apdbCassandraSchema.py

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# This file is part of dax_apdb.
#
# Developed for the LSST Data Management System.
# This product includes software developed by the LSST Project
# (http://www.lsst.org).
# See the COPYRIGHT file at the top-level directory of this distribution
# for details of code ownership.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
from __future__ import annotations
 
__all__ = ["ApdbCassandraSchema"]
 
import enum
import logging
from collections.abc import Mapping
from typing import TYPE_CHECKING
 
import felis.datamodel
 
from .. import schema_model
from ..apdbSchema import ApdbSchema, ApdbTables
 
if TYPE_CHECKING:
    import cassandra.cluster
 
 
_LOG = logging.getLogger(__name__)
 
 
class InconsistentSchemaError(RuntimeError):
    """Exception raised when schema state is inconsistent."""
 
 
@enum.unique
class ExtraTables(enum.Enum):
    """Names of the extra tables used by Cassandra implementation."""
 
    ApdbReplicaChunks = "ApdbReplicaChunks"
    """Name of the table for replica chunk records."""
 
    DiaObjectChunks = "DiaObjectChunks"
    """Name of the table for DIAObject chunk data."""
 
    DiaSourceChunks = "DiaSourceChunks"
    """Name of the table for DIASource chunk data."""
 
    DiaForcedSourceChunks = "DiaForcedSourceChunks"
    """Name of the table for DIAForcedSource chunk data."""
 
    DiaSourceToPartition = "DiaSourceToPartition"
    "Maps diaSourceId to its partition values (pixel and time)."
 
    def table_name(self, prefix: str = "") -> str:
        """Return full table name."""
        return prefix + self.value
 
    @classmethod
    def replica_chunk_tables(cls) -> Mapping[ExtraTables, ApdbTables]:
        """Return mapping of tables used for replica chunks storage to their
        corresponding regular tables.
        """
        return {
            cls.DiaObjectChunks: ApdbTables.DiaObject,
            cls.DiaSourceChunks: ApdbTables.DiaSource,
            cls.DiaForcedSourceChunks: ApdbTables.DiaForcedSource,
        }
 
 
class ApdbCassandraSchema(ApdbSchema):
    """Class for management of APDB schema.
 
    Parameters
    ----------
    session : `cassandra.cluster.Session`
        Cassandra session object
    keyspace : `str`
        Keyspace name for all tables.
    schema_file : `str`
        Name of the YAML schema file.
    schema_name : `str`, optional
        Name of the schema in YAML files.
    prefix : `str`, optional
        Prefix to add to all schema elements.
    time_partition_tables : `bool`
        If `True` then schema will have a separate table for each time
        partition.
    enable_replica : `bool`, optional
        If `True` then use additional tables for replica chunks.
    """
 
    _type_map = {
        felis.datamodel.DataType.double: "DOUBLE",
        felis.datamodel.DataType.float: "FLOAT",
        felis.datamodel.DataType.timestamp: "TIMESTAMP",
        felis.datamodel.DataType.long: "BIGINT",
        felis.datamodel.DataType.int: "INT",
        felis.datamodel.DataType.short: "INT",
        felis.datamodel.DataType.byte: "TINYINT",
        felis.datamodel.DataType.binary: "BLOB",
        felis.datamodel.DataType.char: "TEXT",
        felis.datamodel.DataType.string: "TEXT",
        felis.datamodel.DataType.unicode: "TEXT",
        felis.datamodel.DataType.text: "TEXT",
        felis.datamodel.DataType.boolean: "BOOLEAN",
        schema_model.ExtraDataTypes.UUID: "UUID",
    }
    """Map YAML column types to Cassandra"""
 
    _time_partitioned_tables = [
        ApdbTables.DiaObject,
        ApdbTables.DiaSource,
        ApdbTables.DiaForcedSource,
    ]
    _spatially_partitioned_tables = [ApdbTables.DiaObjectLast]
 
    def __init__(
        self,
        session: cassandra.cluster.Session,
        keyspace: str,
        schema_file: str,
        schema_name: str = "ApdbSchema",
        prefix: str = "",
        time_partition_tables: bool = False,
        enable_replica: bool = False,
    ):
        super().__init__(schema_file, schema_name)
 
        self._session = session
        self._keyspace = keyspace
        self._prefix = prefix
        self._time_partition_tables = time_partition_tables
        self._enable_replica = enable_replica
        self._has_replica_chunks: bool | None = None
 
        self._apdb_tables = self._apdb_tables_schema(time_partition_tables)
        self._extra_tables = self._extra_tables_schema()
 
    def _apdb_tables_schema(self, time_partition_tables: bool) -> Mapping[ApdbTables, schema_model.Table]:
        """Generate schema for regular APDB tables."""
        apdb_tables: dict[ApdbTables, schema_model.Table] = {}
 
