def _check_shard_information(shard_id, destn_group_id, mysqldump_binary,
mysqlclient_binary, split_value, config_file, prune_limit, cmd,
update_only):
"""Verify the sharding information before starting a re-sharding operation.
:param shard_id: The destination shard ID.
:param destn_group_id: The Destination group ID.
:param mysqldump_binary: The path to the mysqldump binary.
:param mysqlclient_binary: The path to the mysqlclient binary.
:param split_value: The point at which the sharding definition
should be split.
:param config_file: The complete path to the fabric configuration
file.
:param prune_limit: The number of DELETEs that should be
done in one batch.
:param cmd: Indicates if it is a split or a move being executed.
:param update_only: If the operation is a update only operation.
"""
if not _services_utils.is_valid_binary(mysqldump_binary):
raise _errors.ShardingError(
_services_sharding.MYSQLDUMP_NOT_FOUND % mysqldump_binary)
if not _services_utils.is_valid_binary(mysqlclient_binary):
raise _errors.ShardingError(
_services_sharding.MYSQLCLIENT_NOT_FOUND % mysqlclient_binary)
if cmd == "SPLIT":
range_sharding_spec, _, shard_mappings, _ = \
_services_sharding.verify_and_fetch_shard(shard_id)
upper_bound = \
SHARDING_SPECIFICATION_HANDLER[shard_mappings[0].type_name].\
get_upper_bound(
range_sharding_spec.lower_bound,
range_sharding_spec.shard_mapping_id,
shard_mappings[0].type_name
)
#If the underlying sharding scheme is a HASH. When a shard is split,
#all the tables that are part of the shard, have the same sharding
#scheme. All the shard mappings associated with this shard_id will be
#of the same sharding type. Hence it is safe to use one of the shard
#mappings.
if shard_mappings[0].type_name == "HASH":
if split_value is not None:
raise _errors.ShardingError(
_services_sharding.NO_LOWER_BOUND_FOR_HASH_SHARDING
)
if upper_bound is None:
#While splitting a range, retrieve the next upper bound and
#find the mid-point, in the case where the next upper_bound
#is unavailable pick the maximum value in the set of values in
#the shard.
upper_bound = HashShardingSpecification.fetch_max_key(shard_id)
#Calculate the split value.
split_value = \
SHARDING_DATATYPE_HANDLER[shard_mappings[0].type_name].\
split_value(
range_sharding_spec.lower_bound,
upper_bound
)
elif split_value is not None:
if not (SHARDING_DATATYPE_HANDLER[shard_mappings[0].type_name].\
is_valid_split_value(
split_value, range_sharding_spec.lower_bound,
upper_bound
)
):
raise _errors.ShardingError(
_services_sharding.INVALID_LOWER_BOUND_VALUE %
(split_value, )
)
elif split_value is None:
raise _errors.ShardingError(
_services_sharding.SPLIT_VALUE_NOT_DEFINED
)
#Ensure that the group does not already contain a shard.
if Shards.lookup_shard_id(destn_group_id) is not None:
raise _errors.ShardingError(
_services_sharding.SHARD_MOVE_DESTINATION_NOT_EMPTY %
(destn_group_id, )
)
#Fetch the group information for the source shard that
#needs to be moved.
source_shard = Shards.fetch(shard_id)
if source_shard is None:
raise _errors.ShardingError(
_services_sharding.SHARD_NOT_FOUND % (shard_id, ))
#Fetch the group_id and the group that hosts the source shard.
source_group_id = source_shard.group_id
destn_group = Group.fetch(destn_group_id)
if destn_group is None:
raise _errors.ShardingError(
_services_sharding.SHARD_GROUP_NOT_FOUND %
(destn_group_id, ))
if not update_only:
_events.trigger_within_procedure(
BACKUP_SOURCE_SHARD, shard_id, source_group_id, destn_group_id,
mysqldump_binary, mysqlclient_binary, split_value, config_file,
prune_limit, cmd, update_only
)
else:
_events.trigger_within_procedure(
SETUP_RESHARDING_SWITCH, shard_id, source_group_id, destn_group_id,
split_value, prune_limit, cmd, update_only
)
def _check_shard_information(shard_id, destn_group_id, mysqldump_binary,
mysqlclient_binary, split_value, config_file,
prune_limit, cmd, update_only):
"""Verify the sharding information before starting a re-sharding operation.
