Cloud Firestore is a NoSQL document database that simplifies storing, syncing, and querying data for your mobile and web apps at global scale.

Cloud Firestore is a fast, fully managed, serverless, cloud-native NoSQL document database that simplifies storing, syncing, and querying data for your mobile, web, and IoT apps at global scale.

Its client libraries provide live synchronization and offline support, while its security features and integrations with Firebase and Google Cloud Platform (GCP) accelerate building truly serverless apps.

Here’s other stuff it’s good at:

Sync data across devices, on or offline

With Cloud Firestore, your applications can be updated in near real time when data on the back end changes. This is not only great for building collaborative multi-user mobile applications, but also means you can keep your data in sync with individual users who might want to use your app from multiple devices.

With Firebase Realtime Database, we felt we had built the best force-plate testing software on the market. Thanks to Cloud Firestore, in only two weeks, we built a system that’s significantly better and includes features we never thought possible to ship on Day 1.

Chris Wales, CTO, Hawkin Dynamics

Cloud Firestore has full offline support, so you can access and make changes to your data, and those changes will be synced to the cloud when the client comes back online. Built-in offline support leverages local cache to serve and store data, so your app remains responsive regardless of network latency or internet connectivity.

Simple and effortless

Cloud Firestore’s robust client libraries make it easy for you to update and receive new data while worrying less about establishing network connections or unforeseen race conditions. It can scale effortlessly as your app grows. Cloud Firestore allows you to run sophisticated queries against your data. This gives you more flexibility in the way you structure your data and can often mean that you have to do less filtering on the client, which keeps your network calls and data usage more efficient.

Enterprise-grade, scalable NoSQL

Cloud Firestore is a fast and fully managed NoSQL cloud database. It is built to scale and takes advantage of GCP’s powerful infrastructure, with automatic horizontal scaling in and out, in response to your application’s load. Security access controls for data are built in and enable you to handle data validation via a configuration language.

Editor’s note: Streak makes a CRM add-on for Gmail, and recently adopted Cloud Spanner to take advantage of its scalability and SQL capabilities to implement a graph data model. Read on to learn about their decision, what they love about the system, and the ways in which it still needs work.]  

Streak is a customer relationship management (CRM) tool built directly into Gmail. It is used for sales, marketing, hiring, and just about anything else you can think of.

We built it because out of the box, email is actually a really crummy team sharing system. By adding a layer of organization on top of email, Streak lets you add email threads directly into its spreadsheet view, making it useful as a workflow tool with capabilities including task creation, email template management, and easy data entry.

Streak has been integrated with G Suite (originally Google Apps For Your Domain) since its inception so when choosing a cloud, it made sense to colocate our server stack with Google Cloud.

Likewise, Streak was on Google App Engine from the start, and we slowly added other GCP services as the offerings improved or as our use cases became more complex.

In addition to App Engine, we use Google Kubernetes Engine to run a bunch of our compute workload, including both application servers and our offline processes like indexers and task queue consumers.

We use Cloud Dataflow for both streaming event processing and logs ETL, and BigQuery for all of our analytics queries. We use Cloud Pub/Sub for interacting with the Gmail watch API, as well as Stackdriver (logging, tracing, monitoring, errors) and OpenCensus to dig into any operational issues as they arise.

Then, on the database front, we recently started using Cloud Spanner, Google Cloud’s scalable relational database service. Before that, we stored most of our business data in Cloud Datastore, Google Cloud’s NoSQL document database.

Partially, that was historical, since Cloud Datastore was GCP’s only managed database when we wrote the Streak backend. And we’ve been very happy with how easy Cloud Datastore is to maintain. Between Google App Engine and Cloud Datastore, we’ve never had to have an explicit infrastructure on-call rotation.

But as more users rely on Streak to collaborate with larger and larger teams, we were feeling the pain of not having a fully relational database. We found ourselves having to manually join data in our application, which increased application latency and increased the time developers spent coding workarounds and debugging that complexity.

We found we needed two things out of our database: a scalable relational store and a graph store that could power next-gen Streak features. At the same time, we wanted a single database that could handle both use cases and wouldn’t increase our operational burden. This meant finding a managed service to give us more query flexibility, so we decided to give Cloud Spanner a try.

Of course, we didn’t want to migrate our existing stack to a new data platform without first testing it out (never a smart strategy). But since most of our existing data model required transactional updates with other entities, pulling out a single entity to test was challenging. We did have a feature in our pipeline that necessitated a graph data store and that was removed from our other data: our email metadata indexing system.

