At a glance
| Supported databases | MariaDB Server and Enterprise Server, Galera Cluster, primary/replica setups; other MySQL-protocol servers may work but are not the design target |
| Pooling modes | Not documented as a separate pooling mode in the pages checked; Readwritesplit keeps backend connections per client session |
| Routing and read/write splitting | Readwritesplit (query level), Readconnroute (connection level), SchemaRouter (sharding), Binlogrouter, Mirror, Diff, KafkaCDC, KafkaImporter, Exasol router |
| Load balancing and failover | Monitor-driven automatic failover and switchover for MariaDB replication; transaction replay on a replacement server |
| Authentication and TLS | Multiple client and backend authentication plugins (25.10); SET SESSION AUTHORIZATION with MariaDB 12; TLS settings not reviewed in detail |
| Read consistency | causal_reads modes (local, global, fast, universal and others) using MASTER_GTID_WAIT |
| Deployment | Self-hosted on Linux; MariaDB Enterprise Kubernetes Operator is part of the Enterprise Platform |
| Licensing | Proprietary from 25.01, production use needs a MariaDB Enterprise subscription (quote only); 24.02 and older under BSL 1.1 |
MaxScale is the natural proxy for teams already paying for MariaDB Enterprise: it combines query-level read/write splitting, transaction replay and a monitor that performs automatic failover and switchover for MariaDB replication. It is no longer an open source option, though, and it is designed and tested for MariaDB, so MySQL or PostgreSQL shops should look elsewhere.
Overview
MariaDB MaxScale is a database proxy that sits between applications and MariaDB servers. It is built from plugins: routers decide where queries go (Readwritesplit sends writes to the primary and reads to replicas at query level; Readconnroute balances at connection level; SchemaRouter shards by database; Binlogrouter acts as a binlog server; Mirror, Diff and Kafka routers handle specialised traffic), monitors track the backend topology, and filters can modify requests and responses, for example to mask data. The MariaDB Monitor can promote a replica when the primary fails and run planned switchovers.
MaxScale is maintained by MariaDB plc, which K1 Investment Management took private in September 2024 and which has since bought SkySQL (August 2025) and GridGain (completed March 2026). Up to 24.02 MaxScale was source-available under the Business Source License, with each version converting to GPL v2 or later on a change date (for 24.02, 10 April 2027). From 25.01 it is proprietary and sold as part of MariaDB Enterprise Platform. The 25.10 series (GA 22 October 2025) added OpenTelemetry metrics export, multiple authentication plugins and MariaDB 12 SET SESSION AUTHORIZATION support.
Key features
- Readwritesplit router with query-level read/write splitting, transaction replay and causal reads
- MariaDB Monitor with automatic failover (including a safe mode that avoids failover when data loss is certain) and switchover
- Readconnroute for connection-level balancing and SchemaRouter for simple database-level sharding
- Binlogrouter that serves binary logs to replicas to reduce load on the primary
- Workload Capture and Replay filter and Diff router (25.01) for testing upgrades against real traffic
- Filters for data masking and request or response rewriting
- OpenTelemetry metrics export and multiple client and backend authentication plugins (25.10)
Integrations and ecosystem
Pros and cons
Pros
- Deep integration with MariaDB replication and Galera, including automatic failover
- Transaction replay and causal reads reduce visible errors and stale reads during failover and with replica lag
- Wide router set beyond read/write splitting, such as binlog serving, Kafka CDC and workload replay
- Commercial support from the MariaDB vendor as part of an Enterprise subscription
Cons
- Closed source since 25.01; the BSL open source version is no longer supported or maintained
- Production use of current versions needs a MariaDB Enterprise subscription, priced by quote
- Designed and tested for MariaDB; MySQL-protocol servers may work but are not the target, and no PostgreSQL support is documented
Pricing
Since MaxScale 25.01 (16 January 2025) MariaDB licenses MaxScale under a closed-source commercial licence, and its FAQ says production use needs an active MariaDB Enterprise subscription. MaxScale is listed as included in all three MariaDB Enterprise Platform tiers (Platform, Platform Plus and Platform Ultimate), which are priced by quote only, with no list prices on the pricing page. Older releases (24.02, 23.08 and earlier) stay under the Business Source License 1.1, which allows free production use with fewer than three server instances; the GitHub README says this open source version is no longer supported or maintained.
Pricing checked on the vendor's official page on 7 November 2026. Prices change; confirm before buying.
Who it is best for
MariaDB Enterprise customers running replication or Galera clusters who want vendor-supported read/write splitting, automatic failover and transaction replay.
Typical use cases
- Scaling reads across MariaDB replicas while sending writes to the primary
- Automatic primary failover and planned switchover for MariaDB replication
- Capturing production workload and replaying it to validate a MariaDB upgrade
- Streaming changes to Kafka from MariaDB through the KafkaCDC router
Who should look elsewhere
- Teams that want an open source proxy for MySQL or MariaDB: see ProxySQL.
- MySQL InnoDB Cluster users: MySQL Router is the matching router.
Verdict
For MariaDB Enterprise customers MaxScale is the obvious proxy, with failover, transaction replay and causal reads that generic TCP balancers cannot match. The licence change makes it a commercial component rather than a free tool, so teams without a MariaDB subscription will usually compare it against ProxySQL instead.
Frequently asked questions
Is MariaDB MaxScale open source?
Not any more. Versions up to 24.02 were source-available under the Business Source License 1.1, which converts each version to GPL v2 or later on a change date (24.02 on 10 April 2027). From 25.01 (January 2025) MaxScale uses a closed-source commercial licence.
Can I use MaxScale for free?
Current versions need an active MariaDB Enterprise subscription for production use. The old BSL versions allow free production use with fewer than three server instances, but the GitHub README says that version is no longer supported or maintained.
How is MaxScale sold?
As part of MariaDB Enterprise Platform: the pricing page lists the MaxScale proxy as included in Platform, Platform Plus and Platform Ultimate, all priced by quote.
MaxScale or ProxySQL?
MaxScale is MariaDB's own proxy, tuned for MariaDB with monitor-driven failover, transaction replay and causal reads, and is commercial. ProxySQL is GPL v3, covers MySQL, MariaDB and PostgreSQL, and routes by configurable query rules.
Sources
- MariaDB MaxScale documentation
- MaxScale 25.10.4 release notes
- MaxScale Readwritesplit reference
- MariaDB FAQ: MariaDB MaxScale (licensing)
- Introducing MariaDB MaxScale 25.01 GA (licence change)
- MariaDB pricing (Enterprise Platform tiers)
- MaxScale GitHub repository (BSL versions)
- K1 acquires MariaDB (press release)
Checked November 2026.
Listed in: Database Proxy & Connection Pooling.
How we research reviews and what star ratings mean: our editorial method.