双节点：dual
双节点配置模板，有限高可用部署，允许宕机特定一台服务器。
Categories:
此模板使用双节点部署，实现一主一备的 “半-高可用” 部署，如果您只有两台服务器，这是一个不错的选择。
配置概览
- 配置名称：
dual - 节点数量： 双节点
- 配置说明：两节点模版，有限高可用部署，允许特定一台服务器宕机。
- 适用系统：
el8,el9,d12,u22,u24 - 适用架构：
x86_64,aarch64 - 相关配置：
- Vagrant：双节点
pigsty/vagrant/spec/dual.rb
配置说明
启用方式：在 configure 过程中使用 -c dual 参数：
./configure -c dual [-i <primary_ip>]
配置生成完成后，您还需要将 10.10.10.11 占位节点 IP 地址修改为您的从库节点 IP 地址。
配置内容
源文件地址：pigsty/conf/dual.yml
# It is recommended to use at least three nodes in production deployment.
# But sometimes, there are only two nodes available, that's dual.yml for
#
# In this setup, we have two nodes, .10 (admin_node) and .11 (pgsql_priamry):
#
# If .11 is down, .10 will take over since the dcs:etcd is still alive
# If .10 is down, .11 (pgsql primary) will still be functioning as a primary if:
# - Only dcs:etcd is down
# - Only pgsql is down
# if both etcd & pgsql are down (e.g. node down), the primary will still demote itself.
all:
children:
# infra cluster for proxy, monitor, alert, etc..
infra: { hosts: { 10.10.10.10: { infra_seq: 1 } } }
# etcd cluster for ha postgres
etcd: { hosts: { 10.10.10.10: { etcd_seq: 1 } }, vars: { etcd_cluster: etcd } }
# minio cluster, optional backup repo for pgbackrest
#minio: { hosts: { 10.10.10.10: { minio_seq: 1 } }, vars: { minio_cluster: minio } }
# postgres cluster 'pg-meta' with single primary instance
pg-meta:
hosts:
10.10.10.10: { pg_seq: 1, pg_role: replica }
10.10.10.11: { pg_seq: 2, pg_role: primary } # <----- use this as primary by default
vars:
pg_cluster: pg-meta
pg_databases: [ { name: meta ,baseline: cmdb.sql ,comment: pigsty meta database ,schemas: [ pigsty ] ,extensions: [ { name: vector }] } ]
pg_users:
- { name: dbuser_meta ,password: DBUser.Meta ,pgbouncer: true ,roles: [ dbrole_admin ] ,comment: pigsty admin user }
- { name: dbuser_view ,password: DBUser.Viewer ,pgbouncer: true ,roles: [ dbrole_readonly ] ,comment: read-only viewer for meta database }
node_crontab: [ '00 01 * * * postgres /pg/bin/pg-backup full' ] # make a full backup every 1am
pg_vip_enabled: true
pg_vip_address: 10.10.10.2/24
pg_vip_interface: eth1
vars: # global parameters
version: v3.2.2 # pigsty version string
admin_ip: 10.10.10.10 # admin node ip address
region: default # upstream mirror region: default,china,europe
node_tune: oltp # node tuning specs: oltp,olap,tiny,crit
pg_conf: oltp.yml # pgsql tuning specs: {oltp,olap,tiny,crit}.yml
infra_portal: # domain names and upstream servers
home : { domain: h.pigsty }
grafana : { domain: g.pigsty ,endpoint: "${admin_ip}:3000" , websocket: true }
prometheus : { domain: p.pigsty ,endpoint: "${admin_ip}:9090" }
alertmanager : { domain: a.pigsty ,endpoint: "${admin_ip}:9093" }
blackbox : { endpoint: "${admin_ip}:9115" }
loki : { endpoint: "${admin_ip}:3100" }
#minio : { domain: m.pigsty ,endpoint: "${admin_ip}:9001" ,scheme: https ,websocket: true }
# consider using local fs or external s3 service for cold backup storage in dual node configuration
#pgbackrest_method: minio
#----------------------------------#
# Repo, Node, Packages
#----------------------------------#
# if you wish to customize your own repo, change these settings:
repo_modules: infra,node,pgsql # install upstream repo during repo bootstrap
repo_remove: true # remove existing repo on admin node during repo bootstrap
node_repo_modules: local # install the local module in repo_upstream for all nodes
node_repo_remove: true # remove existing node repo for node managed by pigsty
repo_packages: [ # default packages to be downloaded
node-bootstrap, infra-package, infra-addons, node-package1, node-package2, pgsql-common #,docker
]
repo_extra_packages: [ # default postgres packages to be downloaded
