Couchbase vs Aerospike for Mission-Critical Applications: Operational Excellence

Enterprise architects often find themselves in a conundrum when choosing a NoSQL database for their next-gen platform. They are faced with a dreaded question: Should we go with performance, or manageability? Unfortunately, enterprises building mission-critical applications often need more than just raw speed. 

So, what is the right choice? Performance or manageability? That is a tough question! and the honest answer is: enterprises want both. But, manageability often wins in the long run, especially at scale. Their workloads not only demands performance but scalability, flexibility, manageability, and operational resilience. 

After narrowing down the list of high performance enterprise grade NoSQL databases, there usually are two top contenders: Aerospike and Couchbase.

Aerospike vs. Couchbase

Aerospike claims to have serious speed. Just like Couchbase, It can handle millions of key-value operations per second with microsecond latency. As per Aerospike’s claims, its lean and performance-oriented architecture offers predictable latency and strong durability, especially for real-time, key-value workloads. 

Supposed to be a good fit for high-frequency use cases like:

• • Real-time bidding in ad tech
  • Telecom routing
  • Ultra-low-latency fraud scoring

Its hybrid memory architecture and deterministic performance enable it to deliver with millisecond latency. 

Couchbase is designed with modular architecture that allows services such as data, indexing, queries, and analytics to scale independently—reducing resource contention and improving operational control. Its memory-first architecture and in-built cache enables it to deliver sub-millisecond latency.

Multi-dimensional scaling (MDS) allows Couchbase to fine-tune performance based on workload patterns without overprovisioning, which is crucial for cost-effective scalability. Its strengths:

• • Memory-First Architecture with in-built cache
  • Key-value and JSON document access
  • A powerful SQL-like, ANCI SQL complaint query language (SQL++)
  • Secondary indexing out of the box
  • Native support for mobile and edge sync
  • Real-time analytics and Vector search built-in
  • Kubernetes-native deployments with a mature Autonomous Operator

Performance is not everything!

Keep in mind that engineers always push for raw speed. But, there are other teams too. Ops teams plead for something that does not require custom scripts and late-night firefighting. Compliance always wants granular control over data replication. No one wants another tool that only experts and professional services could configure, operate and make hard cash.

Let us explore a bit more of these real world factors that need to be considered alongside raw performance for a reliable production environment.

Monitoring and observability

While Aerospike offers integration with observability stacks like Prometheus and Grafana, Couchbase provides rich, built-in telemetry out of the box:

• • Real-time metrics dashboards for memory, CPU, disk I/O, query performance and many more.
  • Per-service observability (query, index, data, etc.)
  • Integrated logging and alerting
  • Support for integrations with enterprise observability tools (Grafana, Splunk, Datadog, New Relic, etc.)

This visibility helps teams identify bottlenecks, anticipate capacity issues, and respond quickly to incidents—all key requirements for 24×7 applications.

Maintenance without downtime

Couchbase was designed with operations in mind. You can perform:

• • Rolling upgrades and patching with zero downtime
  • Online rebalancing to scale nodes in or out as needed
  • Fine-grained backup and restore
  • Built-in auto-failover and intelligent repair

Aerospike provides high availability and robust performance, but operations like rolling upgrades or cluster expansion tend to require more manual oversight and orchestration—especially in more complex environments.

Replication and conflict resolution

Aerospike offers strong, synchronous intra-cluster replication with rack-awareness and fast failover. However:

• • Cross-datacenter replication (XDR) is add-on functionality and typically requires careful configuration and operational tuning
  • Conflict resolution is limited, as Aerospike assumes mostly-write-to-one-region architectures

Whereas Couchbase supports:

• • Intra-cluster replication (via DCP – Database Change Protocol) for HA within a data center
  • Cross Data Center Replication (XDCR) with configurable topologies (one-way, bidirectional, mesh)
  • Mobile-to-edge-to-cloud sync via Couchbase Lite and Sync Gateway
    

Replication in Couchbase is asynchronous, configurable, and fast (memory-to-memory), designed to keep data in sync across multiple regions while maintaining high availability.

