[ovs-dev] [patch v1] ovn: ovn-ctl support to start ovn db servers in backup mode

[Numan Siddique]

On Thu, Sep 1, 2016 at 3:29 PM, Numan Siddique <nusiddiq at redhat.com> wrote:

>
>
> On Thu, Sep 1, 2016 at 10:51 AM, <bschanmu at redhat.com> wrote:
>
>> From: Babu Shanmugam <bschanmu at redhat.com>
>>
>> This patch adds support to start_ovsdb() function in ovn-ctl to start the
>> ovn db servers in backup mode. This can be done in the following ways
>> 1. Use parameters --ovn-nb-sync-from-addr and --ovn-sb-sync-from-addr to
>>    set the addresses of the active server.
>> 2. Create files $etcdir/ovnnb-active.conf and $etcdir/ovnsb-active.conf
>>    with the tcp url of the active servers.
>>
>> If --ovn-nb-sync-from-addr and --ovn-sb-sync-from-addr is used, it will
>> overwrite the contents in the $etcdir/*.conf and use that server as the
>> active server.
>>
>> Additional functions to promote a backup server to active and demote
>> active server to backup mode are also added in this patch
>>
>> Signed-off-by: Babu Shanmugam <bschanmu at redhat.com>
>> ---
>>  ovn/utilities/ovn-ctl | 75 ++++++++++++++++++++++++++++++
>> +++++++++++++++++++++
>>  1 file changed, 75 insertions(+)
>>
>> diff --git a/ovn/utilities/ovn-ctl b/ovn/utilities/ovn-ctl
>> index a4a9817..54c2a72 100755
>> --- a/ovn/utilities/ovn-ctl
>> +++ b/ovn/utilities/ovn-ctl
>> @@ -26,6 +26,8 @@ for dir in "$sbindir" "$bindir" /sbin /bin /usr/sbin
>> /usr/bin; do
>>  done
>>
>>
>> +ovnnb_active_conf_file="$etcdir/ovnnb-active.conf"
>> +ovnsb_active_conf_file="$etcdir/ovnsb-active.conf"
>>  ## ----- ##
>>  ## start ##
>>  ## ----- ##
>> @@ -45,6 +47,42 @@ stop_ovsdb () {
>>      fi
>>  }
>>
>> +promote_ovnnb() {
>>
>
> ​I think this function is setting the ovsdb-server to ​backup which is not
> a promotion, rather its demotion.
> I think better name would be to use "set_active" or something similar.
> Calling the unixctl command "
> ​
> ovsdb-server/
> ​
> ​
> disconnect-active-ovsdb-server
> ​" would make the ovsdb-server to active (if it was in the backup state
> earlier).
> ​
> ​
>
> +    if test ! -z "$DB_NB_SYNC_FROM_ADDR"; then
>> +        echo "tcp:$DB_NB_SYNC_FROM_ADDR:$DB_NB_SYNC_FROM_PORT" >
>> $ovnnb_active_conf_file
>> +    fi
>> +
>> +    if test -e $ovnnb_active_conf_file; then
>> +        ovs-appctl -t $rundir/ovnnb_db.ctl
>> ​​
>> ovsdb-server/set-active-ovsdb-server `cat $ovnnb_active_conf_file`
>> +    else
>> +        echo >&2 "$0: active server details not set"
>> +        exit 1
>> +    fi
>> +}
>> +
>> +promote_ovnsb() {
>> +    if test ! -z "$DB_SB_SYNC_FROM_ADDR"; then
>> +        echo "tcp:$DB_SB_SYNC_FROM_ADDR:$DB_SB_SYNC_FROM_PORT" >
>> $ovnsb_active_conf_file
>> +    fi
>> +
>> +    if test -e $ovnsb_active_conf_file; then
>> +        ovs-appctl -t $rundir/ovnsb_db.ctl
>> ​​
>> ovsdb-server/set-active-ovsdb-server `cat $ovnsb_active_conf_file`
>> +    else
>> +        echo >&2 "$0: active server details not set"
>> +        exit 1
>> +    fi
>> +}
>> +
>> +demote_ovnnb() {
>>
>
> Similar comment as above. Its better to rename this function to
> "set_backup" or something similar.
> Calling the unixctl commands ​
>
> ​"
> ​
> ​​
> ovsdb-server/set-active-ovsdb-server
> ​" followed by "
> ​
> ovsdb-server/
> ​
> ​
> connect-active-ovsdb-server​" should make the ovsdb-server to act as a
> backup server. Calling only "
> ​
> ovsdb-server/set-active-ovsdb-server
> ​" will not connect to the active server.
>
>
>
> +    rm -f $ovnnb_active_conf_file
>> +    ovs-appctl -t $rundir/ovnnb_db.ctl ovsdb-server/
>> ​​
>> disconnect-active-ovsdb-server
>> +}
>> +
>> +demote_ovnsb() {
>> +    rm -f $ovnsb_active_conf_file
>> +    ovs-appctl -t $rundir/ovnsb_db.ctl ovsdb-server/
>> ​​
>> disconnect-active-ovsdb-server
>> +}
>> +
>>  start_ovsdb () {
>>      # Check and eventually start ovsdb-server for Northbound DB
>>      if ! pidfile_is_running $DB_NB_PID; then
>> @@ -54,6 +92,14 @@ start_ovsdb () {
>>
>>          set "$@" --detach $OVN_NB_LOG --log-file=$OVN_NB_LOGFILE
>> --remote=punix:$DB_NB_SOCK --remote=ptcp:$DB_NB_PORT:$DB_NB_ADDR
>> --pidfile=$DB_NB_PID --unixctl=ovnnb_db.ctl
>>
>> +        if test ! -z "$
>> ​​
>> DB_NB_SYNC_FROM_ADDR"; then
>> +            echo "tcp:$DB_NB_SYNC_FROM_ADDR:$DB_NB_SYNC_FROM_PORT" >
>> $ovnnb_active_conf_file
>>
>
>
> ​It is also possible that we can start ovsdb-server as active and then
> transition to backup. So it would be better to honor the variables ​
>
> ​"
> ​
> DB_NB
> ​/SB​
> _SYNC_FROM_ADDR
> ​"​
> ​
> ​ and "
> ​
> DB_NB
> ​/SB​
> _SYNC_
> ​FROM_PORT"​
> ​
> ​ in the promote and demote functions. In the case of pacemaker resources,
> if proper preference constraints are not set, pacemaker/or any other HA
> manager can choose any one node as master after starting the resources. And
> when a new master is chosen, the other slaves should reconnect to the new
> master. so the client of this script can call demote (or set_backup)
> function setting these variables properly.
>
>

