diff --git a/swh/storage/archiver/director.py b/swh/storage/archiver/director.py index 04282a2a7..c1691edb9 100644 --- a/swh/storage/archiver/director.py +++ b/swh/storage/archiver/director.py @@ -1,244 +1,218 @@ # Copyright (C) 2015 The Software Heritage developers # See the AUTHORS file at the top-level directory of this distribution # License: GNU General Public License version 3, or any later version # See top-level LICENSE file for more information import swh +import logging from datetime import datetime -from swh.core import hashutil, config +from swh.core import hashutil from swh.scheduler.celery_backend.config import app from . import tasks # NOQA -from ..db import cursor_to_bytes DEFAULT_CONFIG = { 'objstorage_path': '/tmp/swh-storage/objects', 'batch_max_size': 50, 'archival_max_age': 3600, 'retention_policy': 2, 'asynchronous': True, 'dbname': 'softwareheritage', 'user': 'root' } task_name = 'swh.storage.archiver.tasks.SWHArchiverTask' +logger = logging.getLogger() + class ArchiverDirector(): """Process the files in order to know which one is needed as backup. The archiver director processes the files in the local storage in order to know which one needs archival and it delegates this task to archiver workers. Attributes: master_storage: the local storage of the master server. slave_storages: Iterable of remote obj storages to the slaves servers used for backup. - batch_max_size: The number of content items that can be given - to the same archiver worker. - archival_max_age: Delay given to the worker to copy all the files - in a given batch. - retention_policy: Required number of copies for the content to - be considered safe. + config: Archiver_configuration. A dictionary that must contain + the following keys. + objstorage_path (string): the path of the objstorage of the + master. + batch_max_size (int): The number of content items that can be + given to the same archiver worker. + archival_max_age (int): Delay given to the worker to copy all + the files in a given batch. + retention_policy (int): Required number of copies for the + content to be considered safe. + asynchronous (boolean): Indicate whenever the archival should + run in asynchronous mode or not. """ def __init__(self, db_conn, config): """ Constructor of the archiver director. Args: db_conn: db_conn: Either a libpq connection string, or a psycopg2 connection. - config: Archiver_configuration. A dictionnary that must contains + config: Archiver_configuration. A dictionary that must contains the following keys. objstorage_path (string): the path of the objstorage of the master. batch_max_size (int): The number of content items that can be given to the same archiver worker. - archival_max_age (int): Delay given to the worker to cpy all + archival_max_age (int): Delay given to the worker to copy all the files in a given batch. retention_policy (int): Required number of copies for the content to be considered safe. asynchronous (boolean): Indicate whenever the archival should run in asynchronous mode or not. """ # Get the local storage of the master and remote ones for the slaves. self.master_storage_args = [db_conn, config['objstorage_path']] master_storage = swh.storage.get_storage('local_storage', self.master_storage_args) slaves = { id: url for id, url in master_storage.db.archive_ls() } # TODO Database should be initialized somehow before going in # production. For now, assumes that the database contains # datas for all the current content. self.master_storage = master_storage self.slave_storages = slaves - self.batch_max_size = config['batch_max_size'] - self.archival_max_age = config['archival_max_age'] - self.retention_policy = config['retention_policy'] - self.is_asynchronous = config['asynchronous'] + self.config = config def run(self): """ Run the archiver director. The archiver director will check all the contents of the archiver database and do the required backup jobs. """ - run_fn = (self.run_async_worker - if self.is_asynchronous - else self.run_sync_worker) + if self.config['asynchronous']: + run_fn = self.run_async_worker + else: + run_fn = self.run_sync_worker for batch in self.get_unarchived_content(): run_fn(batch) def run_async_worker(self, batch): """ Produce a worker that will be added to the task queue. """ task = app.tasks[task_name] task.delay(batch, self.master_storage_args, - self.slave_storages, self.retention_policy) + self.slave_storages, self.config['retention_policy']) def run_sync_worker(self, batch): """ Run synchronously a worker