For use cases requiring active-active multi-region deployments or mobile/disconnected edge scenarios, Couchbase provides more mature and flexible tooling.

In a multi-region setup, Couchbase’s XDCR makes replication a breeze. A simple API call and SQL++-style filter ensures only the right data flowed to the right region:

In contrast, doing the same in Aerospike means configuration files, writing Lua functions, deploying them, and testing manually. Not ideal for agile environments.

Conflict resolution

One of the most critical aspects of running globally distributed applications is replication and how the system handles conflicts. Enterprises generally run an active-active setup which, most of the time, needs data synchronization and often bi-directionally. 

For example, the platform needed to operate in North America and Europe simultaneously. Couchbase supports built-in conflict resolution with custom logic and timestamp-based rules, including:

• • Automatic conflict resolution based on a configurable policy: timestamp-based, custom revision ID, or application-defined logic
  • Built-in tooling to audit and resolve data divergence across replicas

Whereas with Aerospike you will need to handle conflicts at the app level. 

That is generally a dealbreaker. This becomes essential when you operate in edge environments (e.g., retail stores, mobile devices) or deal with eventual consistency in multi-region architectures.

Compliance

In today’s regulatory landscape, features like XDCR filtering are not just nice-to-haves—they’re critical for compliance with data sovereignty, privacy, and retention laws. 

Legal and compliance teams are not so forgiving generally. They usually bring up issues like:

“We can’t replicate all user data to Europe. And, we need proof that sensitive fields are excluded.”

Couchbase’s built-in filtering capabilities allow organizations to replicate only the necessary subset of data—for example, excluding personally identifiable information (PII) or region-specific records—ensuring that sensitive data stays within required geographic or jurisdictional boundaries. 

This fine-grained control simplifies adherence to GDPR, HIPAA and other compliance frameworks without requiring custom scripts or external data processing layers.

Aerospike can do it too but it’ll take custom UDFs, more testing, and ops overhead.

Built-in filtering: a Couchbase advantage for simplicity and compliance

One of the most impactful operational differences between Couchbase and Aerospike lies in how replication filtering is implemented.

In Couchbase, filtering is a first-class, declarative feature of XDCR. You can specify filter conditions directly in the UI, CLI, or REST API using SQL++-style expressions (e.g., type = 'premium' AND region = 'EU')—no external scripting or cluster redeployments required.

In Aerospike, filtering is not native to XDR. Instead, it requires writing custom Lua-based User-Defined Functions (UDFs), deploying them to the cluster, and referencing them in the config. This introduces language switching, extra operational overhead, and higher risk when deploying changes—especially in production environments.

In short, Couchbase makes replication filtering easier, safer, and more maintainable, giving teams more control without complexity.

Real-world comparison: setting up cross-data center replication (XDCR)

Aerospike’s XDR is configured at the namespace and datacenter level using the aerospike.conf file. While powerful, it’s a more manual process and filtering requires user-defined functions (UDFs).

Sample Aerospike XDR Configuration (aerospike.conf):

If you want to filter records, you must create a UDF written in Lua, deploy it to the cluster, and reference it in the config.

Example UDF (filter_records.lua):

UDF registration:

Downsides:

• • Filter logic must be written in Lua, deployed, and referenced
  • Changes require config reloads or restarts
  • No declarative filtering by default
  • Monitoring replication status is CLI-heavy

Couchbase XDCR is fully configurable via UI, CLI (couchbase-cli), or REST API. It supports declarative filtering, dynamic reconfiguration, and rich monitoring—all without restarts.

Example: Creating a Replication via REST API

Filtering in Couchbase XDCR (by key or document field):

You can even use Regular Expressions or advanced boolean logic in filters:

UI Example:

• • Go to XDCR tab
  • Click Add Replication
  • Enter source & destination
  • Add optional filter expression
  • Click Create

In summary

Enterprises running mission-critical systems often look beyond just throughput and latency. 

They seek platforms that provide operational efficiency, observability, and resilience across a global footprint. The engineering team could focus on features, not firefighting. The ops team had dashboards, not anxiety. The compliance team had auditable, selective replication.

Because in the end, raw performance wins POCs, but operational simplicity wins production.