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https://github.com/chocobn69/pglogical_upgrade_demo
Demonstration of postgresql upgrade using pglogical
https://github.com/chocobn69/pglogical_upgrade_demo
Last synced: 13 days ago
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Demonstration of postgresql upgrade using pglogical
- Host: GitHub
- URL: https://github.com/chocobn69/pglogical_upgrade_demo
- Owner: chocobn69
- Created: 2018-03-09T15:48:48.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2018-10-29T10:53:41.000Z (about 6 years ago)
- Last Synced: 2024-10-12T00:37:30.788Z (27 days ago)
- Language: Dockerfile
- Size: 13.7 KB
- Stars: 2
- Watchers: 3
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# pg logical test
We will test logical replication between db with different version and locale
- db1 : 9.6 and en_US.UTF-8
- db2 : 11 and C
## links
- https://www.postgresql.org/docs/11/static/sql-createsubscription.html
- https://www.postgresql.org/docs/9.6/static/logicaldecoding-example.html
- https://www.2ndquadrant.com/en/resources/pglogical/pglogical-docs/
## Initial setup
Here is the docker-compose.yml I will use:
```yaml
version: '3.5'
services:
db1:
image: postgres:9
restart: always
environment:
POSTGRES_PASSWORD: db1
POSTGRES_INITDB_ARGS: '--locale=en_US.UTF-8'
volumes:
- ./my-postgres-db1.conf:/etc/postgresql/postgresql.conf
- ./my-pg_hba.conf:/etc/postgresql/pg_hba.conf
command: -c config_file=/etc/postgresql/postgresql.conf
db2:
image: postgres:11
restart: always
environment:
POSTGRES_PASSWORD: db2
POSTGRES_INITDB_ARGS: '--locale=C --encoding=UTF8'
volumes:
- ./my-postgres-db2.conf:/etc/postgresql/postgresql.conf
- ./my-pg_hba.conf:/etc/postgresql/pg_hba.conf
command: -c config_file=/etc/postgresql/postgresql.conf
```
You have to generate postgresql.conf and pg_hba.conf file according to pglogical replication tutorial
https://www.2ndquadrant.com/en/resources/pglogical/pglogical-installation-instructions/
Let's launch the stack : `docker-compose up -d`
Now we can connect to first db1 db : `docker exec -ti pglogical_upgrade_demo_db1_1 psql -U postgres`
And second (db2) `docker exec -ti pglogical_upgrade_demo_db2_1 psql -U postgres -p 6432`
## Initial structure / datas
As we will migrate an existing database, we will create initial tables and datas on db1.
Structure :
```sql
create table table1(id serial primary key, comment text);
create table table2(id serial primary key, comment text);
```
Note: The structure must be created both on db1 and db2, as pglogical does not handle
initial DDL.
Datas on db1 only:
```sql
insert into table1(comment)
select md5(random()::text)
from generate_series (1,1000);
insert into table2(comment)
select md5(random()::text)
from generate_series (1,1000);
```
## pglogical install
postgresql.conf
```conf
wal_level = 'logical'
max_worker_processes = 10 # one per database needed on provider node
# one per node needed on subscriber node
max_replication_slots = 10 # one per node needed on provider node
max_wal_senders = 10 # one per node needed on provider node
shared_preload_libraries = 'pglogical'
track_commit_timestamp = on
```
On each node
```sql
CREATE EXTENSION pglogical;
```
Then on db1 (provider node)
```sql
SELECT pglogical.create_node(
node_name := 'provider1',
dsn := 'host=db1 port=5432 dbname=postgres'
);
```
Add all tables in replication set on db1
```sql
SELECT pglogical.replication_set_add_all_tables('default', ARRAY['public']);
```
Then on db2 (subscriber)
```sql
SELECT pglogical.create_node(
node_name := 'subscriber1',
dsn := 'host=db2 port=6432 dbname=postgres'
);
```
Then start replication on db2
```sql
SELECT pglogical.create_subscription(
subscription_name := 'subscription1',
provider_dsn := 'host=db1 port=5432 dbname=postgres'
);
```