on the given batch. """ task = app.tasks[task_name] task(batch, self.master_storage_args, - self.slave_storages, self.retention_policy) + self.slave_storages, self.config) def get_unarchived_content(self): """ get all the contents that needs to be archived. Yields: - A batch of contents. Batches are dictionnaries which associates + A batch of contents. Batches are dictionaries which associates a content id to the data about servers that contains it or not. {'id1': {'present': [('slave1', 'slave1_url')], 'missing': [('slave2', 'slave2_url'), ('slave3', 'slave3_url')] }, 'id2': {'present': [], 'missing': [ ('slave1', 'slave1_url'), ('slave2', 'slave2_url'), ('slave3', 'slave3_url') - ] + ]} } Where keys (idX) are sha1 of the content and (slaveX, slaveX_url) are ids and urls of the storage slaves. At least all the content that don't have enough copies on the backups servers are distributed into these batches. """ # Get the data about each content referenced into the archiver. missing_copy = {} for content_id in self.master_storage.db.content_archive_ls(): - # Do some initializations db_content_id = '\\x' + hashutil.hash_to_hex(content_id[0]) - # Query in order to know in which servers the content is saved. + # Fetch the datas about archival status of the content backups = self.master_storage.db.content_archive_get( content=db_content_id ) for _content_id, server_id, status, mtime in backups: - - # If the content is ongoing but still have time, there is - # another worker working on this content. - if status == 'ongoing': - mtime = mtime.replace(tzinfo=None) - elapsed = (datetime.now() - mtime).total_seconds() - if elapsed < self.archival_max_age: - continue + virtual_status = self.get_virtual_status(status, mtime) server_data = (server_id, self.slave_storages[server_id]) + missing_copy.setdefault( db_content_id, {'present': [], 'missing': []} - ).setdefault(status, []).append(server_data) + ).setdefault(virtual_status, []).append(server_data) # Check the content before archival. - # TODO catch exception and try to restore the file from an - # archive? - self.master_storage.objstorage.check(content_id[0]) - - if len(missing_copy) >= self.batch_max_size: + try: + self.master_storage.objstorage.check(content_id[0]) + except Exception as e: + # Exception can be Error or ObjNotFoundError. + logger.error(e) + # TODO Do something to restore the content? + + if len(missing_copy) >= self.config['batch_max_size']: yield missing_copy missing_copy = {} if len(missing_copy) > 0: yield missing_copy + def get_virtual_status(self, status, mtime): + """ Compute the virtual presence of a content. -def initialize_content_archive(db, sample_size, names=['Local']): - """ Initialize the content_archive table with a sample. - - From the content table, get a sample of id, and fill the - content_archive table with those id in order to create a test sample - for the archiver. - - Args: - db: The database of the storage. - sample_size (int): The size of the sample to create. - names: A list of archive names. Those archives must already exists. - Archival status of the archives content will be erased on db. - - Returns: - Tha amount of entry created. - """ - with db.transaction() as cur: - cur.execute('DELETE FROM content_archive') - - with db.transaction() as cur: - cur.execute('SELECT sha1 from content limit %d' % sample_size) - ids = list(cursor_to_bytes(cur)) - - for id, in ids: - tid = r'\x' + hashutil.hash_to_hex(id) + If the status is ongoing but the time is not elasped, the archiver + consider it will be present in the futur, and so consider it as + present. + However, if the time is elasped, the copy may have failed, so consider + the content as missing. - with db.transaction() as cur: - for name in names: - s = """INSERT INTO content_archive - VALUES('%s'::sha1, '%s', 'missing', now()) - """ % (tid, name) - cur.execute(s) + Arguments: + status (string): One of ('present', 'missing', 'ongoing'). The + status of the content. + mtime (datetime): Time at which the content have been updated for + the last time. - print('Initialized database with', sample_size * len(names), 'items') - return sample_size * len(names) + Returns: + The virtual status of the studied content, which is 'present' or + 'missing'. - -def add_content_to_objstore(director, source, content_ids): - """ Fill the objstore according to the database - - Get the current status of the database and fill the objstorage of the - master storage according to these data. - Content are fetched from the