Skip to content
Database

Apache Cassandra to Google Cloud Spanner integration — real-time, two-way sync

Keep Apache Cassandra and Google Cloud Spanner in sync without custom scripts. Cut weeks of integration work, eliminate silent data drift, and give your team a single, reliable source of truth.

  • SOC 2 and 6 other compliance frameworks
  • POC with real engineers in minutes

Adopted by fast-scaling companies moving mission-critical data in real time

Case study
Migrated from MuleSoft
Case study
Migrated from Celigo
Migrated from Heroku Connect
Migrated from Matillion
Case study
Migrated from Fivetran
Case study
Migrated from Celigo
Why teams connect Apache Cassandra and Google Cloud Spanner

Keep Apache Cassandra and Google Cloud Spanner synchronized in real time, across engines, regions, or services, in one or both directions.

Two databases that must agree is one of the oldest problems in engineering: different engines for different workloads, separate services with overlapping reference data, a migration in flight, or regional instances that share a subset of records. Hand-rolled replication across systems means change capture, conflict handling, and type mapping, all built and maintained by your team.

Stacksync syncs tables or collections between Apache Cassandra and Google Cloud Spanner continuously and bi-directionally, translating types between the two engines and resolving conflicts by rules you configure. Rows written on either side appear on the other within seconds.

Common use cases

  • 01 Consolidate data from multiple keyspaces or clusters into one reporting store.
  • 02 Replicate high-volume event or profile tables from Cassandra into a warehouse for analytics that CQL cannot express.
  • 03 Run a two-way sync between Spanner and a SaaS tool so edits made by ops teams land back in the application database.
  • 04 Consolidate data from a globally distributed Spanner deployment into regional business systems.

Common sync patterns

Regional or environment copies

Mirror selected tables to another region or environment continuously, filtered to just the rows that should travel.

Cross-engine sync

Keep the same dataset live in both Apache Cassandra and Google Cloud Spanner, so each workload runs on the engine that suits it.

Migration with zero-downtime cutover

When one database is replacing the other, sync both directions during the transition and switch traffic when ready, without a freeze window.

What you can sync between Apache Cassandra and Google Cloud Spanner

Representative objects on each side — any object or custom field can map to any target. Schemas are auto-detected; types are converted between the two systems.

Apache Cassandra objects Google Cloud Spanner objects How this pairing syncs
Tables Wide-column tables addressed by partition key, the unit of row-level sync. Tables Relational tables mapped one-to-one to sync targets. Same entity on both sides — records pair one-to-one and field-level changes reconcile in both directions.
Secondary Indexes Optional indexes that allow filtered reads outside the partition key. Secondary indexes Used to make incremental read queries efficient on non-key columns. Same entity on both sides — records pair one-to-one and field-level changes reconcile in both directions.
User-Defined Types Composite column types that syncs must flatten or map to structured fields. Rows The unit of read and write in each sync cycle, keyed by primary key. User-Defined Types is specific to Apache Cassandra and Rows to Google Cloud Spanner — each maps to any object or custom field on the other side.
Collections List, set, and map columns handled with type-aware field mapping. Interleaved tables Child rows physically co-located with parents; synced as related records. Collections is specific to Apache Cassandra and Interleaved tables to Google Cloud Spanner — each maps to any object or custom field on the other side.
Counters Increment-only counter columns, usually read-only in syncs. Change streams Capture inserts, updates, and deletes for log-style change data capture. Counters is specific to Apache Cassandra and Change streams to Google Cloud Spanner — each maps to any object or custom field on the other side.
Keyspaces Top-level namespaces with replication settings that scope a sync connection. Views Read-only projections useful for shaping data before it leaves Spanner. Keyspaces is specific to Apache Cassandra and Views to Google Cloud Spanner — each maps to any object or custom field on the other side.

How changes propagate between Apache Cassandra and Google Cloud Spanner

Each direction of the sync is driven by what the source system can signal and what the destination accepts — detection, delivery, and expected latency below.

Apache Cassandra Google Cloud Spanner Sub-second propagation

DetectionChanges in Apache Cassandra are captured at the source via change data capture — no polling loop against its API. Commit-log based CDC on tables with CDC enabled, or polling using writetime metadata and timestamp columns.

DeliveryEach detected change is applied to Google Cloud Spanner as a row-level write, with types converted between the two schemas.

Google Cloud Spanner Apache Cassandra Sub-second propagation

DetectionChanges in Google Cloud Spanner are captured at the source via change data capture — no polling loop against its API. Change streams (log-style CDC), or timestamp-based polling queries.

DeliveryEach detected change is written to Apache Cassandra through its API, with automatic retries and rate-limit backoff.

