def copy_collection(source, dest, state_path, percent): """ Copies all documents from source to destination collection. Inserts documents in batches using insert workers, which are each run in their own greenlet. Ensures that the destination is empty before starting the copy. Does no safety checks -- this is up to the caller. @param source dict of (host, port, db, collection) for the source @param dest dict of (host, port, db, collection) for the destination @param state_path path of state database @param percent percentage of documents to copy """ gevent.monkey.patch_socket() # open state database state_db = CopyStateDB(state_path) # connect to mongo source_client = utils.mongo_connect(source, ensure_direct=True, max_pool_size=30, read_preference=ReadPreference.SECONDARY, document_class=FasterOrderedDict) source_collection = source_client[source['db']][source['collection']] if source_client.is_mongos: raise Exception("for performance reasons, sources must be mongod instances; %s:%d is not", source['host'], source['port']) dest_client = utils.mongo_connect(dest, max_pool_size=30, document_class=FasterOrderedDict) dest_collection = dest_client[dest['db']][dest['collection']] # record timestamp of last oplog entry, so that we know where to start applying ops # later oplog_ts = utils.get_last_oplog_entry(source_client)['ts'] state_db.update_oplog_ts(source, dest, oplog_ts) # for testing copying of indices quickly if percent == 0: log.info("skipping copy because of --percent 0 parameters") state_db.update_state(source, dest, CopyStateDB.STATE_WAITING_FOR_INDICES) return stats = Stats() stats.total_docs = int(source_collection.count()) if percent: # hack-ish but good enough for a testing-only feature stats.total_docs = int(stats.total_docs * (float(percent)/100.0)) # get all _ids, which works around a mongo bug/feature that causes massive slowdowns # of long-running, large reads over time ids = [] cursor = source_collection.find( projection={'_id':True}, modifiers={'$snapshot':True} ) cursor.batch_size(5000) insert_pool = Pool(INSERT_POOL_SIZE) stats_greenlet = gevent.spawn(_copy_stats_worker, stats) for doc in cursor: _id = doc['_id'] if percent is not None and not utils.id_in_subset(_id, percent): continue # when we've gathered enough _ids, spawn a worker greenlet to batch copy the # documents corresponding to them ids.append(_id) if len(ids) % INSERT_SIZE == 0: outgoing_ids = ids ids = [] insert_pool.spawn(_find_and_insert_batch_worker, source_collection=source_collection, dest_collection=dest_collection, ids=outgoing_ids, stats=stats) gevent.sleep() # insert last batch of documents if len(ids) > 0: _find_and_insert_batch_worker(source_collection=source_collection, dest_collection=dest_collection, ids=ids, stats=stats) stats.log() # wait until all other outstanding inserts have finished insert_pool.join() stats_greenlet.kill() log.info("done with initial copy") state_db.update_state(source, dest, CopyStateDB.STATE_WAITING_FOR_INDICES)
def copy_collection(source, dest, state_path, percent): """ Copies all documents from source to destination collection. Inserts documents in batches using insert workers, which are each run in their own greenlet. Ensures that the destination is empty before starting the copy. Does no safety checks -- this is up to the caller. @param source dict of (host, port, db, collection) for the source @param dest dict of (host, port, db, collection) for the destination @param state_path path of state database @param percent percentage of documents to copy """ gevent.monkey.patch_socket() # open state database state_db = CopyStateDB(state_path) # connect to mongo source_client = utils.mongo_connect( source['host'], source['port'], ensure_direct=True, max_pool_size=30, read_preference=ReadPreference.SECONDARY, document_class=FasterOrderedDict) source_collection = source_client[source['db']][source['collection']] if source_client.is_mongos: raise Exception( "for performance reasons, sources must be mongod instances; %s:%d is not", source['host'], source['port']) dest_client = utils.mongo_connect(dest['host'], dest['port'], max_pool_size=30, document_class=FasterOrderedDict) dest_collection = dest_client[dest['db']][dest['collection']] # record timestamp of last oplog entry, so that we know where to start applying ops # later oplog_ts = utils.get_last_oplog_entry(source_client)['ts'] state_db.update_oplog_ts(source, dest, oplog_ts) # for testing copying of indices quickly if percent == 0: log.info("skipping copy because of --percent 0 parameters") state_db.update_state(source, dest, CopyStateDB.STATE_WAITING_FOR_INDICES) return stats = Stats() stats.total_docs = int(source_collection.count()) if percent: # hack-ish but good enough for a testing-only feature stats.total_docs = int(stats.total_docs * (float(percent) / 100.0)) # get all _ids, which works around a mongo bug/feature that causes massive slowdowns # of long-running, large reads over time ids = [] cursor = source_collection.find(fields=["_id"], snapshot=True, timeout=False) cursor.batch_size(5000) insert_pool = Pool(INSERT_POOL_SIZE) stats_greenlet = gevent.spawn(_copy_stats_worker, stats) for doc in cursor: _id = doc['_id'] if percent is not None and not utils.id_in_subset(_id, percent): continue # when we've gathered enough _ids, spawn a worker greenlet to batch copy the # documents corresponding to them ids.append(_id) if len(ids) % INSERT_SIZE == 0: outgoing_ids = ids ids = [] insert_pool.spawn(_find_and_insert_batch_worker, source_collection=source_collection, dest_collection=dest_collection, ids=outgoing_ids, stats=stats) gevent.sleep() # insert last batch of documents if len(ids) > 0: _find_and_insert_batch_worker(source_collection=source_collection, dest_collection=dest_collection, ids=ids, stats=stats) stats.log() # wait until all other outstanding inserts have finished insert_pool.join() stats_greenlet.kill() log.info("done with initial copy") state_db.update_state(source, dest, CopyStateDB.STATE_WAITING_FOR_INDICES)
def compare_collections(source, dest, percent, error_bp, recent_ops, ids_file): """ compares two collections, using retries to see if collections are eventually consistent @param source_collection source for data @param dest_collection copied data to verify @param percent percentage of documents to verify @param ids_file files containing querie """ MismatchLogger.collection_name = source['collection'] # setup client connections source_client = utils.mongo_connect(source, ensure_direct=True, maxPoolSize=POOL_SIZE, slave_okay=True, document_class=dict) source_collection = source_client[source['db']][source['collection']] dest_client = utils.mongo_connect(dest, ensure_direct=True, maxPoolSize=POOL_SIZE, slave_okay=True, document_class=dict) dest_collection = dest_client[dest['db']][dest['collection']] # setup stats stats = CompareStats() compare_pool = gevent.pool.Pool(POOL_SIZE) retry_pool = gevent.pool.Pool(POOL_SIZE * 5) # get just _id's first, because long-running queries degrade significantly # over time; reading just _ids is fast enough (or small enough?) not to suffer # from this degradation if recent_ops: id_getter = _get_ids_for_recent_ops(source_client, recent_ops) stats.total_docs = recent_ops if source_client.is_mongos: log.error( "cannot read oplogs through mongos; specify mongod instances instead" ) return elif ids_file: id_getter = _get_ids_in_file(ids_file) stats.total_docs = id_getter.next() else: id_getter = _get_all_ids(source_collection) stats.total_docs = source_collection.count() if percent is not None: stats.total_docs = int(float(stats.total_docs) * percent / 100.0) stats_greenlet = gevent.spawn(_stats_worker, stats) # read documents in batches, but perform retries individually in separate greenlets _ids = [] for _id in id_getter: if percent is not None and not utils.id_in_subset(_id, percent): continue _ids.append(_id) if len(_ids) == READ_SIZE: _ids_to_compare = _ids _ids = [] compare_pool.spawn(_compare_ids_worker, _ids=_ids_to_compare, source_collection=source_collection, dest_collection=dest_collection, stats=stats, retry_pool=retry_pool) # compare final batch of _id's if _ids: compare_pool.spawn(_compare_ids_worker, _ids=_ids, source_collection=source_collection, dest_collection=dest_collection, stats=stats, retry_pool=retry_pool) # wait for all greenlets to finish compare_pool.join() retry_pool.join() stats_greenlet.kill() stats.log() log.info("compare finished")
def copy_collection(manifest, state_path, percent): """ Copies all documents from source to destination collection. Inserts documents in batches using insert workers, which are each run in their own greenlet. Does no safety checks -- this is up to the caller. @param manifest dict of (srchost, srcport, srcuser, srcpwd, srcdb, srccol, desthost, destport, destuser, destpwd, destdb, destcol) @param state_path path of state database @param percent percentage of documents to copy """ gevent.monkey.patch_socket() # open state database state_db = CopyStateDB(state_path) # connect to mongo source_client = utils.mongo_connect( manifest['srchost'], manifest['srcport'], manifest['srcuser'], manifest['srcpwd'], maxPoolSize=30, read_preference=ReadPreference.SECONDARY, document_class=FasterOrderedDict) source_collection = source_client[manifest['srcdb']][manifest['srccol']] if source_client.is_mongos: raise Exception( "for performance reasons, sources must be mongod instances; %s:%d is not", manifest['srchost'], source['srcport']) dest_client = utils.mongo_connect(manifest['desthost'], manifest['destport'], manifest['destuser'], manifest['destpwd'], maxPoolSize=30, document_class=FasterOrderedDict) dest_collection = dest_client[manifest['destdb']][manifest['destcol']] # for testing copying of indices quickly if percent == 0: log.info("skipping copy because of --percent 0 parameters") state_db.update_state(manifest, CopyStateDB.STATE_APPLYING_OPLOG) return stats = Stats() stats.total_docs = int(source_collection.count(filter=manifest["query"])) if percent: # hack-ish but good enough for a testing-only feature stats.total_docs = int(stats.total_docs * (float(percent) / 100.0)) # get all _ids, which works around a mongo bug/feature that causes massive slowdowns # of long-running, large reads over time ids = [] cursor = source_collection.find(filter=manifest["query"], projection={"_id": True}, no_cursor_timeout=False) cursor.batch_size(5000) insert_pool = Pool(INSERT_POOL_SIZE) stats_greenlet = gevent.spawn(_copy_stats_worker, stats) for doc in cursor: _id = doc['_id'] if percent is not None and not utils.id_in_subset(_id, percent): continue # when we've gathered enough _ids, spawn a worker greenlet to batch copy the # documents corresponding to them ids.append(_id) if len(ids) % INSERT_SIZE == 0: outgoing_ids = ids ids = [] insert_pool.spawn(_find_and_insert_batch_worker, source_collection=source_collection, dest_collection=dest_collection, ids=outgoing_ids, stats=stats) gevent.sleep() # insert last batch of documents if len(ids) > 0: _find_and_insert_batch_worker(source_collection=source_collection, dest_collection=dest_collection, ids=ids, stats=stats) stats.log() # wait until all other outstanding inserts have finished insert_pool.join() stats_greenlet.kill() srccount = stats.total_docs destcount = dest_collection.count(filter=manifest["query"]) if srccount == destcount: log.info("COPY SUCCEED. srccount(%d) == destcount(%d)" % (srccount, destcount)) else: log.error("COPY FAILED. srccount(%d) != destcount(%d)" % (srccount, destcount)) state_db.update_state(manifest, CopyStateDB.STATE_APPLYING_OPLOG)
def apply_oplog(source, dest, percent, state_path): """ Applies oplog entries from source to destination. Since the oplog storage format has known and possibly unknown idiosyncracies, we take a conservative approach. For each insert or delete op, we can easily replay those. For updates, we do the following: 1. Note the _id of the updated document 2. Retrieved the updated document from the source 3. Upsert the updated document in the destination @param oplog oplog collection from the source mongod instance @param start_ts timestamp at which we should start replaying oplog entries @param source_collection collection we're reading from @param dest_collection collection we're writing to @param checkpoint_ts_func function that, when called, persists oplog timestamp to disk @param """ gevent.monkey.patch_socket() stats = ApplyStats() apply_workers = Pool(20) # connect to state db state_db = CopyStateDB(state_path) # connect to mongo source_client = utils.mongo_connect(source, ensure_direct=True, max_pool_size=30, read_preference=ReadPreference.SECONDARY, document_class=FasterOrderedDict) source_collection = source_client[source['db']][source['collection']] dest_client = utils.mongo_connect(dest, max_pool_size=30, document_class=FasterOrderedDict) dest_collection = dest_client[dest['db']][dest['collection']] oplog = source_client['local']['oplog.rs'] # print stats periodically stats.paused = True stats_greenlet = gevent.spawn(oplog_stats_worker, stats) # checkpoint oplog position to disk periodically checkpoint_greenlet = gevent.spawn(oplog_checkpoint_worker, stats, source, dest, state_db) # figure out where we need to start reading oplog entries; rewind our oplog timestamp # a bit, to avoid issues with the user pressing Control-C while some ops are pending # # this works, because oplog entries are idempotent start_ts_orig = state_db.get_oplog_ts(source, dest) start_ts = bson.Timestamp(time=start_ts_orig.time-TS_REWIND, inc=0) log.info("starting apply at %s", start_ts) # perform tailing oplog query using the oplog_replay option to efficiently find # our starting position in the oplog query = {} query['ts'] = {'$gte': start_ts} query['ns'] = source_collection.full_name cursor = oplog.find( query, cursor_type=CursorType.TAILABLE_AWAIT, ) cursor.add_option(pymongo.cursor._QUERY_OPTIONS['oplog_replay']) while True: for op in cursor: stats.paused = False _id = _op_id(op) if percent and not utils.id_in_subset(_id, percent): continue stats.ops_retrieved += 1 # block *all* further ops from being applied if there's a pending # op on the current _id, to ensure serialization while _id in stats.pending_ids: gevent.sleep(0.1) stats.sleeps += 1 # do the real oplog work in a greenlet from the pool stats.pending_ids.add(_id) apply_workers.spawn(_apply_op_worker, op, source_collection, dest_collection, stats) # update our last timestamp; this is *not* guaranteed to be the timestamp of the # most recent op, which is impossible because of our out-of-order execution # # this is an approximation that needs to be accurate to within TS_REWIND seconds stats.last_ts = op['ts'] # while we have a tailable cursor, it can stop iteration if no more results come back # in a reasonable time, so sleep for a bit then try to continue iteration if cursor.alive: log.debug("replayed all oplog entries; sleeping...") stats.paused = True gevent.sleep(2) stats.paused = False else: log.error("cursor died on us!") break # just to silence pyflakes... stats_greenlet.kill() checkpoint_greenlet.kill()
def apply_oplog(source, dest, percent, state_path): """ Applies oplog entries from source to destination. Since the oplog storage format has known and possibly unknown idiosyncracies, we take a conservative approach. For each insert or delete op, we can easily replay those. For updates, we do the following: 1. Note the _id of the updated document 2. Retrieved the updated document from the source 3. Upsert the updated document in the destination @param oplog oplog collection from the source mongod instance @param start_ts timestamp at which we should start replaying oplog entries @param source_collection collection we're reading from @param dest_collection collection we're writing to @param checkpoint_ts_func function that, when called, persists oplog timestamp to disk @param """ gevent.monkey.patch_socket() stats = ApplyStats() apply_workers = Pool(20) # connect to state db state_db = CopyStateDB(state_path) # connect to mongo source_client = utils.mongo_connect( source, ensure_direct=True, max_pool_size=30, read_preference=ReadPreference.SECONDARY, document_class=FasterOrderedDict, ) source_collection = source_client[source["db"]][source["collection"]] dest_client = utils.mongo_connect(dest, max_pool_size=30, document_class=FasterOrderedDict) dest_collection = dest_client[dest["db"]][dest["collection"]] oplog = source_client["local"]["oplog.rs"] # print stats periodically stats.paused = True stats_greenlet = gevent.spawn(oplog_stats_worker, stats) # checkpoint oplog position to disk periodically checkpoint_greenlet = gevent.spawn(oplog_checkpoint_worker, stats, source, dest, state_db) # figure out where we need to start reading oplog entries; rewind our oplog timestamp # a bit, to avoid issues with the user pressing Control-C while some ops are pending # # this works, because