feat(db): add robust psycopg2 pool with health checks, keepalives, and safer caching behavior
This commit is contained in:
Cipher Vance
parent
46093d2b56
commit
0bab1b5dd8
1 changed files with 258 additions and 192 deletions
450
database.py
450
database.py
|
|
@ -1,172 +1,220 @@
|
|||
import os
|
||||
import psycopg2
|
||||
from psycopg2 import pool, IntegrityError, OperationalError
|
||||
from dotenv import load_dotenv
|
||||
import time
|
||||
import logging
|
||||
import threading
|
||||
import time
|
||||
import atexit
|
||||
from contextlib import contextmanager
|
||||
import psycopg2
|
||||
from psycopg2 import pool, IntegrityError
|
||||
from psycopg2 import extensions
|
||||
from dotenv import load_dotenv
|
||||
|
||||
load_dotenv()
|
||||
|
||||
# Global connection pool
|
||||
logger = logging.getLogger(__name__)
|
||||
logger.setLevel(logging.INFO)
|
||||
|
||||
_connection_pool = None
|
||||
_pool_lock = threading.Lock()
|
||||
_pool_stats = {
|
||||
'connections_created': 0,
|
||||
'connections_failed': 0,
|
||||
'pool_recreated': 0
|
||||
"connections_checked_out": 0,
|
||||
"connections_failed": 0,
|
||||
"pool_recreated": 0,
|
||||
}
|
||||
|
||||
logger = logging.getLogger(__name__)
|
||||
|
||||
class SimpleRobustPool:
|
||||
"""Simplified robust connection pool"""
|
||||
|
||||
"""
|
||||
Thread-safe, robust connection pool wrapper for psycopg2
|
||||
with connection health checks and automatic recovery.
|
||||
"""
|
||||
|
||||
def __init__(self, minconn=3, maxconn=15, **kwargs):
|
||||
self.minconn = minconn
|
||||
self.maxconn = maxconn
|
||||
self.kwargs = kwargs
|
||||
self.pool = None
|
||||
self._create_pool()
|
||||
|
||||
|
||||
def _create_pool(self):
|
||||
"""Create or recreate the connection pool"""
|
||||
"""Create or recreate the underlying connection pool."""
|
||||
try:
|
||||
if self.pool:
|
||||
try:
|
||||
self.pool.closeall()
|
||||
except:
|
||||
except Exception:
|
||||
pass
|
||||
|
||||
|
||||
self.pool = psycopg2.pool.ThreadedConnectionPool(
|
||||
minconn=self.minconn,
|
||||
maxconn=self.maxconn,
|
||||
**self.kwargs
|
||||
**self.kwargs,
|
||||
)
|
||||
_pool_stats["pool_recreated"] += 1
|
||||
logger.info(
|
||||
"DB pool created: min=%s max=%s host=%s db=%s",
|
||||
self.minconn,
|
||||
self.maxconn,
|
||||
self.kwargs.get("host"),
|
||||
self.kwargs.get("database"),
|
||||
)
|
||||
_pool_stats['pool_recreated'] += 1
|
||||
logger.info(f"Connection pool created: {self.minconn}-{self.maxconn} connections")
|
||||
|
||||
except Exception as e:
|
||||
logger.error(f"Failed to create connection pool: {e}")
|
||||
raise
|
||||
|
||||
def _test_connection(self, conn):
|
||||
"""Simple connection test without transaction conflicts"""
|
||||
|
||||
def _healthy(self, conn) -> bool:
|
||||
"""
|
||||
Validate a connection with a real round-trip and
|
||||
make sure it's not in an aborted transaction.
