I'm running two replicated databases with Docker and tried to add a load balancer (HAProxy), but every time I do docker compose up, I get the following log:
haproxy-1 | Connect from 192.168.65.1:27560 to 172.21.0.4:5432 (pgsql/TCP)
haproxy-1 | Connect from 192.168.65.1:41348 to 172.21.0.4:5432 (pgsql/TCP)
pg_primary-1 | 2024-06-18 14:50:12.989 UTC [357] LOG: invalid length of startup packet
pg_replica-1 | 2024-06-18 14:50:14.094 UTC [304] LOG: invalid length of startup packet
haproxy-1 | Connect from 192.168.65.1:34021 to 172.21.0.4:5432 (pgsql/TCP)
pg_primary-1 | 2024-06-18 14:50:14.103 UTC [366] LOG: invalid length of startup packet
haproxy-1 | Connect from 192.168.65.1:38342 to 172.21.0.4:5432 (pgsql/TCP)
pg_replica-1 | 2024-06-18 14:50:14.114 UTC [313] LOG: invalid length of startup packet
haproxy-1 | Connect from 192.168.65.1:24032 to 172.21.0.4:5432 (pgsql/TCP)
pg_primary-1 | 2024-06-18 14:50:15.705 UTC [368] LOG: invalid length of startup packet
haproxy-1 | Connect from 192.168.65.1:61890 to 172.21.0.4:5432 (pgsql/TCP)
haproxy-1 | Connect from 192.168.65.1:37349 to 172.21.0.4:5432 (pgsql/TCP)
pg_replica-1 | 2024-06-18 14:50:16.293 UTC [315] LOG: invalid length of startup packet
pg_primary-1 | 2024-06-18 14:50:16.299 UTC [369] LOG: invalid length of startup packet
haproxy-1 | Connect from 192.168.65.1:18951 to 172.21.0.4:5432 (pgsql/TCP)
pg_replica-1 | 2024-06-18 14:50:16.309 UTC [316] LOG: invalid length of startup packet
haproxy-1 | Connect from 192.168.65.1:22642 to 172.21.0.4:5432 (pgsql/TCP)
haproxy-1 | Connect from 192.168.65.1:31553 to 172.21.0.4:5432 (pgsql/TCP)
pg_primary-1 | 2024-06-18 14:50:16.483 UTC [371] LOG: invalid length of startup packet
pg_primary-1 | 2024-06-18 14:51:21.182 UTC [51] LOG: checkpoint starting: time
pg_primary-1 | 2024-06-18 14:51:25.360 UTC [51] LOG: checkpoint complete: wrote 42 buffers (0.3%); 0 WAL file(s) added, 0 removed, 1 recycled; write=4.148 s, sync=0.011 s, total=4.178 s; sync files=10, longest=0.007 s, average=0.002 s; distance=16644 kB, estimate=16644 kB; lsn=0/30413D0, redo lsn=0/3041398
My Docker Compose file is structured like this:
services:
pg_primary:
image: postgres:16
user: postgres
restart: always
healthcheck:
test: 'pg_isready -U user --dbname=postgres'
interval: 10s
timeout: 5s
retries: 5
ports:
- 5432:5432
environment:
POSTGRES_USER: user
POSTGRES_PASSWORD: password
POSTGRES_HOST_AUTH_METHOD: "scram-sha-256\nhost replication all 0.0.0.0/0 md5"
POSTGRES_INITDB_ARGS: "--auth-host=scram-sha-256"
command: |
postgres
-c wal_level=replica
-c hot_standby=on
-c max_wal_senders=10
-c max_replication_slots=10
-c hot_standby_feedback=on
volumes:
- ${PWD}/00_init.sql:/docker-entrypoint-initdb.d/00_init.sql:ro
pg_replica:
image: postgres:16
user: postgres
restart: always
healthcheck:
test: 'pg_isready -U user --dbname=postgres'
interval: 10s
timeout: 5s
retries: 5
ports:
- 5433:5432
environment:
PGUSER: replicator
PGPASSWORD: replicator_password
command: |
bash -c "
until pg_basebackup --pgdata=/var/lib/postgresql/data -R --slot=replication_slot --host=pg_primary --port=5432
do
echo 'Waiting for primary to connect..'
sleep 1s
done
echo 'Backup done, starting replica...'
chmod 0700 /var/lib/postgresql/data
postgres
"
depends_on:
- pg_primary
pgadmin:
image: dpage/pgadmin4
restart: always
ports:
- 8080:80
environment:
PGADMIN_DEFAULT_EMAIL: admin@example.com
PGADMIN_DEFAULT_PASSWORD: admin
depends_on:
- pg_primary
- pg_replica
haproxy:
image: haproxy:2.5
restart: always
ports:
- 5434:5432
volumes:
- ./haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro
depends_on:
- pg_primary
- pg_replica
entrypoint: ["sh", "-c", "sleep 10 && haproxy -f /usr/local/etc/haproxy/haproxy.cfg"]
I'm running two replicated databases with Docker and tried to add a load balancer (HAProxy), but every time I do docker compose up, I get the following log:
My Docker Compose file is structured like this: