lbaas-member-update weight property does not reflect in haproxy config file

[Paco Peng]

when to update the weight of members, it does not refelect in the haproxy config consistently .please check below two case for more details.

Case 1: update one property in one command
##list the initial member status
stack@nsj29:~$ neutron lbaas-member-list 199110de-f8b5-4696-a45f-fce2fa3d35e4
+--------------------------------------+--------+------------+---------------+--------+--------------------------------------+----------------+
| id | name | address | protocol_port | weight | subnet_id | admin_state_up |
+--------------------------------------+--------+------------+---------------+--------+--------------------------------------+----------------+
| 4dd3f086-dff7-4cdc-96e4-5008822fb33c | node01 | 10.0.0.121 | 80 | 1 | 92460cf7-ffcd-462a-b7d1-01f8a69766ae | False |
| 253cf421-c03b-47a4-a05f-5c0e7e1587bf | node2 | 10.0.0.122 | 80 | 1 | 92460cf7-ffcd-462a-b7d1-01f8a69766ae | False |
+--------------------------------------+--------+------------+---------------+--------+--------------------------------------+----------------+

##record the initial config of haproxy
backend 199110de-f8b5-4696-a45f-fce2fa3d35e4
    mode http
    balance roundrobin
    stick-table type ip size 10k
    stick on src
    option forwardfor
    server 4dd3f086-dff7-4cdc-96e4-5008822fb33c 10.0.0.121:80 weight 1
    server 253cf421-c03b-47a4-a05f-5c0e7e1587bf 10.0.0.122:80 weight 1
##take a update action on node01
stack@nsj29:~$ neutron lbaas-member-update 4dd3f086-dff7-4cdc-96e4-5008822fb33c 199110de-f8b5-4696-a45f-fce2fa3d35e4 --weight=10
Updated member: 4dd3f086-dff7-4cdc-96e4-5008822fb33c
##take a update action on node2
stack@nsj29:~$ neutron lbaas-member-update 253cf421-c03b-47a4-a05f-5c0e7e1587bf 199110de-f8b5-4696-a45f-fce2fa3d35e4 --weight=10
Updated member: 253cf421-c03b-47a4-a05f-5c0e7e1587bf

##wait for 2~3 minutes, check the haproxy configuration
cat /var/lib/octavia/294489f1-9e48-4a83-8840-b28e212fad06/haproxy.cfg
............#skipped useless line
backend 199110de-f8b5-4696-a45f-fce2fa3d35e4
    mode http
    balance roundrobin
    stick-table type ip size 10k
    stick on src
    option forwardfor
    server 4dd3f086-dff7-4cdc-96e4-5008822fb33c 10.0.0.121:80 weight 10
    server 253cf421-c03b-47a4-a05f-5c0e7e1587bf 10.0.0.122:80 weight 1

##Rerun the update command on node2
stack@nsj29:~$ neutron lbaas-member-update 253cf421-c03b-47a4-a05f-5c0e7e1587bf 199110de-f8b5-4696-a45f-fce2fa3d35e4 --weight=10
Updated member: 253cf421-c03b-47a4-a05f-5c0e7e1587bf

##check the haproxy configuration,this time it will record the change in haproxy config
backend 199110de-f8b5-4696-a45f-fce2fa3d35e4
    mode http
    balance roundrobin
    stick-table type ip size 10k
    stick on src
    option forwardfor
    server 4dd3f086-dff7-4cdc-96e4-5008822fb33c 10.0.0.121:80 weight 10
    server 253cf421-c03b-47a4-a05f-5c0e7e1587bf 10.0.0.122:80 weight 10

Case 2: update two update properties in one command
##initial memeber status
stack@nsj29:~$ neutron lbaas-member-list 199110de-f8b5-4696-a45f-fce2fa3d35e4
+--------------------------------------+--------+------------+---------------+--------+--------------------------------------+----------------+
| id | name | address | protocol_port | weight | subnet_id | admin_state_up |
+--------------------------------------+--------+------------+---------------+--------+--------------------------------------+----------------+
| 4dd3f086-dff7-4cdc-96e4-5008822fb33c | node01 | 10.0.0.121 | 80 | 10 | 92460cf7-ffcd-462a-b7d1-01f8a69766ae | False |
| 253cf421-c03b-47a4-a05f-5c0e7e1587bf | node02 | 10.0.0.122 | 80 | 10 | 92460cf7-ffcd-462a-b7d1-01f8a69766ae | False |
+--------------------------------------+--------+------------+---------------+--------+--------------------------------------+----------------+
## update on node01
stack@nsj29:~$ neutron lbaas-member-update 4dd3f086-dff7-4cdc-96e4-5008822fb33c 199110de-f8b5-4696-a45f-fce2fa3d35e4 --weight=20 --name node01
Updated member: 4dd3f086-dff7-4cdc-96e4-5008822fb33c

##check the haproxy configuration, nothing changed in the haproxy file
backend 199110de-f8b5-4696-a45f-fce2fa3d35e4
    mode http
    balance roundrobin
    stick-table type ip size 10k
    stick on src
    option forwardfor
    server 4dd3f086-dff7-4cdc-96e4-5008822fb33c 10.0.0.121:80 weight 10
    server 253cf421-c03b-47a4-a05f-5c0e7e1587bf 10.0.0.122:80 weight 10

##take update on node02
stack@nsj29:~$ neutron lbaas-member-update 253cf421-c03b-47a4-a05f-5c0e7e1587bf 199110de-f8b5-4696-a45f-fce2fa3d35e4 --weight=20 --name node02
Updated member: 253cf421-c03b-47a4-a05f-5c0e7e1587bf

##check the haproxy configuration,it will take the previouse command's result into haproxy configure , not the latest command
backend 199110de-f8b5-4696-a45f-fce2fa3d35e4
    mode http
    balance roundrobin
    stick-table type ip size 10k
    stick on src
    option forwardfor
    server 4dd3f086-dff7-4cdc-96e4-5008822fb33c 10.0.0.121:80 weight 20
    server 253cf421-c03b-47a4-a05f-5c0e7e1587bf 10.0.0.122:80 weight 10

[Michael Johnson (johnsom)]

This was fixed in: https://review.openstack.org/#/c/280478/

[Bhaargavi Natarajan (bnatara)]

Verified in the build taken from master on Feb 25, 2016. Issue does not appear.