|
||||
"""
|
||||
try:
|
||||
if conn.closed:
|
||||
return False
|
||||
|
||||
# Simple test that doesn't interfere with transactions
|
||||
conn.poll()
|
||||
return conn.status == psycopg2.extensions.STATUS_READY or conn.status == psycopg2.extensions.STATUS_BEGIN
|
||||
|
||||
|
||||
txn_status = conn.get_transaction_status()
|
||||
if txn_status == extensions.TRANSACTION_STATUS_INERROR:
|
||||
try:
|
||||
conn.rollback()
|
||||
except Exception:
|
||||
return False
|
||||
|
||||
if not conn.autocommit:
|
||||
conn.autocommit = True
|
||||
|
||||
with conn.cursor() as cur:
|
||||
cur.execute("SELECT 1")
|
||||
cur.fetchone()
|
||||
return True
|
||||
except Exception:
|
||||
return False
|
||||
|
||||
|
||||
def getconn(self, retry_count=2):
|
||||
"""Get a connection with simplified retry logic"""
|
||||
for attempt in range(retry_count):
|
||||
"""
|
||||
Get a connection, validating it before handing out.
|
||||
On repeated failures, recreate the pool once.
|
||||
"""
|
||||
last_err = None
|
||||
|
||||
for attempt in range(retry_count + 1):
|
||||
try:
|
||||
conn = self.pool.getconn()
|
||||
|
||||
# Simple connection test
|
||||
if not self._test_connection(conn):
|
||||
logger.warning("Got bad connection, discarding and retrying")
|
||||
if not self._healthy(conn):
|
||||
logger.warning("Discarding unhealthy connection")
|
||||
try:
|
||||
self.pool.putconn(conn, close=True)
|
||||
except:
|
||||
except Exception:
|
||||
pass
|
||||
last_err = last_err or Exception("Unhealthy connection")
|
||||
time.sleep(0.2)
|
||||
continue
|
||||
|
||||
_pool_stats['connections_created'] += 1
|
||||
|
||||
_pool_stats["connections_checked_out"] += 1
|
||||
return conn
|
||||
|
||||
|
||||
except Exception as e:
|
||||
logger.error(f"Error getting connection (attempt {attempt + 1}): {e}")
|
||||
_pool_stats['connections_failed'] += 1
|
||||
|
||||
if attempt == retry_count - 1:
|
||||
# Last attempt failed, try to recreate pool
|
||||
logger.warning("Recreating connection pool due to failures")
|
||||
try:
|
||||
self._create_pool()
|
||||
conn = self.pool.getconn()
|
||||
if self._test_connection(conn):
|
||||
return conn
|
||||
except Exception as recreate_error:
|
||||
logger.error(f"Failed to recreate pool: {recreate_error}")
|
||||
raise
|
||||
|
||||
# Wait before retry
|
||||
time.sleep(0.5)
|
||||
|
||||
raise Exception("Failed to get connection after retries")
|
||||
|
||||
def putconn(self, conn, close=False):
|
||||
"""Return connection to pool"""
|
||||
last_err = e
|
||||
_pool_stats["connections_failed"] += 1
|
||||
logger.error(
|
||||
"Error getting connection (attempt %s/%s): %s",
|
||||
attempt + 1,
|
||||
retry_count + 1,
|
||||
e,
|
||||
)
|
||||
time.sleep(0.3)
|
||||
|
||||
logger.warning("Recreating DB pool due to repeated failures")
|
||||
self._create_pool()
|
||||
try:
|
||||
# Check if connection should be closed
|
||||
if conn.closed or close:
|
||||
conn = self.pool.getconn()
|
||||
if self._healthy(conn):
|
||||
_pool_stats["connections_checked_out"] += 1
|
||||
return conn
|
||||
self.pool.putconn(conn, close=True)
|
||||
except Exception as e:
|
||||
last_err = e
|
||||
|
||||
raise last_err or Exception("Failed to get a healthy DB connection")
|
||||
|
||||
def putconn(self, conn, close=False):
|
||||
"""Return a connection to the pool, closing it if it's bad."""
