Automatic Simple Read/Write Splitting Plugin

The Automatic Simple Read/Write Splitting Plugin (autoSimpleReadWriteSplitting) combines the automatic, SQL-driven routing of the Automatic Read/Write Splitting Plugin with the two-endpoint model of the Simple Read/Write Splitting Plugin.

Instead of relying on cluster topology, the plugin routes between two endpoints you supply — one for reads and one for writes — and it decides which endpoint to use per statement by analyzing the SQL:

• SELECT statements are routed to the read endpoint.
• INSERT, UPDATE, DELETE, and DDL statements are routed to the write endpoint.
• SELECT ... FOR UPDATE (and other row-locking SELECT variants) are routed to the write endpoint.
• The /*@reader*/, /*@writer*/, and /*@keep*/ routing hints are honored, exactly as in the Automatic Read/Write Splitting Plugin.
• While a transaction is open or autocommit is disabled, the connection is pinned (no re-routing).

The plugin also still honors Connection#setReadOnly calls, so applications may mix explicit read-only toggles with automatic routing.

This plugin is intended for deployments that have no Aurora topology to query — for example community databases, RDS Proxy, or custom routing — but still want per-statement read/write routing without changing application code.

Plugin Availability

This plugin is part of the unified read/write splitting plugin family. See the CHANGELOG for the release it first appears in.

Loading the Automatic Simple Read/Write Splitting Plugin

The plugin is not loaded by default. To load it, include autoSimpleReadWriteSplitting in the wrapperPlugins connection parameter. Because routing is driven by SQL analysis, the sqlParser plugin must be listed before it in the plugin chain, and the com.github.jsqlparser:jsqlparser dependency must be on the classpath (see Required dependency: JSQLParser).

final Properties properties = new Properties();
properties.setProperty(PropertyDefinition.PLUGINS.name, "sqlParser,autoSimpleReadWriteSplitting");
properties.setProperty("srwWriteEndpoint", "test-db.cluster-XYZ.us-east-2.rds.amazonaws.com");
properties.setProperty("srwReadEndpoint", "test-db.cluster-ro-XYZ.us-east-2.rds.amazonaws.com");

The driver performs plugin sorting by default (see the autoSortWrapperPluginOrder configuration parameter), which keeps sqlParser ahead of autoSimpleReadWriteSplitting.

Configuration Parameters

This plugin accepts the same endpoint parameters as the Simple Read/Write Splitting Plugin:

Parameter	Value	Required	Description	Default Value
srwWriteEndpoint	String	Yes	The endpoint to connect to for write routing (and when setReadOnly(false) is called).	null
srwReadEndpoint	String	Yes	The endpoint to connect to for read routing (and when setReadOnly(true) is called).	null
verifyNewSrwConnections	Boolean	No	Enables writer/reader verification for new connections. See the Simple Read/Write Splitting Plugin.	true
verifyInitialConnectionType	String	No	If verifyNewSrwConnections is true, verifies the initial opened connection to be a writer or reader.	null
srwConnectRetryTimeoutMs	Integer	No	Maximum allowed time in milliseconds for retrying connection attempts.	60000
srwConnectRetryIntervalMs	Integer	No	Time delay in milliseconds between connection retries.	1000
cachedReaderKeepAliveTimeoutMs	Integer	No	Timeout for the cached reader connection. 0 reuses the same cached reader for the lifetime of the Connection.	0

It also accepts the family-wide queryLevelLoadBalancing, loadBalancingIncludeWriter, and allowStatementRecreationOnConnectionSwitch parameters — see Query-level load balancing. Because each read statement is a routing point, query-level load balancing rotates reads per query.

Like the other SQL-routing plugins, it accepts assumeWriteTransaction (default false) to route a transaction that was not declared read-only to the writer, including its leading reads. Recommended for Spring/JPA applications; see Transactions and autocommit for the rationale and the recommended setReadOnly/setAutoCommit sequence.

Limitations

All limitations of the Automatic Read/Write Splitting Plugin (including the handling of CallableStatement and unparseable SQL) and the Simple Read/Write Splitting Plugin apply.

Verify plugin compatibility within your driver configuration using the compatibility guide.

Related pages

• Automatic Read/Write Splitting Plugin — SQL-driven routing over cluster topology.
• Simple Read/Write Splitting Plugin — setReadOnly-driven routing over two endpoints.
• Read/Write Splitting Plugin — shared behavior, internal connection pooling, and query-level load balancing.