Transcrição do relatório / tutorial "Gerenciando clusters PostgreSQL altamente disponíveis usando o Patroni". A. Klyukin, A. Kukushkin
O Patroni é um aplicativo Python para criar clusters PostgreSQL altamente acessíveis com base na replicação de streaming. É usado por empresas como Red Hat, IBM Compose, Zalando e muitas outras. Com sua ajuda, você pode transformar o sistema dos nós mestre e escravo (réplica primária) em um cluster altamente acessível com suporte para comutação automática controlada (comutação) e emergência (failover). O Patroni facilita a adição de novas réplicas a um cluster existente, suporta mudanças dinâmicas na configuração do PostgreSQL simultaneamente em todos os nós do cluster e muitos outros recursos, como replicação síncrona, ações personalizadas ao alternar nós, API REST, capacidade de executar comandos personalizados para criar uma réplica em vez de pg_basebackup, interação com Kubernetes etc.
Os alunos da classe master aprenderão em detalhes como o Patroni funciona, adquirem habilidades práticas na criação de clusters altamente acessíveis com base nele, familiarizam-se com vários recursos adicionais e participam do diagnóstico de problemas. Os seguintes tópicos serão abordados:
- escopo: quais tarefas de alta disponibilidade são resolvidas com sucesso pela Patroni
- revisão de arquitetura
- criando um cluster de teste
- utilitário patronictl
- Alteração na configuração do PostgreSQL para o cluster gerenciado Patroni
- Monitoramento de API
- abordagens de troca de clientes
- recursos adicionais: comutação manual, reinicialização programada, modo de pausa
- configuração de replicação síncrona
- extensibilidade e versatilidade
- erros freqüentes e seu diagnóstico
No final, há uma enquete: "Em quantas postagens o tutorial deve ser dividido? Por favor vote."
( ) ! , tutorial Patroni. . – . Zalando . Patroni. , . , , , , failover Patroni. - , , , .
$ git clone https://github.com/alexeyklyukin/patroni-training
$ cd patroni-training
$ vagrant up
$ vagrant ssh
$ sudo -iu postgres
$ cd patroni
$ ls
postgres0.yml postgres1.yml postgres2.yml
vagrant’. , , ( , ), vagrant GitHub, , vagrantfile. vagrant up vagrant ssh. , etcd, Postgres Patroni. , .
, . , , , , . . , , , Patroni.
Patroni , postgres-. , failover. Zalando . Patroni , postgres-. .
( ) . , , . failover. , , . , .
Patroni, , , .
, Patroni. , . , Patroni , .
, , Patroni , .
Patroni , . , failover, callback .
, -.
Patroni. , failover . , Patroni. .
, Patroni. , Patroni , , , point in time recovery .
, , Patroni GitHub. , .
. Patroni failover.
( ) ! Patroni, High Availability, , Postgres .
- - . - , . , , Postgres. , , DRDB LVM.
, , , Corosync, PaceMaker. . . PaceMaker , . , , . - - . , , , , .
, – . , Postgres 10- . trigger-based , , .
. , , , , . - , , , . - , , . . () .
, 2009- Postgres 9.0, . . , , High Availability .
, multi-master’ , . . BDR bucardo. , . BDR, bucardo . . - . . , . , . , . High Availability .
? . , standby , - .
, major versions.
: , primary. standby , . - , . , , standby .
. . - . . . , . , , standby - , , . ?
. split-brain .
. standby - .
, , ? -, . . , , . failover. , , . , , , , ? . . .
. , standby . , , , standby. , , . standby . split-brained.
. , , .
. , primary , . – . ? , , , , .
(: )
, . , , STONITH. - – « ».
Quorum . - , . .
Watchdog. , , , . , - Patroni, Watchdog . , Postgres .
, «Compose». Compose IBM. . , Postgres daemon`a, instance Postgres. - , lock, . lock' , .
Bot . , Postgres , , .
, . , . etcd . 30 . , ttl. , .
- , . , .
, , etcd. .
? , . - , . . WAL . , , , wal_position 100, . . . etcd.
etcd? , . . . , , , , .
, C , , B .
, C , promote Postgres. B , A, , C.
etcd. , , -, Patroni distributed consistency store, , Etcd, Consul, Zookeeper. Kybernetes API.
Etcd RAFT. , .
, etcd leader election, , , , .
Patroni . Patroni Python. Zalando, . , . . Cybertec. , Postages. Patroni .
( ) , Patroni . , , , High Availability .
. , . , vagrant. . vagrant ssh , sudo -iu postgres Patroni.
High Availability Patroni .
Patroni – . vagrant’ etcd. , instance etcd. production , , , instance etcd, etcd , . , . , , etcd production. , High Availability , Patroni .
Postgres, Patroni. yml-. yml-? GitHub, Patroni – open source , GitHub yml-. , , . . . git clone https://github.com/zalando/patroni.git, , Python . .
C 26:33 dem.
. Postgres. Patroni. . patroni postgres0.yml. Patroni. , Patroni.
Patroni , . -, initdb. Initdb . initdb. , . , , lock, . . , . : «lock owner: postgresql0; I om postgresql0», . . , , .
. patroni postgres1.yml. ? etcd-. , . . etcd , . , initdb , pg_basebackup. Postgres, . .
. Postgres. Postgres . . , WAL-. , .
? , , Patroni . , Patroni . Postgres , . , - , wal-, . , wal-, . . .
Postgres , . . . , Postgres wal- . , .
, , , wal- . . , . Patroni . , , .
? , , Patroni . Patroni , . .
. , . Patroni, Postgres. «postgres1», postgres1 – . , Patroni - . . . , lock postgresql0, potstresql1, . . – , – , lock, . promote, , lock. Patroni . , , . . , , , Patroni , .
? . ? python-etcd. . . patroni-training, vagrant. pip install python-etcd. etcd Patroni. , Patroni, . Patroni etcd .
? , Patronictl. Patronictl Patroni. .
? . Patroni «patronictl», . . . , , . . «list».
? . , «postgresql0» «postgresql1», , . , . , . , . Postgres, . . Postgres . (Lag) – , . , , . , Patroni Patronictl . , , .
, , failover. Patroni.
? , Patroni failover. . switchover, failover. Switchover – , - . , failover ( – ) – , - . , Patroni .
failover. ? Patroni . Patroni . «kill Patroni», «kill Patroni», Postgres. ctrl+Z, . . Patroni background , .
. . «ctrl+Z» . .
? . ? Patroni . etcd . . – 30 . «ttl». . . Patroni. 8 , 10 , . , , , failover. , 30 .
? . ? warning . Patroni «request failed», . . GET request. ? Patroni , lock’a etcd . . lock , Patroni . : « – ?». , Patroni wal’, . . .
, . . : « ?». , Patroni . , , promotion, . . . : promoted self to leader by acquiring session lock.
: Patroni ?
: , . .
, , . promotion.
: etcd Patroni?
: , . Etcd – , , , . – . etcd , . . , Patroni . , . , Postgres, etcd. - , etcd.
etcd, Patroni, Postgres, .
etcd , – , . etcd Postgres, etcd - . etcd , .
: etcd, network partition, . . ?
: network partition. etcd , . , , . , , . , , . .
, , promotion. . , , lock, postgres1 .
. , postgres0 , Patroni? Patroni, Postgres . Postgres .
, , , - . Postgres , split-brain, . . .
. , promotion . , , Patroni.
- . , split-brain. , Patroni split-brain.
? . , «split-brain». Postgres. . .
. . Patroni, . – . Patroni, , . , .
, – , . ? demoting Postgres , . . . Postgres – immediate shutdown . Postgres immediate shutdown. shutdown, . . , . . , demoting, . . promotion, lock’. Postgres.
crash recovery, immediate shutdown – . pg_rewind. Pg_rewind , . crash recovery mode single user. , single user . pg_rewind, Patroni , , promotion.
. . crash recovery. , wal-. wal- . , split-brain, – , , create table split-brain. pg_rewind.
pg_rewind? Postgres, , . , , promotion.
. «running pg_rewind from postgresql1». Pg_rewind , split-brain, . , rewind, – done. , . , – postgresql1, – postgresql0. . . , , , split-brain (split-brain , Patroni, Patroni, split-brain ), . . . Patroni , . , pg_rewind .
Patronictl. , , postgreslq1. postgresql0, postgresql1. , , postgresql0 , , . . failover , Patroni .
: , ?
: . . . , , . . split-brain, . Patroni – split-brains, .
. . . . - . , . Patroni. . , .
? etcd. , . etcdctl. , etcd. Consul, ZooKeeper Kubernetes. .
Etcd – -. - . - . , , , . . postgresql0 porsgresql1. initialize, , , , . . . , - , . initialize , .
, . . , members/postgresql1. json, .
, url, Postgres. api_url, . . url, Patroni, promotion, Patroni – . . Patroni , . . xlog’ wal’ , . . wal-. timeline.
. history. , timeline history, , promotion , , . . , promotion. . . , failover.
, . , Postgres.
? . . , , postgresql.conf autosystem , , . , , - , . , shared_buffers max_connections . .
? , , maintenance_work_mem work_mem, Postgres , .
Patronictl. . – edit-config. . .
? «maintenance_work_mem» work_mem. Postgres, parameters. . – 128 MB.
. Patroni , , , ? , .
, . . , SIGHUP. , Postgres . SIGHUP maintenance_work_memory , 128 MB.
. SIGHUP 128 MB.
. . . , Patroni reloading . . . . Patroni .
Patronictl . .
. maintenance_work_mem , .
, , , . edit-config. maintenance_work_memory «max_connections». ? , postgres-. , max_connections, , .
Max_connection , .
max_connection – 101. , . . Max_connection , 101. , . , . - ? , .
? , Postgres. Patroni . , , , , . : « production ?». Patroni .
, ? Patroni. REST API. Patroni REST API, , , etcd.
. ? , – . . , , ? , «pending_restart» «true». . . pending_restart – . . «true». , , , , , .
, . , . , . . ?
Patronictl list , . Patronictl , . ?
Patronictl, . . Patroni «patronictl restart». , , . . , , . . postgresql1 postgresql2. production , failover, .
.
, . ? , . , . . . , .
– max_connections . «show max_connections». – 101. . 101. (: , max_connections 100) . . max_connections. Patroni . .
, . max_connections , max_connections . max_connections , , , . Patroni . Patroni .
. . , , max_connections , . Patroni , Postgres max_connections.
. . Batman – . , . - .
Patroni , , - .
Patroni. . . Postgres, Patroni , yml. : « , promotion?».
ttl, . . etcd . ttl .
, Patroni. Patroni , , - , , , . , , failover.
, . . , , «loop_wait». . . , .
, loop_wait , ttl? Patroni . , , , . promotion - . . . . , .
, ttl , loop_wait. , Patroni etcd, «demoting», etcd , , . retry_timeout.
, : ttl , loop_wait + 2 retry_timeout. , loop_wait, retry_timeout ttl.
? . . . loop_wait , ttl . loop_wait 10 , ttl 5. , Patroni . , .
«patronictl edit-config» ttl 5 , loop_wait 10 . , .
. , watchdog’, Patroni, , . watchdog, , . ? , .
Postgres . «acquired session lock as a leader». ? Patroni , , Patroni . , . . , . , , . . . .
, . , . . . . , REST API , , . , promotion. .
etcd . , . , «following a different leader», . . . etcd , , . . . . . . , . , .
, , , . . , , . . . , . , , . . , ttl , loop_wait + retry_timeout *2.
: , , ttl. ttl, , , . . loop_wait . , .
, , retry_timeout . , . retry_timeout - etcd, Patroni demoting . -, , , , ttl 60 , , switches . 30 . -, .
Patroni. , . Patroni. bootstrap . bootstrap ttl loop_wait, retry_timeout, . , Postgres.
bootstrap ? etcd, bootstrap etcd. . , ttl, loop_wait. . , , etcd .
, PostgreSQL «use_pg_rewind», , pg_rewind. Patroni, Postgres. Postgres. , . . . . , .
, , bootstrap Patroni, . Patronictl, . . etcd. Patronictl .
. . , , etcd , bootstrap, , . .
? Postgres? .
– patroni.yaml. bootstrap. , , PostgreSQL. PostgreSQL , , . . . Patroni - . . , , , 16 B , MB, 4 B shared buffers, 1 B. shared buffers. . . – Patroni . bootstrap, .
. etcd. etcd config. .
etcdctl ls / service/batman/config
. , etcd . Patroni.yaml, . . - . production, , , - .
- Postgres. alter system -.
. , etcd . , bootstrap, . , retry_timeout, Postgres. etcd - postgresql parameters. , , Patroni , Patroni, .
patronictl , . , json, patronictl yml, – . json – .
etcd. patroni.yaml, , etcd . . . work_mem etcd 16 MB, patroni.yaml 12 MB. Patroni.yaml . ? Patroni postgres’ , 12 MB. Alter System, , . . patroni.yaml etcd.