|
||||
try:
|
||||
bad = (
|
||||
conn.closed
|
||||
or conn.get_transaction_status()
|
||||
== extensions.TRANSACTION_STATUS_INERROR
|
||||
)
|
||||
if bad:
|
||||
try:
|
||||
conn.rollback()
|
||||
except Exception:
|
||||
pass
|
||||
close = True
|
||||
|
||||
|
||||
self.pool.putconn(conn, close=close)
|
||||
|
||||
except Exception as e:
|
||||
logger.error(f"Error returning connection to pool: {e}")
|
||||
try:
|
||||
conn.close()
|
||||
except:
|
||||
except Exception:
|
||||
pass
|
||||
|
||||
|
||||
def closeall(self):
|
||||
"""Close all connections"""
|
||||
if self.pool:
|
||||
self.pool.closeall()
|
||||
try:
|
||||
self.pool.closeall()
|
||||
except Exception:
|
||||
pass
|
||||
|
||||
def get_connection_pool():
|
||||
"""Initialize and return the connection pool"""
|
||||
"""
|
||||
Initialize and return the global connection pool.
|
||||
Includes TCP keepalives and statement_timeout to detect dead/stuck sessions.
|
||||
"""
|
||||
global _connection_pool
|
||||
with _pool_lock:
|
||||
if _connection_pool is None:
|
||||
try:
|
||||
_connection_pool = SimpleRobustPool(
|
||||
minconn=int(os.getenv('DB_POOL_MIN', 3)),
|
||||
maxconn=int(os.getenv('DB_POOL_MAX', 15)),
|
||||
host=os.getenv("PG_HOST"),
|
||||
port=int(os.getenv("PG_PORT", 5432)),
|
||||
database=os.getenv("PG_DATABASE"),
|
||||
user=os.getenv("PG_USER"),
|
||||
password=os.getenv("PG_PASSWORD"),
|
||||
connect_timeout=int(os.getenv('DB_CONNECT_TIMEOUT', 10)),
|
||||
application_name="rideaware_newsletter"
|
||||
)
|
||||
logger.info("Database connection pool initialized successfully")
|
||||
|
||||
except Exception as e:
|
||||
logger.error(f"Error creating connection pool: {e}")
|
||||
raise
|
||||
|
||||
conn_kwargs = dict(
|
||||
host=os.getenv("PG_HOST"),
|
||||
port=int(os.getenv("PG_PORT", 5432)),
|
||||
database=os.getenv("PG_DATABASE"),
|
||||
user=os.getenv("PG_USER"),
|
||||
password=os.getenv("PG_PASSWORD"),
|
||||
connect_timeout=int(os.getenv("DB_CONNECT_TIMEOUT", 10)),
|
||||
application_name="rideaware_app",
|
||||
keepalives=1,
|
||||
keepalives_idle=int(os.getenv("PG_KEEPALIVE_IDLE", 30)),
|
||||
keepalives_interval=int(os.getenv("PG_KEEPALIVE_INTERVAL", 10)),
|
||||
keepalives_count=int(os.getenv("PG_KEEPALIVE_COUNT", 3)),
|
||||
options="-c statement_timeout={}".format(
|
||||
int(os.getenv("PG_STATEMENT_TIMEOUT_MS", 5000))
|
||||
),
|
||||
)
|
||||
_connection_pool = SimpleRobustPool(
|
||||
minconn=int(os.getenv("DB_POOL_MIN", 3)),
|
||||
maxconn=int(os.getenv("DB_POOL_MAX", 15)),
|
||||
**conn_kwargs,
|
||||
)
|
||||
logger.info("Database connection pool initialized")
|
||||
return _connection_pool
|
||||
|
||||
@contextmanager
|
||||
def get_db_connection():
|
||||
"""Context manager for database connections"""
|
||||
"""
|
||||
Context manager that yields a healthy connection and
|
||||
ensures proper cleanup/rollback on errors.
