milvus/shards/mishards/router/plugins/file_based_hash_ring_router.py
XuPeng-SH b520e60b8a
[skip ci](shards): fix #1679 (#1681)
Signed-off-by: peng.xu <peng.xu@zilliz.com>
2020-03-17 11:06:51 +08:00

87 lines
3.1 KiB
Python

import logging
from sqlalchemy import exc as sqlalchemy_exc
from sqlalchemy import and_, or_
from mishards.models import Tables
from mishards.router import RouterMixin
from mishards import exceptions, db
from mishards.hash_ring import HashRing
logger = logging.getLogger(__name__)
class Factory(RouterMixin):
name = 'FileBasedHashRingRouter'
def __init__(self, writable_topo, readonly_topo, **kwargs):
super(Factory, self).__init__(writable_topo=writable_topo,
readonly_topo=readonly_topo)
def routing(self, table_name, partition_tags=None, metadata=None, **kwargs):
range_array = kwargs.pop('range_array', None)
return self._route(table_name, range_array, partition_tags, metadata, **kwargs)
def _route(self, table_name, range_array, partition_tags=None, metadata=None, **kwargs):
# PXU TODO: Implement Thread-local Context
# PXU TODO: Session life mgt
if not partition_tags:
cond = and_(
or_(Tables.table_id == table_name, Tables.owner_table == table_name),
Tables.state != Tables.TO_DELETE)
else:
cond = and_(Tables.state != Tables.TO_DELETE,
Tables.owner_table == table_name,
Tables.partition_tag.in_(partition_tags))
try:
tables = db.Session.query(Tables).filter(cond).all()
except sqlalchemy_exc.SQLAlchemyError as e:
raise exceptions.DBError(message=str(e), metadata=metadata)
if not tables:
raise exceptions.TableNotFoundError('{}:{}'.format(table_name, partition_tags), metadata=metadata)
total_files = []
for table in tables:
files = table.files_to_search(range_array)
total_files.append(files)
db.remove_session()
servers = self.readonly_topo.group_names
logger.info('Available servers: {}'.format(list(servers)))
ring = HashRing(servers)
routing = {}
for files in total_files:
for f in files:
target_host = ring.get_node(str(f.id))
sub = routing.get(target_host, None)
if not sub:
sub = {}
routing[target_host] = sub
kv = sub.get(f.table_id, None)
if not kv:
kv = []
sub[f.table_id] = kv
sub[f.table_id].append(str(f.id))
return routing
@classmethod
def Create(cls, **kwargs):
writable_topo = kwargs.pop('writable_topo', None)
if not writable_topo:
raise RuntimeError('Cannot find \'writable_topo\' to initialize \'{}\''.format(self.name))
readonly_topo = kwargs.pop('readonly_topo', None)
if not readonly_topo:
raise RuntimeError('Cannot find \'readonly_topo\' to initialize \'{}\''.format(self.name))
router = cls(writable_topo=writable_topo, readonly_topo=readonly_topo, **kwargs)
return router
def setup(app):
logger.info('Plugin \'{}\' Installed In Package: {}'.format(__file__, app.plugin_package_name))
app.on_plugin_setup(Factory)