffic (HTTP(s), HTTPS/2, HTTPS/3 with gRPC, TCP/SSL, UDP, and QUIC) to multiple backends to avoid congestion, reduce latency, increase security, and reduce costs. It is built on the same frontend-serving infrastructure that powers Google services, supporting millions of queries per second with consistent high performance and low latency.

To serve massive amounts of traffic, Google built the first scaled-out software-defined load balancing, Maglev, which has been serving global traffic since 2008. It has sustained the rapid global growth of Google services, and it also provides network load balancing functions for Google Cloud Platform customers. To accommodate ever-increasing traffic, Maglev is specifically optimized for packet processing performance with Linux Kernel Offload. Maglev is also equipped with consistent hashing and connection tracking features, to minimize the negative impact of unforeseen faults and failures on connection-oriented protocols.

Another key enabler to support this global-scale is that our Cloud Load Balancers are built on top of QUIC(RFC9000), a protocol developed from the original Google QUIC) (gQUIC). HTTP/3 is supported between the External HTTP(S) Load Balancer, Cloud CDN, and end clients. And once enabled, customers typically see dramatic improvements in performance and throughput.

Google Cloud already supports HTTP3 in Cloud Load Balancer. To use HTTP/3 for your applications, you can enable it on your external HTTPS Load Balancers via the Google Cloud Console or the gCloud SDK with a single click.

If your service is sensitive to latency, QUIC will make it faster because it establishes connections with reduced handshakes. When a web client uses TCP and TLS, it requires two to three round trips with a server to establish a secure connection before the browser can send a request. With QUIC, if a client has connected with a given server before, it can start sending data without any round trips, so your web pages will load faster.

QUIC has advantages over legacy TCP as follows.

Summary

Since 2008, Google has been an innovator in software-defined networking, supporting applications running at massive scale. Google Cloud Load Balancers support HTTP3 and QUIC as a next generation web transport protocol, which significantly improves customer traffic latency. Google Load Balancers also have incorporated the Envoy proxy as a foundational technology, providing our customers with advanced traffic management that’s compatible with the open source Envoy ecosystem. This allows our users to have the choice to combine Google’s fully-managed Cloud Load Balancers with open source Envoy Proxies, to enable consistent traffic management capabilities across a multi-cloud distributed environment. And with Hybrid Load Balancing, customers can leverage our 173+ world wide PoPs to seamlessly manage traffic across Google Cloud, on-premises and other cloud providers.

Google Cloud Load Balancers include all these capabilities natively. And when used together, they support globally-scaled applications that run seamlessly across the heterogeneous environments many enterprises deploy today.