I saw the following error on the UI, in a topology that includes a Kafka spout. I don’t know if it’s something to worry about or not.
2017-06-13 20:05:58.634 o.a.s.u.TopologySpoutLag [WARN] Exception message:Error: Could not find or load main class .usr.share.storm.toollib.storm-kafka-monitor-1.1.0-sources.jar org.apache.storm.utils.ShellUtils$ExitCodeException: Error: Could not find or load main class .usr.share.storm.toollib.storm-kafka-monitor-1.1.0-sources.jar at org.apache.storm.utils.ShellUtils.runCommand(ShellUtils.java:230) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.utils.ShellUtils.run(ShellUtils.java:160) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.utils.ShellUtils$ShellCommandExecutor.execute(ShellUtils.java:370) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.utils.ShellUtils.execCommand(ShellUtils.java:460) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.utils.ShellUtils.execCommand(ShellUtils.java:443) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.utils.TopologySpoutLag.getLagResultForKafka(TopologySpoutLag.java:163) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.utils.TopologySpoutLag.getLagResultForNewKafkaSpout(TopologySpoutLag.java:189) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.utils.TopologySpoutLag.lag(TopologySpoutLag.java:57) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.ui.core$topology_lag.invoke(core.clj:805) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.ui.core$fn__9583.invoke(core.clj:1165) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.compojure.core$make_route$fn__5976.invoke(core.clj:100) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.compojure.core$if_route$fn__5964.invoke(core.clj:46) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.compojure.core$if_method$fn__5957.invoke(core.clj:31) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.compojure.core$routing$fn__5982.invoke(core.clj:113) ~[storm-core-1.1.0.jar:1.1.0] at clojure.core$some.invoke(core.clj:2570) ~[clojure-1.7.0.jar:?] at org.apache.storm.shade.compojure.core$routing.doInvoke(core.clj:113) ~[storm-core-1.1.0.jar:1.1.0] at clojure.lang.RestFn.applyTo(RestFn.java:139) ~[clojure-1.7.0.jar:?] at clojure.core$apply.invoke(core.clj:632) ~[clojure-1.7.0.jar:?] at org.apache.storm.shade.compojure.core$routes$fn__5986.invoke(core.clj:118) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.ring.middleware.cors$wrap_cors$fn__8891.invoke(cors.clj:149) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.ring.middleware.json$wrap_json_params$fn__8838.invoke(json.clj:56) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.ring.middleware.multipart_params$wrap_multipart_params$fn__6618.invoke(multipart_params.clj:118) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.ring.middleware.reload$wrap_reload$fn__7901.invoke(reload.clj:22) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.ui.helpers$requests_middleware$fn__6871.invoke(helpers.clj:50) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.ui.core$catch_errors$fn__9758.invoke(core.clj:1428) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.ring.middleware.keyword_params$wrap_keyword_params$fn__6538.invoke(keyword_params.clj:35) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.ring.middleware.nested_params$wrap_nested_params$fn__6581.invoke(nested_params.clj:84) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.ring.middleware.params$wrap_params$fn__6510.invoke(params.clj:64) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.ring.middleware.multipart_params$wrap_multipart_params$fn__6618.invoke(multipart_params.clj:118) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.ring.middleware.flash$wrap_flash$fn__6833.invoke(flash.clj:35) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.ring.middleware.session$wrap_session$fn__6819.invoke(session.clj:98) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.ring.util.servlet$make_service_method$fn__6368.invoke(servlet.clj:127) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.ring.util.servlet$servlet$fn__6372.invoke(servlet.clj:136) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.ring.util.servlet.proxy$javax.servlet.http.HttpServlet$ff19274a.service(Unknown Source) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:654) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1320) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.logging.filters.AccessLoggingFilter.handle(AccessLoggingFilter.java:47) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.logging.filters.AccessLoggingFilter.doFilter(AccessLoggingFilter.java:39) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1291) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.hadoop.security.authentication.server.AuthenticationFilter.doFilter(AuthenticationFilter.java:572) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.hadoop.security.authentication.server.AuthenticationFilter.doFilter(AuthenticationFilter.java:542) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1291) ~[storm-core-1.1.0.jar:1.1.0] at sun.reflect.GeneratedMethodAccessor23.invoke(Unknown Source) ~[?:?] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_121] at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_121] at clojure.lang.Reflector.invokeMatchingMethod(Reflector.java:93) ~[clojure-1.7.0.jar:?] at clojure.lang.Reflector.invokeInstanceMethod(Reflector.java:28) ~[clojure-1.7.0.jar:?] at org.apache.storm.ui.helpers$x_frame_options_filter_handler$fn__6964.invoke(helpers.clj:189) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.ui.helpers.proxy$java.lang.Object$Filter$abec9a8f.doFilter(Unknown Source) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1291) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.servlets.CrossOriginFilter.handle(CrossOriginFilter.java:247) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.servlets.CrossOriginFilter.doFilter(CrossOriginFilter.java:210) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1291) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:443) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1044) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:372) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:978) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:135) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.server.Server.handle(Server.java:369) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:486) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.server.AbstractHttpConnection.headerComplete(AbstractHttpConnection.java:933) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:995) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:644) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:235) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:82) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:668) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:52) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:608) ~[storm-core-1.1.0.jar:1.1.0] at org.apache.storm.shade.org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:543) ~[storm-core-1.1.0.jar:1.1.0] at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121]
