import cStringIO import datetime import hashlib import logging import math import os import pycurl import Queue import re import socket import ssl import sys import threading import timer import urlparse import arvados import arvados.config as config import arvados.errors import arvados.retry as retry import arvados.util _logger = logging.getLogger('arvados.keep') global_client_object = None # Monkey patch TCP constants when not available (apple). Values sourced from: # http://www.opensource.apple.com/source/xnu/xnu-2422.115.4/bsd/netinet/tcp.h if sys.platform == 'darwin': if not hasattr(socket, 'TCP_KEEPALIVE'): socket.TCP_KEEPALIVE = 0x010 if not hasattr(socket, 'TCP_KEEPINTVL'): socket.TCP_KEEPINTVL = 0x101 if not hasattr(socket, 'TCP_KEEPCNT'): socket.TCP_KEEPCNT = 0x102 class KeepLocator(object): EPOCH_DATETIME = datetime.datetime.utcfromtimestamp(0) HINT_RE = re.compile(r'^[A-Z][A-Za-z0-9@_-]+$') def __init__(self, locator_str): self.hints = [] self._perm_sig = None self._perm_expiry = None pieces = iter(locator_str.split('+')) self.md5sum = next(pieces) try: self.size = int(next(pieces)) except StopIteration: self.size = None for hint in pieces: if self.HINT_RE.match(hint) is None: raise ValueError("invalid hint format: {}".format(hint)) elif hint.startswith('A'): self.parse_permission_hint(hint) else: self.hints.append(hint) def __str__(self): return '+'.join( str(s) for s in [self.md5sum, self.size, self.permission_hint()] + self.hints if s is not None) def stripped(self): if self.size is not None: return "%s+%i" % (self.md5sum, self.size) else: return self.md5sum def _make_hex_prop(name, length): # Build and return a new property with the given name that # must be a hex string of the given length. data_name = '_{}'.format(name) def getter(self): return getattr(self, data_name) def setter(self, hex_str): if not arvados.util.is_hex(hex_str, length): raise ValueError("{} is not a {}-digit hex string: {}". format(name, length, hex_str)) setattr(self, data_name, hex_str) return property(getter, setter) md5sum = _make_hex_prop('md5sum', 32) perm_sig = _make_hex_prop('perm_sig', 40) @property def perm_expiry(self): return self._perm_expiry @perm_expiry.setter def perm_expiry(self, value): if not arvados.util.is_hex(value, 1, 8): raise ValueError( "permission timestamp must be a hex Unix timestamp: {}". format(value)) self._perm_expiry = datetime.datetime.utcfromtimestamp(int(value, 16)) def permission_hint(self): data = [self.perm_sig, self.perm_expiry] if None in data: return None data[1] = int((data[1] - self.EPOCH_DATETIME).total_seconds()) return "A{}@{:08x}".format(*data) def parse_permission_hint(self, s): try: self.perm_sig, self.perm_expiry = s[1:].split('@', 1) except IndexError: raise ValueError("bad permission hint {}".format(s)) def permission_expired(self, as_of_dt=None): if self.perm_expiry is None: return False elif as_of_dt is None: as_of_dt = datetime.datetime.now() return self.perm_expiry <= as_of_dt class Keep(object): """Simple interface to a global KeepClient object. THIS CLASS IS DEPRECATED. Please instantiate your own KeepClient with your own API client. The global KeepClient will build an API client from the current Arvados configuration, which may not match the one you built. """ _last_key = None @classmethod def global_client_object(cls): global global_client_object # Previously, KeepClient would change its behavior at runtime based # on these configuration settings. We simulate that behavior here # by checking the values and returning a new KeepClient if any of # them have changed. key = (config.get('ARVADOS_API_HOST'), config.get('ARVADOS_API_TOKEN'), config.flag_is_true('ARVADOS_API_HOST_INSECURE'), config.get('ARVADOS_KEEP_PROXY'), config.get('ARVADOS_EXTERNAL_CLIENT') == 'true', os.environ.get('KEEP_LOCAL_STORE')) if (global_client_object is None) or (cls._last_key != key): global_client_object = KeepClient() cls._last_key = key return global_client_object @staticmethod def get(locator, **kwargs): return Keep.global_client_object().get(locator, **kwargs) @staticmethod def put(data, **kwargs): return Keep.global_client_object().put(data, **kwargs) class KeepBlockCache(object): # Default RAM cache is 256MiB def __init__(self, cache_max=(256 * 1024 * 1024)): self.cache_max = cache_max self._cache = [] self._cache_lock = threading.Lock() class CacheSlot(object): __slots__ = ("locator", "ready", "content") def __init__(self, locator): self.locator = locator self.ready = threading.Event() self.content = None def get(self): self.ready.wait() return self.content def set(self, value): self.content = value self.ready.set() def size(self): if self.content is None: return 0 else: return len(self.content) def cap_cache(self): '''Cap the cache size to self.cache_max''' with self._cache_lock: # Select all slots except those where ready.is_set() and content is # None (that means there was an error reading the block). self._cache = [c for c in self._cache if not (c.ready.is_set() and c.content is None)] sm = sum([slot.size() for slot in self._cache]) while len(self._cache) > 0 and sm > self.cache_max: for i in xrange(len(self._cache)-1, -1, -1): if self._cache[i].ready.is_set(): del self._cache[i] break sm = sum([slot.size() for slot in self._cache]) def _get(self, locator): # Test if the locator is already in the cache for i in xrange(0, len(self._cache)): if self._cache[i].locator == locator: n = self._cache[i] if i != 0: # move it to the front del self._cache[i] self._cache.insert(0, n) return n return None def get(self, locator): with self._cache_lock: return self._get(locator) def reserve_cache(self, locator): '''Reserve a cache slot for the specified locator, or return the existing slot.''' with self._cache_lock: n = self._get(locator) if n: return n, False else: # Add a new cache slot for the locator n = KeepBlockCache.CacheSlot(locator) self._cache.insert(0, n) return n, True class Counter(object): def __init__(self, v=0): self._lk = threading.Lock() self._val = v def add(self, v): with self._lk: self._val += v def get(self): with self._lk: return self._val class KeepClient(object): # Default Keep server connection timeout: 2 seconds # Default Keep server read timeout: 256 seconds # Default Keep server bandwidth minimum: 32768 bytes per second # Default Keep proxy connection timeout: 20 seconds # Default Keep proxy read timeout: 256 seconds # Default Keep proxy bandwidth minimum: 32768 bytes per second DEFAULT_TIMEOUT = (2, 256, 32768) DEFAULT_PROXY_TIMEOUT = (20, 256, 32768) class KeepService(object): """Make requests to a single Keep service, and track results. A KeepService is intended to last long enough to perform one transaction (GET or PUT) against one Keep service. This can involve calling either get() or put() multiple times in order to retry after transient failures. However, calling both get() and put() on a single instance -- or using the same instance to access two different Keep services -- will not produce sensible behavior. """ HTTP_ERRORS = ( socket.error, ssl.SSLError, arvados.errors.HttpError, ) def __init__(self, root, user_agent_pool=Queue.LifoQueue(), upload_counter=None, download_counter=None, **headers): self.root = root self._user_agent_pool = user_agent_pool self._result = {'error': None} self._usable = True self._session = None self.get_headers = {'Accept': 'application/octet-stream'} self.get_headers.update(headers) self.put_headers = headers self.upload_counter = upload_counter self.download_counter = download_counter def usable(self): """Is it worth attempting a request?""" return self._usable def finished(self): """Did the request succeed or encounter permanent failure?""" return self._result['error'] == False or not self._usable def last_result(self): return self._result def _get_user_agent(self): try: return self._user_agent_pool.get(False) except Queue.Empty: return pycurl.Curl() def _put_user_agent(self, ua): try: ua.reset() self._user_agent_pool.put(ua, False) except: ua.close() @staticmethod def _socket_open(family, socktype, protocol, address=None): """Because pycurl doesn't have CURLOPT_TCP_KEEPALIVE""" s = socket.socket(family, socktype, protocol) s.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1) # Will throw invalid protocol error on mac. This test prevents that. if hasattr(socket, 'TCP_KEEPIDLE'): s.