# BasicExecutionEngine Errors **URL:** \ **Category:** Ignition\ **Created:** [December 20, 2018, 7:51pm UTC](https://forum.inductiveautomation.com/t/basicexecutionengine-errors/21548 "2018-12-20T19:51:07Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![WillMT10](https://avatars.discourse-cdn.com/v4/letter/w/7feea3/32.png) [@WillMT10](https://forum.inductiveautomation.com/u/WillMT10)\ **Post date:** [December 20, 2018, 7:51pm UTC](https://forum.inductiveautomation.com/t/basicexecutionengine-errors/21548/1 "2018-12-20T19:51:07Z")
Periodically, one of our Gateways will get a “BasicExecutionEngine: Uncaught exception executing self scheduled runnable” error. Sometimes we will get a few in short order, other times they are more spread out. The errors will have one of two different messages, I’ve copied the two different messages below. I made some updates today to the Named Queries to better protect against NULL parameters being passed in. This seems to have reduced the frequency of the errors - and it appears that we now only get the error with the short error message - but they still trigger periodically (sometimes every few minutes, other times, every few seconds). Lastly, I turned on Trace Logging for the NamedQueries.executor and noticed that the errors seem to only occur during “Next maint interval is X millis. ExpirationMap size is Y, cache size is Y” log messages. Not sure if this points to anything but thought it was interesting. I’ve included a portion of this trace below (last snippit). That is not all of the “maint interval” messages in the log, there were a lot more but didn’t think adding all of them would help anyone. Let me know if there are any other logs that would help. Ignition 7.9.8 (b2018060714) Windows 7 PC 64-bit 8 Core 2.4 GHz 32 GB Ram (24 GB allocated to Ignition) SSD **Error message that appears with a more detailed message:** ```auto INFO | jvm 1 | 2018/12/20 10:34:43 | java.lang.NullPointerException: null INFO | jvm 1 | 2018/12/20 10:34:43 | at com.inductiveautomation.ignition.gateway.project.NamedQueryExecutor.run(NamedQueryExecutor.java:239) INFO | jvm 1 | 2018/12/20 10:34:43 | at com.inductiveautomation.ignition.common.execution.impl.BasicExecutionEngine$SelfSchedulingRunner.run(BasicExecutionEngine.java:483) INFO | jvm 1 | 2018/12/20 10:34:43 | at com.inductiveautomation.ignition.common.execution.impl.BasicExecutionEngine$TrackedTask.run(BasicExecutionEngine.java:565) INFO | jvm 1 | 2018/12/20 10:34:43 | at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) INFO | jvm 1 | 2018/12/20 10:34:43 | at java.util.concurrent.FutureTask.run(Unknown Source) INFO | jvm 1 | 2018/12/20 10:34:43 | at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(Unknown Source) INFO | jvm 1 | 2018/12/20 10:34:43 | at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source) INFO | jvm 1 | 2018/12/20 10:34:43 | at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) INFO | jvm 1 | 2018/12/20 10:34:43 | at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) INFO | jvm 1 | 2018/12/20 10:34:43 | at java.lang.Thread.run(Unknown Source) ``` **Other times this error will appear (since updating the Named Queries this is the only message that has appeared):** ```auto INFO | jvm 1 | 2018/12/20 11:09:43 | E [C.BasicExecutionEngine] [19:09:43]: Uncaught exception executing self scheduled runnable. INFO | jvm 1 | 2018/12/20 11:09:43 | java.lang.NullPointerException: null ``` **Log with NamedQueries.executor set to Trace:** ```auto INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553091920 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | E [C.BasicExecutionEngine] [19:09:43]: Uncaught exception executing self scheduled runnable. INFO | jvm 1 | 2018/12/20 11:09:43 | java.lang.NullPointerException: null INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553177449 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553180015 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553248439 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553251432 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553274525 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553265117 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553293770 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553301040 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553343805 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553353640 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553363476 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553350219 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553367325 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553384003 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553383148 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553407524 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553417360 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553421637 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553432755 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553456276 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553466967 millis. ExpirationMap size is 2, cache size is 2 INFO | jvm 1 | 2018/12/20 11:09:43 | T [N.executor] [19:09:43]: Next maint interval is 6890553475520 millis. ExpirationMap size is 2, cache size is 2 ... Plus MANY more lines of the same thing ``` ---
**Author:** ![WillMT10](https://avatars.discourse-cdn.com/v4/letter/w/7feea3/32.png) [@WillMT10](https://forum.inductiveautomation.com/u/WillMT10)\ **Post date:** [December 20, 2018, 8:11pm UTC](https://forum.inductiveautomation.com/t/basicexecutionengine-errors/21548/2 "2018-12-20T20:11:47Z")
Last 5 minutes or so: ```auto BasicExecutionEngine 20Dec2018 15:10:49 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:10:40 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:10:31 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:10:27 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:10:26 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:10:19 Tried to unregister non existant unit [namedquery cache maintenance scanning_scada]. BasicExecutionEngine 20Dec2018 15:10:19 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:10:19 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:10:19 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:10:19 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:10:19 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:10:19 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:10:01 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:09:54 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:09:52 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:09:39 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:09:33 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:09:31 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:09:23 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:09:19 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:09:00 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:08:56 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:08:50 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:08:48 Tried to unregister non existant unit [namedquery cache maintenance scanning_scada]. BasicExecutionEngine 20Dec2018 15:08:48 Tried to unregister non existant unit [namedquery cache maintenance scanning_scada]. BasicExecutionEngine 20Dec2018 15:08:48 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:08:48 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:08:48 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:08:48 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:08:46 Tried to unregister non existant unit [namedquery cache maintenance scanning_scada]. BasicExecutionEngine 20Dec2018 15:08:46 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:08:46 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:08:46 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:08:46 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:08:46 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:08:46 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:08:46 Unregistering unit [namedquery cache maintenance scanning_scada], allow interrupt: true BasicExecutionEngine 20Dec2018 15:08:43 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:08:33 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:08:22 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:08:19 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:08:08 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:08:04 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:07:56 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:07:32 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:07:19 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:07:15 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:07:05 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:06:53 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:06:50 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:06:35 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:06:21 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:06:08 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:06:06 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:06:02 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:05:57 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:05:56 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:05:34 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:05:32 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:05:30 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:05:03 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:04:45 Uncaught exception executing self scheduled runnable. BasicExecutionEngine 20Dec2018 15:04:21 Uncaught exception executing self scheduled runnable. ``` ---
**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:** [December 20, 2018, 8:55pm UTC](https://forum.inductiveautomation.com/t/basicexecutionengine-errors/21548/3 "2018-12-20T20:55:17Z")
I would upgrade your system - there were a few changes made to the named query cache system in 7.9.9 that should resolve this. ---
**Author:** ![WillMT10](https://avatars.discourse-cdn.com/v4/letter/w/7feea3/32.png) [@WillMT10](https://forum.inductiveautomation.com/u/WillMT10)\ **Post date:** [December 20, 2018, 8:57pm UTC](https://forum.inductiveautomation.com/t/basicexecutionengine-errors/21548/4 "2018-12-20T20:57:04Z")
Ok, good to hear. Will do and thank you.