        # add columns and index for partitioning.
        for table, apdb_table_def in self.tableSchemas.items():
            part_columns = []
            add_columns = []
            primary_key = apdb_table_def.primary_key[:]
            if table in self._spatially_partitioned_tables:
                # DiaObjectLast does not need temporal partitioning
                part_columns = ["apdb_part"]
                add_columns = part_columns
            elif table in self._time_partitioned_tables:
                if time_partition_tables:
                    part_columns = ["apdb_part"]
                else:
                    part_columns = ["apdb_part", "apdb_time_part"]
                add_columns = part_columns
            elif table is ApdbTables.SSObject:
                # For SSObject there is no natural partition key but we have
                # to partition it because there are too many of them. I'm
                # going to partition on its primary key (and drop separate
                # primary key index).
                part_columns = ["ssObjectId"]
                primary_key = []
            elif table is ApdbTables.metadata:
                # Metadata is in one partition because we want to read all of
                # it in one query, add an extra column for partition.
                part_columns = ["meta_part"]
                add_columns = part_columns
            else:
                # TODO: Do not know what to do with the other tables
                continue
 
            column_defs = []
            if add_columns:
                column_defs = [
                    schema_model.Column(
                        id=f"#{name}", name=name, datatype=felis.datamodel.DataType.long, nullable=False
                    )
                    for name in add_columns
                ]
 
            annotations = dict(apdb_table_def.annotations)
            annotations["cassandra:apdb_column_names"] = [column.name for column in apdb_table_def.columns]
            if part_columns:
                annotations["cassandra:partitioning_columns"] = part_columns
 
            apdb_tables[table] = schema_model.Table(
                id=apdb_table_def.id,
                name=apdb_table_def.name,
                columns=column_defs + apdb_table_def.columns,
                primary_key=primary_key,
                indexes=[],
                constraints=[],
                annotations=annotations,
            )
 
        return apdb_tables
 
    def _extra_tables_schema(self) -> Mapping[ExtraTables, schema_model.Table]:
        """Generate schema for extra tables."""
        extra_tables: dict[ExtraTables, schema_model.Table] = {}
 
        # This table maps DiaSource ID to its partitions in DiaSource table and
        # DiaSourceChunks tables.
        extra_tables[ExtraTables.DiaSourceToPartition] = schema_model.Table(
            id="#" + ExtraTables.DiaSourceToPartition.value,
            name=ExtraTables.DiaSourceToPartition.table_name(self._prefix),
            columns=[
                schema_model.Column(
                    id="#diaSourceId",
                    name="diaSourceId",
                    datatype=felis.datamodel.DataType.long,
                    nullable=False,
                ),
                schema_model.Column(
                    id="#apdb_part", name="apdb_part", datatype=felis.datamodel.DataType.long, nullable=False
                ),
                schema_model.Column(
                    id="#apdb_time_part",
                    name="apdb_time_part",
                    datatype=felis.datamodel.DataType.int,
                    nullable=False,
                ),
                schema_model.Column(
                    id="#apdb_replica_chunk",
                    name="apdb_replica_chunk",
                    datatype=felis.datamodel.DataType.long,
                    nullable=True,
                ),
            ],
            primary_key=[],
            indexes=[],
            constraints=[],
            annotations={"cassandra:partitioning_columns": ["diaSourceId"]},
        )
 
        replica_chunk_column = schema_model.Column(
            id="#apdb_replica_chunk",
            name="apdb_replica_chunk",
            datatype=felis.datamodel.DataType.long,
            nullable=False,
        )
 
        if not self._enable_replica:
            return extra_tables
 
        # Table containing insert IDs, this one is not partitioned, but
        # partition key must be defined.
        extra_tables[ExtraTables.ApdbReplicaChunks] = schema_model.Table(
            id="#" + ExtraTables.ApdbReplicaChunks.value,
            name=ExtraTables.ApdbReplicaChunks.table_name(self._prefix),
            columns=[
                schema_model.Column(
                    id="#partition", name="partition", datatype=felis.datamodel.DataType.int, nullable=False
                ),
                replica_chunk_column,
                schema_model.Column(
                    id="#last_update_time",
                    name="last_update_time",
                    datatype=felis.datamodel.DataType.timestamp,
                    nullable=False,
                ),
                schema_model.Column(
                    id="#unique_id",
                    name="unique_id",
                    datatype=schema_model.ExtraDataTypes.UUID,
                    nullable=False,
                ),
            ],
            primary_key=[replica_chunk_column],
            indexes=[],
            constraints=[],
            annotations={"cassandra:partitioning_columns": ["partition"]},
        )
 