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPIDLE, 75) s.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPINTVL, 75) return s def get(self, locator, method="GET", timeout=None): # locator is a KeepLocator object. url = self.root + str(locator) _logger.debug("Request: %s %s", method, url) curl = self._get_user_agent() ok = None try: with timer.Timer() as t: self._headers = {} response_body = cStringIO.StringIO() curl.setopt(pycurl.NOSIGNAL, 1) curl.setopt(pycurl.OPENSOCKETFUNCTION, self._socket_open) curl.setopt(pycurl.URL, url.encode('utf-8')) curl.setopt(pycurl.HTTPHEADER, [ '{}: {}'.format(k,v) for k,v in self.get_headers.iteritems()]) curl.setopt(pycurl.WRITEFUNCTION, response_body.write) curl.setopt(pycurl.HEADERFUNCTION, self._headerfunction) if method == "HEAD": curl.setopt(pycurl.NOBODY, True) self._setcurltimeouts(curl, timeout) try: curl.perform() except Exception as e: raise arvados.errors.HttpError(0, str(e)) self._result = { 'status_code': curl.getinfo(pycurl.RESPONSE_CODE), 'body': response_body.getvalue(), 'headers': self._headers, 'error': False, } ok = retry.check_http_response_success(self._result['status_code']) if not ok: self._result['error'] = arvados.errors.HttpError( self._result['status_code'], self._headers.get('x-status-line', 'Error')) except self.HTTP_ERRORS as e: self._result = { 'error': e, } self._usable = ok != False if self._result.get('status_code', None): # The client worked well enough to get an HTTP status # code, so presumably any problems are just on the # server side and it's OK to reuse the client. self._put_user_agent(curl) else: # Don't return this client to the pool, in case it's # broken. curl.close() if not ok: _logger.debug("Request fail: GET %s => %s: %s", url, type(self._result['error']), str(self._result['error'])) return None if method == "HEAD": _logger.info("HEAD %s: %s bytes", self._result['status_code'], self._result.get('content-length')) return True _logger.info("GET %s: %s bytes in %s msec (%.3f MiB/sec)", self._result['status_code'], len(self._result['body']), t.msecs, (len(self._result['body'])/(1024.0*1024))/t.secs if t.secs > 0 else 0) if self.download_counter: self.download_counter.add(len(self._result['body'])) resp_md5 = hashlib.md5(self._result['body']).hexdigest() if resp_md5 != locator.md5sum: _logger.warning("Checksum fail: md5(%s) = %s", url, resp_md5) self._result['error'] = arvados.errors.HttpError( 0, 'Checksum fail') return None return self._result['body'] def put(self, hash_s, body, timeout=None): url = self.root + hash_s _logger.debug("Request: PUT %s", url) curl = self._get_user_agent() ok = None try: with timer.Timer() as t: self._headers = {} body_reader = cStringIO.StringIO(body) response_body = cStringIO.StringIO() curl.setopt(pycurl.NOSIGNAL, 1) curl.setopt(pycurl.OPENSOCKETFUNCTION, self._socket_open) curl.setopt(pycurl.URL, url.encode('utf-8')) # Using UPLOAD tells cURL to wait for a "go ahead" from the # Keep server (in the form of a HTTP/1.1 "100 Continue" # response) instead of sending the request body immediately. # This allows the server to reject the request if the request # is invalid or the server is read-only, without waiting for # the client to send the entire block. curl.setopt(pycurl.UPLOAD, True) curl.setopt(pycurl.INFILESIZE, len(body)) curl.setopt(pycurl.READFUNCTION, body_reader.read) curl.setopt(pycurl.HTTPHEADER, [ '{}: {}'.format(k,v) for k,v in self.put_headers.iteritems()]) curl.setopt(pycurl.WRITEFUNCTION, response_body.write) curl.setopt(pycurl.HEADERFUNCTION, self._headerfunction) self._setcurltimeouts(curl, timeout) try: curl.perform() except Exception as e: raise arvados.errors.HttpError(0, str(e)) self._result = { 'status_code': curl.getinfo(pycurl.RESPONSE_CODE), 'body': response_body.getvalue(), 'headers': self._headers, 'error': False, } ok = retry.check_http_response_success(self._result['status_code']) if not ok: self._result['error'] = arvados.errors.HttpError( self._result['status_code'], self._headers.get('x-status-line', 'Error')) except self.HTTP_ERRORS as e: self._result = { 'error': e, } self._usable = ok != False # still usable if ok is True or None if