I'm creating a process instance as such:
processInstance = runtimeService.startProcessInstanceByKeyAndTenantId(key, initialParameters, tenantId + (isTest ? TEST_TENANT_SUFFIX : PRODUCTION_TENANT_SUFFIX));
which always returns a processInstance, but sometimes(seemingly randomly) the returned process instance does not exist in the database:
historyService.createHistoricProcessInstanceQuery().processInstanceId(processInstance.getId()).singleResult() == null
runtimeService.createProcessInstanceQuery().processInstanceId(processInstance.getId()).singleResult() == null
I've also logged the mariadb queries and I've noticed that the times that the instance does not exist; no insert queries are logged in the database, so the process instance was not inserted and then deleted.
these problems started appearing after migrating to activiti6