[pgpool-committers: 8095] pgpool: [New-Feature] Enable dynamic cluster membership of watchdog nod

[Muhammad Usama]

[New-Feature] Enable dynamic cluster membership of watchdog nodes

Enables dynamic watchdog cluster definition by introducing the concept of
Member and Nonmember watchdog nodes. If the node's membership gets revoked
from the watchdog cluster, then the cluster re-calibrate itself dynamically
to adjust all subsequent majority rule computations.

Three new settings wd_no_show_node_removal_timeout, wd_lost_node_removal_timeout
and wd_remove_shutdown_nodes are added to configure the membership
criteria of the watchdog nodes.

Branch
------
master

Details
-------
https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=3a1216d779e5e5fc73618db53056e65c90702a45
Author: Muhammad Usama <m.usama at highgo.ca>

Modified Files
--------------
src/config/pool_config_variables.c   |  29 ++++++++
src/include/pcp/pcp.h                |   4 +
src/include/pool_config.h            |  12 +++
src/include/watchdog/watchdog.h      |  12 +++
src/include/watchdog/wd_commands.h   |   2 +
src/libs/pcp/pcp.c                   |  25 +++++++
src/sample/pgpool.conf.sample-stream |  23 ++++++
src/tools/pcp/pcp_frontend_client.c  |  42 ++++++-----
src/watchdog/watchdog.c              | 137 ++++++++++++++++++++++++++++++++---
src/watchdog/wd_commands.c           |  14 ++++
10 files changed, 272 insertions(+), 28 deletions(-)