# TagHistoryManager().queryHistory : java.lang.IllegalArgumentException: Comparison method violates its general contract! **URL:** \ **Category:** Module Development\ **Tags:** ignition80\ **Created:** [December 4, 2020, 2:05pm UTC](https://forum.inductiveautomation.com/t/taghistorymanager-queryhistory-java-lang-illegalargumentexception-comparison-method-violates-its-general-contract/41206 "2020-12-04T14:05:24Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\ **Post date:** [December 4, 2020, 2:05pm UTC](https://forum.inductiveautomation.com/t/taghistorymanager-queryhistory-java-lang-illegalargumentexception-comparison-method-violates-its-general-contract/41206/1 "2020-12-04T14:05:24Z")
**Ignition 8.1.0** I use **TagHistoryManager().queryHistory** to retrieve some history data from a module (gateway scope) Sometimes, I have the following exception: ```auto ResultWriter 03Dec2020 16:20:20 Error executing historical tag read. java.lang.IllegalArgumentException: Comparison method violates its general contract! ``` what does it mean ? ```auto BasicTagHistoryQueryParams tagHistoryQueryParams = new BasicTagHistoryQueryParams(); // /!\ Flag.and() doesn't mutate the object, it returns a new one Flags flags = Flags.of(TagHistoryQueryFlags.BOUNDING_VALUES_YES, TagHistoryQueryFlags.NO_INTERPOLATION, TagHistoryQueryFlags.NO_SCANCLASS_VALIDATION, TagHistoryQueryFlags.NO_CACHE, TagHistoryQueryFlags.NO_PREPROCESSED_DATA); tagHistoryQueryParams.setQueryFlags(flags); tagHistoryQueryParams.setReturnSize(-1); tagHistoryQueryParams.setAggregationMode(AggregationMode.LastValue); tagHistoryQueryParams.setStartDate(startDate); tagHistoryQueryParams.setEndDate(endDate); // Tall : Column format is fixed at "path, value, quality, timestamp". tagHistoryQueryParams.setReturnFormat(ReturnFormat.Tall); tagHistoryQueryParams.setPaths(paths); BasicStreamingDataset streamingDataset = new BasicStreamingDataset(); logger.debug("queryHistoryDataChanges() - begin"); this.gatewayContext.getTagHistoryManager().queryHistory(tagHistoryQueryParams, streamingDataset); ``` ```auto ResultWriter 03Dec2020 16:20:20 Error executing historical tag read. java.lang.IllegalArgumentException: Comparison method violates its general contract! at java.base/java.util.ComparableTimSort.mergeHi(Unknown Source) at java.base/java.util.ComparableTimSort.mergeAt(Unknown Source) at java.base/java.util.ComparableTimSort.mergeCollapse(Unknown Source) at java.base/java.util.ComparableTimSort.sort(Unknown Source) at java.base/java.util.Arrays.sort(Unknown Source) at java.base/java.util.Arrays.sort(Unknown Source) at java.base/java.util.ArrayList.sort(Unknown Source) at java.base/java.util.Collections.sort(Unknown Source) at com.inductiveautomation.gateway.tags.history.query.DatasourceQueryExecutor.runSpecialValueQuery(DatasourceQueryExecutor.java:864) at com.inductiveautomation.gateway.tags.history.query.DatasourceQueryExecutor.readSeedValues(DatasourceQueryExecutor.java:699) at com.inductiveautomation.gateway.tags.history.query.DatasourceQueryExecutor.primeRead(DatasourceQueryExecutor.java:885) at com.inductiveautomation.ignition.gateway.sqltags.history.query.AbstractHistoryLoader.startReading(AbstractHistoryLoader.java:118) at com.inductiveautomation.ignition.gateway.sqltags.history.query.AggregateHistoryQueryExecutor.startReading(AggregateHistoryQueryExecutor.java:85) at com.inductiveautomation.ignition.gateway.sqltags.history.query.HistoryWriter.readData(HistoryWriter.java:312) at com.inductiveautomation.ignition.gateway.sqltags.history.query.HistoryWriter.execute(HistoryWriter.java:230) at com.inductiveautomation.ignition.gateway.sqltags.history.TagHistoryManagerImpl.queryHistory(TagHistoryManagerImpl.java:538) at com.bouyguesenergiesservices.ignition.gateway.replay.tag.QueryHistoryTall.queryHistoryDataChanges(QueryHistoryTall.java:1108) at com.bouyguesenergiesservices.ignition.gateway.replay.tag.QueryHistoryTall.queryHistory(QueryHistoryTall.java:886) at com.bouyguesenergiesservices.ignition.gateway.replay.tag.QueryHistoryTall.lambda$queryHistoryAsync$0(QueryHistoryTall.java:170) at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(Unknown Source) at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.exec(Unknown Source) at java.base/java.util.concurrent.ForkJoinTask.doExec(Unknown Source) at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(Unknown Source) at java.base/java.util.concurrent.ForkJoinPool.scan(Unknown Source) at java.base/java.util.concurrent.ForkJoinPool.runWorker(Unknown Source) ``` ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [December 4, 2020, 2:10pm UTC](https://forum.inductiveautomation.com/t/taghistorymanager-queryhistory-java-lang-illegalargumentexception-comparison-method-violates-its-general-contract/41206/2 "2020-12-04T14:10:56Z")
I think this is a bug on our side. Not sure there’s anything you can do to fix it. I’ll make a ticket… ---
