How to fix Operator intervention in PostgreSQL

# On Linux/macOS
sudo systemctl status postgresql

# Or check if postgres process is running
ps aux | grep postgres

# Or try connecting
psql -U postgres -d postgres -c "SELECT version()"

# Common log locations
sudo tail -f /var/log/postgresql/postgresql.log
sudo tail -f /var/lib/postgresql/14/main/log/postgresql.log

# Or query the logs if the server is running
psql -U postgres -c "SELECT * FROM pg_read_file('/var/log/postgresql/postgresql.log', true) LIMIT 50"

# On Linux with systemd
sudo systemctl restart postgresql

# On macOS with Homebrew
brew services restart postgresql

# Or using pg_ctl if installed
sudo -u postgres /usr/lib/postgresql/14/bin/pg_ctl -D /var/lib/postgresql/14/main start

# Python example
import psycopg2
try:
    conn = psycopg2.connect("dbname=mydb user=postgres")
    cursor = conn.cursor()
    # Retry your operation
except psycopg2.OperationalError as e:
    print(f"Connection failed: {e}")
    # Wait and retry

// Node.js example
const { Client } = require('pg');
const client = new Client();
await client.connect().catch(err => {
  console.error('Connection failed:', err);
  setTimeout(() => client.connect(), 5000); // Retry after 5 seconds
});

# Python with pgbouncer connection pooling
# Use a connection pool to handle admin shutdowns gracefully
from sqlalchemy import create_engine
from sqlalchemy.pool import NullPool

engine = create_engine(
    'postgresql://user:password@localhost:6432/mydb',
    pool_size=5,
    max_overflow=10,
    pool_recycle=3600,
    echo=False,
    connect_args={"connect_timeout": 5}
)

# Implement retry logic
import time
max_retries = 3
for attempt in range(max_retries):
    try:
        with engine.connect() as conn:
            result = conn.execute("SELECT * FROM users")
        break
    except Exception as e:
        if attempt < max_retries - 1:
            time.sleep(2 ** attempt)  # Exponential backoff
        else:
            raise