Rate-limit considerations

  • Apache Cassandra: No API quotas; throughput is governed by cluster capacity and consistency-level choices.
  • Google Cloud Spanner: Throughput is bounded by the instance's provisioned compute capacity rather than a fixed API quota.
What ships with Apache Cassandra ⇄ Google Cloud Spanner

Connect Apache Cassandra and Google Cloud Spanner for flexible, real-time data sync.

Real-time sync, workflow automation, event queues, EDI, and monitoring, for every Apache Cassandra–Google Cloud Spanner connection.

Real-time

Two-way sync

Changes in Apache Cassandra or Google Cloud Spanner instantly reflect in both systems. No stale data, no manual imports.

No-code + pro-code

Workflow automation

Trigger automated workflows whenever Apache Cassandra or Google Cloud Spanner data changes, update records, fire webhooks, or kick off sequences without brittle API scripts.

At scale

Event queues

Handle millions of events per minute without losing a single Apache Cassandra or Google Cloud Spanner record.

Observability

Monitoring

Track your Apache Cassandra ⇄ Google Cloud Spanner sync health, view errors, and replay failed events in one click.

Trading partners

EDI

Transform legacy EDI complexity into simple database interactions between Apache Cassandra and Google Cloud Spanner.

How the Apache Cassandra and Google Cloud Spanner connectors work

Apache Cassandra

Integration surface
CQL over the Cassandra native binary protocol
Authentication
Database credentials (password authenticator); TLS and role-based grants where configured
Change detection
Commit-log based CDC on tables with CDC enabled, or polling using writetime metadata and timestamp columns
Capabilities
read · write · CDC
Rate limits
No API quotas; throughput is governed by cluster capacity and consistency-level choices

Google Cloud Spanner

Integration surface
gRPC/REST client API with SQL query surface (GoogleSQL and PostgreSQL-interface dialects)
Authentication
Google Cloud IAM (service accounts)
Change detection
Change streams (log-style CDC), or timestamp-based polling queries
Capabilities
read · write · CDC
Rate limits
Throughput is bounded by the instance's provisioned compute capacity rather than a fixed API quota.
How it works

How to connect Apache Cassandra to Google Cloud Spanner — three steps, no code

Configure and sync within minutes, no code. Whether you sync 50k or 100M+ records, Stacksync handles the queues, infra, and plumbing. Integrations are non-invasive and need zero setup on your systems.

  1. 01

    Connect your apps

    Authenticate Apache Cassandra and Google Cloud Spanner with each platform's native method — OAuth, API keys, or service accounts — plus secure options like SSH tunneling, IP whitelisting, and VPC peering.

    • OAuth 2.0
    • SSH tunnel
    • VPC peering
    Apache Cassandra connected
    Google Cloud Spanner connected
    OAuth 2.0
    SSH tunnel
    SSL certificate
    VPC peering
  2. 02

    Choose tables

    Pick the Apache Cassandra and Google Cloud Spanner objects to sync — Stacksync auto-detects both schemas, including custom fields where the platform exposes them. Sync to existing tables, or let Stacksync create new ones with ideal data types.

    • Standard objects
    • Custom objects
    • Auto-schema
    objects · Apache Cassandra ⇄ Google Cloud Spanner
    Customers 12,480
    Sales Orders 8,213
    Invoices 5,902
    Items 1,344
  3. 03

    Map fields

    Fields map automatically even when names and types differ. Stacksync handles transformation and type casting for you, zero configuration required.

    • Auto-map
    • Type casting
    • Transforms
    Apache Cassandra Google Cloud Spanner
    Company company_name text
    Email email text
    Amount amount numeric
    Created created_at timestamp
Try interactive demo
FAQ

Apache Cassandra and Google Cloud Spanner integration FAQ

SECURITY

Security teams trust Stacksync

As a data company, we understand the importance of keeping your data secure. Stacksync is built with security best practices to keep your data safe at every layer, and is DPF-certified for US, EU, UK and CH data transfers.

Learn more about security
SOC 2 Type II
ISO 27001
HIPAA BAA
GDPR
CCPA
DPF US-EU-UK-CH
→ SECURITY WITH BENEFITS

SSO & SCIM

Let your users access Stacksync from your centralized user management systems. Works with Okta, Azure, Google SSO and more.

Alerts

Immediately get alerted about record syncing issues over email, Slack, PagerDuty and WhatsApp. Resolve issues from a centralized dashboard with retry and revert options.

Secure connection options

Securely connects to your systems with:

OAuth 2 SSH Tunnelling SSL certificates IP Whitelisting VPN gateway VPC peering and more

Related integrations

Every pair below is a real-time, two-way sync. Search all 353 integrations available for Apache Cassandra and Google Cloud Spanner.

Popular · 3 of 353
All Apache Cassandra integrations All Google Cloud Spanner integrations Browse all integrations
Coworkers laughing in front of a laptop in a casual office setting

Your last integration took months.
Your next one takes a prompt.

Book a demo Tour the platform on your own