# -*- coding: utf-8 -*- # Copyright 2015 OpenMarket Ltd # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. from synapse.http.servlet import parse_integer, parse_string from synapse.http.server import request_handler, finish_request from synapse.replication.pusher_resource import PusherResource from synapse.replication.presence_resource import PresenceResource from synapse.api.errors import SynapseError from twisted.web.resource import Resource from twisted.web.server import NOT_DONE_YET from twisted.internet import defer import ujson as json import collections import logging logger = logging.getLogger(__name__) REPLICATION_PREFIX = "/_synapse/replication" STREAM_NAMES = ( ("events",), ("presence",), ("typing",), ("receipts",), ("user_account_data", "room_account_data", "tag_account_data",), ("backfill",), ("push_rules",), ("pushers",), ("caches",), ("to_device",), ("public_rooms",), ) class ReplicationResource(Resource): """ HTTP endpoint for extracting data from synapse. The streams of data returned by the endpoint are controlled by the parameters given to the API. To return a given stream pass a query parameter with a position in the stream to return data from or the special value "-1" to return data from the start of the stream. If there is no data for any of the supplied streams after the given position then the request will block until there is data for one of the streams. This allows clients to long-poll this API. The possible streams are: * "streams": A special stream returing the positions of other streams. * "events": The new events seen on the server. * "presence": Presence updates. * "typing": Typing updates. * "receipts": Receipt updates. * "user_account_data": Top-level per user account data. * "room_account_data: Per room per user account data. * "tag_account_data": Per room per user tags. * "backfill": Old events that have been backfilled from other servers. * "push_rules": Per user changes to push rules. * "pushers": Per user changes to their pushers. * "caches": Cache invalidations. The API takes two additional query parameters: * "timeout": How long to wait before returning an empty response. * "limit": The maximum number of rows to return for the selected streams. The response is a JSON object with keys for each stream with updates. Under each key is a JSON object with: * "position": The current position of the stream. * "field_names": The names of the fields in each row. * "rows": The updates as an array of arrays. There are a number of ways this API could be used: 1) To replicate the contents of the backing database to another database. 2) To be notified when the contents of a shared backing database changes. 3) To "tail" the activity happening on a server for debugging. In the first case the client would track all of the streams and store it's own copy of the data. In the second case the client might theoretically just be able to follow the "streams" stream to track where the other streams are. However in practise it will probably need to get the contents of the streams in order to expire the any in-memory caches. Whether it gets the contents of the streams from this replication API or directly from the backing store is a matter of taste. In the third case the client would use the "streams" stream to find what streams are available and their current positions. Then it can start long-polling this replication API for new data on those streams. """ def __init__(self, hs): Resource.__init__(self) # Resource is old-style, so no super() self.version_string = hs.version_string self.store = hs.get_datastore() self.sources = hs.get_event_sources() self.presence_handler = hs.get_presence_handler() self.typing_handler = hs.get_typing_handler() self.notifier = hs.notifier self.clock = hs.get_clock() self.putChild("remove_pushers", PusherResource(hs)) self.putChild("syncing_users", PresenceResource(hs)) def render_GET(self, request): self._async_render_GET(request) return NOT_DONE_YET @defer.inlineCallbacks def current_replication_token(self): stream_token = yield self.sources.get_current_token() backfill_token = yield self.store.get_current_backfill_token() push_rules_token, room_stream_token = self.store.get_push_rules_stream_token() pushers_token = self.store.get_pushers_stream_token() caches_token = self.store.get_cache_stream_token() public_rooms_token = self.store.get_current_public_room_stream_id() defer.returnValue(_ReplicationToken( room_stream_token, int(stream_token.presence_key), int(stream_token.typing_key), int(stream_token.receipt_key), int(stream_token.account_data_key), backfill_token, push_rules_token, pushers_token, 0, # State stream is no longer a thing caches_token, int(stream_token.to_device_key), int(public_rooms_token), )) @request_handler() @defer.inlineCallbacks def _async_render_GET(self, request): limit = parse_integer(request, "limit", 100) timeout = parse_integer(request, "timeout", 10 * 1000) request.setHeader(b"Content-Type", b"application/json") request_streams = { name: parse_integer(request, name) for names in STREAM_NAMES for name in names } request_streams["streams"] = parse_string(request, "streams") def replicate(): return self.replicate(request_streams, limit) writer = yield self.notifier.wait_for_replication(replicate, timeout) result = writer.finish() for stream_name, stream_content in result.items(): logger.info( "Replicating %d rows of %s from %s -> %s", len(stream_content["rows"]), stream_name, request_streams.get(stream_name), stream_content["position"], ) request.write(json.dumps(result, ensure_ascii=False)) finish_request(request) @defer.inlineCallbacks def replicate(self, request_streams, limit): writer = _Writer() current_token = yield self.current_replication_token() logger.debug("Replicating up to %r", current_token) if limit == 0: raise SynapseError(400, "Limit cannot be 0") yield self.account_data(writer, current_token, limit, request_streams) yield self.events(writer, current_token, limit, request_streams) # TODO: implement limit yield self.presence(writer, current_token, request_streams) yield self.typing(writer, current_token, request_streams) yield self.receipts(writer, current_token, limit, request_streams) yield self.push_rules(writer, current_token, limit, request_streams) yield self.pushers(writer, current_token, limit, request_streams) yield self.caches(writer, current_token, limit, request_streams) yield self.to_device(writer, current_token, limit, request_streams) yield self.public_rooms(writer, current_token, limit, request_streams) self.streams(writer, current_token, request_streams) logger.debug("Replicated %d rows", writer.total) defer.returnValue(writer) def streams(self, writer, current_token, request_streams): request_token = request_streams.get("streams") streams = [] if request_token is not None: if request_token == "-1": for names, position in zip(STREAM_NAMES, current_token): streams.extend((name, position) for name in names) else: items = zip( STREAM_NAMES, current_token, _ReplicationToken(request_token) ) for names, current_id, last_id in items: if last_id < current_id: streams.extend((name, current_id) for name in names) if streams: writer.write_header_and_rows( "streams", streams, ("name", "position"), position=str(current_token) ) @defer.inlineCallbacks def events(self, writer, current_token, limit, request_streams): request_events = request_streams.get("events") request_backfill = request_streams.get("backfill") if request_events is not None or request_backfill is not None: if request_backfill is None: request_events = current_token.events if request_backfill is None: request_backfill = current_token.backfill no_new_tokens = ( request_events == current_token.events and request_backfill == current_token.backfill ) if no_new_tokens: return res = yield self.store.get_all_new_events( request_backfill, request_events, current_token.backfill, current_token.events, limit ) upto_events_token = _position_from_rows( res.new_forward_events, current_token.events ) upto_backfill_token = _position_from_rows( res.new_backfill_events, current_token.backfill ) if request_events != upto_events_token: writer.write_header_and_rows("events", res.new_forward_events, ( "position", "internal", "json", "state_group" ), position=upto_events_token) if request_backfill != upto_backfill_token: writer.write_header_and_rows("backfill", res.new_backfill_events, ( "position", "internal", "json", "state_group", ), position=upto_backfill_token) writer.write_header_and_rows( "forward_ex_outliers", res.forward_ex_outliers, ("position", "event_id", "state_group"), ) writer.write_header_and_rows( "backward_ex_outliers", res.backward_ex_outliers, ("position", "event_id", "state_group"), ) writer.write_header_and_rows( "state_resets", res.state_resets, ("position",), ) @defer.inlineCallbacks def presence(self, writer, current_token, request_streams): current_position = current_token.presence request_presence = request_streams.get("presence") if request_presence is not None and request_presence != current_position: presence_rows = yield self.presence_handler.get_all_presence_updates( request_presence, current_position ) upto_token = _position_from_rows(presence_rows, current_position) writer.write_header_and_rows("presence", presence_rows, ( "position", "user_id", "state", "last_active_ts", "last_federation_update_ts", "last_user_sync_ts", "status_msg", "currently_active", ), position=upto_token) @defer.inlineCallbacks def typing(self, writer, current_token, request_streams): current_position = current_token.typing request_typing = request_streams.get("typing") if request_typing is not None and request_typing != current_position: # If they have a higher token than current max, we can assume that # they had been talking to a previous instance of the master. Since # we reset the token on restart, the best (but hacky) thing we can # do is to simply resend down all the typing notifications. if request_typing > current_position: request_typing = 0 typing_rows = yield self.typing_handler.get_all_typing_updates( request_typing, current_position ) upto_token = _position_from_rows(typing_rows, current_position) writer.write_header_and_rows("typing", typing_rows, ( "position", "room_id", "typing" ), position=upto_token) @defer.inlineCallbacks def receipts(self, writer, current_token, limit, request_streams): current_position = current_token.receipts request_receipts = request_streams.get("receipts") if request_receipts is not None and request_receipts != current_position: receipts_rows = yield self.store.get_all_updated_receipts( request_receipts, current_position, limit ) upto_token = _position_from_rows(receipts_rows, current_position) writer.write_header_and_rows("receipts", receipts_rows, ( "position", "room_id", "receipt_type", "user_id", "event_id", "data" ), position=upto_token) @defer.inlineCallbacks def account_data(self, writer, current_token, limit, request_streams): current_position = current_token.account_data user_account_data = request_streams.get("user_account_data") room_account_data = request_streams.get("room_account_data") tag_account_data = request_streams.get("tag_account_data") if user_account_data is not None or room_account_data is not None: if user_account_data is None: user_account_data = current_position if room_account_data is None: room_account_data = current_position no_new_tokens = ( user_account_data == current_position and room_account_data == current_position ) if no_new_tokens: return user_rows, room_rows = yield self.store.get_all_updated_account_data( user_account_data, room_account_data, current_position, limit ) upto_users_token = _position_from_rows(user_rows, current_position) upto_rooms_token = _position_from_rows(room_rows, current_position) writer.write_header_and_rows("user_account_data", user_rows, ( "position", "user_id", "type", "content" ), position=upto_users_token) writer.write_header_and_rows("room_account_data", room_rows, ( "position", "user_id", "room_id", "type", "content" ), position=upto_rooms_token) if tag_account_data is not None: tag_rows = yield self.store.get_all_updated_tags( tag_account_data, current_position, limit ) upto_tag_token = _position_from_rows(tag_rows, current_position) writer.write_header_and_rows("tag_account_data", tag_rows, ( "position", "user_id", "room_id", "tags" ), position=upto_tag_token) @defer.inlineCallbacks def push_rules(self, writer, current_token, limit, request_streams): current_position = current_token.push_rules push_rules = request_streams.get("push_rules") if push_rules is not None and push_rules != current_position: rows = yield self.store.get_all_push_rule_updates( push_rules, current_position, limit ) upto_token = _position_from_rows(rows, current_position) writer.write_header_and_rows("push_rules", rows, ( "position", "event_stream_ordering", "user_id", "rule_id", "op", "priority_class", "priority", "conditions", "actions" ), position=upto_token) @defer.inlineCallbacks def pushers(self, writer, current_token, limit, request_streams): current_position = current_token.pushers pushers = request_streams.get("pushers") if pushers is not None and pushers != current_position: updated, deleted = yield self.store.get_all_updated_pushers( pushers, current_position, limit ) upto_token = _position_from_rows(updated, current_position) writer.write_header_and_rows("pushers", updated, ( "position", "user_id", "access_token", "profile_tag", "kind", "app_id", "app_display_name", "device_display_name", "pushkey", "ts", "lang", "data" ), position=upto_token) writer.write_header_and_rows("deleted_pushers", deleted, ( "position", "user_id", "app_id", "pushkey" ), position=upto_token) @defer.inlineCallbacks def caches(self, writer, current_token, limit, request_streams): current_position = current_token.caches caches = request_streams.get("caches") if caches is not None and caches != current_position: updated_caches = yield self.store.get_all_updated_caches( caches, current_position, limit ) upto_token = _position_from_rows(updated_caches, current_position) writer.write_header_and_rows("caches", updated_caches, ( "position", "cache_func", "keys", "invalidation_ts" ), position=upto_token) @defer.inlineCallbacks def to_device(self, writer, current_token, limit, request_streams): current_position = current_token.to_device to_device = request_streams.get("to_device") if to_device is not None and to_device != current_position: to_device_rows = yield self.store.get_all_new_device_messages( to_device, current_position, limit ) upto_token = _position_from_rows(to_device_rows, current_position) writer.write_header_and_rows("to_device", to_device_rows, ( "position", "user_id", "device_id", "message_json" ), position=upto_token) @defer.inlineCallbacks def public_rooms(self, writer, current_token, limit, request_streams): current_position = current_token.public_rooms public_rooms = request_streams.get("public_rooms") if public_rooms is not None and public_rooms != current_position: public_rooms_rows = yield self.store.get_all_new_public_rooms( public_rooms, current_position, limit ) upto_token = _position_from_rows(public_rooms_rows, current_position) writer.write_header_and_rows("public_rooms", public_rooms_rows, ( "position", "room_id", "visibility" ), position=upto_token) class _Writer(object): """Writes the streams as a JSON object as the response to the request""" def __init__(self): self.streams = {} self.total = 0 def write_header_and_rows(self, name, rows, fields, position=None): if position is None: if rows: position = rows[-1][0] else: return self.streams[name] = { "position": position if type(position) is int else str(position), "field_names": fields, "rows": rows, } self.total += len(rows) def __nonzero__(self): return bool(self.total) def finish(self): return self.streams class _ReplicationToken(collections.namedtuple("_ReplicationToken", ( "events", "presence", "typing", "receipts", "account_data", "backfill", "push_rules", "pushers", "state", "caches", "to_device", "public_rooms", ))): __slots__ = [] def __new__(cls, *args): if len(args) == 1: streams = [int(value) for value in args[0].split("_")] if len(streams) < len(cls._fields): streams.extend([0] * (len(cls._fields) - len(streams))) return cls(*streams) else: return super(_ReplicationToken, cls).__new__(cls, *args) def __str__(self): return "_".join(str(value) for value in self) def _position_from_rows(rows, current_position): """Calculates a position to return for a stream. Ideally we want to return the position of the last row, as that will be the most correct. However, if there are no rows we fall back to using the current position to stop us from repeatedly hitting the storage layer unncessarily thinking there are updates. (Not all advances of the token correspond to an actual update) We can't just always return the current position, as we often limit the number of rows we replicate, and so the stream may lag. The assumption is that if the storage layer returns no new rows then we are not lagging and we are at the `current_position`. """ if rows: return rows[-1][0] return current_position