|
||||
"""
|
||||
conn = None
|
||||
try:
|
||||
pool = get_connection_pool()
|
||||
conn = pool.getconn()
|
||||
yield conn
|
||||
|
||||
except Exception as e:
|
||||
logger.error(f"Database connection error: {e}")
|
||||
if conn:
|
||||
try:
|
||||
conn.rollback()
|
||||
except:
|
||||
except Exception:
|
||||
pass
|
||||
raise
|
||||
|
||||
finally:
|
||||
if conn:
|
||||
try:
|
||||
|
|
@ -176,16 +224,10 @@ def get_db_connection():
|
|||
logger.error(f"Error returning connection: {e}")
|
||||
|
||||
def get_connection():
|
||||
"""Get a connection from the pool (legacy interface)"""
|
||||
try:
|
||||
pool = get_connection_pool()
|
||||
return pool.getconn()
|
||||
except Exception as e:
|
||||
logger.error(f"Error getting connection from pool: {e}")
|
||||
raise
|
||||
pool = get_connection_pool()
|
||||
return pool.getconn()
|
||||
|
||||
def return_connection(conn):
|
||||
"""Return a connection to the pool (legacy interface)"""
|
||||
try:
|
||||
pool = get_connection_pool()
|
||||
pool.putconn(conn)
|
||||
|
|
@ -193,149 +235,173 @@ def return_connection(conn):
|
|||
logger.error(f"Error returning connection to pool: {e}")
|
||||
|
||||
def close_all_connections():
|
||||
"""Close all connections in the pool"""
|
||||
global _connection_pool
|
||||
with _pool_lock:
|
||||
if _connection_pool:
|
||||
try:
|
||||
_connection_pool.closeall()
|
||||
logger.info("All database connections closed")
|
||||
logger.info("All DB connections closed")
|
||||
except Exception as e:
|
||||
logger.error(f"Error closing connections: {e}")
|
||||
finally:
|
||||
_connection_pool = None
|
||||
|
||||
def get_pool_stats():
|
||||
"""Get connection pool statistics"""
|
||||
return _pool_stats.copy()
|
||||
|
||||
def column_exists(cursor, table_name, column_name):
|
||||
"""Check if a column exists in a table"""
|
||||
cursor.execute("""
|
||||
def column_exists(cursor, table_name, column_name) -> bool:
|
||||
cursor.execute(
|
||||
"""
|
||||
SELECT EXISTS (
|
||||
SELECT 1
|
||||
FROM information_schema.columns
|
||||
SELECT 1
|
||||
FROM information_schema.columns
|
||||
WHERE table_name = %s AND column_name = %s
|
||||
)
|
||||
""", (table_name, column_name))
|
||||
return cursor.fetchone()[0]
|
||||
|
||||
def index_exists(cursor, index_name):
|
||||
"""Check if an index exists"""
|
||||
cursor.execute("""
|
||||
SELECT EXISTS (
|
||||
SELECT 1 FROM pg_class c
|
||||
JOIN pg_namespace n ON n.oid = c.relnamespace
|
||||
WHERE c.relname = %s AND n.nspname = 'public'
|
||||
)
|
||||
""", (index_name,))
|
||||
return cursor.fetchone()[0]
|
||||
""",
|
||||
(table_name, column_name),
|
||||
)
|
||||
return bool(cursor.fetchone()[0])
|
||||
|
||||
def init_db():
|
||||
"""Initialize database tables and indexes"""
|
||||
"""
|
||||
Initialize tables and indexes idempotently.