How your client software handles email metadata indexing can make or break the useability of a system.  Think about how many times somebody forgets to reply-all or that you receive a forwarded thread with thirty emails in reverse-chronological order. Within our own inboxes, we rely on Gmail’s UI to nicely organize email threads, but that organization breaks down when working with a team or across organizational boundaries.

We decided to fix that in the Streak product by organizing metadata (i.e., headers but not message content) from users’ email by using Cloud Spanner as a graph database. Using a graph database lets us answer questions like “What are all the emails on this thread in the inboxes of everybody on my team?” and “Who on my team has previously talked with the organization that this prospect works at?”

In our model, the nodes of the graph are either an email message, a person (email address) or a company (a domain). Then we have four different types of “edges”— properties by which nodes in a graph connect to one another:

1. Message to message (thread): messages that are on the same thread have an edge between them. The reason we do this is because we want to show users a list of threads to answer their questions, not messages, so we need to be able to get the spanning set of messages.
2. Message to message (same RFC id): A core value proposition of Streak is being able to see the “unified” version of a thread that shows each person on a team’s version of the email thread. To make sure we are getting each user’s version of a thread when we issue a query, there needs to be an edge between a message in the queryer’s inbox and the same message in their team’s inbox. In case you’re curious, Streak uses the RFC message id to determine that two messages across inboxes are actually the same.
3. Email address to message: a message has an edge to an email address if it was either the from, to, cc, or bcc on the message. This edge is crucial for queries that start with: “Show me all threads between this person and our team.”

Domain to message: a message has an edge to a domain if the domain is present in any of the from, to, cc, or bcc addresses on the message. This edge is similarly used for queries that start with “Show me all threads between this company and our team.”

Using Cloud Spanner’s distributed SQL capabilities and scalability to build a graph database also let us answer the important follow-up question: “Which threads have I been granted permission to view?” And while a lot of these questions could be answered per-user by a traditional relational database, scale limitations have to be taken into consideration, especially as we plan for 10x or more data volume growth as both our user base grows and as their inboxes accumulate more emails. A graph database model is simply a better fit for Streak’s collaboration model with many-to-many mappings between users and teams, and will allow us to query the data in any number of configurations, without worrying about scale limitations or having to manually shard a relational database. Cloud Spanner gives us queryability and scalability.

Taking the Cloud Spanner plunge

With so many advantages to it, we went ahead and began building out our metadata system with Cloud Spanner as a back-end.

Adopting Cloud Spanner has been great. Here are some of the high points:

1. The fast distributed queries and transactions are absolutely real. We have global indexes across our entire dataset and we haven’t had to spend very much time at all thinking about co-locating data. In particular, we only use interleaved tables for values that would be repeated fields in Cloud Datastore, and that hasn’t been a problem for us yet.
2. We haven’t had any reliability problems whatsoever, despite averaging 20K writes/sec in steady state.
3. Once we optimized our queries on realistic data, Cloud Spanner scaled up in a surprisingly predictable way. You need to run queries after you’ve populated data, do the explain to figure out how the query planner is executing the query, and add indexes/modify queries to make sure they’re performant.
4. Compared to the hoops some traditional relational databases make you jump through, Cloud Spanner’s online schema changes and index builds are magical. There is no downtime for these operations.

Overall, the experience has been encouraging, and we’re planning to move 20 TB of existing data in Cloud Datastore to Cloud Spanner as well. We built out an ORM library for Java on top of Cloud Spanner called Ratchet and are testing a framework for dual-writing entities to both Cloud Datastore and Cloud Spanner to support the rest of the migration. We now store about 40 TB of email metadata in Cloud Spanner, which makes us a large user of Cloud Spanner.

In short, if you’re starting to outgrow your NoSQL database, and want to move to a managed SQL database, give Cloud Spanner a try. You definitely want to model out your costs and try out a proof of concept, both to see how it works on your workload and to get familiar with the quirks of the system. But you don’t need to spend much time worrying about the reliability of the product: it’s there.

Picking the right database for your application is not easy. The choice depends heavily on your use case—transactional processing, analytical processing, in-memory database, and so on—but it also depends on other factors. This post covers the different database options available within Google Cloud across relational (SQL) and non-relational (NoSQL) databases and explains which use cases are best suited for each database option. 

