HTTPS Collection Causing Error: Root cause of ServletException. java.lang.IllegalStateException: Response already committed

[rurobin]

With multiple different Linux servers running WebLogic managed servers (within the same WebLogic domain); we have prometheus making https calls to collect metrics. When prometheus makes the calls, we find the following error message repeated within the managed server's log file:

####<Jun 17, 2020, 7:42:02,598 PM GMT> <serverabc0.mytest.com> <myapp_ui2> <[ACTIVE] ExecuteThread: '9' for queue: 'weblogic.kernel.Default (self-tuning)'> <> <> <1592422922598> <[severity-value: 8] [rid: 0] [partition-id: 0] [partition-name: DOMAIN] > <[ServletContext@1977811861[app:wls-exporter module:wls-exporter.war path:null spec-version:3.1]] Root cause of ServletException.
java.lang.IllegalStateException: Response already committed
at weblogic.servlet.internal.ServletResponseImpl.objectIfCommitted(ServletResponseImpl.java:1898)
at weblogic.servlet.internal.ServletResponseImpl.sendError(ServletResponseImpl.java:764)
at weblogic.servlet.internal.ServletResponseImpl.sendError(ServletResponseImpl.java:713)
at io.prometheus.wls.rest.PassThroughAuthenticationServlet.doWithAuthentication(PassThroughAuthenticationServlet.java:80)
at io.prometheus.wls.rest.ExporterServlet.doGet(ExporterServlet.java:45)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:286)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:260)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:137)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:350)
at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:25)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at oracle.security.jps.ee.http.JpsAbsFilter$3.run(JpsAbsFilter.java:174)
at java.security.AccessController.doPrivileged(Native Method)
at oracle.security.jps.util.JpsSubject.doAsPrivileged(JpsSubject.java:315)
at oracle.security.jps.ee.util.JpsPlatformUtil.runJaasMode(JpsPlatformUtil.java:650)
at oracle.security.jps.ee.http.JpsAbsFilter.runJaasMode(JpsAbsFilter.java:112)
at oracle.security.jps.ee.http.JpsAbsFilter.doFilterInternal(JpsAbsFilter.java:292)
at oracle.security.jps.ee.http.JpsAbsFilter.doFilter(JpsAbsFilter.java:149)
at oracle.security.jps.ee.http.JpsFilter.doFilter(JpsFilter.java:94)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at oracle.security.wls.filter.SSOSessionSynchronizationFilter.doFilter(SSOSessionSynchronizationFilter.java:294)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at oracle.dms.servlet.DMSServletFilter.doFilter(DMSServletFilter.java:248)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3706)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3672)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:328)
at weblogic.security.service.SecurityManager.runAsForUserCode(SecurityManager.java:197)
at weblogic.servlet.provider.WlsSecurityProvider.runAsForUserCode(WlsSecurityProvider.java:203)
at weblogic.servlet.provider.WlsSubjectHandle.run(WlsSubjectHandle.java:71)
at weblogic.servlet.internal.WebAppServletContext.doSecuredExecute(WebAppServletContext.java:2443)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2291)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2269)
at weblogic.servlet.internal.ServletRequestImpl.runInternal(ServletRequestImpl.java:1705)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1665)
at weblogic.servlet.provider.ContainerSupportProviderImpl$WlsRequestExecutor.run(ContainerSupportProviderImpl.java:272)
at weblogic.invocation.ComponentInvocationContextManager._runAs(ComponentInvocationContextManager.java:352)
at weblogic.invocation.ComponentInvocationContextManager.runAs(ComponentInvocationContextManager.java:337)
at weblogic.work.LivePartitionUtility.doRunWorkUnderContext(LivePartitionUtility.java:57)
at weblogic.work.PartitionUtility.runWorkUnderContext(PartitionUtility.java:41)
at weblogic.work.SelfTuningWorkManagerImpl.runWorkUnderContext(SelfTuningWorkManagerImpl.java:652)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:420)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:360)

The prometheus configuration is as follows:

   - job_name: 'wls_monitor_exporter'
     static_configs:
     - targets: [ 'serverabc0.mytest.com:6013', 'serverabd0.mytest.com:6013', 'serverabe0.mytest.com:6013', 'serverabf0.mytest.com:6013', 'serverabg0.mytest.com:6013', 'serverabh0.mytest.com:6013', 'serverabi0.mytest.com:6013', 'serverabj0.mytest.com:6013', 'serverabk0.mytest.com:6013', 'serverabl0.mytest.com:6013', ]
     scheme: 'https'
     tls_config:
       insecure_skip_verify: true
     metrics_path: '/wls-exporter/metrics'
     basic_auth:
       username: 'prometheus'
       password: 'xxxxxxxxx'