self._result.get('status_code', None): # Client is functional. See comment in get(). self._put_user_agent(curl) else: curl.close() if not ok: _logger.debug("Request fail: PUT %s => %s: %s", url, type(self._result['error']), str(self._result['error'])) return False _logger.info("PUT %s: %s bytes in %s msec (%.3f MiB/sec)", self._result['status_code'], len(body), t.msecs, (len(body)/(1024.0*1024))/t.secs if t.secs > 0 else 0) if self.upload_counter: self.upload_counter.add(len(body)) return True def _setcurltimeouts(self, curl, timeouts): if not timeouts: return elif isinstance(timeouts, tuple): if len(timeouts) == 2: conn_t, xfer_t = timeouts bandwidth_bps = KeepClient.DEFAULT_TIMEOUT[2] else: conn_t, xfer_t, bandwidth_bps = timeouts else: conn_t, xfer_t = (timeouts, timeouts) bandwidth_bps = KeepClient.DEFAULT_TIMEOUT[2] curl.setopt(pycurl.CONNECTTIMEOUT_MS, int(conn_t*1000)) curl.setopt(pycurl.LOW_SPEED_TIME, int(math.ceil(xfer_t))) curl.setopt(pycurl.LOW_SPEED_LIMIT, int(math.ceil(bandwidth_bps))) def _headerfunction(self, header_line): header_line = header_line.decode('iso-8859-1') if ':' in header_line: name, value = header_line.split(':', 1) name = name.strip().lower() value = value.strip() elif self._headers: name = self._lastheadername value = self._headers[name] + ' ' + header_line.strip() elif header_line.startswith('HTTP/'): name = 'x-status-line' value = header_line else: _logger.error("Unexpected header line: %s", header_line) return self._lastheadername = name self._headers[name] = value # Returning None implies all bytes were written class KeepWriterQueue(Queue.Queue): def __init__(self, copies): Queue.Queue.__init__(self) # Old-style superclass self.wanted_copies = copies self.successful_copies = 0 self.response = None self.successful_copies_lock = threading.Lock() self.pending_tries = copies self.pending_tries_notification = threading.Condition() def write_success(self, response, replicas_nr): with self.successful_copies_lock: self.successful_copies += replicas_nr self.response = response with self.pending_tries_notification: self.pending_tries_notification.notify_all() def write_fail(self, ks): with self.pending_tries_notification: self.pending_tries += 1 self.pending_tries_notification.notify() def pending_copies(self): with self.successful_copies_lock: return self.wanted_copies - self.successful_copies def get_next_task(self): with self.pending_tries_notification: while True: if self.pending_copies() < 1: # This notify_all() is unnecessary -- # write_success() already called notify_all() # when pending<1 became true, so it's not # possible for any other thread to be in # wait() now -- but it's cheap insurance # against deadlock so we do it anyway: self.pending_tries_notification.notify_all() # Drain the queue and then raise Queue.Empty while True: self.get_nowait() self.task_done() elif self.pending_tries > 0: service, service_root = self.get_nowait() if service.finished(): self.task_done() continue self.pending_tries -= 1 return service, service_root elif self.empty(): self.pending_tries_notification.notify_all() raise Queue.Empty else: self.pending_tries_notification.wait() class KeepWriterThreadPool(object): def __init__(self, data, data_hash, copies, max_service_replicas, timeout=None): self.total_task_nr = 0 self.wanted_copies = copies if (not max_service_replicas) or (max_service_replicas >= copies): num_threads = 1 else: num_threads = int(math.ceil(float(copies) / max_service_replicas)) _logger.debug("Pool max threads is %d", num_threads) self.workers = [] self.queue = KeepClient.KeepWriterQueue(copies) # Create workers for _ in range(num_threads): w = KeepClient.KeepWriterThread(self.queue, data, data_hash, timeout) self.workers.append(w) def add_task(self, ks, service_root): self.queue.put((ks, service_root)) self.total_task_nr += 1 def done(self): return self.queue.successful_copies def join(self): # Start workers for worker in self.workers: worker.start() # Wait for finished work self.queue.join() def response(self): return self.queue.response class KeepWriterThread(threading.Thread): TaskFailed = RuntimeError() def __init__(self, queue, data, data_hash, timeout=None): super(KeepClient.KeepWriterThread, self).