Error "An attempt by a client to checkout a Connection has timed out." when a HTTP request follows Database Connector

Database Connector's response time gets higher and eventually leads error "An attempt by a client to checkout a Connection has timed out." is thrown from the log.
This issue is seen when there is a HTTP Requester followed Database Connector and using Database data to send request.

ERROR 2022-03-09 16:48:35,061 [[MuleRuntime].uber.04: [dbtest].dbtestFlow.BLOCKING @16ba322f] [processor: dbtestFlow/processors/0; event: 894e30d0-9f6c-11ec-bc45-acde48001122] org.mule.runtime.core.internal.exception.OnErrorPropagateHandler: 
********************************************************************************
Message               : An attempt by a client to checkout a Connection has timed out.
Element               : dbtestFlow/processors/0 @ dbtest:dbtest.xml:23 (Select)
Element DSL           : <db:select doc:name="Select" doc:id="73ba8f8e-fecb-4e45-89bf-445033bb003f" config-ref="Database_Config">
<db:sql><![CDATA[
SELECT * FROM dummy;
]]></db:sql>
</db:select>
Error type            : DB:CONNECTIVITY
FlowStack             : at dbtestFlow(dbtestFlow/processors/0 @ dbtest:dbtest.xml:23 (Select))
Payload               : null
Payload Type          : null
--------------------------------------------------------------------------------
Root Exception stack trace:
com.mchange.v2.resourcepool.TimeoutException: A client timed out while waiting to acquire a resource from com.mchange.v2.resourcepool.BasicResourcePool@32f4877 -- timeout at awaitAvailable()
	at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1505)
	at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:644)
	at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:554)
	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutAndMarkConnectionInUse(C3P0PooledConnectionPool.java:758)
	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:685)
	at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:140)
	at org.mule.db.commons.shaded.internal.domain.connection.JdbcConnectionFactory.createConnection(JdbcConnectionFactory.java:52)
	at org.mule.db.commons.shaded.internal.domain.connection.DbConnectionProvider.connect(DbConnectionProvider.java:137)
	at org.mule.db.commons.shaded.internal.domain.connection.DbConnectionProvider.connect(DbConnectionProvider.java:72)
	at org.mule.runtime.module.extension.internal.runtime.config.ClassLoaderConnectionProviderWrapper.connect(ClassLoaderConnectionProviderWrapper.java:60)
	at org.mule.runtime.core.internal.connection.ConnectionUtils.connect(ConnectionUtils.java:52)
	at org.mule.runtime.core.internal.connection.AbstractConnectionProviderWrapper.connect(AbstractConnectionProviderWrapper.java:63)
	at org.mule.runtime.core.internal.connection.ErrorTypeHandlerConnectionProviderWrapper.connect(ErrorTypeHandlerConnectionProviderWrapper.java:64)
	at org.mule.runtime.core.internal.connection.ConfigNameResolverConnectionProviderWrapper.connect(ConfigNameResolverConnectionProviderWrapper.java:50)
	at org.mule.runtime.core.internal.connection.ConnectionUtils.connect(ConnectionUtils.java:52)
	at org.mule.runtime.core.internal.connection.AbstractConnectionProviderWrapper.connect(AbstractConnectionProviderWrapper.java:63)
	at org.mule.runtime.core.internal.connection.DefaultConnectionProviderWrapper.connect(DefaultConnectionProviderWrapper.java:52)
	at org.mule.runtime.core.internal.connection.NullConnectionManagementStrategy.getConnectionHandler(NullConnectionManagementStrategy.java:40)
	at org.mule.runtime.core.internal.connection.DefaultConnectionManager.getConnection(DefaultConnectionManager.java:247)
	at org.mule.runtime.core.internal.connection.DelegateConnectionManagerAdapter$EagerConnectionManagerAdapter.getConnection(DelegateConnectionManagerAdapter.java:160)
	at org.mule.runtime.core.internal.connection.DelegateConnectionManagerAdapter.getConnection(DelegateConnectionManagerAdapter.java:82)
	at org.mule.runtime.module.extension.internal.runtime.connectivity.ExtensionConnectionSupplier.getTransactionlessConnectionHandler(ExtensionConnectionSupplier.java:112)
	at org.mule.runtime.module.extension.internal.runtime.connectivity.ExtensionConnectionSupplier.getTransactedConnectionHandler(ExtensionConnectionSupplier.java:72)
	at org.mule.runtime.module.extension.internal.runtime.connectivity.ExtensionConnectionSupplier.getConnection(ExtensionConnectionSupplier.java:62)
	at org.mule.runtime.module.extension.internal.runtime.streaming.PagingProviderProducer$StickyConnectionSupplierFactory$1.getChecked(PagingProviderProducer.java:268)
	at org.mule.runtime.module.extension.internal.runtime.streaming.PagingProviderProducer$StickyConnectionSupplierFactory$1.getChecked(PagingProviderProducer.java:264)
	at org.mule.runtime.core.api.util.func.CheckedSupplier.get(CheckedSupplier.java:25)
	at org.mule.runtime.api.util.LazyValue.get(LazyValue.java:75)
	at org.mule.runtime.module.extension.internal.runtime.streaming.PagingProviderProducer$StickyConnectionSupplierFactory.getConnectionSupplier(PagingProviderProducer.java:275)
	at org.mule.runtime.module.extension.internal.runtime.streaming.PagingProviderProducer.getConnectionSupplier(PagingProviderProducer.java:224)
	at org.mule.runtime.module.extension.internal.runtime.streaming.PagingProviderProducer.withConnection(PagingProviderProducer.java:154)
	at org.mule.runtime.module.extension.internal.runtime.streaming.PagingProviderProducer.withConnection(PagingProviderProducer.java:150)
