File size: 12,381 Bytes
2ed8996 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 | """
Fallback database configuration for AegisLM SaaS Backend.
SQLite fallback database implementation with automatic failover
when PostgreSQL is unavailable.
"""
import asyncio
import logging
from typing import AsyncGenerator, Optional, Tuple, Any
from pathlib import Path
from sqlalchemy import create_engine, text, event
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker
from sqlalchemy.exc import SQLAlchemyError, IllegalStateChangeError
from sqlalchemy.pool import StaticPool
import time
from fastapi import HTTPException, status
from core.config import settings
logger = logging.getLogger(__name__)
# Global variables for database engines with proper type hinting
primary_engine: Optional[Any] = None # sqlalchemy.ext.asyncio.AsyncEngine
fallback_engine: Optional[Any] = None
AsyncSessionLocal: Optional[async_sessionmaker] = None
FallbackSessionLocal: Optional[async_sessionmaker] = None
current_db_type: str = "primary" # "primary" or "fallback"
async def init_database_engines():
"""Initialize both primary and fallback database engines."""
global primary_engine, fallback_engine, AsyncSessionLocal, FallbackSessionLocal
# Initialize Primary PostgreSQL Engine
try:
primary_engine = create_async_engine(
settings.DATABASE_URL,
pool_pre_ping=True,
pool_recycle=3600,
pool_size=settings.DATABASE_POOL_SIZE,
max_overflow=settings.DATABASE_MAX_OVERFLOW,
echo=settings.DEBUG
)
AsyncSessionLocal = async_sessionmaker(
primary_engine,
class_=AsyncSession,
expire_on_commit=False
)
logger.info("Primary PostgreSQL engine initialized")
except Exception as e:
logger.error(f"Failed to initialize primary PostgreSQL engine: {e}")
primary_engine = None
AsyncSessionLocal = None
# Initialize Fallback SQLite Engine
if settings.ENABLE_SQLITE_FALLBACK:
try:
# Ensure the database directory exists
db_path = Path(settings.SQLITE_DATABASE_PATH)
db_path.parent.mkdir(parents=True, exist_ok=True)
sqlite_url = f"sqlite+aiosqlite:///{settings.SQLITE_DATABASE_PATH}"
fallback_engine = create_async_engine(
sqlite_url,
poolclass=StaticPool,
connect_args={
"check_same_thread": False,
"timeout": settings.SQLITE_FALLBACK_TIMEOUT
},
echo=settings.DEBUG
)
FallbackSessionLocal = async_sessionmaker(
fallback_engine,
class_=AsyncSession,
expire_on_commit=False
)
# Enable SQLite foreign keys
@event.listens_for(fallback_engine.sync_engine, "connect")
def set_sqlite_pragma(dbapi_connection, connection_record):
cursor = dbapi_connection.cursor()
cursor.execute("PRAGMA foreign_keys=ON")
cursor.close()
logger.info("Fallback SQLite engine initialized")
except Exception as e:
logger.error(f"Failed to initialize fallback SQLite engine: {e}")
fallback_engine = None
FallbackSessionLocal = None
async def get_active_session() -> Tuple[AsyncSession, str]:
"""
Get an active database session with automatic fallback.
Returns:
Tuple[AsyncSession, str]: Database session and database type ("primary" or "fallback")
"""
global current_db_type
# Try primary database first
if current_db_type == "primary" and primary_engine and AsyncSessionLocal:
try:
session = AsyncSessionLocal()
# Test connection
await session.execute(text("SELECT 1"))
return session, "primary"
except Exception as e:
logger.warning(f"Primary database connection failed: {e}")
await session.close()
current_db_type = "fallback"
# Fallback to SQLite
if settings.ENABLE_SQLITE_FALLBACK and fallback_engine and FallbackSessionLocal:
session = None
try:
session = FallbackSessionLocal()
# Test connection
await session.execute(text("SELECT 1"))
logger.info("Using SQLite fallback database")
return session, "fallback"
except Exception as e:
logger.error(f"Fallback database connection failed: {e}")
if session:
await session.close()
raise Exception("Both primary and fallback databases are unavailable")
# Try to reconnect to primary if fallback is disabled
if AsyncSessionLocal:
session = None
try:
session = AsyncSessionLocal()
await session.execute(text("SELECT 1"))
current_db_type = "primary"
return session, "primary"
except Exception as e:
logger.error(f"Primary database reconnection failed: {e}")
if session:
await session.close()
raise Exception("No database connection available")
async def get_db() -> AsyncGenerator[AsyncSession, None]:
"""
Dependency to get async database session with automatic fallback.