:param shard_id: The destination shard ID.
:param destn_group_id: The Destination group ID.
:param mysqldump_binary: The path to the mysqldump binary.
:param mysqlclient_binary: The path to the mysqlclient binary.
:param split_value: The point at which the sharding definition
should be split.
:param config_file: The complete path to the fabric configuration
file.
:param prune_limit: The number of DELETEs that should be
done in one batch.
:param cmd: Indicates if it is a split or a move being executed.
:param update_only: If the operation is a update only operation.
"""
if not _services_utils.is_valid_binary(mysqldump_binary):
raise _errors.ShardingError(_services_sharding.MYSQLDUMP_NOT_FOUND %
mysqldump_binary)
if not _services_utils.is_valid_binary(mysqlclient_binary):
raise _errors.ShardingError(_services_sharding.MYSQLCLIENT_NOT_FOUND %
mysqlclient_binary)
if cmd == "SPLIT":
range_sharding_spec, _, shard_mappings, _ = \
_services_sharding.verify_and_fetch_shard(shard_id)
upper_bound = \
SHARDING_SPECIFICATION_HANDLER[shard_mappings[0].type_name].\
get_upper_bound(
range_sharding_spec.lower_bound,
range_sharding_spec.shard_mapping_id,
shard_mappings[0].type_name
)
#If the underlying sharding scheme is a HASH. When a shard is split,
#all the tables that are part of the shard, have the same sharding
#scheme. All the shard mappings associated with this shard_id will be
#of the same sharding type. Hence it is safe to use one of the shard
#mappings.
if shard_mappings[0].type_name == "HASH":
if split_value is not None:
raise _errors.ShardingError(
_services_sharding.NO_LOWER_BOUND_FOR_HASH_SHARDING)
if upper_bound is None:
#While splitting a range, retrieve the next upper bound and
#find the mid-point, in the case where the next upper_bound
#is unavailable pick the maximum value in the set of values in
#the shard.
upper_bound = HashShardingSpecification.fetch_max_key(shard_id)
#Calculate the split value.
split_value = \
SHARDING_DATATYPE_HANDLER[shard_mappings[0].type_name].\
split_value(
range_sharding_spec.lower_bound,
upper_bound
)
elif split_value is not None:
if not (SHARDING_DATATYPE_HANDLER[shard_mappings[0].type_name].\
is_valid_split_value(
split_value, range_sharding_spec.lower_bound,
upper_bound
)
):
raise _errors.ShardingError(
_services_sharding.INVALID_LOWER_BOUND_VALUE %
(split_value, ))
elif split_value is None:
raise _errors.ShardingError(
_services_sharding.SPLIT_VALUE_NOT_DEFINED)
#Ensure that the group does not already contain a shard.
if Shards.lookup_shard_id(destn_group_id) is not None:
raise _errors.ShardingError(
_services_sharding.SHARD_MOVE_DESTINATION_NOT_EMPTY %
(destn_group_id, ))
#Fetch the group information for the source shard that
#needs to be moved.
source_shard = Shards.fetch(shard_id)
if source_shard is None:
raise _errors.ShardingError(_services_sharding.SHARD_NOT_FOUND %
(shard_id, ))
#Fetch the group_id and the group that hosts the source shard.
source_group_id = source_shard.group_id
destn_group = Group.fetch(destn_group_id)
if destn_group is None:
raise _errors.ShardingError(_services_sharding.SHARD_GROUP_NOT_FOUND %
(destn_group_id, ))
if not update_only:
_events.trigger_within_procedure(BACKUP_SOURCE_SHARD, shard_id,
source_group_id, destn_group_id,
mysqldump_binary, mysqlclient_binary,
split_value, config_file, prune_limit,
cmd, update_only)
else:
_events.trigger_within_procedure(SETUP_RESHARDING_SWITCH, shard_id,
source_group_id, destn_group_id,
split_value, prune_limit, cmd,
update_only)
