[pgpool-general: 9215] Re: Load balancing of write queries among health-checked nodes

[me+pgpool at kotovalexarian.com]

>> One downside of the configuration is, if pgpool-A goes down, client-A
>> cannot send queries to pgpool-A. client-A has to switch the connection
>> to pgpool-B or pgpool-C if it wants to continue processing.
> 
> To mitigate the problem, you could specify multiple host in your client. i.e.:
> psql "host=A,B port=9999,9999 dbname=test" for client-A. This will try
> A first but if A is down, it will try B next.

Will libpq just test connectivity with the Pgpool instances, or it may 
test whether the Pgpool instance is detached from the cluster? Of course 
libpq doesn't know about Pgpool, it just uses the PostgreSQL protocol, 
but in case of a detached Pgpool instance will an SQL statement fail 
with such an error message so that libpq will try the next host?