litellm/litellm-proxy-extras/litellm_proxy_extras/migration_lock.py

89 lines
3.8 KiB
Python

import random
import time
from collections.abc import Generator, Mapping
from contextlib import contextmanager
from dataclasses import dataclass
from typing import TYPE_CHECKING, Final
from urllib.parse import parse_qsl, urlencode, urlsplit, urlunsplit
from litellm_proxy_extras._logging import logger
from litellm_proxy_extras.prisma_toolchain import MIGRATION_LOCK_TIMEOUT_ENV_VAR, migration_lock_timeout
MIGRATION_LOCK_KEY: Final = int.from_bytes(b"llm_mig2", "big")
if TYPE_CHECKING:
import psycopg
def migration_environment(environment: Mapping[str, str]) -> Mapping[str, str]:
database_url: Final = environment.get("DATABASE_URL")
direct_url: Final = environment.get("DIRECT_URL")
if not database_url or not direct_url:
return environment
schema: Final = next((value for key, value in parse_qsl(urlsplit(database_url).query) if key == "schema"), "public")
direct: Final = urlsplit(direct_url)
parameters: Final = tuple((key, value) for key, value in parse_qsl(direct.query) if key != "schema")
return {
**environment,
"DATABASE_URL": urlunsplit(direct._replace(query=urlencode((*parameters, ("schema", schema))))),
}
@dataclass(frozen=True, slots=True)
class _LockResult:
acquired: bool
def _try_lock(connection: "psycopg.Connection[tuple[object, ...]]", key: int = MIGRATION_LOCK_KEY) -> bool:
from psycopg.rows import class_row
with connection.cursor(row_factory=class_row(_LockResult)) as cursor:
row: Final = cursor.execute("SELECT pg_try_advisory_xact_lock(%s) AS acquired", (key,)).fetchone()
return row is not None and row.acquired
@dataclass(frozen=True, slots=True)
class MigrationCoordinator:
connection: "psycopg.Connection[tuple[object, ...]]"
def check_connection(self) -> None:
self.connection.execute("SELECT 1")
def acquire_prisma_lock(self) -> None:
deadline: Final = time.monotonic() + migration_lock_timeout()
while time.monotonic() < deadline:
if _try_lock(self.connection, 72707369):
return
time.sleep(min(random.uniform(0.5, 1.5), max(0.0, deadline - time.monotonic())))
raise RuntimeError(
"Timed out waiting for Prisma's lock to recover migration history. LiteLLM startup has stopped. "
"Another migration or a pooled database session may still hold the lock. Check the database lock holder. "
"When using a transaction pooler, configure DIRECT_URL to reach the same database without the pooler."
)
@contextmanager
def migration_lock(database_url: str) -> Generator[MigrationCoordinator, None, None]:
import psycopg
wait_seconds: Final = migration_lock_timeout()
deadline: Final = time.monotonic() + wait_seconds
try:
with psycopg.connect(database_url, connect_timeout=10, autocommit=True) as connection:
coordinator: Final = MigrationCoordinator(connection)
logger.info("Waiting for the v2 migration coordinator lock (up to %ss)", wait_seconds)
while time.monotonic() < deadline:
with connection.transaction():
if _try_lock(connection):
logger.info("Acquired the v2 migration coordinator lock")
yield coordinator
coordinator.check_connection()
return
time.sleep(min(random.uniform(0.5, 1.5), max(0.0, deadline - time.monotonic())))
except psycopg.Error as exc:
raise RuntimeError(f"Lost or could not establish v2 migration coordination with the database: {exc}") from exc
raise RuntimeError(
f"Timed out waiting for another v2 migration resolver after {wait_seconds}s. "
f"Check the running migration or increase {MIGRATION_LOCK_TIMEOUT_ENV_VAR}."
)