        for chunk_table_enum, apdb_table_enum in ExtraTables.replica_chunk_tables().items():
            apdb_table_def = self.tableSchemas[apdb_table_enum]
 
            extra_tables[chunk_table_enum] = schema_model.Table(
                id="#" + chunk_table_enum.value,
                name=chunk_table_enum.table_name(self._prefix),
                columns=[replica_chunk_column] + apdb_table_def.columns,
                primary_key=apdb_table_def.primary_key[:],
                indexes=[],
                constraints=[],
                annotations={
                    "cassandra:partitioning_columns": ["apdb_replica_chunk"],
                    "cassandra:apdb_column_names": [column.name for column in apdb_table_def.columns],
                },
            )
 
        return extra_tables
 
    @property
    def has_replica_chunks(self) -> bool:
        """Whether insert ID tables are to be used (`bool`)."""
        if self._has_replica_chunks is None:
            self._has_replica_chunks = self._enable_replica and self._check_replica_chunks()
        return self._has_replica_chunks
 
    def _check_replica_chunks(self) -> bool:
        """Check whether database has tables for tracking insert IDs."""
        table_name = ExtraTables.ApdbReplicaChunks.table_name(self._prefix)
        query = "SELECT count(*) FROM system_schema.tables WHERE keyspace_name = %s and table_name = %s"
        result = self._session.execute(query, (self._keyspace, table_name))
        row = result.one()
        return bool(row[0])
 
    def empty(self) -> bool:
        """Return True if database schema is empty.
 
        Returns
        -------
        empty : `bool`
            `True` if none of the required APDB tables exist in the database,
            `False` if all required tables exist.
 
        Raises
        ------
        InconsistentSchemaError
            Raised when some of the required tables exist but not all.
        """
        query = "SELECT table_name FROM system_schema.tables WHERE keyspace_name = %s"
        result = self._session.execute(query, (self._keyspace,))
        table_names = set(row[0] for row in result.all())
 
        existing_tables = []
        missing_tables = []
        for table_enum in self._apdb_tables:
            table_name = table_enum.table_name(self._prefix)
            if self._time_partition_tables and table_enum in self._time_partitioned_tables:
                # Check prefix for time-partitioned tables.
                exists = any(table.startswith(f"{table_name}_") for table in table_names)
            else:
                exists = table_name in table_names
            if exists:
                existing_tables.append(table_name)
            else:
                missing_tables.append(table_name)
 
        if not missing_tables:
            return False
        elif not existing_tables:
            return True
        else:
            raise InconsistentSchemaError(
                f"Only some required APDB tables exist: {existing_tables}, missing tables: {missing_tables}"
            )
 
    def tableName(self, table_name: ApdbTables | ExtraTables) -> str:
        """Return Cassandra table name for APDB table."""
        return table_name.table_name(self._prefix)
 
    def keyspace(self) -> str:
        """Return Cassandra keyspace for APDB tables."""
        return self._keyspace
 
    def getColumnMap(self, table_name: ApdbTables | ExtraTables) -> Mapping[str, schema_model.Column]:
        """Return mapping of column names to Column definitions.
 
        Parameters
        ----------
        table_name : `ApdbTables`
            One of known APDB table names.
 
        Returns
        -------
        column_map : `dict`
            Mapping of column names to `ColumnDef` instances.
        """
        table_schema = self._table_schema(table_name)
        cmap = {column.name: column for column in table_schema.columns}
        return cmap
 
    def apdbColumnNames(self, table_name: ApdbTables | ExtraTables) -> list[str]:
        """Return a list of columns names for a table as defined in APDB
        schema.
 
        Parameters
        ----------
        table_name : `ApdbTables` or `ExtraTables`
            Enum for a table in APDB schema.
 
        Returns
        -------
        columns : `list` of `str`
            Names of regular columns in the table.
        """
        table_schema = self._table_schema(table_name)
        return table_schema.annotations["cassandra:apdb_column_names"]
 
    def partitionColumns(self, table_name: ApdbTables | ExtraTables) -> list[str]:
        """Return a list of columns used for table partitioning.
 
        Parameters
        ----------
        table_name : `ApdbTables`
            Table name in APDB schema
 
        Returns
        -------
        columns : `list` of `str`
            Names of columns used for partitioning.
        """
        table_schema = self._table_schema(table_name)
        return table_schema.annotations.get("cassandra:partitioning_columns", [])
 
    def clusteringColumns(self, table_name: ApdbTables | ExtraTables) -> list[str]:
        """Return a list of columns used for clustering.
 
