import zlib
from typing import ContextManager, Mapping, Optional
import dagster._check as check
import sqlalchemy as db
import sqlalchemy.dialects as db_dialects
import sqlalchemy.pool as db_pool
from dagster._config.config_schema import UserConfigSchema
from dagster._core.storage.config import PostgresStorageConfig, pg_config
from dagster._core.storage.runs import (
DaemonHeartbeatsTable,
InstanceInfo,
RunStorageSqlMetadata,
SqlRunStorage,
)
from dagster._core.storage.runs.schema import KeyValueStoreTable, SnapshotsTable
from dagster._core.storage.runs.sql_run_storage import SnapshotType
from dagster._core.storage.sql import (
AlembicVersion,
check_alembic_revision,
create_engine,
run_alembic_upgrade,
stamp_alembic_rev,
)
from dagster._daemon.types import DaemonHeartbeat
from dagster._serdes import ConfigurableClass, ConfigurableClassData, serialize_value
from dagster._utils import utc_datetime_from_timestamp
from sqlalchemy.engine import Connection
from ..utils import (
create_pg_connection,
pg_alembic_config,
pg_statement_timeout,
pg_url_from_config,
retry_pg_connection_fn,
retry_pg_creation_fn,
)
[docs]class PostgresRunStorage(SqlRunStorage, ConfigurableClass):
"""Postgres-backed run storage.
Users should not directly instantiate this class; it is instantiated by internal machinery when
``dagster-webserver`` and ``dagster-graphql`` load, based on the values in the ``dagster.yaml`` file in
``$DAGSTER_HOME``. Configuration of this class should be done by setting values in that file.
To use Postgres for all of the components of your instance storage, you can add the following
block to your ``dagster.yaml``:
.. literalinclude:: ../../../../../../examples/docs_snippets/docs_snippets/deploying/dagster-pg.yaml
:caption: dagster.yaml
:lines: 1-8
:language: YAML
If you are configuring the different storage components separately and are specifically
configuring your run storage to use Postgres, you can add a block such as the following
to your ``dagster.yaml``:
.. literalinclude:: ../../../../../../examples/docs_snippets/docs_snippets/deploying/dagster-pg-legacy.yaml
:caption: dagster.yaml
:lines: 1-10
:language: YAML
Note that the fields in this config are :py:class:`~dagster.StringSource` and
:py:class:`~dagster.IntSource` and can be configured from environment variables.
"""
def __init__(
self,
postgres_url: str,
should_autocreate_tables: bool = True,
inst_data: Optional[ConfigurableClassData] = None,
):
self._inst_data = check.opt_inst_param(inst_data, "inst_data", ConfigurableClassData)
self.postgres_url = postgres_url
self.should_autocreate_tables = check.bool_param(
should_autocreate_tables, "should_autocreate_tables"
)
# Default to not holding any connections open to prevent accumulating connections per DagsterInstance
self._engine = create_engine(
self.postgres_url,
isolation_level="AUTOCOMMIT",
poolclass=db_pool.NullPool,
)
self._index_migration_cache = {}
# Stamp and create tables if the main table does not exist (we can't check alembic
# revision because alembic config may be shared with other storage classes)
if self.should_autocreate_tables:
table_names = retry_pg_connection_fn(lambda: db.inspect(self._engine).get_table_names())
if "runs" not in table_names:
retry_pg_creation_fn(self._init_db)
self.migrate()
self.optimize()
elif "instance_info" not in table_names:
InstanceInfo.create(self._engine)
super().__init__()
def _init_db(self) -> None:
with self.connect() as conn:
with conn.begin():
RunStorageSqlMetadata.create_all(conn)
# This revision may be shared by any other dagster storage classes using the same DB
stamp_alembic_rev(pg_alembic_config(__file__), conn)
def optimize_for_webserver(self, statement_timeout: int, pool_recycle: int) -> None:
# When running in dagster-webserver, hold 1 open connection and set statement_timeout
existing_options = self._engine.url.query.get("options")
