Getting error DPR-ERR-2056 The Report Server is not responding

Symptom

When we execute Reports in distributed environment intermittent failures observed with error: DPR-ERR-2056 The Report Server is not responding.

The cogserver.log of one of the dispatcher will show below errors:
<IP>:<port> 4915570 2016-04-25 09:11:51.341 +5:30 0 BITSrv 1003 1 Audit.RTUsage.BITSrv Failure CCL-SRV-0501 The BIBusTKServer process caught an unexpected exception. <Messages><Message Name="CCLMessage" File="cclbitmsgs" Severity="Error" Nesting="0" ><MessageText>CCL-SRV-0501 The BIBusTKServer process caught an unexpected exception.</MessageText></Message><Message Name="CCLMessageString" File="" Severity="Error" Nesting="0" ><MessageText>CCLRuntimeError</MessageText></Message><Message Name="CCLMessageString" File="" Severity="Error" Nesting="0" ><MessageText>CCL-PLG-0001 Failed to load the pluggable shared library. Could not load module ./RSReportService.so. Dependent module libRSRequest.so could not be loaded. Could not load module libRSRequest.so. System error: No such file or directory Could not load module ../bin/RSBIBusPlugin.cpi. Dependent module ./RSReportService.so could not be loaded. (../bin/RSBIBusPlugin.cpi) </MessageText></Message></Messages>

<IP>:<port> 9896300 2016-04-25 09:11:56.365 +5:30 WebContainer : 8 caf 2047 1 Audit.dispatcher.caf Request Failure SecureErrorId: 2016-04-25-09:11:56.364-#118 Original Error: DPR-ERR-2056 The Report Server is not responding. Handler trace back: [the_dispatcher] com.cognos.pogo.handlers.performance.PerformanceIndicationHandler [the_dispatcher] com.cognos.pogo.handlers.logic.ChainHandler [service_lookup] com.cognos.pogo.handlers.engine.ServiceLookupHandler [rxBalancedRequest] com.cognos.pogo.handlers.logic.ChainHandler [service_lookup] com.cognos.pogo.handlers.engine.ServiceLookupHandler [reportservicechain] com.cognos.pogo.handlers.logic.ChainHandler [warp_with_authenticate] com.cognos.pogo.handlers.logic.ChainHandler [do_warp] com.cognos.pogo.handlers.logic.ChainHandler [warpmta] com.cognos.pogo.reportservice.ReportServerHandler

<IP>:<port> 9896300 2016-04-25 09:11:56.362 +5:30 5E88E000C55271B756CFEAFF3754B2DF88FEC8EB h2C4d229M9vsCsql4q8C44swl8MyGlyl8hCjG9Cw 3 WebContainer : 8 DISP 1003 1 Audit.Other.dispatcher.DISP.pogo pogo com.cognos.pogo.reportservice.RequestInvoker Failure <messages><message><messageString>DPR-DPR-1035 Dispatcher detected an error.</messageString></message></messages> DPR-ERR-2074 Failed to receive a timely response from an external process with a PID 4915570. Ensure that the process with a process ID 4915570 is started. If the cause of problem cannot be determined, increase the logging level for the target service in the IBM Cognos Administration tool and reproduce the conditions that caused the error. If the problem persists, see the problem determination information on the IBM Cognos Support Portal page at http://www-947.ibm.com/support/entry/portal/Overview/Software/Information_Management/Cognos