Source code for bigchaindb.backend.rethinkdb.admin
"""Database configuration functions."""
import logging
import rethinkdb as r
from bigchaindb.backend import admin
from bigchaindb.backend.schema import TABLES
from bigchaindb.backend.exceptions import OperationError
from bigchaindb.backend.utils import module_dispatch_registrar
from bigchaindb.backend.rethinkdb.connection import RethinkDBConnection
logger = logging.getLogger(__name__)
register_admin = module_dispatch_registrar(admin)
@register_admin(RethinkDBConnection)
[docs]def get_config(connection, *, table):
"""Get the configuration of the given table.
Args:
connection (:class:`~bigchaindb.backend.connection.Connection`):
A connection to the database.
table (str): The name of the table to get the configuration for.
Returns:
dict: The configuration of the given table
"""
return connection.run(r.table(table).config())
@register_admin(RethinkDBConnection)
[docs]def reconfigure(connection, *, table, shards, replicas,
primary_replica_tag=None, dry_run=False,
nonvoting_replica_tags=None):
"""Reconfigures the given table.
Args:
connection (:class:`~bigchaindb.backend.connection.Connection`):
A connection to the database.
table (str): The name of the table to reconfigure.
shards (int): The number of shards, an integer from 1-64.
replicas (:obj:`int` | :obj:`dict`):
* If replicas is an integer, it specifies the number of
replicas per shard. Specifying more replicas than there
are servers will return an error.
* If replicas is a dictionary, it specifies key-value pairs
of server tags and the number of replicas to assign to
those servers::
{'africa': 2, 'asia': 4, 'europe': 2, ...}
primary_replica_tag (str): The primary server specified by its
server tag. Required if ``replicas`` is a dictionary. The
tag must be in the ``replicas`` dictionary. This must not be
specified if ``replicas`` is an integer. Defaults to
``None``.
dry_run (bool): If ``True`` the generated configuration will not
be applied to the table, only returned. Defaults to
``False``.
nonvoting_replica_tags (:obj:`list` of :obj:`str`): Replicas
with these server tags will be added to the
``nonvoting_replicas`` list of the resulting configuration.
Defaults to ``None``.
Returns:
dict: A dictionary with possibly three keys:
* ``reconfigured``: the number of tables reconfigured. This
will be ``0`` if ``dry_run`` is ``True``.
* ``config_changes``: a list of new and old table
configuration values.
* ``status_changes``: a list of new and old table status
values.
For more information please consult RethinkDB's
documentation `ReQL command: reconfigure
<https://rethinkdb.com/api/python/reconfigure/>`_.
Raises:
OperationError: If the reconfiguration fails due to a
RethinkDB :exc:`ReqlOpFailedError` or
:exc:`ReqlQueryLogicError`.
"""
params = {
'shards': shards,
'replicas': replicas,
'dry_run': dry_run,
}
if primary_replica_tag:
params.update(
primary_replica_tag=primary_replica_tag,
nonvoting_replica_tags=nonvoting_replica_tags,
)
try:
return connection.run(r.table(table).reconfigure(**params))
except (r.ReqlOpFailedError, r.ReqlQueryLogicError) as e:
raise OperationError('Failed to reconfigure tables.') from e
@register_admin(RethinkDBConnection)
[docs]def set_shards(connection, *, shards, dry_run=False):
"""Sets the shards for the tables
:const:`~bigchaindb.backend.schema.TABLES`.
Args:
connection (:class:`~bigchaindb.backend.connection.Connection`):
A connection to the database.
shards (int): The number of shards, an integer from 1-64.
dry_run (bool): If ``True`` the generated configuration will not
be applied to the table, only returned. Defaults to
``False``.
Returns:
dict: A dictionary with the configuration and status changes.
For more details please see :func:`.reconfigure`.
"""
changes = {}
for table in TABLES:
replicas = len(
get_config(connection, table=table)['shards'][0]['replicas'])
change = reconfigure(
connection,
table=table,
shards=shards,
replicas=replicas,
dry_run=dry_run,
)
changes[table] = change
return changes
@register_admin(RethinkDBConnection)
[docs]def set_replicas(connection, *, replicas, dry_run=False):
"""Sets the replicas for the tables
:const:`~bigchaindb.backend.schema.TABLES`.
Args:
connection (:class:`~bigchaindb.backend.connection.Connection`):
A connection to the database.
replicas (int): The number of replicas per shard. Specifying
more replicas than there are servers will return an error.
dry_run (bool): If ``True`` the generated configuration will not
be applied to the table, only returned. Defaults to
``False``.
Returns:
dict: A dictionary with the configuration and status changes.
For more details please see :func:`.reconfigure`.
"""
changes = {}
for table in TABLES:
shards = len(get_config(connection, table=table)['shards'])
change = reconfigure(
connection,
table=table,
shards=shards,
replicas=replicas,
dry_run=dry_run,
)
changes[table] = change
return changes