Relational databases 

In relational databases information is stored in tables, rows and columns, which typically works best for structured data. As a result they are used for applications in which the structure of the data does not change often. SQL (Structured Query Language) is used when interacting with most relational databases. They offer ACID consistency mode for the data, which means:

• Atomic: All operations in a transaction succeed or the operation is rolled back.
• Consistent: On the completion of a transaction, the database is structurally sound.
• Isolated: Transactions do not contend with one another. Contentious access to data is moderated by the database so that transactions appear to run sequentially.
• Durable: The results of applying a transaction are permanent, even in the presence of failures.

Because of these properties, relational databases are used in applications that require high accuracy and for transactional queries such as financial and retail transactions. For example: In banking when a customer makes a funds transfer request, you want to make sure the transaction is possible and it actually happens on the most up-to-date account balance, in this case an error or resubmit request is likely fine.

There are three relational database options in Google Cloud: Cloud SQL, Cloud Spanner, and Bare Metal Solution.

Cloud SQL: Provides managed MySQL, PostgreSQL and SQL Server databases on Google Cloud. It reduces maintenance cost and automates database provisioning, storage capacity management, back ups, and out-of-the-box high availability and disaster recovery/failover. For these reasons it is best for general-purpose web frameworks, CRM, ERP, SaaS and e-commerce applications.

Cloud Spanner: Cloud Spanner is an enterprise-grade, globally-distributed, and strongly-consistent database that offers up to 99.999% availability, built specifically to combine the benefits of relational database structure with non-relational horizontal scale. It is a unique database that combines ACID transactions, SQL queries, and relational structure with the scalability that you typically associate with non-relational or NoSQL databases. As a result, Spanner is best used for applications such as gaming, payment solutions, global financial ledgers, retail banking and inventory management that require ability to scale limitlessly with strong-consistency and high-availability. 

Bare Metal Solution: Provides hardware to run specialized workloads with low latency on Google Cloud. This is specifically useful if there is an Oracle database that you want to lift and shift into Google Cloud. This enables data center retirements and paves a path to modernize legacy applications. 

Non-relational databases

Non-relational databases (or NoSQL databases) store compex, unstructured data in a non-tabular form such as documents. Non-relational databases are often used when large quantities of complex and diverse data need to be organized. Unlike relational databases, they perform faster because a query doesn’t have to access several tables to deliver an answer, making them ideal for storing data that may change frequently or for applications that handle many different kinds of data. 

For example, an apparel store might have a database in which shirts have their own document containing all of their information, including size, brand, and color with room for adding more parameters later such as sleeve size, collars, and so on.

Qualities that make NoSQL databases fast:

• Eventual consistency: stores usually exhibit consistency at some later point (e.g., lazily at read time)
• Horizontal scaling, usually using hashed distributions
• Typically, they are optimized for a specific workload pattern (i.e., key-value, graph, wide-column)
• Typically, they don’t support cross shard transactions or flexible isolation modes.

Because of these properties, non-relational databases are used in applications that require large scale, reliability, availability, and frequent data changes.They can easily scale horizontally by adding more servers, unlike some relational databases, which scale vertically by increasing the machine size as the data grows. Although, some relations databases such as Cloud Spanner support scale-out and strict consistency.

Non-relational databases can store a variety of unstructured data such as documents, key-value, graphs, wide columns, and more. Here are your non-relational database options in Google Cloud: 

• Document databases: Store information as documents (in formats such as JSON and XML). For example: Firestore
• Key-value stores: Group associated data in collections with records that are identified with unique keys for easy retrieval. Key-value stores have just enough structure to mirror the value of relational databases while still preserving the benefits of NoSQL. For example: Datastore, Bigtable, Memorystore
• In-memory database: Purpose-built database that relies primarily on memory for data storage. These are designed to attain minimal response time by eliminating the need to access disks. They are ideal for applications that require microsecond response times and can have large spikes in traffic. For example: Memorystore
• Wide-column databases: Use the tabular format but allow a wide variance in how data is named and formatted in each row, even in the same table. They have some basic structure while preserving a lot of flexibility. For example: Bigtable
• Graph databases: Use graph structures to define the relationships between stored data points; useful for identifying patterns in unstructured and semi-structured information. For example: JanusGraph

There are three non-relational databases in Google Cloud:

• Firestore: Is a serverless document database which scales on demand and acts as a backend-as-a-service. It is DBaaS that increases the speed of building applications. It is perfect for all general purpose uses cases such as ecommerce, gaming, IoT and real time dashboards. With Firestore users can interact with and collaborate on live and offline data making it great for real-time application and mobile apps.  
• Cloud Bigtable: Cloud Bigtable is a sparsely populated table that can scale to billions of rows and thousands of columns, enabling you to store terabytes or even petabytes of data. It is ideal for storing very large amounts of single-keyed data with very low latency. It supports high read and write throughput at sub-millisecond latency, and it is an ideal data source for MapReduce operations. It also supports the open-source HBase API standard to easily integrate with the Apache ecosystem including HBase, Beam, Hadoop and Spark along with Google Cloud ecosystem.
• Memorystore: Memorystore is a fully managed in-memory data store service for Redis and Memcached at Google Cloud. It is best for in-memory and transient data stores and automates the complex tasks of provisioning, replication, failover, and patching so you can spend more time coding. Because it offers extremely low latency and high performance, Memorystore is great for web and mobile, gaming, leaderboard, social, chat, and news feed applications.

