We are using the camunda version 7.6.0, The below exception occur randomly. 1st time its fail with the below exception and then we rerun again it is working, but after the successive run the service tasks after the signal are not working.
Exception:
ENGINE-16004 Exception while closing command context: ENGINE-03004 Exception while executing Database Operation ‘DELETE ExecutionEntity[128145346]’ with message ’
Error updating database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Cannot delete or update a parent row: a foreign key constraint fails (prd_camunda.ACT_RU_EXECUTION, CONSTRAINT ACT_FK_EXE_PARENT FOREIGN KEY (PARENT_ID_) REFERENCES ACT_RU_EXECUTION (ID_))
The error may involve
org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.deleteExecution-Inline
The error occurred while setting parameters
SQL: delete from ACT_RU_EXECUTION where ID_ = ? and REV_ = ?
Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Cannot delete or update a parent row: a foreign key constraint fails (prd_camunda.ACT_RU_EXECUTION, CONSTRAINT ACT_FK_EXE_PARENT FOREIGN KEY (PARENT_ID_) REFERENCES ACT_RU_EXECUTION (ID_))'. Flush summary:
note: before it is working fine but after some millions of records, it make problem.