**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\ **Post date:** [December 4, 2020, 2:41pm UTC](https://forum.inductiveautomation.com/t/taghistorymanager-queryhistory-java-lang-illegalargumentexception-comparison-method-violates-its-general-contract/41206/3 "2020-12-04T14:41:30Z")
thanks, I stay tuned. ---
**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\ **Post date:** [December 15, 2020, 8:55pm UTC](https://forum.inductiveautomation.com/t/taghistorymanager-queryhistory-java-lang-illegalargumentexception-comparison-method-violates-its-general-contract/41206/4 "2020-12-15T20:55:40Z")
Did you find anything ? ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [December 15, 2020, 9:00pm UTC](https://forum.inductiveautomation.com/t/taghistorymanager-queryhistory-java-lang-illegalargumentexception-comparison-method-violates-its-general-contract/41206/5 "2020-12-15T21:00:01Z")
The ticket has been designated to be picked up “next sprint”. I don’t have any more details about it. ---
**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\ **Post date:** [January 12, 2021, 7:32pm UTC](https://forum.inductiveautomation.com/t/taghistorymanager-queryhistory-java-lang-illegalargumentexception-comparison-method-violates-its-general-contract/41206/6 "2021-01-12T19:32:10Z")
This is fixed in 8.1.2. ---
**Author:** ![zacharyw.larson](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zacharyw.larson/32/23749_2.png) [@zacharyw.larson](https://forum.inductiveautomation.com/u/zacharyw.larson)\ **Post date:** [June 27, 2022, 2:19pm UTC](https://forum.inductiveautomation.com/t/taghistorymanager-queryhistory-java-lang-illegalargumentexception-comparison-method-violates-its-general-contract/41206/7 "2022-06-27T14:19:17Z")
what if you can’t switch from 8.1.0? any insight on how to make it either happen less often, or avoid it? I have a report using a historian query, and just that page is giving me the error of comparison method violates its general contract. @paul-griffith broke on Sunday, had been working ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [June 27, 2022, 2:24pm UTC](https://forum.inductiveautomation.com/t/taghistorymanager-queryhistory-java-lang-illegalargumentexception-comparison-method-violates-its-general-contract/41206/8 "2022-06-27T14:24:25Z")
> [@zacharyw.larson](#): > > what if you can’t switch from 8.1.0? Then you can't get fixes. Upgrades contain bug fixes. No upgrade, no bug fix. Sometimes there are work-arounds, sometimes not. As noted above, this is one of the unfortunate "nots". ---
**Author:** ![zacharyw.larson](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zacharyw.larson/32/23749_2.png) [@zacharyw.larson](https://forum.inductiveautomation.com/u/zacharyw.larson)\ **Post date:** [June 27, 2022, 2:56pm UTC](https://forum.inductiveautomation.com/t/taghistorymanager-queryhistory-java-lang-illegalargumentexception-comparison-method-violates-its-general-contract/41206/9 "2022-06-27T14:56:58Z")
I am going to avoid the simple table in reports for now, as it seems like the only thing that broke. (8.1.0) I don’t know if it uses the history manager in a similar manner. Other pages were not impacted. None of my pages use the getTagHistoryManager() function afaik. I think a reset of my gateway would temporarily fix the issue, but I don’t have the ability to do that yet. ---
**Author:** ![jlandwerlen](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@jlandwerlen](https://forum.inductiveautomation.com/u/jlandwerlen)\ **Post date:** [June 27, 2022, 3:38pm UTC](https://forum.inductiveautomation.com/t/taghistorymanager-queryhistory-java-lang-illegalargumentexception-comparison-method-violates-its-general-contract/41206/10 "2022-06-27T15:38:11Z")
> [@zacharyw.larson](#): > > what if you can't switch from 8.1.0? Just for my silly curiosity 🙂 , but why can't you? ---
**Author:** ![zacharyw.larson](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zacharyw.larson/32/23749_2.png) [@zacharyw.larson](https://forum.inductiveautomation.com/u/zacharyw.larson)\ **Post date:** [June 27, 2022, 3:49pm UTC](https://forum.inductiveautomation.com/t/taghistorymanager-queryhistory-java-lang-illegalargumentexception-comparison-method-violates-its-general-contract/41206/11 "2022-06-27T15:49:31Z")
I am too far down the totem pole of my company. Also, they had paid someone to make a bunch stuff in Ignition, and they don’t want to pay them to fix that stuff if it breaks upgrading probably.