[pgpool-general: 4179] Re: pcp_detach_node / pcp_attach_node - wrong primary on failback.sh

[Tatsuo Ishii]

> Hi,
> 
> *using postgresql 9.3.1 and pgpool 3.42*
> 
> I try to write failover & failback mechanism using pgpool attach/detach pcp
> command.
> but sometimes I had noticed that the argument send to the failback script
> are wrong (new primary hostname is not right):

There's no parameter for new primary hostname.  If you care about
primary node, you should use %P.

#   %P = old primary node id

Note that "master node" != "primary node" in pgpool-II terms. The
master node is a live node which has the youngest node id.
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp

> # *psql -U postgres -h 192.168.15.59 -p 9999 template1 -c "show
> pool_nodes;"*
> Password for user postgres:
>  node_id |   hostname    | port | status | lb_weight |  role
> ---------+---------------+------+--------+-----------+---------
>  0       | 192.168.15.55 | 5432 | 2      | 0.500000  | standby
>  1       | 192.168.15.56 | 5432 | 2      | 0.500000  | primary
> (2 rows)
> 
> 
> #* pcp_detach_node -d 10 192.168.15.59 9898 user password 0*
> DEBUG: send: tos="R", len=44
> DEBUG: recv: tos="r", len=21, data=AuthenticationOK
> DEBUG: send: tos="D", len=6
> DEBUG: recv: tos="d", len=20, data=CommandComplete
> DEBUG: send: tos="X", len=4
> 
> 
> [root at mgrdb-56 etc]# *psql -U postgres -h 192.168.15.59 -p 9999 template1
> -c "show pool_nodes;"*
> Password for user postgres:
>  node_id |   hostname    | port | status | lb_weight |  role
> ---------+---------------+------+--------+-----------+---------
>  0       | 192.168.15.55 | 5432 | 3      | 0.500000  | standby
>  1       | 192.168.15.56 | 5432 | 2      | 0.500000  | primary
> (2 rows)
> 
> 
> 
> 
> 
> # *pcp_attach_node -d 10 192.168.15.59 9898 user password 0*
> DEBUG: send: tos="R", len=44
> DEBUG: recv: tos="r", len=21, data=AuthenticationOK
> DEBUG: send: tos="D", len=6
> DEBUG: recv: tos="c", len=20, data=CommandComplete
> DEBUG: send: tos="X", len=4
> 
> 
> 
> *failback.sh script is being executed:*
> *from pgpool.conf:*
> *failback_command='/etc/pgpool-II/recovery/failback.sh %d %h %H %m %M %D %R
> %r'*
> 
> *from failback.sh:*
> *NODE_ID=$1*
> *HOST_NAME=$2*
> *NEW_MASTER_HOSTNAME=$3*
> *NEW_MASTER_NODE_ID=$4*
> *OLD_MASTER_NODE_ID=$5*
> *DATABASE_CLUSTER_PATH=$6*
> *MASTER_CLUSTER_PATH=$7*
> *NEW_MASTER_PORT=$8*
> 
> *function log()*
> *{*
> *###log error messages###*
> *[ ! "$1" ] && return 0*
> */bin/echo "[$(/bin/date +%m/%d/%y\ %H:%M:%S.%2N)] - $1" >>
> $PGHOME/failback.log*
> *}*
> 
> *log ""*
> *log "--- failback of $HOST_NAME ---"*
> *log ""*
> *log "node_id: $NODE_ID"*
> *log "hostname: $HOST_NAME"*
> *log "hostname of new master: $NEW_MASTER_HOSTNAME"*
> *log "new master node id: $NEW_MASTER_NODE_ID"*
> *log "old master node id: $OLD_MASTER_NODE_ID"*
> *log "database cluster path: $DATABASE_CLUSTER_PATH"*
> *log "master database cluster path: $MASTER_CLUSTER_PATH"*
> *log "master port: $NEW_MASTER_PORT"*
> *for i in $*; do*
> *  log "$i"*
> *done*
> *exit 0*
> 
> 
> 
> *and the log outputs:*
> 
> *[11/09/15 19:02:00.66] - --- failback of 192.168.15.55 ---*
> *[11/09/15 19:02:00.66] - node_id: 0*
> *[11/09/15 19:02:00.67] - hostname: 192.168.15.55*
> *[11/09/15 19:02:00.67] - hostname of new master: 192.168.15.55*
> *[11/09/15 19:02:00.67] - new master node id: 0*
> *[11/09/15 19:02:00.67] - old master node id: 1*
> *[11/09/15 19:02:00.67] - database cluster path:
> /home/postgres/databases/fabrix*
> *[11/09/15 19:02:00.68] - master database cluster path:
> /home/postgres/databases/fabrix*
> *[11/09/15 19:02:00.68] - master port: 5432*
> *[11/09/15 19:02:00.68] - 0*
> *[11/09/15 19:02:00.68] - 192.168.15.55*
> *[11/09/15 19:02:00.68] - 192.168.15.55*
> *[11/09/15 19:02:00.69] - 0*
> *[11/09/15 19:02:00.69] - 1*
> *[11/09/15 19:02:00.69] - /home/postgres/databases/fabrix*
> *[11/09/15 19:02:00.69] - /home/postgres/databases/fabrix*
> *[11/09/15 19:02:00.69] - 5432*
> 
> 
> 
> as you can tell the new master us not 192.168.15.55 , should be
> 192.168.15.56.
> 
> 
> Please advice,
> 
> cohavisi