__init__() self.timeout = timeout self.queue = queue self.data = data self.data_hash = data_hash self.daemon = True def run(self): while True: try: service, service_root = self.queue.get_next_task() except Queue.Empty: return try: locator, copies = self.do_task(service, service_root) except Exception as e: if e is not self.TaskFailed: _logger.exception("Exception in KeepWriterThread") self.queue.write_fail(service) else: self.queue.write_success(locator, copies) finally: self.queue.task_done() def do_task(self, service, service_root): success = bool(service.put(self.data_hash, self.data, timeout=self.timeout)) result = service.last_result() if not success: if result.get('status_code', None): _logger.debug("Request fail: PUT %s => %s %s", self.data_hash, result['status_code'], result['body']) raise self.TaskFailed _logger.debug("KeepWriterThread %s succeeded %s+%i %s", str(threading.current_thread()), self.data_hash, len(self.data), service_root) try: replicas_stored = int(result['headers']['x-keep-replicas-stored']) except (KeyError, ValueError): replicas_stored = 1 return result['body'].strip(), replicas_stored def __init__(self, api_client=None, proxy=None, timeout=DEFAULT_TIMEOUT, proxy_timeout=DEFAULT_PROXY_TIMEOUT, api_token=None, local_store=None, block_cache=None, num_retries=0, session=None): """Initialize a new KeepClient. Arguments: :api_client: The API client to use to find Keep services. If not provided, KeepClient will build one from available Arvados configuration. :proxy: If specified, this KeepClient will send requests to this Keep proxy. Otherwise, KeepClient will fall back to the setting of the ARVADOS_KEEP_SERVICES or ARVADOS_KEEP_PROXY configuration settings. If you want to KeepClient does not use a proxy, pass in an empty string. :timeout: The initial timeout (in seconds) for HTTP requests to Keep non-proxy servers. A tuple of three floats is interpreted as (connection_timeout, read_timeout, minimum_bandwidth). A connection will be aborted if the average traffic rate falls below minimum_bandwidth bytes per second over an interval of read_timeout seconds. Because timeouts are often a result of transient server load, the actual connection timeout will be increased by a factor of two on each retry. Default: (2, 256, 32768). :proxy_timeout: The initial timeout (in seconds) for HTTP requests to Keep proxies. A tuple of three floats is interpreted as (connection_timeout, read_timeout, minimum_bandwidth). The behavior described above for adjusting connection timeouts on retry also applies. Default: (20, 256, 32768). :api_token: If you're not using an API client, but only talking directly to a Keep proxy, this parameter specifies an API token to authenticate Keep requests. It is an error to specify both api_client and api_token. If you specify neither, KeepClient will use one available from the Arvados configuration. :local_store: If specified, this KeepClient will bypass Keep services, and save data to the named directory. If unspecified, KeepClient will fall back to the setting of the $KEEP_LOCAL_STORE environment variable. If you want to ensure KeepClient does not use local storage, pass in an empty string. This is primarily intended to mock a server for testing. :num_retries: The default number of times to retry failed requests. This will be used as the default num_retries value when get() and put() are called. Default 0. """ self.lock = threading.Lock() if proxy is None: if config.get('ARVADOS_KEEP_SERVICES'): proxy = config.get('ARVADOS_KEEP_SERVICES') else: proxy = config.get('ARVADOS_KEEP_PROXY') if api_token is None: if api_client is None: api_token = config.get('ARVADOS_API_TOKEN') else: api_token = api_client.api_token elif api_client is not None: raise ValueError( "can't build KeepClient with both API client and token") if local_store is None: local_store = os.environ.get('KEEP_LOCAL_STORE') self.block_cache = block_cache if block_cache else KeepBlockCache() self.timeout = timeout self.proxy_timeout = proxy_timeout self._user_agent_pool = Queue.LifoQueue() self.upload_counter = Counter() self.download_counter = Counter() self.put_counter = Counter() self.get_counter = Counter() self.hits_counter = Counter() self.misses_counter = Counter() if local_store: self.local_store = local_store self.get = self.local_store_get self.put = self.local_store_put else: self.num_retries = num_retries self.max_replicas_per_service = None if proxy: proxy_uris = proxy.split() for i in range(len(proxy_uris)): if not proxy_uris[i].endswith('/'): proxy_uris[i] += '/' # URL validation url = urlparse.urlparse(proxy_uris[i]) if not (url.scheme and url.netloc): raise arvados.errors.ArgumentError("Invalid proxy URI: {}".format(proxy_uris[i])) self.api_token = api_token self._gateway_services = {} self._keep_services = [{ 'uuid': "00000-bi6l4-%015d" % idx, 'service_type': 'proxy', '_service_root': uri, } for idx, uri in enumerate(proxy_uris)] self._writable_services = self._keep_services self.using_proxy = True self._static_services_list = True else: # It's important to avoid instantiating an API client # unless we actually need one, for testing's sake. if api_client is None: api_client = arvados.api('v1') self.api_client = api_client self.api_token = api_client.api_token self._gateway_services = {} self._keep_services = None self._writable_services = None self.using_proxy = None self._static_services_list = False def current_timeout(self, attempt_number): """Return the appropriate timeout to use for this client. The proxy timeout setting if the backend service is currently a proxy, the regular timeout setting otherwise. The `attempt_number` indicates how many times the operation has been tried already (starting from 0 for the first try), and scales the connection timeout portion of the return value accordingly. """ # TODO(twp): the timeout should be a property of a # KeepService, not a KeepClient. See #4488. t = self.proxy_timeout if self.using_proxy else self.timeout if len(t) == 2: return (t[0] * (1 << attempt_number), t[1]) else: return (t[0] * (1 << attempt_number), t[1], t[2]) def _any_nondisk_services(self, service_list): return any(ks.get('service_type', 'disk') != 'disk' for ks in service_list) def build_services_list(self, force_rebuild=False): if (self._static_services_list or (self._keep_services and not force_rebuild)): return with self.lock: try: keep_services = self.api_client.keep_services().accessible() except Exception: # API server predates Keep services. keep_services = self.api_client.keep_disks().list() # Gateway services are only used when specified by UUID, # so there's nothing to gain by filtering them by # service_type. self._gateway_services = {ks['uuid']: ks for ks in keep_services.execute()['items']} if not self._gateway_services: raise arvados.errors.NoKeepServersError() # Precompute the base URI for each service. for r in self._gateway_services.itervalues(): host = r['service_host'] if not host.startswith('[') and host.find(':') >= 0: # IPv6 URIs must be formatted like http://[::1]:80/... host = '[' + host + ']' r['_service_root'] = "{}://{}:{:d}/".format( 'https' if r['service_ssl_flag'] else 'http', host, r['service_port']) _logger.debug(str(self._gateway_services)) self._keep_services = [ ks for ks in self._gateway_services.itervalues() if not ks.get('service_type', '').startswith('gateway:')] self._writable_services = [ks for ks in self._keep_services if not ks.get('read_only')] # For disk type services, max_replicas_per_service is 1 # It is unknown (unlimited) for other service types. if self._any_nondisk_services(self._writable_services): self.max_replicas_per_service = None else: self.max_replicas_per_service = 1 def _service_weight(self, data_hash, service_uuid): """Compute the weight of a Keep service endpoint for a data block with a known hash. The weight is md5(h + u) where u is the last 15 characters of the service endpoint's UUID. """ return hashlib.md5(data_hash + service_uuid[-15:]).hexdigest() def weighted_service_roots(self, locator, force_rebuild=False, need_writable=False): """Return an array of Keep service endpoints, in the order in which they should be probed when reading or writing data with the given hash+hints. """ self.build_services_list(force_rebuild) sorted_roots = [] # Use the services indicated by the given +K@... remote # service hints, if any are present and can be resolved to a # URI. for hint in locator.hints: if hint.startswith('K@'): if len(hint) == 7: sorted_roots.append( "https://keep.