Package oracle.ucp

Interface UniversalConnectionPool

  • public interface UniversalConnectionPool
    A connection pool that pools any type of connection (called a physical connection).

    There are several key objects that make up the connection pool:

    • The physical pool itself
    • The connection factory adapter
    • The pooled connection
    • The connection retrieval info object

    Physical Pool The physical pool maintains pooled connections that can be borrowed from the pool, returned to the pool, or closed and not returned to the pool. The pool keeps track of the connections that are available (so that they can be borrowed) and connections that are in use (so they can be reaped if it is determined that they are no longer valid).

    Connection Factory Adapter The connection pool must rely on another entity to create and close connections because connection pools can pool any type of connection. This is the responsibility of the connection factory adapter. A connection factory adapter is tied to a specific resource (JDBC, JCA, LDAP, and so forth). When the connection pool needs to create a new connection, it asks the connection factory adapter to do so. The returned connection is placed inside a UniversalPooledConnection object that is then placed into the connection pool. When the connection pool closes a connection, it hands the connection to the connection factory adapter which then closes the connection.

    Pooled Connections Each pooled connection in the connection pool is an instance of UniversalPooledConnection. The pooled connection decorates a physical connection (created by the connection factory adapter) which can be borrowed.

    Connection Retrieval Info The connection retrieval info object is used by the connection factory adapter to create connections. It contains resource-specific information that the connection factory adapter uses to create connections. For example, the JDBC connection retrieval info object maintains the user and password that are used to create a connection from a JDBC resource. The JCA connection retrieval info object maintains the Subject and JCA ConnectionRequestInfo object.

    Pool Properties The pool provides some properties for users to customize the pool's behavior, such as:

    • minPoolSize The minimum number of connections that the pool maintains.
    • maxPoolSize The maximum number of connections that the pool maintains.
    • initialPoolSize The initial number of connections in the pool.

    Statistics The pool maintains some statistics such as:

    • The number of connections that are in use (borrowed) at any given time.
    • The number of connections that are available (not in use) at any given time.
    • The number of physical connections created by the resource.
    • The number of physical connections closed by the resource.

    Lifecycle A connection pool has a lifecycle. See UniversalConnectionPoolLifeCycleState for details. A connection pool is started by calling the start() method and stopped by calling the stop() method. Connections may not be borrowed until the connection pool has been started or after the pool has been stopped (unless the pool has been started again).

    See Also:
    UniversalPooledConnection, ConnectionFactoryAdapter, ConnectionRetrievalInfo, UniversalConnectionPoolStatistics, UniversalConnectionPoolLifeCycleState

    • Method Detail

      • refresh

        void refresh()
      throws UniversalConnectionPoolException
        Allows connections in the pool, both borrowed and available ones, to be replaced with new/fresh connections. All of the available connections are removed before replacing them with new connections. However, a borrowed connection is marked for removal. When such a borrowed connection is returned to the pool, it is closed and replaced with a new connection with the same user credentials.
        Throws:
        UniversalConnectionPoolException - in case it was not possible to refresh.

      • purge

        void purge()
    throws UniversalConnectionPoolException
        Removes all connections from the connection pool. The primary difference in behavior between this and refresh() is that the connection pool is left empty with no connections available after calling purge(). Some of the connection pool properties such as minPoolSize or initialPoolSize may not be honored when purging connections from the pool.

        Note that both borrowed and available connections are removed when this API is called. Any borrowed connections incur an exception after this API is called. The user is expected to retry and obtain a new connection from the pool.

        Throws:
        UniversalConnectionPoolException - in case it was not possible to purge.

      • reconfigure

        void reconfigure​(java.util.Properties props)
          throws UniversalConnectionPoolException
        Allows a connection pool to be reconfigured gracefully with a different set of properties that specify the behavior of the connection pool at runtime. Reconfiguration of connection pool properties is always non-disruptive. If this operation cannot be completed right away, then the call returns and the enforcement of the properties continue to occur asynchronously.
        Parameters:
        props - Containing new set of pool properties for reconfiguration.
        Throws:
        UniversalConnectionPoolException - in case it wat not possible to reconfigure.

      • start

        void start​(boolean keepMetadataConn)
    throws UniversalConnectionPoolException
        Starts the connection pool.
        Parameters:
        keepMetadataConn - keep metadata connection in the working set even if init pool size is 0 (because the next operation will be "borrow").
        Throws:
        UniversalConnectionPoolException - If an error occurs during start.

      • getName

        java.lang.String getName()
        Gets the name of the connection pool.
        Returns:
        The name of the connection pool.

