Thanks Eric!

A quick test by @jcallicoat shows that the package seems to have resolved the issue.

root@XXXXXX-cinder01_cinder_volumes_container-45d8c323:/tmp# for i in {1..100} ; do diff -u <(/usr/sbin/tgtadm -L iscsi --mode target --op show | fgrep Target) <(/usr/sbin/tgtadm -L iscsi --mode target --op show | fgrep Target) ; sleep 1 ; done
--- /dev/fd/63	2015-09-24 01:35:14.491460650 +0000
+++ /dev/fd/62	2015-09-24 01:35:14.491460650 +0000
@@ -578,5 +578,3 @@
Target 607: iqn.2010-10.org.openstack:volume-c04e678e-0f5c-40b1-8f13-3c5928cf9177
Target 608: iqn.2010-10.org.openstack:volume-102fc5d2-93e4-4e34-b616-947cd685004c
Target 609: iqn.2010-10.org.openstack:volume-9009a826-dc4e-43e9-9413-896713f94144
-Target 610: iqn.2010-10.org.openstack:volume-c4210e46-aa24-4176-b719-f8c201b44fdf
-Target 611: iqn.2010-10.org.openstack:volume-c3fb534a-ccca-4fbd-93ef-fb7ae6370936
--- /dev/fd/63	2015-09-24 01:35:19.599588811 +0000
+++ /dev/fd/62	2015-09-24 01:35:19.599588811 +0000
@@ -578,3 +578,4 @@
Target 607: iqn.2010-10.org.openstack:volume-c04e678e-0f5c-40b1-8f13-3c5928cf9177
Target 608: iqn.2010-10.org.openstack:volume-102fc5d2-93e4-4e34-b616-947cd685004c
Target 609: iqn.2010-10.org.openstack:volume-9009a826-dc4e-43e9-9413-896713f94144
+Target 610: iqn.2010-10.org.openstack:volume-c4210e46-aa24-4176-b719-f8c201b44fdf
--- /dev/fd/63	2015-09-24 01:35:29.815845124 +0000
+++ /dev/fd/62	2015-09-24 01:35:29.815845124 +0000
@@ -578,6 +578,3 @@
Target 607: iqn.2010-10.org.openstack:volume-c04e678e-0f5c-40b1-8f13-3c5928cf9177
Target 608: iqn.2010-10.org.openstack:volume-102fc5d2-93e4-4e34-b616-947cd685004c
Target 609: iqn.2010-10.org.openstack:volume-9009a826-dc4e-43e9-9413-896713f94144
-Target 610: iqn.2010-10.org.openstack:volume-c4210e46-aa24-4176-b719-f8c201b44fdf
-Target 611: iqn.2010-10.org.openstack:volume-c3fb534a-ccca-4fbd-93ef-fb7ae6370936
-Target 612: iqn.2010-10.org.openstack:volume-85ea7e62-5317-44f5-8a27-114299924a74
--- /dev/fd/63	2015-09-24 01:35:33.899947586 +0000
+++ /dev/fd/62	2015-09-24 01:35:33.899947586 +0000
@@ -578,5 +578,3 @@
Target 607: iqn.2010-10.org.openstack:volume-c04e678e-0f5c-40b1-8f13-3c5928cf9177
Target 608: iqn.2010-10.org.openstack:volume-102fc5d2-93e4-4e34-b616-947cd685004c
Target 609: iqn.2010-10.org.openstack:volume-9009a826-dc4e-43e9-9413-896713f94144
-Target 610: iqn.2010-10.org.openstack:volume-c4210e46-aa24-4176-b719-f8c201b44fdf
-Target 611: iqn.2010-10.org.openstack:volume-c3fb534a-ccca-4fbd-93ef-fb7ae6370936
^C

root@XXXXXX-cinder01_cinder_volumes_container-45d8c323:/tmp# wget https://launchpad.net/~eric-desrochers-z/+archive/ubuntu/tgt1498697/+files/tgt_1.0.43-0ubuntu4.1%7E14.04.1%2B20150923lp1498697%7E1_amd64.deb
--2015-09-24 01:36:22--  https://launchpad.net/~eric-desrochers-z/+archive/ubuntu/tgt1498697/+files/tgt_1.0.43-0ubuntu4.1%7E14.04.1%2B20150923lp1498697%7E1_amd64.deb
Resolving launchpad.net (launchpad.net)... 91.189.89.222, 91.189.89.223
Connecting to launchpad.net (launchpad.net)|91.189.89.222|:443... connected.
HTTP request sent, awaiting response... 302 Moved Temporarily
Location: https://launchpadlibrarian.net/218674274/tgt_1.0.43-0ubuntu4.1%7E14.04.1%2B20150923lp1498697%7E1_amd64.deb [following]
--2015-09-24 01:36:23--  https://launchpadlibrarian.net/218674274/tgt_1.0.43-0ubuntu4.1%7E14.04.1%2B20150923lp1498697%7E1_amd64.deb
Resolving launchpadlibrarian.net (launchpadlibrarian.net)... 91.189.89.228, 91.189.89.229
Connecting to launchpadlibrarian.net (launchpadlibrarian.net)|91.189.89.228|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 204638 (200K) [application/x-debian-package]
Saving to: 'tgt_1.0.43-0ubuntu4.1~14.04.1+20150923lp1498697~1_amd64.deb'

100%[=====================================================================================================================================================>] 204,638      406KB/s   in 0.5s  

2015-09-24 01:36:24 (406 KB/s) - 'tgt_1.0.43-0ubuntu4.1~14.04.1+20150923lp1498697~1_amd64.deb' saved [204638/204638]

root@XXXXXX-cinder01_cinder_volumes_container-45d8c323:/tmp# ar xv tgt_1.0.43-0ubuntu4.1~14.04.1+20150923lp1498697~1_amd64.deb
x - debian-binary
x - control.tar.gz
x - data.tar.xz

root@XXXXXX-cinder01_cinder_volumes_container-45d8c323:/tmp# tar xf data.tar.xz

root@XXXXXX-cinder01_cinder_volumes_container-45d8c323:/tmp# cd usr/sbin/

root@XXXXXX-cinder01_cinder_volumes_container-45d8c323:/tmp/usr/sbin# for i in {1..100} ; do diff -u <(./tgtadm -L iscsi --mode target --op show | fgrep Target) <(./tgtadm -L iscsi --mode target --op show | fgrep Target) ; sleep 1 ; done

root@XXXXXX-cinder01_cinder_volumes_container-45d8c323:/tmp/usr/sbin#