timeout_option = pg_statement_timeout(statement_timeout)
if existing_options:
options = f"{timeout_option} {existing_options}"
else:
options = timeout_option
self._engine = create_engine(
self.postgres_url,
isolation_level="AUTOCOMMIT",
pool_size=1,
connect_args={"options": options},
pool_recycle=pool_recycle,
)
@property
def inst_data(self) -> Optional[ConfigurableClassData]:
return self._inst_data
@classmethod
def config_type(cls) -> UserConfigSchema:
return pg_config()
@classmethod
def from_config_value(
cls, inst_data: Optional[ConfigurableClassData], config_value: PostgresStorageConfig
):
return PostgresRunStorage(
inst_data=inst_data,
postgres_url=pg_url_from_config(config_value),
should_autocreate_tables=config_value.get("should_autocreate_tables", True),
)
@staticmethod
def create_clean_storage(
postgres_url: str, should_autocreate_tables: bool = True
) -> "PostgresRunStorage":
engine = create_engine(
postgres_url, isolation_level="AUTOCOMMIT", poolclass=db_pool.NullPool
)
try:
RunStorageSqlMetadata.drop_all(engine)
finally:
engine.dispose()
return PostgresRunStorage(postgres_url, should_autocreate_tables)
def connect(self) -> ContextManager[Connection]:
return create_pg_connection(self._engine)
def upgrade(self) -> None:
with self.connect() as conn:
run_alembic_upgrade(pg_alembic_config(__file__), conn)
def has_built_index(self, migration_name: str) -> bool:
if migration_name not in self._index_migration_cache:
self._index_migration_cache[migration_name] = super(
PostgresRunStorage, self
).has_built_index(migration_name)
return self._index_migration_cache[migration_name]
def mark_index_built(self, migration_name: str) -> None:
super(PostgresRunStorage, self).mark_index_built(migration_name)
if migration_name in self._index_migration_cache:
del self._index_migration_cache[migration_name]
def add_daemon_heartbeat(self, daemon_heartbeat: DaemonHeartbeat) -> None:
with self.connect() as conn:
# insert or update if already present, using postgres specific on_conflict
conn.execute(
db_dialects.postgresql.insert(DaemonHeartbeatsTable)
.values(
timestamp=utc_datetime_from_timestamp(daemon_heartbeat.timestamp),
daemon_type=daemon_heartbeat.daemon_type,
daemon_id=daemon_heartbeat.daemon_id,
body=serialize_value(daemon_heartbeat),
)
.on_conflict_do_update(
index_elements=[DaemonHeartbeatsTable.c.daemon_type],
set_={
"timestamp": utc_datetime_from_timestamp(daemon_heartbeat.timestamp),
"daemon_id": daemon_heartbeat.daemon_id,
"body": serialize_value(daemon_heartbeat),
},
)
.returning(
# required because sqlalchemy might by default return the declared primary key,
# which might not exist
DaemonHeartbeatsTable.c.daemon_type,
)
)
def set_cursor_values(self, pairs: Mapping[str, str]) -> None:
check.mapping_param(pairs, "pairs", key_type=str, value_type=str)
# pg specific on_conflict_do_update
insert_stmt = db_dialects.postgresql.insert(KeyValueStoreTable).values(
[{"key": k, "value": v} for k, v in pairs.items()]
)
upsert_stmt = insert_stmt.on_conflict_do_update(
index_elements=[
KeyValueStoreTable.c.key,
],
set_={"value": insert_stmt.excluded.value},
).returning(
# required because sqlalchemy might by default return the declared primary key,
# which might not exist
KeyValueStoreTable.c.key
)
with self.connect() as conn:
conn.execute(upsert_stmt)
def _add_snapshot(self, snapshot_id: str, snapshot_obj, snapshot_type: SnapshotType) -> str:
with self.connect() as conn:
snapshot_insert = (
db_dialects.postgresql.insert(SnapshotsTable)
.values(
snapshot_id=snapshot_id,
snapshot_body=zlib.compress(serialize_value(snapshot_obj).encode("utf-8")),
snapshot_type=snapshot_type.value,
)
.on_conflict_do_nothing()
)
conn.execute(snapshot_insert)
return snapshot_id
def alembic_version(self) -> AlembicVersion:
alembic_config = pg_alembic_config(__file__)
with self.connect() as conn:
return check_alembic_revision(alembic_config, conn)