source, which is a storage. - - Args: - director (ArchiverDirector): The archiver director containing - the master storage to fill. - source (Storage): A storage that contains the content for all the - ids in content_ids. - content_ids: A list of ids that should be added to the master object - storage. - """ - for res in source.content_get(content_ids): - content_data = res['data'] - director.master_storage.objstorage.add_bytes(content_data) - - -if __name__ == '__main__': - import sys - - conf = config.read(sys.argv[1], DEFAULT_CONFIG) - cstring = 'dbname={} user={}'.format(conf['dbname'], conf['user']) - - director = ArchiverDirector(cstring, conf) - director.run() + Raises: + ValueError: if the status is not one 'present', 'missing' + or 'ongoing' + """ + if status in ('present', 'missing'): + return status + + # If the status is 'ongoing' but there is still time, another worker + # may still be on the task. + if status == 'ongoing': + mtime = mtime.replace(tzinfo=None) + elapsed = (datetime.now() - mtime).total_seconds() + if elapsed <= self.config['archival_max_age']: + return 'present' + else: + return 'missing' + else: + raise ValueError("status must be either 'present', 'missing' " + "or 'ongoing'") diff --git a/swh/storage/archiver/tasks.py b/swh/storage/archiver/tasks.py index e96a63346..0b7ce61e7 100644 --- a/swh/storage/archiver/tasks.py +++ b/swh/storage/archiver/tasks.py @@ -1,20 +1,20 @@ # Copyright (C) 2015 The Software Heritage developers # See the AUTHORS file at the top-level directory of this distribution # License: GNU General Public License version 3, or any later version # See top-level LICENSE file for more information from swh.scheduler.task import Task from .worker import ArchiverWorker class SWHArchiverTask(Task): """ Main task that archive a batch of content. """ task_queue = 'swh_storage_archive_worker' def run(self, batch, master_storage_args, - slave_storages, retention_policy): + slave_storages, config): aw = ArchiverWorker(batch, master_storage_args, - slave_storages, retention_policy) + slave_storages, config) if aw.run(): self.log("Successful backup for a batch of size %s" % len(batch)) diff --git a/swh/storage/archiver/worker.py b/swh/storage/archiver/worker.py index 7f2d41fe8..8fda96bc1 100644 --- a/swh/storage/archiver/worker.py +++ b/swh/storage/archiver/worker.py @@ -1,164 +1,239 @@ # Copyright (C) 2015 The Software Heritage developers # See the AUTHORS file at the top-level directory of this distribution # License: GNU General Public License version 3, or any later version # See top-level LICENSE file for more information import random +import logging from .copier import ArchiverCopier from .. import get_storage from datetime import datetime +logger = logging.getLogger() + class ArchiverWorker(): """ Do the required backups on a given batch of contents. Process the content of a content batch in order to do the needed backups on the slaves servers. Attributes: batch: The content this worker has to archive, which is a dictionary that associates a content's sha1 id to the list of servers where the content is present or missing (see ArchiverDirector::get_unarchived_content). master_storage_args: The connection argument to initialize the - master storage where is the content location. + master storage with the db connection url & the object storage + path. slave_storages: A map that associates server_id to the remote server. - retention_policy: The required number of copies for a content to be - considered safe. + config: Archiver_configuration. A dictionary that must contains + the following keys. + objstorage_path (string): the path of the objstorage of the + master. + batch_max_size (int): The number of content items that can be + given to the same archiver worker. + archival_max_age (int): Delay given to the worker to copy all + the files in a given batch. + retention_policy (int): Required number of copies for the + content to be considered safe. + asynchronous (boolean): Indicate whenever the archival should + run in asynchronous mode or not. """ - def __init__(self, batch, master_storage_args, - slave_storages, retention_policy): + def __init__(self, batch, master_storage_args, slave_storages, config): """ Constructor of the ArchiverWorker class. Args: - batch: A batch of content, which is a dictionnary that associates + batch: A batch of content, which is a dictionary that associates a content's sha1 id to the list of servers where the content is present. - master_storage: The master storage where is