      • setName

        void setName​(java.lang.String name)
        Sets the name of the connection pool.
        Parameters:
        name - The name of the connection pool.

      • getInitialPoolSize

        int getInitialPoolSize()
        Gets the initial pool size.
        Returns:
        the initial pool size.

      • setInitialPoolSize

        void setInitialPoolSize​(int initialPoolSize)
                 throws UniversalConnectionPoolException
        Sets the initial pool size. This is the number of connections that are created and placed in the pool upon initialization.
        Parameters:
        initialPoolSize - the initial pool size.
        Throws:
        UniversalConnectionPoolException - in case it was not possible to set initial pool size.

      • getMinPoolSize

        int getMinPoolSize()
        Gets the minimum number of connections that the connection pool maintains.
        Returns:
        The minimum number of connections.

      • setMinPoolSize

        void setMinPoolSize​(int minPoolSize)
             throws UniversalConnectionPoolException
        Sets the minimum number of connections. If the number of available connections PLUS the number of connections in use IS LESS THAN the minimum, then the connection is returned to the pool. Otherwise, the connection is closed.
        Parameters:
        minPoolSize - The minimum number of connections.
        Throws:
        UniversalConnectionPoolException - in case it was not possible to set min pool size.

      • getMaxPoolSize

        int getMaxPoolSize()
        Gets the maximum number of connections that the connection pool maintains.
        Returns:
        The maximum number of connections.

      • setMaxPoolSize

        void setMaxPoolSize​(int maxPoolSize)
             throws UniversalConnectionPoolException
        Sets the maximum number of connections. The maximum number of connections includes the number of connections that are in use as well as the number of available connections.
        Parameters:
        maxPoolSize - The maximum number of connections.
        Throws:
        UniversalConnectionPoolException - in case it was not possible to set max pool size.

      • getInactiveConnectionTimeout

        int getInactiveConnectionTimeout()
        Gets the inactive connection timeout value.
        Returns:
        The inactive connection timeout.

      • setInactiveConnectionTimeout

        void setInactiveConnectionTimeout​(int inactiveConnectionTimeout)
                           throws UniversalConnectionPoolException
        Sets the inactive connection timeout. This timeout determines how long an available connection remains in the connection pool before it is removed from the pool.
        Parameters:
        inactiveConnectionTimeout - The inactive connection timeout (in seconds).
        Throws:
        UniversalConnectionPoolException - in case it was not possible to set timeout.

      • getAbandonedConnectionTimeout

        int getAbandonedConnectionTimeout()
        Gets the abandoned connection timeout value.
        Returns:
        The abandoned connection timeout.

      • setAbandonedConnectionTimeout

        void setAbandonedConnectionTimeout​(int abandonedConnectionTimeout)
                            throws UniversalConnectionPoolException
        Sets the abandoned connection timeout. This timeout determines how long a borrowed connection can remain unused before it is considered abandoned and reclaimed by the connection pool.
        Parameters:
        abandonedConnectionTimeout - The value of how long a connection has not been used before it is abandoned (in seconds).
        Throws:
        UniversalConnectionPoolException - in case it was not possible to set timeout.

      • getConnectionWaitTimeout

        int getConnectionWaitTimeout()
        Gets the amount of time to wait (in seconds) for a used connection to be released by a client. This only applies when the maximum number of connections has been borrowed from the connection pool. When a client tries to borrow a connection from the pool and all connections are in use, the connection pool waits for a connection to be released back to the pool.
        Returns:
        The connection wait timeout.

      • setConnectionWaitTimeout

        void setConnectionWaitTimeout​(int waitTimeout)
                       throws UniversalConnectionPoolException
        Sets the amount of time to wait (in seconds) for a used connection to be released by a client.
        Parameters:
        waitTimeout - The amount of time to wait.
        Throws:
        UniversalConnectionPoolException - in case it was not possible to set timeout.

      • getTimeToLiveConnectionTimeout

        int getTimeToLiveConnectionTimeout()
        Gets the maximum time (in seconds) a connection may remain in-use. The used connection is unconditionally returned to the connection pool when this timeout expires. A value of 0 means that the feature is not enabled.
        Returns:
        The maximum time (in seconds) a used connection may be active.

      • setTimeToLiveConnectionTimeout

        void setTimeToLiveConnectionTimeout​(int timeToLiveConnectionTimeout)
                             throws UniversalConnectionPoolException
        Sets the maximum time (in seconds) a connection may remain in-use.
        Parameters:
        timeToLiveConnectionTimeout - The maximum time (in seconds) a used connection may be active.
        Throws:
        UniversalConnectionPoolException - in case it was not possible to set timeout.

