#  vim:ts=4:sts=4:sw=4:et
#
#  Author: Hari Sekhon
#  Date: 2017-12-16 10:32:58 +0000 (Sat, 16 Dec 2017)
#
#  https://github.com/HariSekhon/HAProxy-configs
#
#  License: see accompanying Hari Sekhon LICENSE file
#
#  If you're using my code you're welcome to connect with me on LinkedIn and optionally send me feedback to help steer this or other code I publish
#
#  https://www.linkedin.com/in/HariSekhon
#

# ============================================================================ #
#        H A P r o x y  -  A p a c h e   D r i l l (centralized foreman)
# ============================================================================ #

# Centralizes the foreman Drill query planning node so all queries appear in one UI
#
# This is a workaround to the lack of a default global query list across all Drill foreman nodes as documented here:
#
# https://issues.apache.org/jira/browse/DRILL-6061

# Put only 2-3 Drill foreman nodes in an Active / Standby configuration for redundancy - under normal operating circumstances
# only the first will be used for query planning so you can see all queries in the same Drill UI.
#
# Beware this will limit scalability of the query planning, coordination and final aggregation steps.

# If you have a clustered filesystem such as MapR-FS or HDFS then configuring the PStore to exist on it and Using the 'source' option in the default adjacent apache-drill.cfg is a better option and should be preferred:
#
# https://drill.apache.org/docs/persistent-configuration-storage/

# Beware that the Apache Drill health check API is not always reliable, as documented in this bug:
#
# https://issues.apache.org/jira/browse/DRILL-5990

frontend apache-drill-ui
    description "Apache Drill UI"
    bind *:8047
    default_backend apache-drill-ui

frontend apache-drill-sql
    description "Apache Drill SQL"
    bind *:31010
    mode tcp
    option tcplog
    default_backend apache-drill-sql

backend apache-drill-ui
    description "Apache Drill UI"
    balance first
    option httpchk GET /status
    http-check expect string Running
    acl internal_networks src 192.168.0.0/16 172.16.0.0/12 10.0.0.0/8 127.0.0.1
    http-request deny if ! internal_networks
    server apache-drill apache-drill:8047 check
    server drill drill:8047 check backup
    server docker docker:8047 check backup
    server 192.168.99.199 192.168.99.100:8047 check backup

backend apache-drill-sql
    description "Apache Drill SQL"
    balance first
    mode tcp
    acl internal_networks src 192.168.0.0/16 172.16.0.0/12 10.0.0.0/8 127.0.0.1
    tcp-request content reject if ! internal_networks
    option httpchk GET /status
    http-check expect string Running
    server apache-drill apache-drill:31010 check port 8047
    server drill drill:31010 check port 8047 backup
    server docker docker:31010 check port 8047 backup
    server 192.168.99.100 192.168.99.100:31010 check port 8047 backup