7.4

2 If the procedure in step 1 fails, start a shell session and try to determine the node with the most
recent state. Start a shell session to all the available cluster nodes and try to start their databases by
running the following shell command: service vpostgres start
3 Use the following procedure for each node that has a running local database to determine the node
with the most recent state.
a Run the following command to determine the node with the most recent state. If the command
returns f, then it is the node with most recent state and you can proceed to step 4.
su - postgres
psql vcac
vcac=# select pg_is_in_recovery();
pg_is_in_recovery
n
If this command returns an f, then this node has the most recent state.
n
If the node returns a t, run the following command on the node:
SELECT pg_last_xlog_receive_location() as receive_loc, pg_last_xlog_replay_location() as
replay_loc, extract(epoch from pg_last_xact_replay_timestamp()) as replay_timestamp;
This command should return a result similar to the following.
vcac=# SELECT pg_last_xlog_receive_location() as receive_loc, pg_last_xlog_replay_location()
as replay_loc, extract(epoch from pg_last_xact_replay_timestamp()) as replay_timestamp;
receive_loc | replay_loc | replay_timestamp
-------------+------------+------------------
0/20000000 | 0/203228A0 | 1491577215.68858
(1 row)
4 Compare the results for each node to determine which one has the most recent state.
Select the node with greatest value under the receive_loc column. If equal, select the greatest from
the replay_loc column and then, if again equal, select the node with greatest value of
replay_timestamp.
5 Run the following command on the node with the most recent state: vcac-vami psql-promote-
master -force
6 Open the /etc/haproxy/conf.d/10-psql.cfg file in a text editor and update the following line.
server masterserver sc-rdops-vm06-dhcp-170-156.eng.vmware.com:5432 check on-marked-up shutdown-
backup-sessions
To read as follows with the current node FQDN:
server masterserver current-node-fqdn:5432 check on-marked-up shutdown-backup-sessions
7 Save the file.
8 Run the service haproxy restart command.
Managing vRealize Automation
VMware, Inc. 36