the bugzilla ticket you have provided doesn't seem to provide a fix to the issue, does it?
although my error is similar to what is shown in the link you provided, so i have tried to restart neutron but the issue is not resolved.
==============================================================================================
root@controller:/etc/neutron# journalctl -u neutron-openvswitch-agent -f
-- Logs begin at Mon 2021-07-05 17:48:05 IST. --
Sep 09 14:08:28 controller ovs-vsctl[20957]: ovs|00001|vsctl|INFO|Called as /usr/bin/ovs-vsctl --timeout=5 --id=@manager -- create Manager "target=\"ptcp:6640:127.0.0.1\"" -- add Open_vSwitch . manager_options @manager
Sep 09 14:08:28 controller ovs-vsctl[20957]: ovs|00002|ovsdb_idl|WARN|transaction error: {"details":"Transaction causes multiple rows in \"Manager\" table to have identical values (\"ptcp:6640:127.0.0.1\") for index on column \"target\". First row, with UUID dd5aace9-e7b8-4c78-865e-353df69b6286, was inserted by this transaction. Second row, with UUID cb7a5e48-4ebc-4de4-9289-36aab899abaa, existed in the database before this transaction and was not modified by the transaction.","error":"constraint violation"}
Sep 09 14:08:28 controller ovs-vsctl[20957]: ovs|00003|db_ctl_base|ERR|transaction error: {"details":"Transaction causes multiple rows in \"Manager\" table to have identical values (\"ptcp:6640:127.0.0.1\") for index on column \"target\". First row, with UUID dd5aace9-e7b8-4c78-865e-353df69b6286, was inserted by this transaction. Second row, with UUID cb7a5e48-4ebc-4de4-9289-36aab899abaa, existed in the database before this transaction and was not modified by the transaction.","error":"constraint violation"}
Sep 09 14:08:28 controller sudo[20948]: pam_unix(sudo:session): session closed for user root
Sep 09 14:08:28 controller sudo[20960]: neutron : TTY=unknown ; PWD=/var/lib/neutron ; USER=root ; COMMAND=/usr/bin/neutron-rootwrap /etc/neutron/rootwrap.conf ovs-vsctl --timeout=5 --id=@manager -- create Manager target="ptcp:6640:127.0.0.1" -- add Open_vSwitch . manager_options @manager
Sep 09 14:08:28 controller sudo[20960]: pam_unix(sudo:session): session opened for user root by (uid=0)
Sep 09 14:08:28 controller ovs-vsctl[20963]: ovs|00001|vsctl|INFO|Called as /usr/bin/ovs-vsctl --timeout=5 --id=@manager -- create Manager "target=\"ptcp:6640:127.0.0.1\"" -- add Open_vSwitch . manager_options @manager
Sep 09 14:08:28 controller ovs-vsctl[20963]: ovs|00002|ovsdb_idl|WARN|transaction error: {"details":"Transaction causes multiple rows in \"Manager\" table to have identical values (\"ptcp:6640:127.0.0.1\") for index on column \"target\". First row, with UUID cb7a5e48-4ebc-4de4-9289-36aab899abaa, existed in the database before this transaction and was not modified by the transaction. Second row, with UUID e43c5cbc-6a91-4384-9acd-6751d6fec9e4, was inserted by this transaction.","error":"constraint violation"}
Sep 09 14:08:28 controller ovs-vsctl[20963]: ovs|00003|db_ctl_base|ERR|transaction error: {"details":"Transaction causes multiple rows in \"Manager\" table to have identical values (\"ptcp:6640:127.0.0.1\") for index on column \"target\". First row, with UUID cb7a5e48-4ebc-4de4-9289-36aab899abaa, existed in the database before this transaction and was not modified by the transaction. Second row, with UUID e43c5cbc-6a91-4384-9acd-6751d6fec9e4, was inserted by this transaction.","error":"constraint violation"}
Sep 09 14:08:28 controller sudo[20960]: pam_unix(sudo:session): session closed for user root
============================================================================================
the bugzilla ticket you have provided doesn't seem to provide a fix to the issue, does it?
although my error is similar to what is shown in the link you provided, so i have tried to restart neutron but the issue is not resolved.