the whole content. + master_storage_args: The master storage arguments. slave_storages: A map that associates server_id to the remote server. - retention_policy: The required number of copies for a content to - be considered safe. + config: Archiver_configuration. A dictionary that must contains + the following keys. + objstorage_path (string): the path of the objstorage of the + master. + batch_max_size (int): The number of content items that can be + given to the same archiver worker. + archival_max_age (int): Delay given to the worker to copy all + the files in a given batch. + retention_policy (int): Required number of copies for the + content to be considered safe. + asynchronous (boolean): Indicate whenever the archival should + run in asynchronous mode or not. """ self.batch = batch self.master_storage = get_storage('local_storage', master_storage_args) self.slave_storages = slave_storages - self.retention_policy = retention_policy + self.config = config def __choose_backup_servers(self, allowed_storage, backup_number): """ Choose the slave servers for archival. Choose the given amount of servers among those which don't already contain a copy of the content. Args: allowed_storage: servers when the content is not already present. backup_number (int): The number of servers we have to choose in order to fullfill the objective. """ # In case there is not enough backup servers to get all the backups # we need, just do our best. # TODO such situation can only be caused by an incorrect configuration # setting. Do a verification previously. backup_number = min(backup_number, len(allowed_storage)) # TODO Find a better (or a good) policy to choose the backup servers. # The random choice should be equivalently distributed between # servers for a great amount of data, but don't take care of servers # capacities. return random.sample(allowed_storage, backup_number) def __get_archival_status(self, content_id, server): + """ Get the archival status of the required content. + + Attributes: + content_id (string): Sha1 of the content. + server: Tuple (archive_id, archive_url) of the archive server. + Returns: + A dictionary that contains all the required data : 'content_id', + 'archive_id', 'status', and 'mtime' + """ t, = list( self.master_storage.db.content_archive_get(content_id, server[0]) ) return { 'content_id': t[0], 'archive_id': t[1], 'status': t[2], 'mtime': t[3] } def __content_archive_update(self, content_id, archive_id, new_status=None): + """ Update the status of a archive content and set it's mtime to now() + + Change the last modification time of an archived content and change + its status to the given one. + + Args: + content_id (string): The content id. + archive_id (string): The id of the concerned archive. + new_status (string): One of missing, ongoing or present, this + status will replace the previous one. If not given, the + function only changes the mtime of the content. + """ self.master_storage.db.content_archive_update( content_id, archive_id, new_status ) - def run(self): - """ Do the task expected from the archiver worker. - - Process the content in the batch, ensure that the elements still need - an archival, and spawn copiers to copy files in each destinations. - """ - - def content_filter(content, destination): - """ Indicates whenever a content need archivage. + def need_archival(self, content, destination): + """ Indicates whenever a content need archivage. - Filter function that returns True if a given content - still require to be archived. + Filter function that returns True if a given content + still require to be archived. - Args: - content (str): Sha1 of a content. - destination: Tuple (archive id, archive url). - """ - archival_status = self.__get_archival_status( - content, - destination - ) - if archival_status: - status = archival_status['status'] - # If the archive is already present, no need to backup. - if status == 'present': - return False - # If the content is ongoing but still have time, there is - # another worker working on this content. - elif status == 'ongoing': - elapsed = datetime.now() - archival_status['mtime']\ - .total_seconds() - if elapsed < self.master_storage.archival_max_age: - return False - return True - else: - # TODO this is an error case, the content should always exists. - return None + Args: + content (str): Sha1 of a content. + destination: Tuple (archive id, archive url). + """ + archival_status = self.