oplog entries are idempotent start_ts_orig = state_db.get_oplog_ts(source, dest) start_ts = bson.Timestamp(time=start_ts_orig.time - TS_REWIND, inc=0) log.info("starting apply at %s", start_ts) # perform tailing oplog query using the oplog_replay option to efficiently find # our starting position in the oplog query = {} query["ts"] = {"$gte": start_ts} query["ns"] = source_collection.full_name cursor = oplog.find(query, cursor_type=pymongo.CursorType.TAILABLE_AWAIT, oplog_replay=True) # cursor.add_option(pymongo.cursor._QUERY_OPTIONS['oplog_replay']) print cursor while True: for op in cursor: stats.paused = False _id = _op_id(op) if percent and not utils.id_in_subset(_id, percent): continue stats.ops_retrieved += 1 # block *all* further ops from being applied if there's a pending # op on the current _id, to ensure serialization while _id in stats.pending_ids: gevent.sleep(0.1) stats.sleeps += 1 # do the real oplog work in a greenlet from the pool stats.pending_ids.add(_id) apply_workers.spawn(_apply_op_worker, op, source_collection, dest_collection, stats) # update our last timestamp; this is *not* guaranteed to be the timestamp of the # most recent op, which is impossible because of our out-of-order execution # # this is an approximation that needs to be accurate to within TS_REWIND seconds stats.last_ts = op["ts"] # while we have a tailable cursor, it can stop iteration if no more results come back # in a reasonable time, so sleep for a bit then try to continue iteration if cursor.alive: log.debug("replayed all oplog entries; sleeping...") stats.paused = True gevent.sleep(2) stats.paused = False else: log.error("cursor died on us!") break # just to silence pyflakes... stats_greenlet.kill() checkpoint_greenlet.kill()
def compare_collections(source, dest, percent, error_bp, recent_ops, ids_file): """ compares two collections, using retries to see if collections are eventually consistent @param source_collection source for data @param dest_collection copied data to verify @param percent percentage of documents to verify @param ids_file files containing querie """ MismatchLogger.collection_name = source['collection'] # setup client connections source_client = utils.mongo_connect(source['host'], source['port'], ensure_direct=True, max_pool_size=POOL_SIZE, slave_okay=True, document_class=dict) source_collection = source_client[source['db']][source['collection']] dest_client = utils.mongo_connect(dest['host'], dest['port'], ensure_direct=True, max_pool_size=POOL_SIZE, slave_okay=True, document_class=dict) dest_collection = dest_client[dest['db']][dest['collection']] # setup stats stats = CompareStats() compare_pool = gevent.pool.Pool(POOL_SIZE) retry_pool = gevent.pool.Pool(POOL_SIZE * 5) # get just _id's first, because long-running queries degrade significantly # over time; reading just _ids is fast enough (or small enough?) not to suffer # from this degradation if recent_ops: id_getter = _get_ids_for_recent_ops(source_client, recent_ops) stats.total_docs = recent_ops if source_client.is_mongos: log.error("cannot read oplogs through mongos; specify mongod instances instead") return elif ids_file: id_getter = _get_ids_in_file(ids_file) stats.total_docs = id_getter.next() else: id_getter = _get_all_ids(source_collection) stats.total_docs = source_collection.count() if percent is not None: stats.total_docs = int(float(stats.total_docs) * percent / 100.0) stats_greenlet = gevent.spawn(_stats_worker, stats) # read documents in batches, but perform retries individually in separate greenlets _ids = [] for _id in id_getter: if percent is not None and not utils.id_in_subset(_id, percent): continue _ids.append(_id) if len(_ids) == READ_SIZE: _ids_to_compare = _ids _ids = [] compare_pool.spawn(_compare_ids_worker, _ids=_ids_to_compare, source_collection=source_collection, dest_collection=dest_collection, stats=stats, retry_pool=retry_pool) # compare final batch of _id's if _ids: compare_pool.spawn(_compare_ids_worker, _ids=_ids, source_collection=source_collection, dest_collection=dest_collection, stats=stats, retry_pool=retry_pool) # wait for all greenlets to finish compare_pool.join() retry_pool.join() stats_greenlet.kill() stats.log() log.info("compare finished")