Conclusion

Choosing a relational or a non-relational database largely depends on the use case. Broadly, if your application requires ACID transactions and your data structure is not going to change much, select a relational database. 

In Google Cloud use Cloud SQL for any general-purpose SQL database and Cloud Spanner for large-scale globally scalable, strongly consistent use cases. In general, if your data structure may change later and if scale and availability is a bigger requirement than consistency then a non-relational database is a preferable choice.  Google Cloud offers Firestore, Memorystore, and Cloud Bigtable to support a variety of use cases across the document, key-value, and wide column database spectrum.

For more comparison resources on each database check out the overview. For more hands-on experience with Bigtable, check out our on-demand training here and learn about migrating databases to managed services check out this whitepaper.  

https://youtube.com/watch?v=2TZXSnCTd7E%3Fenablejsapi%3D1%26

For more #GCPSketchnote, follow the GitHub repo. For similar cloud content follow me on Twitter @pvergadia and keep an eye out on thecloudgirl.dev.

Editor’s note: Bitly, the link & QR Code management platform, migrated 80 billion rows of link data to Cloud Bigtable. Here’s how and why they moved this data from a MySQL database, all in just six days.

Our goal at Bitly is simple: Make your life easier with connections. Whether you’re sharing links online, connecting the physical and digital worlds with custom QR Codes or creating a killer Link-in-bio, we’re here to help make that happen.

Bitly customers run the gamut from your local middle school to most of the Fortune 500 with every use case you can think of in play. On a typical day, we process approximately 360 million link clicks and QR Code scans and support the creation of 6-7 million links or QR Codes for more than 350,000 unique users.

At the heart of our platform is link data consisting of three major datasets for the approximately 40 billion active links in our system (and counting). For years we stored this data in a self-managed, manually sharded MySQL database. While that setup served us well over time, it did present some challenges as we looked to expand and move into the future. 

MySQL: Challenges and growing pains

First, performing operational actions like software and security upgrades or database host provisioning — all while keeping the databases 100% available for our customers — was challenging to say the least.

Additionally, the backup and restore process was both costly and time-consuming. Daily backups for the growing dataset took almost an entire day to complete. And if we ever had to restore the entire data set, it would have undoubtedly taken at least two people working for several days — not a fun prospect and thankfully something we never had to do.

While manual sharding for MySQL offers good key distribution across physical and logical shards, it’s pretty high-maintenance — we tried to avoid touching our sharding config because of how error-prone making changes was. And even with a forward-thinking shard allocation, we found this approach to have a limited lifespan. 

And finally, when we turned our attention towards multi-region and global distribution, manually sharded MySQL proved to be a major hurdle, especially compared to the convenience of a managed service that handles geo-distribution for us.

As we thought about the future of our data and how to best meet our expansion goals, we determined that an update was necessary. We needed a system more set up for growth and increased reliability, preferably one with built-in functionality for replication and scaling. Investigation and research brought us to Cloud Bigtable, Google Cloud’s enterprise-grade NoSQL database service.

The Bitly link, in a nutshell

Before we dive into the Bigtable migration, it’s useful to understand the basics of our link management system. When a user shortens a long URL with Bitly, information is saved to the backend data stores through our API layer. This information consists of a Bitly short link and the corresponding destination link for proper routing, as well as some additional metadata. When a user clicks the Bitly short link, our services query these same backend data stores for the redirect destination for the request. This basic flow, which also includes other Bitly link options like custom back-halves, is the backbone of the Bitly link management platform.