__get_archival_status( + content, + destination + ) + status = archival_status['status'] + mtime = archival_status['mtime'] + # If the archive is already present, no need to backup. + if status == 'present': + return False + # If the content is ongoing but still have time, there is + # another worker working on this content. + elif status == 'ongoing': + mtime = mtime.replace(tzinfo=None) + elapsed = (datetime.now() - mtime).total_seconds() + if elapsed <= self.config['archival_max_age']: + return False + return True + + def sort_content_by_archive(self): + """ Create a map {archive_server -> list of content) + + Create a mapping that associate to a archive server all the + contents that needs to be archived in it by the current worker. + + The map is in the form of : + { + (archive_1, archive_1_url): [content1, content2, content_3] + (archive_2, archive_2_url): [content1, content3] + } + Returns: + The created mapping. + """ slaves_copy = {} for content_id in self.batch: - # Choose some servers to upload the content + # Choose some servers to upload the content among the missing ones. server_data = self.batch[content_id] - + nb_present = len(server_data['present']) + nb_backup = self.config['retention_policy'] - nb_present backup_servers = self.__choose_backup_servers( server_data['missing'], - self.retention_policy - len(server_data['present']) + nb_backup ) # Fill the map destination -> content to upload for server in backup_servers: slaves_copy.setdefault(server, []).append(content_id) + return slaves_copy + + def run(self): + """ Do the task expected from the archiver worker. - # At this point, check the archival status of the content in order to - # know if it is still needed. + Process the content in the batch, ensure that the elements still need + an archival, and spawn copiers to copy files in each destinations. + """ + # Get a map (archive -> [contents]) + slaves_copy = self.sort_content_by_archive() + + # At this point, re-check the archival status in order to know if the + # job have been done by another worker. for destination in slaves_copy: - contents = [] - for content in slaves_copy[destination]: - if content_filter(content, destination): - self.__content_archive_update(content, destination[0], - new_status='ongoing') - contents.append(content) - slaves_copy[destination] = contents - - # Spawn a copier for each destination that will copy all the - # needed content. + # list() is needed because filter's result will be consumed twice. + slaves_copy[destination] = list(filter( + lambda content_id: self.need_archival(content_id, destination), + slaves_copy[destination] + )) + for content_id in slaves_copy[destination]: + self.__content_archive_update(content_id, destination[0], + new_status='ongoing') + + # Spawn a copier for each destination for destination in slaves_copy: - ac = ArchiverCopier( - destination, slaves_copy[destination], - self.master_storage) - if ac.run(): - # Once the archival complete, update the database. - for content_id in slaves_copy[destination]: - self.__content_archive_update(content_id, destination[0], - new_status='present') + try: + self.run_copier(destination, slaves_copy[destination]) + except: + logger.error('Unable to copy a batch to %s' % destination) + + def run_copier(self, destination, contents): + """ Run a copier in order to archive the given contents + + Upload the given contents to the given archive. + If the process fail, the whole content is considered uncopied + and remains 'ongoing', waiting to be rescheduled as there is + a delay. + + Attributes: + destination: Tuple (archive_id, archive_url) of the destination. + contents: List of contents to archive. + """ + ac = ArchiverCopier(destination, contents, self.master_storage) + if ac.run(): + # Once the archival complete, update the database. + for content_id in contents: + self.__content_archive_update(content_id, destination[0], + new_status='present') diff --git a/swh/storage/tests/test_archiver.py b/swh/storage/tests/test_archiver.py index d92b641ab..472e03e33 100644 --- a/swh/storage/tests/test_archiver.py +++ b/swh/storage/tests/test_archiver.py @@ -1,163 +1,163 @@ # Copyright (C) 2015 The Software Heritage developers # See the AUTHORS file at the top-level directory of this distribution # License: GNU General Public License version 3, or any later version # See top-level LICENSE file for more information import tempfile import unittest import os from nose.tools import istest from nose.plugins.attrib import attr from datetime import datetime, timedelta from swh.core import hashutil from swh.core.tests.db_testing