java.lang.IllegalStateException: Connection pool shut down

Issue

• Camel HTTP producer is throwing "java.lang.IllegalStateException: Connection pool shut down" intermittently
• The IllegalStateException is thrown from toD and recipientList endpoints.

       java.lang.IllegalStateException: Connection pool shut down
    at org.apache.http.util.Asserts.check(Asserts.java:34)
    at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.requestConnection(PoolingHttpClientConnectionManager.java:269)
    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:176)
    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:186)
    at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:89)
    at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:72)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:56)
    at org.apache.camel.component.http.HttpProducer.executeMethod(HttpProducer.java:447)
    at org.apache.camel.component.http.HttpProducer.process(HttpProducer.java:275)
    at org.apache.camel.support.AsyncProcessorConverterHelper$ProcessorToAsyncProcessorBridge.process(AsyncProcessorConverterHelper.java:66)
    at org.apache.camel.impl.engine.CamelInternalProcessor.process(CamelInternalProcessor.java:399)
    at org.apache.camel.processor.MulticastProcessor$MulticastReactiveTask.lambda$run$1(MulticastProcessor.java:541)
    at org.apache.camel.util.concurrent.AsyncCompletionService$Task.run(AsyncCompletionService.java:162)
    at org.apache.camel.impl.engine.DefaultReactiveExecutor$Worker.executeFromQueue(DefaultReactiveExecutor.java:224)
    at org.apache.camel.impl.engine.DefaultReactiveExecutor.executeFromQueue(DefaultReactiveExecutor.java:82)
    at org.apache.camel.impl.engine.DefaultAsyncProcessorAwaitManager.await(DefaultAsyncProcessorAwaitManager.java:96)
    at org.apache.camel.impl.engine.DefaultAsyncProcessorAwaitManager.process(DefaultAsyncProcessorAwaitManager.java:85)
    at org.apache.camel.support.AsyncProcessorSupport.process(AsyncProcessorSupport.java:41)
    at org.apache.camel.component.direct.DirectProducer.process(DirectProducer.java:63)
    at org.apache.camel.component.direct.DirectProducer.process(DirectProducer.java:72)
    at org.apache.camel.processor.SendProcessor.process(SendProcessor.java:172)
    at org.apache.camel.impl.engine.CamelInternalProcessor.process(CamelInternalProcessor.java:399)
    at org.apache.camel.processor.Pipeline$PipelineTask.run(Pipeline.java:109)
    at org.apache.camel.impl.engine.DefaultReactiveExecutor$Worker.schedule(DefaultReactiveExecutor.java:193)
    at org.apache.camel.impl.engine.DefaultReactiveExecutor.scheduleMain(DefaultReactiveExecutor.java:64)
    at org.apache.camel.processor.Pipeline.process(Pipeline.java:184)