Which process is doing this? I'm attaching the compute node's full nova-compute.log file as well.

viouser@compute01:/var/log/nova$ rgrep "Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed"
nova-compute.log.1:2019-07-23 18:29:03.397 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:31:07.005 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:31:34.189 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:41:46.361 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:43:11.220 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:44:09.366 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:45:11.148 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:46:15.007 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:47:13.569 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:48:14.917 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:49:17.761 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:50:18.659 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:51:19.029 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:52:18.168 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:53:20.680 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:54:20.045 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:55:21.127 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:56:20.605 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:57:22.681 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:58:23.279 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log.1:2019-07-23 18:59:26.589 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286

...

nova-compute.log.1:2019-07-23 20:28:37.326 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286
nova-compute.log:2019-07-23 20:29:39.412 13699 DEBUG nova.compute.resource_tracker [req-ad1ccb2c-62d1-49de-a67b-2e910421e64b - - - - -] Instance 004667e4-a4b4-46e9-beb0-cefd7d5f7ee2 actively managed on this compute host and has allocations in placement: {u'resources': {u'VCPU': 8, u'MEMORY_MB': 8192, u'DISK_GB': 240}}. _remove_deleted_instances_allocations /usr/lib/python2.7/dist-packages/nova/compute/resource_tracker.py:1286