​Sorry for this comment. I see that these variables are indeed used in the
demote function​
​


​
>
>> +        fi
>> +
>> +        if test -e $ovnnb_active_conf_file; then
>> +            set "$@" --sync-from=`cat $ovnnb_active_conf_file`
>> +        fi
>> +
>>          $@ $DB_NB_FILE
>>      fi
>>
>> @@ -64,6 +110,15 @@ start_ovsdb () {
>>          set ovsdb-server
>>
>>          set "$@" --detach $OVN_SB_LOG --log-file=$OVN_SB_LOGFILE
>> --remote=punix:$DB_SB_SOCK --remote=ptcp:$DB_SB_PORT:$DB_SB_ADDR
>> --pidfile=$DB_SB_PID --unixctl=ovnsb_db.ctl
>> +
>> +        if test ! -z "$DB_SB_SYNC_FROM_ADDR"; then
>> +            echo "tcp:$DB_SB_SYNC_FROM_ADDR:$DB_SB_SYNC_FROM_PORT" >
>> $ovnsb_active_conf_file
>> +        fi
>> +
>> +        if test -e $ovnsb_active_conf_file; then
>> +            set "$@" --sync-from=`cat $ovnsb_active_conf_file`
>> +        fi
>> +
>>          $@ $DB_SB_FILE
>>      fi
>>  }
>> @@ -176,12 +231,16 @@ set_defaults () {
>>      DB_NB_FILE=$dbdir/ovnnb_db.db
>>      DB_NB_ADDR=0.0.0.0
>>      DB_NB_PORT=6641
>> +    DB_NB_SYNC_FROM_ADDR=
>> +    DB_NB_SYNC_FROM_PORT=6641
>>
>>      DB_SB_SOCK=$rundir/ovnsb_db.sock
>>      DB_SB_PID=$rundir/ovnsb_db.pid
>>      DB_SB_FILE=$dbdir/ovnsb_db.db
>>      DB_SB_ADDR=0.0.0.0
>>      DB_SB_PORT=6642
>> +    DB_SB_SYNC_FROM_ADDR=
>> +    DB_SB_SYNC_FROM_PORT=6642
>>
>>      DB_NB_SCHEMA=$datadir/ovn-nb.ovsschema
>>      DB_SB_SCHEMA=$datadir/ovn-sb.ovsschema
>> @@ -272,6 +331,10 @@ File location options:
>>    --db-sb-port=PORT    OVN Southbound db ptcp port (default: $DB_SB_PORT)
>>    --ovn-nb-logfile=FILE OVN Northbound log file (default:
>> $OVN_NB_LOGFILE)
>>    --ovn-sb-logfile=FILE OVN Southbound log file (default:
>> $OVN_SB_LOGFILE)
>> +  --db-nb-sync-from-addr=ADDR OVN Northbound active db tcp address
>> (default: $DB_NB_SYNC_FROM_ADDR)
>> +  --db-nb-sync-from-port=PORT OVN Northdbound active db tcp port
>> (default: $DB_NB_SYNC_FROM_PORT)
>> +  --db-sb-sync-from-addr=ADDR OVN Southbound active db tcp address
>> (default: $DB_SB_SYNC_FROM_ADDR)
>> +  --db-sb-sync-from-port=ADDR OVN Southbound active db tcp port
>> (default: $DB_SB_SYNC_FROM_PORT)
>>
>>  Default directories with "configure" option and environment variable
>> override:
>>    logs: /usr/local/var/log/openvswitch (--with-logdir, OVS_LOGDIR)
>> @@ -377,6 +440,18 @@ case $command in
>>      status_controller_vtep)
>>          daemon_status ovn-controller-vtep || exit 1
>>          ;;
>> +    promote_ovnnb)
>> +        promote_ovnnb
>> +        ;;
>> +    promote_ovnsb)
>> +        promote_ovnsb
>> +        ;;
>> +    demote_ovnnb)
>> +        demote_ovnnb
>> +        ;;
>> +    demote_ovnsb)
>> +        demote_ovnsb
>> +        ;;
>>      help)
>>          usage
>>          ;;
>> --
>> 1.9.1
>>
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>> http://openvswitch.org/mailman/listinfo/dev
>>
>
>