      • getTimeoutCheckInterval

        int getTimeoutCheckInterval()
        Gets the frequency (in seconds) to enforce the timeout properties. It applies to all of the connection pool timeouts including abandonedConnectionTimeout, inactiveConnectionTimeout, and timeToLiveConnectionTimeout.
        Returns:
        The frequency (in seconds) to enforce the timeout properties.

      • setTimeoutCheckInterval

        void setTimeoutCheckInterval​(int timeoutCheckInterval)
                      throws UniversalConnectionPoolException
        Sets the frequency (in seconds) to enforce the timeout properties.
        Parameters:
        timeoutCheckInterval - The frequency (in seconds) to enforce the timeout properties.
        Throws:
        UniversalConnectionPoolException - in case it was not possible to set timeout.

      • getValidateConnectionOnBorrow

        boolean getValidateConnectionOnBorrow()
        Returns whether or not a connection being borrowed should first be validated. When this property is set to true, connection validity is performed before returning the connection to the user.
        Returns:
        Whether or not a connection being borrowed should first be validated.

      • setValidateConnectionOnBorrow

        void setValidateConnectionOnBorrow​(boolean validateConnectionOnBorrow)
        Sets whether or not a connection being borrowed should first be validated.
        Parameters:
        validateConnectionOnBorrow - Whether or not a connection being borrowed should first be validated.

      • getConnectionHarvestTriggerCount

        int getConnectionHarvestTriggerCount()
        Gets the number of available connections below which the connection pool's connection harvesting occurs. For example, if the value is set to 10, then connection harvesting occurs when the number of available connections drops to 10.
        Returns:
        The number of available connections below which the connection pool's connection harvesting occurs.

      • setConnectionHarvestTriggerCount

        void setConnectionHarvestTriggerCount​(int connectionHarvestTriggerCount)
                               throws UniversalConnectionPoolException
        Sets the number of available connections below which the connection pool's connection harvesting occurs.
        Parameters:
        connectionHarvestTriggerCount - The number of available connections below which the connection pool's connection harvesting occurs.
        Throws:
        UniversalConnectionPoolException - in case it was not possible to set count.

      • getConnectionHarvestMaxCount

        int getConnectionHarvestMaxCount()
        Gets the maximum number of connections that may be harvested when the connection harvesting occurs. Note that it is possible that the number of connections that are harvested may be anywhere from 0 to the connectionHarvestMaxCount.
        Returns:
        The maximum number of connections that may be harvested when the connection harvesting occurs.

      • setConnectionHarvestMaxCount

        void setConnectionHarvestMaxCount​(int connectionHarvestMaxCount)
                           throws UniversalConnectionPoolException
        Sets the maximum number of connections that may be harvested when the connection harvesting occurs.
        Parameters:
        connectionHarvestMaxCount - the maximum number of connections that may be harvested when the connection harvesting occurs.
        Throws:
        UniversalConnectionPoolException - in case it was not possible to set timeout.

      • getAvailableConnectionsCount

        int getAvailableConnectionsCount()
        Gets the number of connections that are available in the connection pool (that is, connections in the pool that are not currently in use by clients).
        Returns:
        The number of connections that are available in the connection pool.

      • getBorrowedConnectionsCount

        int getBorrowedConnectionsCount()
        Gets the number of connections that are actively in use by clients.
        Returns:
        The number of connections that are actively in use by clients.

      • getConnectionRetrievalInfo

        ConnectionRetrievalInfo getConnectionRetrievalInfo()
        Gets the ConnectionRetrievalInfo object which contains user and password information to create the connections.
        Returns:
        ConnectionRetrievalInfo object which contains user and password information to create the connections.

      • setConnectionRetrievalInfo

        void setConnectionRetrievalInfo​(ConnectionRetrievalInfo cri)
        Sets the ConnectionRetrievalInfo for creating the initial connections (physical connections) in the pool based on the initialPoolSize property.
        Parameters:
        cri - The ConnectionRetrievalInfo with user and password for creating the initial connections in the pool.