Yields:
AsyncSession: Database session
"""
session = None
try:
session, db_type = await get_active_session()
logger.debug(f"Using {db_type} database session")
yield session
except Exception as e:
if session:
try:
# Only attempt rollback if the session is still active
if session.is_active:
await session.rollback()
except Exception as rollback_err:
logger.debug(f"Could not rollback session: {rollback_err}")
logger.error(f"Database session error: {e}")
raise
finally:
if session:
try:
await session.close()
except Exception as close_err:
logger.debug(f"Error closing session: {close_err}")
async def get_primary_db() -> AsyncGenerator[AsyncSession, None]:
"""
Dependency to get primary PostgreSQL session only (no fallback).
Yields:
AsyncSession: Primary database session
"""
if not AsyncSessionLocal:
logger.error("Primary database engine not initialized")
raise HTTPException(
status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
detail="Primary database connection unavailable"
)
async with AsyncSessionLocal() as session:
try:
yield session
except Exception as e:
try:
await session.rollback()
except IllegalStateChangeError:
pass
logger.error(f"Primary database session error: {e}")
raise
# No need for session.close() here; context manager handles it safely on block exit
async def get_fallback_db() -> AsyncGenerator[AsyncSession, None]:
"""
Dependency to get SQLite fallback session only.
Yields:
AsyncSession: Fallback database session
"""
if not settings.ENABLE_SQLITE_FALLBACK or not fallback_engine or not FallbackSessionLocal:
raise Exception("Fallback database not available")
# Extra check for analyzer
if FallbackSessionLocal is None:
raise Exception("Fallback database session maker not initialized")
async with FallbackSessionLocal() as session:
try:
yield session
except Exception as e:
try:
await session.rollback()
except IllegalStateChangeError:
pass
logger.error(f"Fallback database session error: {e}")
raise
# Context manager handles closing automatically
async def init_databases():
"""Initialize both primary and fallback databases."""
await init_database_engines()
# Import Base here to avoid circular import
from core.database import Base
# Initialize primary database
if primary_engine:
try:
# Removed await conn.run_sync(Base.metadata.create_all) which deadlocks asyncpg on Neon
logger.info("Primary database connected successfully")
except Exception as e:
logger.error(f"Failed to connect to primary database: {e}")
# Initialize fallback database
if settings.ENABLE_SQLITE_FALLBACK and fallback_engine:
try:
async with fallback_engine.begin() as conn:
await conn.run_sync(Base.metadata.create_all)
logger.info("Fallback database tables initialized")
except Exception as e:
logger.error(f"Failed to initialize fallback database tables: {e}")
async def close_databases():
"""Close all database connections."""
global primary_engine, fallback_engine, AsyncSessionLocal, FallbackSessionLocal
if primary_engine:
await primary_engine.dispose()
primary_engine = None
logger.info("Primary database connection closed")
if fallback_engine:
await fallback_engine.dispose()
fallback_engine = None
logger.info("Fallback database connection closed")
AsyncSessionLocal = None
FallbackSessionLocal = None
async def check_primary_health() -> bool:
"""
Check primary database health.
Returns:
bool: True if primary database is healthy
"""
if not primary_engine or not AsyncSessionLocal:
return False
try:
# Extra check for analyzer
if AsyncSessionLocal is None:
return False
async with AsyncSessionLocal() as session:
await session.execute(text("SELECT 1"))
return True
except Exception:
return False
async def check_fallback_health() -> bool:
"""
Check fallback database health.
Returns:
bool: True if fallback database is healthy
"""
if not settings.ENABLE_SQLITE_FALLBACK or not fallback_engine or not FallbackSessionLocal:
return False
try:
# Extra check for analyzer
if FallbackSessionLocal is None:
return False
async with FallbackSessionLocal() as session:
await session.execute(text("SELECT 1"))
return True
except Exception:
return False
async def check_database_health() -> Tuple[bool, str]:
"""
Check overall database health and current active database.
Returns:
Tuple[bool, str]: Health status and active database type
"""
global current_db_type
primary_healthy = await check_primary_health()
fallback_healthy = await check_fallback_health()
if current_db_type == "primary" and primary_healthy:
return True, "primary"
elif current_db_type == "fallback" and fallback_healthy:
return True, "fallback"
elif primary_healthy:
current_db_type = "primary"
return True, "primary"
elif fallback_healthy:
current_db_type = "fallback"
return True, "fallback"
else:
return False, "none"
async def switch_to_primary():
"""Force switch back to primary database if available."""
global current_db_type
if await check_primary_health():
current_db_type = "primary"
logger.info("Switched back to primary database")
return True
return False
async def switch_to_fallback():
"""Force switch to fallback database."""
global current_db_type
if settings.ENABLE_SQLITE_FALLBACK and await check_fallback_health():
current_db_type = "fallback"
logger.info("Switched to fallback database")
return True
return False
def get_current_database_type() -> str:
"""
Get the current active database type.
Returns:
str: "primary", "fallback", or "none"
"""
return current_db_type
# Import Base at the end to avoid circular import
Base = None
|