import DbTestFixture from server_testing import ServerTestFixture from swh.storage import Storage from swh.storage.exc import ObjNotFoundError from swh.storage.archiver import ArchiverDirector from swh.storage.objstorage.api.client import RemoteObjStorage from swh.storage.objstorage.api.server import app TEST_DIR = os.path.dirname(os.path.abspath(__file__)) TEST_DATA_DIR = os.path.join(TEST_DIR, '../../../../swh-storage-testdata') @attr('db') class TestArchiver(DbTestFixture, ServerTestFixture, unittest.TestCase): """ Test the objstorage archiver. """ TEST_DB_DUMP = os.path.join(TEST_DATA_DIR, 'dumps/swh.dump') def setUp(self): # Launch the backup server self.backup_objroot = tempfile.mkdtemp() self.config = {'storage_base': self.backup_objroot, 'storage_depth': 3} self.app = app super().setUp() # Launch a client to check objects presence print("url", self.url()) self.remote_objstorage = RemoteObjStorage(self.url()) # Create the local storage. self.objroot = tempfile.mkdtemp() self.storage = Storage(self.conn, self.objroot) # Initializes and fill the tables. self.initialize_tables() # Create the archiver self.archiver = self.__create_director() def tearDown(self): self.empty_tables() super().tearDown() def initialize_tables(self): """ Initializes the database with a sample of items. """ # Add an archive self.cursor.execute("""INSERT INTO archives(id, url) VALUES('Local', 'http://localhost:{}/') """.format(self.port)) self.conn.commit() def empty_tables(self): # Remove all content self.cursor.execute('DELETE FROM content_archive') self.cursor.execute('DELETE FROM archives') self.conn.commit() def __add_content(self, content_data, status='missing', date='now()'): # Add the content content = hashutil.hashdata(content_data) content.update({'data': content_data}) self.storage.content_add([content]) # Then update database content_id = r'\x' + hashutil.hash_to_hex(content['sha1']) self.cursor.execute("""INSERT INTO content_archive VALUES('%s'::sha1, 'Local', '%s', %s) """ % (content_id, status, date)) return content['sha1'] def __get_missing(self): self.cursor.execute("""SELECT content_id FROM content_archive WHERE status='missing'""") return self.cursor.fetchall() def __create_director(self, batch_size=5000, archival_max_age=3600, retention_policy=1, asynchronous=False): config = { 'objstorage_path': self.objroot, 'batch_max_size': batch_size, 'archival_max_age': archival_max_age, 'retention_policy': retention_policy, 'asynchronous': asynchronous # Avoid depending on queue for tests. } director = ArchiverDirector(self.conn, config) return director @istest def archive_missing_content(self): """ Run archiver on a missing content should archive it. """ content_data = b'archive_missing_content' id = self.__add_content(content_data) # After the run, the content should be in the archive. self.archiver.run() remote_data = self.remote_objstorage.content_get(id) self.assertEquals(content_data, remote_data) @istest def archive_present_content(self): """ A content that is not 'missing' shouldn't be archived. """ id = self.__add_content(b'archive_present_content', status='present') # After the run, the content should NOT be in the archive.* self.archiver.run() with self.assertRaises(ObjNotFoundError): self.remote_objstorage.content_get(id) @istest def archive_ongoing_remaining(self): """ A content that is ongoing and still have some time to be archived should not be rescheduled. """ id = self.__add_content(b'archive_ongoing_remaining', status='ongoing') items = [x for batch in self.archiver.get_unarchived_content() for x in batch] id = r'\x' + hashutil.hash_to_hex(id) self.assertNotIn(id, items) @istest def archive_ongoing_elapsed(self): """ A content that is ongoing but with elapsed time should be rescheduled. """ # Create an ongoing archive content with time elapsed by 1s. id = self.__add_content( b'archive_ongoing_elapsed', status='ongoing', date="'%s'" % (datetime.now() - timedelta( - seconds=self.archiver.archival_max_age + 1 + seconds=self.archiver.config['archival_max_age'] + 1 )) ) items = [x for batch in self.archiver.get_unarchived_content() for x in batch] id = r'\x' + hashutil.hash_to_hex(id) self.assertIn(id, items) @istest def archive_already_enough(self): """ A content missing should not be archived if there is already enough copies. """ id = self.__add_content(b'archive_alread_enough') director = self.__create_director(retention_policy=0) director.run() with self.assertRaises(ObjNotFoundError): self.remote_objstorage.content_get(id)