|
||||
"""
|
||||
with get_db_connection() as conn:
|
||||
try:
|
||||
with conn.cursor() as cursor:
|
||||
# Create subscribers table
|
||||
cursor.execute("""
|
||||
with conn.cursor() as cur:
|
||||
cur.execute(
|
||||
"""
|
||||
CREATE TABLE IF NOT EXISTS subscribers (
|
||||
id SERIAL PRIMARY KEY,
|
||||
email TEXT UNIQUE NOT NULL
|
||||
email TEXT UNIQUE NOT NULL,
|
||||
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
|
||||
)
|
||||
""")
|
||||
|
||||
# Add created_at column if it doesn't exist
|
||||
if not column_exists(cursor, 'subscribers', 'created_at'):
|
||||
cursor.execute("""
|
||||
ALTER TABLE subscribers
|
||||
ADD COLUMN created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
|
||||
""")
|
||||
logger.info("Added created_at column to subscribers table")
|
||||
|
||||
# Create newsletters table
|
||||
cursor.execute("""
|
||||
CREATE TABLE IF NOT EXISTS newsletters(
|
||||
"""
|
||||
)
|
||||
|
||||
cur.execute(
|
||||
"""
|
||||
CREATE TABLE IF NOT EXISTS newsletters (
|
||||
id SERIAL PRIMARY KEY,
|
||||
subject TEXT NOT NULL,
|
||||
body TEXT NOT NULL,
|
||||
sent_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
|
||||
)
|
||||
""")
|
||||
|
||||
# Create indexes only if they don't exist
|
||||
indexes = [
|
||||
("idx_newsletters_sent_at", "CREATE INDEX IF NOT EXISTS idx_newsletters_sent_at ON newsletters(sent_at DESC)"),
|
||||
("idx_subscribers_email", "CREATE INDEX IF NOT EXISTS idx_subscribers_email ON subscribers(email)"),
|
||||
("idx_subscribers_created_at", "CREATE INDEX IF NOT EXISTS idx_subscribers_created_at ON subscribers(created_at DESC)")
|
||||
]
|
||||
|
||||
for index_name, create_sql in indexes:
|
||||
cursor.execute(create_sql)
|
||||
logger.info(f"Ensured index {index_name} exists")
|
||||
|
||||
conn.commit()
|
||||
logger.info("Database tables and indexes initialized successfully")
|
||||
|
||||
"""
|
||||
)
|
||||
|
||||
cur.execute(
|
||||
"CREATE INDEX IF NOT EXISTS idx_newsletters_sent_at ON newsletters(sent_at DESC)"
|
||||
)
|
||||
cur.execute(
|
||||
"CREATE INDEX IF NOT EXISTS idx_subscribers_email ON subscribers(email)"
|
||||
)
|
||||
cur.execute(
|
||||
"CREATE INDEX IF NOT EXISTS idx_subscribers_created_at ON subscribers(created_at DESC)"
|
||||
)
|
||||
|
||||
conn.commit()
|
||||
logger.info("DB schema ensured successfully")
|
||||
except Exception as e:
|
||||
logger.error(f"Error initializing database: {e}")
|
||||
logger.error(f"Error initializing DB: {e}")
|
||||
conn.rollback()
|
||||
raise
|
||||
|
||||
def add_email(email):
|
||||
"""Add email to subscribers with robust connection handling"""
|
||||
def add_email(email: str) -> bool:
|
||||
"""
|
||||
Insert a subscriber email.
|
||||
Returns True if inserted, False if duplicate or error.
|
||||
"""
|
||||
with get_db_connection() as conn:
|
||||
try:
|
||||
with conn.cursor() as cursor:
|
||||
cursor.execute("INSERT INTO subscribers (email) VALUES (%s)", (email,))
|
||||
conn.commit()
|
||||
logger.info(f"Email added successfully: {email}")
|
||||
return True
|
||||
|
||||
with conn.cursor() as cur:
|
||||
cur.execute(
|
||||
"INSERT INTO subscribers (email) VALUES (%s)",
|
||||
(email,),
|
||||
)
|
||||
conn.commit()
|
||||
logger.info("Email added: %s", email)
|
||||
return True
|
||||
except IntegrityError:
|
||||
# Email already exists
|
||||
conn.rollback()
|
||||
logger.info(f"Email already exists: {email}")
|
||||
logger.info("Email already exists: %s", email)
|
||||
return False
|
||||
|
||||
except Exception as e:
|
||||
conn.rollback()
|
||||
logger.error(f"Error adding email {email}: {e}")
|
||||
logger.error("Error adding email %s: %s", email, e)
|
||||
return False
|
||||
|
||||
def remove_email(email):
|
||||
"""Remove email from subscribers with robust connection handling"""
|
||||
def remove_email(email: str) -> bool:
|
||||
"""
|
||||
Delete a subscriber email.
