[pgpool-hackers: 3524] Refactoring running mode in Pgpool-II

[Tatsuo Ishii]

Currently we have multiple configuration parameters to set the running
mode (i.e. streaming replication mode and native replication mode
etc.). However, actually those modes are mutually exclusive. So why
don't we have a single new parameter, say "running_mode", instead of
multiple parameters like replication_mode, master_slave_mode and
master_slave_sub_mode? It will have enum type values:

streaming_replication
logical_replication
native_replication
slony
raw

If there's no objection, I would like to implement this for 4.2.

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp