Site Reliability Engineer @ 2ndQuadrant
Board Member @ PostgreSQL Europe
MSc Comp. & Systems Eng. @ Tallinn University of Technology
Writes on 2ndQuadrant blog
Does some childish paintings
Loves independent films
From Turkey
PostgreSQL
252
Database
208
Cloud
116
Upgrade
50
Offline Conversion
Online Conversion
[old-primary]
54.171.211.188
[new-primary]
54.246.183.100
[old-standbys]
54.77.249.81
54.154.49.180
[new-standbys:children]
old-standbys
[pgbouncer]
54.154.49.180
$ ansible-playbook -i hosts.ini pglupgrade.yml
Inventory file host.ini
Running pglupgrade playbook
8 plays
config.yml
host.ini
orchestrates
the upgrade
operation
ansible_user: admin
pglupgrade_user: pglupgrade
pglupgrade_pass: pglupgrade123
pglupgrade_database: postgres
replica_user: postgres
replica_pass: ""
pgbouncer_user: pgbouncer
postgres_old_version: 9.5
postgres_new_version: 9.6
subscription_name: upgrade
replication_set: upgrade
initial_standbys: 1
postgres_old_dsn: "dbname={{pglupgrade_database}} host={{groups['old-primary'][0]}} user={{pglupgrade_user}}"
postgres_new_dsn: "dbname={{pglupgrade_database}} host={{groups['new-primary'][0]}} user={{pglupgrade_user}}"
postgres_old_datadir: "/var/lib/postgresql/{{postgres_old_version}}/main"
postgres_new_datadir: "/var/lib/postgresql/{{postgres_new_version}}/main"
postgres_new_confdir: "/etc/postgresql/{{postgres_new_version}}/main"
config.yml
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Metric (1st case) | pg_dump/pg_restore | pg_upgrade | pglupgrade |
---|---|---|---|
Primary Downtime | 00:24:27 | 00:16:25 | 00:00:03 |
Partial cluster HA | 00:24:27 | 00:28:56 | 00:00:03 |
Full cluster capacity | 01:02:27 | 00:28:56 | 00:38:00 |
Length of upgrade | 01:02:27 | 00:28:56 | 01:38:10 |
Extra disk space | 800 MB | 27 GB | 10 GB |
Metric (2nd case) | pg_dump/pg_restore | pg_upgrade | pglupgrade |
---|---|---|---|
Primary Downtime | 00:23:52 | 00:17:03 | 00:00:05 |
Partial cluster HA | 00:23:52 | 00:54:29 | 00:00:05 |
Full cluster capacity | 00:23:52 | 03:19:16 | 00:00:05 |
Length of upgrade | 00:23:52 | 03:19:16 | 01:02:10 |
Extra disk space | 800 MB | 27 GB | 10 GB |
Database size growth during logical replication initialization
Transaction rate and latency during standby cloning process
Transaction rate and latency during the upgrade process
Database clusters can be upgraded with minimal downtime without users being affected while the upgrade is happening.
An application can still respond to the request only with a small drop in performance.
Case studies prove that pglupgrade minimizes the downtime to the level of 3-5 seconds.