        Parameters
        ----------
        table_name : `ApdbTables`
            Table name in APDB schema
 
        Returns
        -------
        columns : `list` of `str`
            Names of columns for used for clustering.
        """
        table_schema = self._table_schema(table_name)
        return [column.name for column in table_schema.primary_key]
 
    def makeSchema(
        self,
        *,
        drop: bool = False,
        part_range: tuple[int, int] | None = None,
        replication_factor: int | None = None,
    ) -> None:
        """Create or re-create all tables.
 
        Parameters
        ----------
        drop : `bool`
            If True then drop tables before creating new ones. Note that
            only tables are dropped and not the whole keyspace.
        part_range : `tuple` [ `int` ] or `None`
            Start and end partition number for time partitions, end is not
            inclusive. Used to create per-partition DiaObject, DiaSource, and
            DiaForcedSource tables. If `None` then per-partition tables are
            not created.
        replication_factor : `int`, optional
            Replication factor used when creating new keyspace, if keyspace
            already exists its replication factor is not changed.
        """
        # Try to create keyspace if it does not exist
        if replication_factor is None:
            replication_factor = 1
        query = (
            f'CREATE KEYSPACE IF NOT EXISTS "{self._keyspace}"'
            " WITH replication = {'class': 'SimpleStrategy', 'replication_factor': "
            f"{replication_factor}"
            "}"
        )
        self._session.execute(query)
 
        for table in self._apdb_tables:
            self._makeTableSchema(table, drop, part_range)
        for extra_table in self._extra_tables:
            self._makeTableSchema(extra_table, drop, part_range)
        # Reset cached information.
        self._has_replica_chunks = None
 
    def _makeTableSchema(
        self,
        table: ApdbTables | ExtraTables,
        drop: bool = False,
        part_range: tuple[int, int] | None = None,
    ) -> None:
        _LOG.debug("Making table %s", table)
 
        fullTable = table.table_name(self._prefix)
 
        table_list = [fullTable]
        if part_range is not None:
            if table in self._time_partitioned_tables:
                partitions = range(*part_range)
                table_list = [f"{fullTable}_{part}" for part in partitions]
 
        if drop:
            queries = [f'DROP TABLE IF EXISTS "{self._keyspace}"."{table_name}"' for table_name in table_list]
            futures = [self._session.execute_async(query, timeout=None) for query in queries]
            for future in futures:
                _LOG.debug("wait for query: %s", future.query)
                future.result()
                _LOG.debug("query finished: %s", future.query)
 
        queries = []
        for table_name in table_list:
            if_not_exists = "" if drop else "IF NOT EXISTS"
            columns = ", ".join(self._tableColumns(table))
            query = f'CREATE TABLE {if_not_exists} "{self._keyspace}"."{table_name}" ({columns})'
            _LOG.debug("query: %s", query)
            queries.append(query)
        futures = [self._session.execute_async(query, timeout=None) for query in queries]
        for future in futures:
            _LOG.debug("wait for query: %s", future.query)
            future.result()
            _LOG.debug("query finished: %s", future.query)
 
    def _tableColumns(self, table_name: ApdbTables | ExtraTables) -> list[str]:
        """Return set of columns in a table
 
        Parameters
        ----------
        table_name : `ApdbTables`
            Name of the table.
 
        Returns
        -------
        column_defs : `list`
            List of strings in the format "column_name type".
        """
        table_schema = self._table_schema(table_name)
 
        # must have partition columns and clustering columns
        part_columns = table_schema.annotations.get("cassandra:partitioning_columns", [])
        clust_columns = [column.name for column in table_schema.primary_key]
        _LOG.debug("part_columns: %s", part_columns)
        _LOG.debug("clust_columns: %s", clust_columns)
        if not part_columns:
            raise ValueError(f"Table {table_name} configuration is missing partition index")
 
        # all columns
        column_defs = []
        for column in table_schema.columns:
            ctype = self._type_map[column.datatype]
            column_defs.append(f'"{column.name}" {ctype}')
 
        # primary key definition
        part_columns = [f'"{col}"' for col in part_columns]
        clust_columns = [f'"{col}"' for col in clust_columns]
        if len(part_columns) > 1:
            columns = ", ".join(part_columns)
            part_columns = [f"({columns})"]
        pkey = ", ".join(part_columns + clust_columns)
        _LOG.debug("pkey: %s", pkey)
        column_defs.append(f"PRIMARY KEY ({pkey})")
 
        return column_defs
 
    def _table_schema(self, table: ApdbTables | ExtraTables) -> schema_model.Table:
        """Return schema definition for a table."""
        if isinstance(table, ApdbTables):
            table_schema = self._apdb_tables[table]
        else:
            table_schema = self._extra_tables[table]
        return table_schema