pg17-main # replace with the following line if you want all extensions
#pg17-core ,pg17-time ,pg17-gis ,pg17-rag ,pg17-fts ,pg17-olap ,pg17-feat ,pg17-lang ,pg17-type ,pg17-func ,pg17-admin ,pg17-stat ,pg17-sec ,pg17-fdw ,pg17-sim ,pg17-etl
]
pg_version: 17 # default postgres version
#pg_extensions: [ pg17-time ,pg17-gis ,pg17-rag ,pg17-fts ,pg17-olap ,pg17-feat ,pg17-lang ,pg17-type ,pg17-func ,pg17-admin ,pg17-stat ,pg17-sec ,pg17-fdw ,pg17-sim ,pg17-etl ]
#pg_extensions: # check extension availability for your OS & PG @ https://ext.pigsty.io/#/list
# - timescaledb periods temporal_tables emaj table_version pg_cron pg_later pg_background #timescaledb_toolkit #pg_timeseries
# - postgis pgrouting pointcloud pg_h3 q3c ogr_fdw geoip pg_polyline pg_geohash mobilitydb
# - pgvector vchord pgvectorscale pg_vectorize pg_similarity smlar pg_summarize pg_tiktoken pg4ml #pgml
# - pg_search pgroonga pg_bigm zhparser pg_bestmatch hunspell
# - pg_analytics pg_duckdb duckdb_fdw pg_parquet pg_fkpart pg_partman plproxy #citus #hydra #pg_strom
# - hll rum pg_graphql pg_jsonschema jsquery pg_hint_plan hypopg index_advisor pg_plan_filter imgsmlr pg_ivm pgmq pgq pg_cardano #age #rdkit
# - pg_tle plv8 pllua pldebugger plpgsql_check plprofiler plsh pljava #plprql #plr #pgtap #faker #dbt2
# - pg_prefix pg_semver pgunit pgpdf pglite_fusion md5hash asn1oid roaringbitmap pgfaceting pgsphere pg_country pg_currency pgmp numeral pg_rational pguint pg_uint128 ip4r pg_uri pgemailaddr pg_acl #debversion pg_rrule timestamp9 chkpass
# - pg_gzip pg_zstd pg_http pg_net pg_smtp_client pg_html5_email_address pgsql_tweaks pg_extra_time count_distinct extra_window_functions first_last_agg tdigest aggs_for_vecs aggs_for_arrays pg_arraymath quantile lower_quantile
# - pg_idkit pg_uuidv7 permuteseq pg_hashids sequential_uuids pg_math pg_random pg_base36 pg_base62 pg_base58 floatvec pg_financial pgjwt pg_hashlib shacrypt cryptint pg_ecdsa pgpcre icu_ext pgqr envvar pg_protobuf url_encode #topn
# - pg_repack pg_squeeze pg_dirtyread pgfincore pg_ddlx pg_prioritize pg_checksums pg_readonly safeupdate pg_permissions pgautofailover pg_catcheck preprepare pgcozy pg_orphaned pg_crash pg_cheat_funcs pg_savior table_log pg_fio #pgpool #pgagent
# - pg_profile pg_show_plans pg_stat_kcache pg_stat_monitor pg_qualstats pg_track_settings pg_wait_sampling system_stats pg_meta pgnodemx pg_sqlog bgw_replstatus pgmeminfo toastinfo pg_explain_ui pg_relusage pagevis #pg_store_plans #powa
# - passwordcheck supautils pgsodium pg_vault pg_session_jwt pg_anon pgsmcrypto pgaudit pgauditlogtofile pg_auth_mon credcheck pgcryptokey pg_jobmon logerrors login_hook set_user pg_snakeoil pgextwlist pg_auditor sslutils pg_noset #pg_tde
# - wrappers mysql_fdw tds_fdw redis_fdw pg_redis_pubsub firebird_fdw aws_s3 log_fdw #multicorn #odbc_fdw #jdbc_fdw #oracle_fdw #db2_fdw #sqlite_fdw #pgbouncer_fdw #mongo_fdw #kafka_fdw #hdfs_fdw
# - orafce pgtt session_variable pg_statement_rollback pgmemcache #pg_dbms_metadata #pg_dbms_lock #pg_dbms_job #wiltondb
# - pglogical pglogical_ticker pgl_ddl_deploy pg_failover_slots wal2json decoderbufs decoder_raw mimeo pg_fact_loader #wal2mongo #repmgr #pg_bulkload
注意事项
通常在生产环境中，完整的高可用部署至少需要三个节点，以确保在任何一台服务器宕机时，集群仍然可以正常运行。 因为高可用故障检测 DCS（etcd） / Patroni需要多数节点的参与，而双节点无法满足这一要求。
但是，有时候只有两台服务器可用，这种情况下，dual 模板是一个可行的选择，假设您有两台服务器：
- 节点A，10.10.10.10 ，默认为管理节点，运行 Infra 基础设施，单节点 etcd，以及 PGSQL 的从库。
- 节点B，10.10.10.11 ，只做为 PGSQL 的主库。
在这种情况下，两节点模版允许 B 节点出现故障，并在故障发生后自动切换到 A 节点。 然而当 A 节点出现故障时（整个节点宕机），则需要人工介入。 不过，如果 A 节点不是整个节点宕机离线，而仅仅是 etcd 或 PostgreSQL 本身的问题，整套系统仍然可以继续正常运行。
此模板使用了一个 L2 VIP 实现高可用接入，如果您的网络条件不允许使用 L2 VIP （例如，在受限制的云环境，或跨交换机广播域），您可以考虑使用 DNS 解析或其他接入方式替代。