redis.clients.jedis.mcf

Class MultiDbConnectionProvider

java.lang.Object

redis.clients.jedis.mcf.MultiDbConnectionProvider

All Implemented Interfaces:

java.lang.AutoCloseable, ConnectionProvider

@Experimental
public class MultiDbConnectionProvider
extends java.lang.Object
implements ConnectionProvider

Author:

Allen Terleto (aterleto)

ConnectionProvider which supports multiple database endpoints each with their own isolated connection pool. With this ConnectionProvider users can seamlessly failover to Disaster Recovery (DR), Backup, and Active-Active database(s) by using simple configuration which is passed through from Resilience4j - docs

Support for manual failback is provided by way of setActiveDatabase(Endpoint)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MultiDbConnectionProvider.Database

Constructor Summary

Constructors

Constructor and Description
MultiDbConnectionProvider(MultiDbConfig multiDbConfig)

Method Summary

Modifier and Type	Method and Description
void	add(MultiDbConfig.DatabaseConfig databaseConfig) Adds a new database endpoint to the provider.
void	assertOperability() Asserts that the active database is operable.
boolean	canIterateFrom(MultiDbConnectionProvider.Database iterateFrom) Indicates the final database endpoint (connection pool), according to the pre-configured list provided at startup via the MultiDbConfig, is unavailable and therefore no further failover is possible.
void	close()
void	forceActiveDatabase(Endpoint endpoint, long forcedActiveDuration)
Endpoint	getActiveEndpoint() Returns the active endpoint Active endpoint is the one which is currently being used for all operations.
Connection	getConnection()
Connection	getConnection(CommandArguments args)
Connection	getConnection(Endpoint endpoint)
java.util.Map<?,Pool<Connection>>	getConnectionMap()
MultiDbConnectionProvider.Database	getDatabase()
MultiDbConnectionProvider.Database	getDatabase(Endpoint endpoint)
io.github.resilience4j.circuitbreaker.CircuitBreaker	getDatabaseCircuitBreaker()
java.util.Set<Endpoint>	getEndpoints() Returns the set of all configured endpoints.
java.util.List<java.lang.Class<? extends java.lang.Throwable>>	getFallbackExceptionList()
boolean	isHealthy(Endpoint endpoint) Returns the health state of the given endpoint
void	onDatabaseSwitch(SwitchReason reason, Endpoint endpoint, MultiDbConnectionProvider.Database database)
void	remove(Endpoint endpoint) Removes a database endpoint from the provider.
void	setActiveDatabase(Endpoint endpoint)
void	setDatabaseSwitchListener(java.util.function.Consumer<DatabaseSwitchEvent> databaseSwitchListener)
void	validateTargetConnection(Endpoint endpoint) Design decision was made to defer responsibility for cross-replication validation to the user.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface redis.clients.jedis.providers.ConnectionProvider

getPrimaryNodesConnectionMap

Constructor Detail

MultiDbConnectionProvider

public MultiDbConnectionProvider(MultiDbConfig multiDbConfig)

Method Detail

add

public void add(MultiDbConfig.DatabaseConfig databaseConfig)

Adds a new database endpoint to the provider.

Parameters:

databaseConfig - the configuration for the new database

Throws:

JedisValidationException - if the endpoint already exists

remove

public void remove(Endpoint endpoint)

Removes a database endpoint from the provider.

Parameters:

endpoint - the endpoint to remove

Throws:

JedisValidationException - if the endpoint doesn't exist or is the last remaining endpoint

assertOperability

@VisibleForTesting
public void assertOperability()

Asserts that the active database is operable. If not, throws an exception.

This method is called by the circuit breaker command executor before executing a command.

Throws:

JedisFailoverException.JedisPermanentlyNotAvailableException - if the there is no operable database and the max number of failover attempts has been exceeded.

JedisFailoverException.JedisTemporarilyNotAvailableException - if the there is no operable database and the max number of failover attempts has not been exceeded.

validateTargetConnection

public void validateTargetConnection(Endpoint endpoint)

Design decision was made to defer responsibility for cross-replication validation to the user. Alternatively there was discussion to handle cross-database replication validation by setting a key/value pair per hashslot in the active connection (with a TTL) and subsequently reading it from the target connection.

getEndpoints

public java.util.Set<Endpoint> getEndpoints()

Returns the set of all configured endpoints.

Returns:

the set of all configured endpoints

setActiveDatabase

public void setActiveDatabase(Endpoint endpoint)

forceActiveDatabase

public void forceActiveDatabase(Endpoint endpoint,
                                long forcedActiveDuration)

close

public void close()

Specified by:

close in interface java.lang.AutoCloseable

getConnection

public Connection getConnection()

Specified by:

getConnection in interface ConnectionProvider

getConnection

public Connection getConnection(Endpoint endpoint)

getConnection

public Connection getConnection(CommandArguments args)

Specified by:

getConnection in interface ConnectionProvider

getConnectionMap

public java.util.Map<?,Pool<Connection>> getConnectionMap()

Specified by:

getConnectionMap in interface ConnectionProvider

getDatabase

public MultiDbConnectionProvider.Database getDatabase()

getDatabase

@VisibleForTesting
public MultiDbConnectionProvider.Database getDatabase(Endpoint endpoint)

getActiveEndpoint

public Endpoint getActiveEndpoint()

Returns the active endpoint

Active endpoint is the one which is currently being used for all operations. It can change at any time due to health checks, failover, failback, etc.

Returns:

the active database endpoint

isHealthy

public boolean isHealthy(Endpoint endpoint)

Returns the health state of the given endpoint

Parameters:

endpoint - the endpoint to check

Returns:

the health status of the endpoint

getDatabaseCircuitBreaker

public io.github.resilience4j.circuitbreaker.CircuitBreaker getDatabaseCircuitBreaker()

canIterateFrom

public boolean canIterateFrom(MultiDbConnectionProvider.Database iterateFrom)

Indicates the final database endpoint (connection pool), according to the pre-configured list provided at startup via the MultiDbConfig, is unavailable and therefore no further failover is possible. Users can manually failback to an available database

onDatabaseSwitch

public void onDatabaseSwitch(SwitchReason reason,
                             Endpoint endpoint,
                             MultiDbConnectionProvider.Database database)

setDatabaseSwitchListener

public void setDatabaseSwitchListener(java.util.function.Consumer<DatabaseSwitchEvent> databaseSwitchListener)

getFallbackExceptionList

public java.util.List<java.lang.Class<? extends java.lang.Throwable>> getFallbackExceptionList()