Where Bigtable comes in

As mentioned, after researching our options, the solution that best fit our needs was Bigtable. It offered the features we were looking for, including:

• A 99.999% SLA 
• Limitless scale
• Single-digit millisecond latency
• A built-in monitoring system 
• Multi-region replication
• Geo-distribution, which allows for seamless replication of data across regions and reduces latency
• On-demand scaling of compute resources and storage, which adjusts to user traffic and allows our system to grow and scale as needed
• Seamless integration with our general architecture; we use Google Cloud services for many other parts of our system, including the APIs that interact with these databases
• A NoSQL database that doesn’t require relational semantics, as the datasets we’re migrating are indexed on a single primary key in our applications 

Making the move

We targeted three of our major, self-managed datasets to migrate. The larger two were organized in a sharded database architecture. The first thing we did for migration was prepare the new Bigtable database. We iterated over a schema design process and conducted a thorough performance analysis of Bigtable to ensure an uninterrupted user experience during and after the migration. After that, we made minor adjustments to our application code so that it could seamlessly integrate and interact with Bigtable. Finally, we implemented a robust post-migration disaster recovery process to mitigate any potential risks.

During the actual migration, we enabled our applications to start a “dual writes” phase. This involved concurrently writing new link data to both our existing MySQL and the new Bigtable tables. Once data started writing to our Bigtable instance, we ran our migration scripts. We used a Go script to walk each of the existing MySQL datasets and insert each row into Bigtable. This enabled us to clean up outdated information and backfill older records with newer field data. 

Cleaning up clutter along the way

In the process of migration, we were actually able to free up a huge amount of storage. Because of the elimination of an early feature of the Bitly platform, we were able to exclude from the migration to Bigtable a little less than half of the total data stored in MySQL. Since we were creating a completely clean dataset, we had the opportunity simply to skip those unneeded rows during the migration. 

Altogether, the migration process walked through 80 billion MySQL rows, which resulted in just over 40 billion records finding their new home in Bigtable. In the end, our starting point with Bigtable is a 26 TB dataset, not including replication. A set of concurrent Go scripts running in parallel on a handful of machines allowed us to complete this migration project in six days. (Go rarely disappoints.)

Write twice, cut once – validation before migration

Next up was the data validation and cutover period when we started returning data from Bigtable, but continued to write to MySQL as a precaution in case we needed to roll back at any point.

As we dove into the validation process, we compared the data between MySQL and Bigtable and noted any discrepancies whenever a link was clicked or created. After verifying that all our responses were stable, we proceeded with a gradual cutover process, rolling out in percentages until we reached 100% Bigtable for all writes and reads. After a comfortable run period, we’ll turn off the dual writes completely and finally decommission our workhorse MySQL hosts to live on a farm upstate.

Google’s got Bitly’s back(ups)

Our data is our lifeline, and we’re doing everything we can to ensure it’s always protected. We put together a redundancy plan using both Bigtable backups as well as a process for keeping a copy of the data outside Bigtable for true disaster recovery. 

The first line of defense involves a switchover to the backup Bigtable dataset in case we need it. Beyond that, we’ve implemented two more layers of defense to protect against instance failure, corrupted data, and any other data failure that would require a restore of one or more tables from backup. 

For this process, we start by creating daily Bigtable backups of our tables that we store for a fixed number of days. Second, we execute a Dataflow job to export our data from Bigtable into Cloud Storage approximately every week. And, if the need arises, we can use Dataflow to import our data back from Cloud Storage into a new Bigtable table.  

While running the Dataflow jobs to export from Bigtable to Cloud Storage, we’ve seen an impressive export speed of 7-8 million rows read per second on average and up to 15 million per second at times. All the while, our production reads and writes continued without disruption. When we tested the Cloud-Storage-to-Bigtable restore job, the write speed, expectedly, increased with instance scale — at the maximum node quota for our regions, we observed an average of just under 2 million rows per second written to our new table.

Short links for the long haul

As mentioned above, not only did Bigtable meet our technical requirements and operational needs, but we also chose Bigtable because it sets us up for future growth. Its ability to scale seamlessly over time while improving our system availability SLA was a major factor in our decision.

As we increase our scale by 5x, 10x, or more, it’s imperative that our data backbone scales accordingly and that the SLAs we provide to customers stay stable or even add another coveted “9”. We have big plans in the coming years and Bigtable will help us achieve them. 

Interested in learning more? We found the following resources to be useful in our journey to Bigtable evaluation and ultimate adoption:

• Evaluate Bigtable schema design for your relational database and application workloads
• Understand how to increase availability and distribute data globally with Bigtable replication in any region combination of your choice
• Learn more about Bigtable backups and importing/exporting data with Bigtable Dataflow templates

Bonus: If you’re interested in learning more of the nuts and bolts of how we migrated the data, I’ll be talking all about that very topic at GopherCon 2023 this September in San Diego!