      • getMaxConnectionReuseTime

        long getMaxConnectionReuseTime()
        Gets the maximum connection reuse time property value. See property description in setMaxConnectionReuseTime().
        Returns:
        Maximum connection reuse time (in seconds)

      • setMaxConnectionReuseTime

        void setMaxConnectionReuseTime​(long maxConnectionReuseTime)
                        throws UniversalConnectionPoolException
        Sets the maximum connection reuse time property. This property specifies the maximum time any connection can potentially be reused after which the pool removes and closes a connection. The value is specified in seconds and must be greater than 0. For example, if the specified value is 3600 seconds, then when a connection is in existence for more than 3600 seconds, the connection is closed and removed from the pool. Connections are closed gracefully after they are returned to the pool and the specified property value has been exceeded. Default is 0, which means this feature is not enabled.
        Parameters:
        maxConnectionReuseTime - Maximum connection reuse time (in seconds).
        Throws:
        UniversalConnectionPoolException - in case it was not possible to set timeout.

      • getMaxConnectionReuseCount

        int getMaxConnectionReuseCount()
        Gets the maximum connection reuse count property value. See property description in setMaxConnectionReuseCount().
        Returns:
        Maximum connection reuse count.

      • setMaxConnectionReuseCount

        void setMaxConnectionReuseCount​(int maxConnectionReuseCount)
                         throws UniversalConnectionPoolException
        Sets the maximum connection reuse count property. This property specifies the maximum number of times any connection can be reused after which the pool removes and closes a connection. The value must be greater than 0 for this feature to be enabled. For example, if the specified value is 100, then when a connection is reused or borrowed 100 times from the pool, it is closed and removed from the pool. Connections are closed gracefully after they are returned to the pool and the property value has been exceeded. Default is 0, which means this feature is not enabled.
        Parameters:
        maxConnectionReuseCount - Maximum connection reuse count.
        Throws:
        UniversalConnectionPoolException - in case it was not possible to set count.

      • getSecondsToTrustIdleConnection

        int getSecondsToTrustIdleConnection()
        Gets the seconds To Trust Idle Connection value which determines whether or not connection validation on borrow should be skipped See property description in setSecondsToTrustIdleConnection().
        Returns:
        Seconds To Trust Idle Connection value.

      • setSecondsToTrustIdleConnection

        void setSecondsToTrustIdleConnection​(int secondsToTrustIdleConnection)
                              throws UniversalConnectionPoolException
        Sets the time in seconds to trust an idle connection to skip a validation test. It works in conjunction with setValidateConnectionOnBorrow(boolean). When set to any positive value, a connection validation during the checkout is skipped if the connection was successfully used and returned to the pool within the time specified for secondsToTrustIdleConnection. Default value is set to 0 seconds which means that the feature is disabled.
        Parameters:
        secondsToTrustIdleConnection - The value of how long a connection can be trusted to skip connectionValidationOnBorrow
        Throws:
        UniversalConnectionPoolException - in case setter was failed.

      • getConnectionLabelingHighCost

        int getConnectionLabelingHighCost()
        Obtains the cost value which identifies a connection as "high-cost" for connection labeling.
        Returns:
        The cost value that identifies a connection as "high-cost" for connection labeling.
        See Also:
        setConnectionLabelingHighCost(int)

      • setConnectionLabelingHighCost

        void setConnectionLabelingHighCost​(int highCost)
                            throws UniversalConnectionPoolException
        Sets the cost value which identifies a connection as "high-cost" for connection labeling. Connection labeling uses the cost(Properties, Properties) method in ConnectionLabelingCallback to find a connection in the pool for a request. When this property is set, connections with a cost value equal to or greater than the property value are considered "high-cost" connections. The default value is Integer.MAX_VALUE.
        Parameters:
        highCost - The cost value that identifies a connection as "high-cost" for connection labeling.
        Throws:
        UniversalConnectionPoolException - If an exception occurs while setting the cost.

      • setHighCostConnectionReuseThreshold

        void setHighCostConnectionReuseThreshold​(int threshold)
                                  throws UniversalConnectionPoolException
        Sets the high-cost connection reuse threshold for connection labeling. This property works together with the ConnectionLabelingHighCost property to determine when high-cost connections are reused for connection labeling. This property specifies a threshold of the number of total connections in the pool. If Connection Labeling finds all available connections are high-cost connections (i.e., the lowest cost value exceeds the ConnectionLabelingHighCost value), it checks this threshold to determine whether to reuse those connections. Only when this threshold is reached, Connection Labeling will try to reuse the high-cost connections in the pool to serve a labeled connection request. Otherwise, Connection Labeling picks a low-cost connection, a no-label connection available in the pool, or creates a brand-new physical connection to serve a labeled request. For example, if the property value is set to 10, Connection Labeling reuses high-cost connections when there are no low-cost connections available and the total connections reach 10. Note that any labeled connection with cost Integer.MAX_VALUE will not be reused. This is consistent with connection labeling behavior when this property and ConnectionLabelingHighCost are not set. A Connection Labeling callback must be registered at the same time for this property to take effect. The default value is 0, which is treated the same way as MinPoolSize.
        Parameters:
        threshold - The high-cost connection reuse threshold to set.
        Throws:
        UniversalConnectionPoolException - If any exception occurs while setting the threshold.

