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Meta Point ClassCastException


  • Hi all,

    I'm doing a pretty simple meta data point that just scales a data point.
    Once an hour, the original data point is updated with 4 readings.

    Upon doing a simple:

    // original is the external context point
    return original.value/100;
    

    This works great for history generation but when triggered by the actual point, I end up with 4 entries with the correct timestamps but all having the same value as the most recent reading. Not entirely sure why.

          Original Point                           Meta Point
    -------------------------------       ----------------------------
    TS                   Value       =>   TS                   Value
    -------------------------------       ----------------------------
    7/7/2020 12:00:00    503633.00        7/7/2020 12:00:00    5036.3
    7/7/2020 11:45:00    503584.00        7/7/2020 11:45:00    5036.3
    7/7/2020 11:30:00    503520.00        7/7/2020 11:30:00    5036.3
    7/7/2020 11:15:00    503383.00        7/7/2020 11:15:00    5036.3
    

    I then tried to be a bit more verbose with:

    // scaled is my meta data point
    scaled.set(original.value/100, original.time);
    

    but this causes a ClassCastException when generating historic data

    ERROR 2020-07-07T11:42:44,559 (com.serotonin.m2m2.meta.MetaPointLocatorRT.execute:301) - Meta script failed for point Water com.serotonin.ShouldNeverHappenException: java.lang.ClassCastException at 
    com.infiniteautomation.mango.spring.service.MangoJavaScriptService.execute(MangoJavaScriptService.java:466) ~[mango-3.7.7.jar:?] at 
    com.infiniteautomation.mango.spring.service.MangoJavaScriptService.execute(MangoJavaScriptService.java:482) ~[mango-3.7.7.jar:?] at 
    com.infiniteautomation.mango.util.script.CompiledMangoJavaScript.execute(CompiledMangoJavaScript.java:240) ~[mango-3.7.7.jar:?] at 
    com.serotonin.m2m2.meta.JavaScriptPointLocatorRT.executeImpl(JavaScriptPointLocatorRT.java:92) ~[?:?] at 
    com.serotonin.m2m2.meta.HistoricalMetaPointLocatorRT.executeImpl(HistoricalMetaPointLocatorRT.java:159) ~[?:?] at 
    com.serotonin.m2m2.meta.MetaPointLocatorRT.execute(MetaPointLocatorRT.java:283) ~[?:?] at 
    com.serotonin.m2m2.meta.MetaPointLocatorRT$ExecutionDelayTimeout.run(MetaPointLocatorRT.java:242) ~[?:?] at 
    com.serotonin.timer.Task.runTask(Task.java:179) ~[mango-3.7.7.jar:?] at 
    com.serotonin.timer.SimulationTimer.fastForwardTo(SimulationTimer.java:89) ~[mango-3.7.7.jar:?] at 
    com.serotonin.m2m2.meta.HistoricalContextPointRT.consumeHistorical(HistoricalContextPointRT.java:59) ~[?:?] at 
    com.infiniteautomation.mango.rest.v2.MetaDataSourceRestController$MetaHistoryGenerationTask.chunkHistoryGeneration(MetaDataSourceRestController.java:792) ~[?:?] at 
    com.infiniteautomation.mango.rest.v2.MetaDataSourceRestController$MetaHistoryGenerationTask.lambda$run$6(MetaDataSourceRestController.java:589) ~[?:?] at 
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[?:?] at 
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[?:?] at 
    java.lang.Thread.run(Thread.java:834) [?:?] Caused by: java.lang.ClassCastException 
    

    After a bit more testing, it seems that the meta data script gets run the correct amount of times but only uses the most recent value for each execution.

    edit 2:
    After a bit more debugging, I can confirm that the script will run for each new entry but only uses the value of the most recent entry.