|
||||
Returns True if removed, False if not found or error.
|
||||
"""
|
||||
with get_db_connection() as conn:
|
||||
try:
|
||||
with conn.cursor() as cursor:
|
||||
cursor.execute("DELETE FROM subscribers WHERE email = %s", (email,))
|
||||
conn.commit()
|
||||
rows_affected = cursor.rowcount
|
||||
|
||||
if rows_affected > 0:
|
||||
logger.info(f"Email removed successfully: {email}")
|
||||
return True
|
||||
else:
|
||||
logger.info(f"Email not found for removal: {email}")
|
||||
return False
|
||||
|
||||
with conn.cursor() as cur:
|
||||
cur.execute(
|
||||
"DELETE FROM subscribers WHERE email = %s",
|
||||
(email,),
|
||||
)
|
||||
removed = cur.rowcount > 0
|
||||
conn.commit()
|
||||
if removed:
|
||||
logger.info("Email removed: %s", email)
|
||||
else:
|
||||
logger.info("Email not found for removal: %s", email)
|
||||
return removed
|
||||
except Exception as e:
|
||||
conn.rollback()
|
||||
logger.error(f"Error removing email {email}: {e}")
|
||||
logger.error("Error removing email %s: %s", email, e)
|
||||
return False
|
||||
|
||||
def get_subscriber_count():
|
||||
"""Get total number of subscribers"""
|
||||
def get_subscriber_count() -> int:
|
||||
with get_db_connection() as conn:
|
||||
try:
|
||||
with conn.cursor() as cursor:
|
||||
cursor.execute("SELECT COUNT(*) FROM subscribers")
|
||||
count = cursor.fetchone()[0]
|
||||
return count
|
||||
|
||||
with conn.cursor() as cur:
|
||||
cur.execute("SELECT COUNT(*) FROM subscribers")
|
||||
(count,) = cur.fetchone()
|
||||
return int(count)
|
||||
except Exception as e:
|
||||
logger.error(f"Error getting subscriber count: {e}")
|
||||
return 0
|
||||
|
||||
# Cleanup function for graceful shutdown
|
||||
import atexit
|
||||
def fetch_all_newsletters(limit: int = 100):
|
||||
"""
|
||||
Return a list of newsletters ordered by sent_at desc.
|
||||
Each item: dict(id, subject, body, sent_at)
|
||||
"""
|
||||
with get_db_connection() as conn:
|
||||
with conn.cursor() as cur:
|
||||
cur.execute(
|
||||
"""
|
||||
SELECT id, subject, body, sent_at
|
||||
FROM newsletters
|
||||
ORDER BY sent_at DESC
|
||||
LIMIT %s
|
||||
""",
|
||||
(limit,),
|
||||
)
|
||||
rows = cur.fetchall()
|
||||
return [
|
||||
{"id": r[0], "subject": r[1], "body": r[2], "sent_at": r[3]}
|
||||
for r in rows
|
||||
]
|
||||
|
||||
def fetch_newsletter_by_id(newsletter_id: int):
|
||||
with get_db_connection() as conn:
|
||||
with conn.cursor() as cur:
|
||||
cur.execute(
|
||||
"""
|
||||
SELECT id, subject, body, sent_at
|
||||
FROM newsletters
|
||||
WHERE id = %s
|
||||
""",
|
||||
(newsletter_id,),
|
||||
)
|
||||
row = cur.fetchone()
|
||||
if not row:
|
||||
return None
|
||||
return {"id": row[0], "subject": row[1], "body": row[2], "sent_at": row[3]}
|
||||
|
||||
atexit.register(close_all_connections)
|
||||
Loading…
Add table
Add a link
Reference in a new issue