      • getMaxConnectionsPerService

        int getMaxConnectionsPerService()
        Gets the maximum number of connections that can be obtained to a particular service, in a shared pool.
        Returns:
        The maximum number of connections that can be obtained to a particular service.

      • setMaxConnectionsPerService

        void setMaxConnectionsPerService​(int maxConnectionsPerService)
                          throws UniversalConnectionPoolException
        Sets the maximum number of connections that can be obtained to a particular service, in a shared pool. An exception is thrown when setting a different maxConnectionsPerService value on a running pool instance.
        Parameters:
        maxConnectionsPerService - The maximum number of connections that can be obtained to a particular service.
        Throws:
        UniversalConnectionPoolException - If any exception occurs while setting the maxConnectionsPerService value.

      • getConnectionRepurposeThreshold

        int getConnectionRepurposeThreshold()
        Gets the connection repurpose threshold for the pool. This property is used in cases when the connection pool is shared by multiple datasources connecting to the same database but using different services.Only when this threshold is reached the pool will try to repurpose connections between different services before trying to create new connections. This property is applicable only for multi-tenant databases.
        Returns:
        connection repurpose threshold property value currently set.

      • getLoginTimeout

        int getLoginTimeout()
        Gets the default maximum time in seconds that a driver will wait while attempting to connect to a database once the driver has been identified.
        Returns:
        timeout in seconds

      • setLoginTimeout

        void setLoginTimeout​(int seconds)
              throws UniversalConnectionPoolException
        Sets the default maximum time in seconds that a driver will wait while attempting to connect to a database once the driver has been identified.
        Parameters:
        seconds - timeout
        Throws:
        UniversalConnectionPoolException - in case of negative value

      • isShareable

        boolean isShareable()
        Returns whether the pool is shareable or not.
        Returns:
        Whether or not pool is shareable.

      • setShardingMode

        void setShardingMode​(boolean shardingMode)
        This API changes the mode of UCP when UCP is using a Sharded Database. By default UCP requires the caller to provide a sharding key for every connection request. When switching off the sharding mode, UCP behaves like a regular connection pool and all the sharding features are disabled so that a caller can request a connection without providing any sharding key.
        Parameters:
        shardingMode - Mode of UCP when using a Sharded Database.

      • getShardingMode

        boolean getShardingMode()
        Returns the mode of UCP when UCP is using a Sharded Database. By default sharding mode is ON which means UCP requires the caller to provide a sharding key for every connection request.
        Returns:
        Mode of UCP when using a Sharded Database.

      • setConnectionValidationTimeout

        void setConnectionValidationTimeout​(int connectionValidationTimeout)
                             throws UniversalConnectionPoolException
        Connection validation timeout setter This property changes the allowed time for a connection valiadation. If a connection validation operation lasts longer than this timeout, it is interrupted and a connection is considered to be invalid.
        Parameters:
        connectionValidationTimeout - validation timeout in seconds
        Throws:
        UniversalConnectionPoolException - gets thrown in case of negation timeout submitted

      • getConnectionValidationTimeout

        int getConnectionValidationTimeout()
        Connection validation timeout getter This property changes the allowed time for a connection valiadation. If a connection validation operation lasts longer than this timeout, it is interrupted and a connection is considered to be invalid.
        Returns:
        connection validation timeout in seconds

      • isReadOnlyInstanceAllowed

        boolean isReadOnlyInstanceAllowed()
        Returns true if the connection borrow is allowed to a read-only instance, false otherwise. This property is applicable to sharded database only. A shard instance can be in read-only mode for a chunk if chunk move/split operation is in progress.
        Returns:
        true if the connection borrow is allowed to a read-only instance, false otherwise.

      • setReadOnlyInstanceAllowed

        void setReadOnlyInstanceAllowed​(boolean readOnlyInstanceAllowed)
        Sets the read-only instance allowed value on the datasource. This property is applicable to sharded database only. When the property value is set to true, UCP allows connection borrow to read-only instances as well otherwise not. A shard instance goes into read-only mode for a chunk if the chunk move/split operation is in progress on that instance. The default value is false which means by default connection borrow is not allowed to a read-only instance.
        Parameters:
        readOnlyInstanceAllowed - whether to allow connection borrow to a read-only instance or not