. . , , postgresql.conf, Patroni , . postgresql.conf. , . . , . Patroni.
include ‘postgresql.base.conf’. .
base . Patroni – , base , - , . . , Git, , .
Patroni? postgresql.conf postgresql.base.conf. , postgres . postgresql.conf, , etcd . postgresql.base.conf.
? alter system. , base.conf . alter system - , , , . , , Patronictl edit-config , maintenance_woke_mem shared_buffers. .
, . . . config. patroni.yaml. patroni.yaml , , config, , . alter system, . - alter system, , , max_connections, Patroni pending_restart.
alter system max_connections .
, . . Shares_buffers.
, . . . , . max_connections, max_locks_per_transaction, wal_level. Wal_revel wal . , . wal’ .
Patroni . , logical.
Patroni? Postgres . . Patroni. Patronictl edit-config . , , , , .
Patroni REST API, . , .
Patroni endpoints REST API. – , GET requests. , options , .
? 200 K, , . PostgreSQL recovery .
200 OK , , read-only , Postgres . . . Postgres , -, 503.
, . , endpoint /master 503.
Patroni. , . . . json-, xlog’, Postgres - . , . , Patroni 200.
endpoint /config. , , Patronicrl. .
Patroni /switchover /failover. Switchover, , . . . , , - , - , , , - . , , .
Patroni REST API Postgres. /restart endpoint.
Patroni . . . , pg_rewind . . , wal’ , , -. – /reinitialize, . . Postgres, - base_backup.
endpoints Patronictl .
Patroni endpoint ? json-. database_system_identifier. , , . , , . batman. , Postgres .
. , .
server_version Postgres. – 10.0. , Postgres .
. , – , , timeline – 2.
xlog -, , xlog’ , .
timestamp – null. replayed_timestamp – null? , . , , , timestamp .
replayed_timestamp - , received 300 . ? ? , , . , received_timestamp , replayed_timestamp. , , , .
endpoints Postgres, Patroni.
endpoints , , - .
HAProxy . HAProxy , , – ? 200, 503. , . HAProxy , , . .
? , - IP -, IP. DNS, IP - .
Patroni - . shell script. Patroni . , Postgres, , on _start, Postgres , on_stop. on_reload, on_restart – .
On_role_change – . , , . . . Patroni pg_ctl promote. Patroni , on_role_change. , , IP , .
? , . IP . HAProxy – . HAProxy , . . confd. , etcd, ZooKeeper . https://github.com/zalando/patroni/blob/master/extras/confd/conf.d/haproxy.toml
, , etcd - . . . , confd . , reload, . . HAProxy.
, template HAProxy. max_connections, - . , .
? «on-marked-down shutdown-sessions». ? , 200, 503 , HAProxy . , , . , Postgres - . . HAProxy . , HAProxy health checks .
? confd, config PgBouncer. , PgBouncer . , , failover , . PgBouncer .
Postgres 10- connection string. read-write libpq . , , . read only -.
callbacks. , -.
callbacks , service_ip ( ip), .
promotion , service_ip. . . , , .
, -, callback , -, , . . . , on_role_change. scope – .
callbacks? . , -. callback , , , callback, . , , -, , IP - , . issue, .
? , - - , ?
tags. Patroni . . etcd, . .
, , nofailover true. false.
noloadbalance. read only, noloadbalance HAProxy , , 503, , true.
. clonefrom. , basebackup. , pg_basebackup , . - , , , . , , , . - clonefrom, Patroni basebackup . , - .
. , - -. . , , . nosync.
Patroni . , - . ? -. - . - , , . . . – . , .
Replicatefrom , . ? Patroni replication-. replication- - , , . . . , , - , , , .
replication-? , wal-, , Postgres - .
, Patroni etcd.
. postges2.yml . , postgres1. , postgres1 replication- postgres2 .
switchover failover? failover ?
Switchover – . . . .
Failover – , .
failover . , ? , . etcd xlog’. . , -, . 10 MB, , . , lag , 10 MB , . , , . manual failover. - , , . . , .
Switchover , . . Patroni. , switchover , . , , Patroni , – - . .. Postgres, Patroni , – . , switchover . , .
switchover.
. . switchover. . , .
. , . , , .
switchover. , : patronictl switchover batman. batman. , Patronictl , etcd.
postgres1. – enter, . . . . . , . , , . . Postgres.
Switchover . , switchover, .
