From an email from Jeff Watts.

Document URL: https://access.redhat.com/documentation/en-us/red_hat_cloudforms/4.2/html-single/configuring_high_availability/#reintroducing_the_failed_node

Suggestions for improvement: 
Corrections needed in the sql commands for 4.2 and 4.5 HA guides.

Additional information: 


The part where it discusses the recovery from the following error: "requested WAL segment 000000020000000000000004 has already been removed" has the problem. It took us a while before we figured it out. All of the sql commands are missing the final semi-colon.

The commands  in step ii:
 
# psql vmdb_production
vmdb_production=#select * from repl_nodes
vmdb_production=#delete from repl_nodes table where id = $cluster_node_id_of_failed node



They should all be appended with a ";".  Should be:
# psql vmdb_production
vmdb_production=#select * from repl_nodes;
vmdb_production=#delete from repl_nodes table where id = $cluster_node_id_of_failed node;