IOException on Graph (found in Logfile)

[StefanPenndorf]

Java Melody Log-Section displays the following Exception/stack trace.

I don't see which section is affected. It might be graphing particular requests because when accessing statistics for a particular HTTP request (part=graph&graph=http) the graphs are always empty. But that might also be another issue ....

SEVERE: Servlet.service() for servlet [default] in context with path [/backend] threw exception

Stack-trace
java.io.IOException: Invalid timestamps specified: 1504686302, 1504686302
      at net.bull.javamelody.internal.model.JRobin.createIOException(JRobin.java:488)
      at net.bull.javamelody.internal.model.JRobin.graph(JRobin.java:262)
      at net.bull.javamelody.internal.web.MonitoringController.doGraph(MonitoringController.java:385)
      at net.bull.javamelody.internal.web.MonitoringController.doReport(MonitoringController.java:189)
      at net.bull.javamelody.internal.web.MonitoringController.doActionIfNeededAndReport(MonitoringController.java:160)
      at net.bull.javamelody.MonitoringFilter.doMonitoring(MonitoringFilter.java:391)
      at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:200)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
      at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:316)
      at[...... stripped Spring Security Filter Chain Stuff to enhance readability - full stacktrace can be provided on request] 
      at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
      at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
      at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
      at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
      at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
      at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
      at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
      at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
      at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
      at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
      at org.apache.coyote.ajp.AbstractAjpProcessor.process(AbstractAjpProcessor.java:873)
      at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:670)
      at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
      at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
      at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
      at java.lang.Thread.run(Thread.java:745)
Caused by: org.jrobin.core.RrdException: Invalid timestamps specified: 1504686302, 1504686302
      at org.jrobin.data.DataProcessor.<init>(DataProcessor.java:101)
      at org.jrobin.graph.RrdGraph.fetchData(RrdGraph.java:535)
      at org.jrobin.graph.RrdGraph.createGraph(RrdGraph.java:80)
      at org.jrobin.graph.RrdGraph.<init>(RrdGraph.java:59)
      at net.bull.javamelody.internal.model.JRobin.graph(JRobin.java:260)
      ... 60 more

EDIT: Effected version 1.68.1 -- cannot upgrade to 1.69.0 at the moment but will do as soon as possible.

[evernat]

Can you give a screenshot of the main monitoring dashboard, to better understand the issue ?

[StefanPenndorf]

Here is a screenshot of the graph that -might- be the source of the stacktrace.

[evernat]

The exception Invalid timestamps specified: 1504686302, 1504686302 means that you can't have a graph from Wed Sep 06 10:25:02 CEST 2017 to the same second.
I have looked at the code and I don't see yet how this exception can be possible.
What version of javamelody do you use?
Do you use a customized version of javamelody?
Do you know how to reproduce the issue?

[StefanPenndorf]

What version of javamelody do you use?

We had the problem with JavaMelody 1.68.1 (see my first post). I've just updated to 1.70 yesterday but we need to wait until next week for the release to go live.

Do you use a customized version of javamelody?

No. We're using maven that means 1.68.1 from maven central was used.

Do you know how to reproduce the issue?

After loading our web app in a browser I switch to java melody, I'll click to see the request graph for a particular request (e.g. Javascript or css resource request) (part=graph&graph=http). Although there are request statistics on JavaMelody main page the graph on detail page is empty. There is no error message in the web/graph.

EDIT: Changed wrong formatting: My comments/answers were displayed as quote.

[evernat]

I have finally found a case when the issue is possible: it is when a javamelody user or a robot of your own asks directly for a graph with a custom period and with not one but both start and end date in the future. Note that the javamelody user or the robot may be in a timezone with a delta of several hours compared with your application, so today for them may be tomorrow for the application.
This is not related to the screenshot above (which is empty because for that large period of time, there are not enough values for that http request to aggregate meaningful averages).
The issue is fixed by 5fcf8ca and ready for the next release (1.72).
A new build should be available soon at:
https://javamelody.ci.cloudbees.com/job/javamelody/net.bull.javamelody$javamelody-core/