. . . . , , . , , , Postgres. - 4 – switchover, , Patroni. AWS. , , , .
, 150 – . Patroni .
«», , . Patronictl . – ? postgresql0 postresql1. : «?». , . , .
patronictl list batman. . . . «switchover», «Successfully failed over to "postgresql0"», . . postgresql0. , postgresql0 – . . . . , real only. .
, stopped running. .
Patroni. ? . lock’. . , , .
, . promote . . , , - , , switchover . . . , . switchover, switchover, . switchover , .
, , , . , , . . manual failover: demoting myself.
. Patroni API Patronictl . switchover High Availability, . . Patroni , demoting, , . . . . switchover, , , . 4 Patroni , , - , , .
, demoting. , . – pg_rewind. pg_rewind clean shutdown.
? . . , switchover. . , switchover, Patroni . , , Patroni switchover. Patronictl , switchover, - . . , , switchover.
Postgres. ? pg_ctl –d data directory restart.
. – , promote. , , , Postgres.
Postgres – , , Postgres.
. . , , «restart». restart’ . . restart’ , , .
scheduled restart. , Postgres , , , , . , scheduled failover. , , restart - . Patroni restart. patronictl list, , .
, Patroni . , Patronictl failover, . . restart , , . , restart . restart , , restart, . , restart , , Patroni, , . lock , restart.
- Postgres pg_ctrl, Patroni . .
GitLab , GitLab ?
, . , , .
, . . Pg_basebackup - - . - . - . , game over. , , - – , , .
Patroni «reinit», , . . . «reinit», , . Patroni , . , . . , Postgres, Postgres , , , . running.
, «patronictl reinit cluster» ? Reinit . Reinit , Postgres , switchover - , . .
. ? Patroni, postgres-. failover. , - .
. , Patroni failover, - postgres-, , - . , – , Patroni . , .
. Patronictl . . . . , . , , etcd . loop_wait.
failover. , , . . - promote.
– etcd, etcd -. , .
– , - etcd.
. . etcd. read-only , , etcd . , , .
, Patroni, Patroni Postgres, , Patroni promote multi-. Patroni .
, Patroni, postgres- .
Postgres Patroni , Patroni . . , - Postgres, , . Postgres, - , . Postgres . Patroni .
, , etcd, etcd, , .
, . . . , , basebackup .
failover. . . , , , Patroni , . . . switchover , , .
. «pause». b, , . , , . - . wait , . , «list» , « », , .
Patroni , , , .
. , Patroni , .
promote , . . . . , «pg_ctl posgresql1 promote».
? Patroni . . . , multi-, . split-brain. split-brain . Patroni . promote.
? Patroni , , lock’ . . . etcd , , etcd , . , , lock’.
lock’, REST API , , 503. lock’ 200. 503? , , REST API . REST API , 503. , , , , 503. , , .
, split-brain , lock’, ? immediate shutdown, . . Patroni , , . immediate shutdown. Postgres . , Patroni pg_rewind , , , .
pg_rewind. standby, secondary. . . . Patroni split-brain, .
. . Patroni . true false.
. ? Patroni , , . «synchronous standby name». Postgres. synchronous standby name, . . .
Patroni failover , . , , , , Patroni failover - , .
? , . - , , - . Patroni? Patroni . . .
, , - nosync, , , Patroni .
. . , . . . , , , .
, , , , . Patroni . synchronous_mode_strict, . . .
, . , , , .
. , Postgres , . – . . . , . , .
«synchronous commit», , . . setting synchronous_commit to local, . . . , . , , . .
, ? , . GitHub, . , . , , Quorum , 10-.
, . . . . . – . synchronous_mode: true. false . – .
, . , lock. . , . , , , . Patroni , «synchronous_standby_names». Postgres, , postgresql1. Postgres , postgresql1 standby.
. patronictl list. , . synchronous standby. , .
endpoint, 200 , . . , endpoint 200. ? , . . . . select . , select , .
endpoint, - , , . endpoint , , .
async endpoint, 200 , . async . , , 503, .
. synchronous_mode: false. . , . list, , . async endpoint, 200. sync endpoint, 503. . . , .
, Patroni.
: « , standby?». , , . : synchronous_mode, synchronous_mode_strict. Strict , . , , . , . . , . , , , Patroni .
Patroni . , , - , . ?
, , basebackup, https://github.com/wal-e/wal-e ( wal-g). , , - , wal-e.
, . , Patroni - , Patroni , - . create_replica_method. .