======= ======= ======= ======= ======= ======= ======= ======= ======= ======= ======= ======= ======= === :/etc/neutron# journalctl -u neutron- openvswitch- agent -f vsctl|INFO| Called as /usr/bin/ovs-vsctl --timeout=5 --id=@manager -- create Manager "target= \"ptcp: 6640:127. 0.0.1\" " -- add Open_vSwitch . manager_options @manager ovsdb_idl| WARN|transactio n error: {"details" :"Transaction causes multiple rows in \"Manager\" table to have identical values (\"ptcp: 6640:127. 0.0.1\" ) for index on column \"target\". First row, with UUID dd5aace9- e7b8-4c78- 865e-353df69b62 86, was inserted by this transaction. Second row, with UUID cb7a5e48- 4ebc-4de4- 9289-36aab899ab aa, existed in the database before this transaction and was not modified by the transaction. ","error" :"constraint violation"} db_ctl_ base|ERR| transaction error: {"details" :"Transaction causes multiple rows in \"Manager\" table to have identical values (\"ptcp: 6640:127. 0.0.1\" ) for index on column \"target\". First row, with UUID dd5aace9- e7b8-4c78- 865e-353df69b62 86, was inserted by this transaction. Second row, with UUID cb7a5e48- 4ebc-4de4- 9289-36aab899ab aa, existed in the database before this transaction and was not modified by the transaction. ","error" :"constraint violation"} sudo:session) : session closed for user root lib/neutron ; USER=root ; COMMAND= /usr/bin/ neutron- rootwrap /etc/neutron/ rootwrap. conf ovs-vsctl --timeout=5 --id=@manager -- create Manager target= "ptcp:6640: 127.0.0. 1" -- add Open_vSwitch . manager_options @manager sudo:session) : session opened for user root by (uid=0) vsctl|INFO| Called as /usr/bin/ovs-vsctl --timeout=5 --id=@manager -- create Manager "target= \"ptcp: 6640:127. 0.0.1\" " -- add Open_vSwitch . manager_options @manager ovsdb_idl| WARN|transactio n error: {"details" :"Transaction causes multiple rows in \"Manager\" table to have identical values (\"ptcp: 6640:127. 0.0.1\" ) for index on column \"target\". First row, with UUID cb7a5e48- 4ebc-4de4- 9289-36aab899ab aa, existed in the database before this transaction and was not modified by the transaction. Second row, with UUID e43c5cbc- 6a91-4384- 9acd-6751d6fec9 e4, was inserted by this transaction. ","error" :"constraint violation"} db_ctl_ base|ERR| transaction error: {"details" :"Transaction causes multiple rows in \"Manager\" table to have identical values (\"ptcp: 6640:127. 0.0.1\" ) for index on column \"target\". First row, with UUID cb7a5e48- 4ebc-4de4- 9289-36aab899ab aa, existed in the database before this transaction and was not modified by the transaction. Second row, with UUID e43c5cbc- 6a91-4384- 9acd-6751d6fec9 e4, was inserted by this transaction. ","error" :"constraint violation"} sudo:session) : session closed for user root ======= ======= ======= ======= ======= ======= ======= ======= ======= ======= ======= ======= =
root@controller
-- Logs begin at Mon 2021-07-05 17:48:05 IST. --
Sep 09 14:08:28 controller ovs-vsctl[20957]: ovs|00001|
Sep 09 14:08:28 controller ovs-vsctl[20957]: ovs|00002|
Sep 09 14:08:28 controller ovs-vsctl[20957]: ovs|00003|
Sep 09 14:08:28 controller sudo[20948]: pam_unix(
Sep 09 14:08:28 controller sudo[20960]: neutron : TTY=unknown ; PWD=/var/
Sep 09 14:08:28 controller sudo[20960]: pam_unix(
Sep 09 14:08:28 controller ovs-vsctl[20963]: ovs|00001|
Sep 09 14:08:28 controller ovs-vsctl[20963]: ovs|00002|
Sep 09 14:08:28 controller ovs-vsctl[20963]: ovs|00003|
Sep 09 14:08:28 controller sudo[20960]: pam_unix(
=======