	at org.mule.runtime.module.extension.internal.runtime.streaming.PagingProviderProducer.performWithConnection(PagingProviderProducer.java:141)
	at org.mule.runtime.module.extension.internal.runtime.streaming.PagingProviderProducer.produce(PagingProviderProducer.java:100)
	at org.mule.runtime.module.extension.internal.runtime.streaming.PagingProviderProducer.produce(PagingProviderProducer.java:54)
	at org.mule.runtime.core.api.streaming.iterator.ListConsumer.loadNextPage(ListConsumer.java:81)
	at org.mule.runtime.module.extension.internal.runtime.operation.OperationMessageProcessorBuilder.lambda$transformPagingDelegate$0(OperationMessageProcessorBuilder.java:93)
	at org.mule.runtime.core.api.util.func.CheckedBiFunction.apply(CheckedBiFunction.java:19)
	at org.mule.runtime.module.extension.internal.runtime.operation.DefaultExecutionMediator$TransformingExecutionCallbackDecorator.complete(DefaultExecutionMediator.java:337)
	at org.mule.runtime.module.extension.internal.runtime.execution.CompletableMethodOperationExecutor.doExecute(CompletableMethodOperationExecutor.java:29)
	at org.mule.runtime.module.extension.internal.runtime.execution.AbstractCompletableMethodOperationExecutor.execute(AbstractCompletableMethodOperationExecutor.java:63)
	at org.mule.runtime.module.extension.internal.runtime.operation.DefaultExecutionMediator.executeCommand(DefaultExecutionMediator.java:232)
	at org.mule.runtime.module.extension.internal.runtime.operation.DefaultExecutionMediator.executeWithInterceptors(DefaultExecutionMediator.java:216)
	at org.mule.runtime.module.extension.internal.runtime.operation.DefaultExecutionMediator.lambda$execute$1(DefaultExecutionMediator.java:135)
	at org.mule.runtime.core.internal.execution.ExecuteCallbackInterceptor.execute(ExecuteCallbackInterceptor.java:15)
	at org.mule.runtime.core.internal.execution.BeginAndResolveTransactionInterceptor.execute(BeginAndResolveTransactionInterceptor.java:76)
	at org.mule.runtime.core.internal.execution.SuspendXaTransactionInterceptor.execute(SuspendXaTransactionInterceptor.java:46)
	at org.mule.runtime.core.internal.execution.ValidateTransactionalStateInterceptor.execute(ValidateTransactionalStateInterceptor.java:43)
	at org.mule.runtime.core.internal.execution.IsolateCurrentTransactionInterceptor.execute(IsolateCurrentTransactionInterceptor.java:37)
	at org.mule.runtime.core.api.execution.TransactionalExecutionTemplate.execute(TransactionalExecutionTemplate.java:139)
	at org.mule.runtime.module.extension.internal.runtime.operation.DefaultExecutionMediator.withExecutionTemplate(DefaultExecutionMediator.java:313)
	at org.mule.runtime.module.extension.internal.runtime.operation.DefaultExecutionMediator.execute(DefaultExecutionMediator.java:134)
	at org.mule.runtime.module.extension.internal.runtime.operation.ComponentMessageProcessor.executeOperation(ComponentMessageProcessor.java:588)
	at org.mule.runtime.module.extension.internal.runtime.operation.ComponentMessageProcessor.prepareAndExecuteOperation(ComponentMessageProcessor.java:811)
	at org.mule.runtime.module.extension.internal.runtime.operation.ComponentMessageProcessor.lambda$onEventSynchronous$16(ComponentMessageProcessor.java:490)
	at org.mule.runtime.module.extension.internal.runtime.operation.ComponentMessageProcessor.onEventSynchronous(ComponentMessageProcessor.java:497)
	at org.mule.runtime.module.extension.internal.runtime.operation.ComponentMessageProcessor.lambda$null$6(ComponentMessageProcessor.java:405)
	at reactor.core.publisher.FluxPeekFuseable$PeekFuseableConditionalSubscriber.onNext(FluxPeekFuseable.java:482)
	at reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onNext(FluxMapFuseable.java:287)
	at reactor.core.publisher.FluxPeekFuseable$PeekFuseableConditionalSubscriber.onNext(FluxPeekFuseable.java:496)
	at org.mule.runtime.core.privileged.processor.chain.AbstractMessageProcessorChain$2.onNext(AbstractMessageProcessorChain.java:477)
	at org.mule.runtime.core.privileged.processor.chain.AbstractMessageProcessorChain$2.onNext(AbstractMessageProcessorChain.java:472)
	at reactor.core.publisher.FluxHide$SuppressFuseableSubscriber.onNext(FluxHide.java:127)
	at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onNext(FluxPeekFuseable.java:204)
	at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:351)
	at reactor.core.publisher.FluxSubscribeOnValue$ScheduledScalar.run(FluxSubscribeOnValue.java:178)
	at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:50)
	at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:27)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at org.mule.service.scheduler.internal.AbstractRunnableFutureDecorator.doRun(AbstractRunnableFutureDecorator.java:113)
	at org.mule.service.scheduler.internal.RunnableFutureDecorator.run(RunnableFutureDecorator.java:54)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

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EXAMPLE DESIGN

It is not uncommon to have such design to integrate data from Database to third party.

The connection borrowed from the database connection pool will not be returned back until the result from database is fully consumed.
This means the connection will not be returned into connection pool until the "For Each" scope reaches last record of data. If each HTTP Request takes 1 second and Database returns 1000 records, the connection will be held 1000 seconds before returning to the pool.