, Patroni , . wal_e. wal_e . , , . , yml, .
? . , , no_master. , , .
? - , . . . Patroni. Patroni , .
, . wal- basebackup, pg_dump.
. – . . . . . wale_restore. , Patroni . wale_restrore. , , . - , . connstring, . ? , , , WAL . , basebackup. . ., , .
no_master. Envdir — , wal_e. , retries. .
, , 0, , . , Patroni . , . .
, , Patroni initdb.
, - . production - . .
custom bootstrap. , custom replica, create method, . . - . . . command. – s3.
point in time recovery. . . , - . - . , . , , s3 - , recovery target timeline.
, s3, Patroni recovery.conf . , , , timeline promote , recovery target timeline, promote , . . target timeline, . . - .
, , Patroni Postgres. Postgres wal’ - , s3 . - promote. Patroni post_bootstrap script. ? - , - . , , .
initdb . . . - initdb. , trust , localhost.
, instance Patroni . . . bootstrap . , . - bootstrap , Patroni initialize . , .
, post_bootstrap . , pg_stat_statements extension temlate1. ? - pg_stat_statements. . extension , superuser, superuser’. .
Patroni. . -, , , . . , scope . batman.
Namespace – , etcd . – , . Patroni, -. , namespace .
- REST API Patroni . Patroni etcd, bootstrap, Postgres, watchdog tags.
restapi , API . SSL authentication.
DCS , etcd, Consul, . , , . , , , - . .
ZooKeeper , , . ZooKeeper . Exhibitor , , , .
Bootstrap . , , Bootstrap , .
bootstrap_method .
. listen_address connect_address. Listen_address – Postgres . Connect_address – , etcd , . .
– authentication. , Patroni superuser . , .
- Postgres .
callback replica_method .
, . , . safety_margin. : «, 5 , , ». . . , -.
tags .
yml-. environment. .
environment variables. Patroni configuration. , environment variables . , - config , .
troubleshooting – , .
, . , .
. . etcd, etcd - , , etcd, . , , etcd . .
. Debian. postgres, pg_ctl path. Patroni. Patroni . subprocess. call, . . . , pg_ctl. , , , Postgres.
. , bindir. , . path , Postgres.
, Patroni . , , . ( 10 ) , , . .
initdb Patronictl.yml. . , «data-checksums», checksums, , . initdb , --data-checksums. --data-checksums: true, - data-checksums. Patroni, , . - data-checksums: true, , , data-checksums . initdb , Patroni , .
. Yaml – , . . . yaml, yaml. yaml , . . yaml , Python, . , yaml , .
, ? , . , . .
, - , yaml , production.
. Debian Ubuntu Postgres, initdb . , -, .
, , initdb, ? , initdb, . postgres- , , , initdb .
Patroni , Patroni « ». , , , . . . , , . , , reinit .
. Debian, -, - .
.
Patroni. GitHub. open source . issue. issue. , .
Patroni. : https://patroni.readthedocs.io. . - , . . , Patroni . . , Kubernetes, , .
docker-, Postgres Patroni . Spilo. GitHub open source, Zalando , Postgres. .
:
( , )
: patroni kubernetes?
: Kubernetes Patroni Spilo. postgres-. open source .
: OpenShift?
: . , , Red Hat . OpenShift, OpenShift , , Red Hat. , .
: , standby. Patroni standby, ?
: , . , Patroni , . , standby. . production, -, , laptop’, .
, , . . - , standby. Patroni , . , ZooKeeper . Patroni . , Patroni , . Patroni. .
: bootstrap S3, ?
: wal-e, - . . . . , .
, S3 Amazon, , – , . S3, Amazon, .
: Postgres pg_ctl, - ?
: Patroni Postgres . , Patroni Postgres. , Patroni Postgres’, . . Patroni .
: « Postgres Patroni?».
: , . ?
: Patroni Postgres ?
: , Patroni . Patroni Postgres. , . , , . , , postmaster, Postgres. , Postgres, Patroni . . – Patroni.
: , ?
: - , Patroni - , , .
: , ?
: Patroni , , . , . . . , , .
: Patroni ?
: , . Patroni - . . , . . Patroni , . , . . . docker-, spilo, spilo Postgres Patroni. Patroni – , .
: Haproxy?
: – . . . , , HAProxy , , . HAProxy, HAProxy . Postgres. O , TCP proxy. postgres-, Postgres.