{}.arvadosapi.com/".format(hint[2:])) elif len(hint) == 29: svc = self._gateway_services.get(hint[2:]) if svc: sorted_roots.append(svc['_service_root']) # Sort the available local services by weight (heaviest first) # for this locator, and return their service_roots (base URIs) # in that order. use_services = self._keep_services if need_writable: use_services = self._writable_services self.using_proxy = self._any_nondisk_services(use_services) sorted_roots.extend([ svc['_service_root'] for svc in sorted( use_services, reverse=True, key=lambda svc: self._service_weight(locator.md5sum, svc['uuid']))]) _logger.debug("{}: {}".format(locator, sorted_roots)) return sorted_roots def map_new_services(self, roots_map, locator, force_rebuild, need_writable, **headers): # roots_map is a dictionary, mapping Keep service root strings # to KeepService objects. Poll for Keep services, and add any # new ones to roots_map. Return the current list of local # root strings. headers.setdefault('Authorization', "OAuth2 %s" % (self.api_token,)) local_roots = self.weighted_service_roots(locator, force_rebuild, need_writable) for root in local_roots: if root not in roots_map: roots_map[root] = self.KeepService( root, self._user_agent_pool, upload_counter=self.upload_counter, download_counter=self.download_counter, **headers) return local_roots @staticmethod def _check_loop_result(result): # KeepClient RetryLoops should save results as a 2-tuple: the # actual result of the request, and the number of servers available # to receive the request this round. # This method returns True if there's a real result, False if # there are no more servers available, otherwise None. if isinstance(result, Exception): return None result, tried_server_count = result if (result is not None) and (result is not False): return True elif tried_server_count < 1: _logger.info("No more Keep services to try; giving up") return False else: return None def get_from_cache(self, loc): """Fetch a block only if is in the cache, otherwise return None.""" slot = self.block_cache.get(loc) if slot is not None and slot.ready.is_set(): return slot.get() else: return None @retry.retry_method def head(self, loc_s, num_retries=None): return self._get_or_head(loc_s, method="HEAD", num_retries=num_retries) @retry.retry_method def get(self, loc_s, num_retries=None): return self._get_or_head(loc_s, method="GET", num_retries=num_retries) def _get_or_head(self, loc_s, method="GET", num_retries=None): """Get data from Keep. This method fetches one or more blocks of data from Keep. It sends a request each Keep service registered with the API server (or the proxy provided when this client was instantiated), then each service named in location hints, in sequence. As soon as one service provides the data, it's returned. Arguments: * loc_s: A string of one or more comma-separated locators to fetch. This method returns the concatenation of these blocks. * num_retries: The number of times to retry GET requests to *each* Keep server if it returns temporary failures, with exponential backoff. Note that, in each loop, the method may try to fetch data from every available Keep service, along with any that are named in location hints in the locator. The default value is set when the KeepClient is initialized. """ if ',' in loc_s: return ''.join(self.get(x) for x in loc_s.split(',')) self.get_counter.add(1) locator = KeepLocator(loc_s) if method == "GET": slot, first = self.block_cache.reserve_cache(locator.md5sum) if not first: self.hits_counter.add(1) v = slot.get() return v self.misses_counter.add(1) # If the locator has hints specifying a prefix (indicating a # remote keepproxy) or the UUID of a local gateway service, # read data from the indicated service(s) instead of the usual # list of local disk services. hint_roots = ['http://keep.{}.arvadosapi.com/'.format(hint[2:]) for hint in locator.hints if hint.startswith('K@') and len(hint) == 7] hint_roots.extend([self._gateway_services[hint[2:]]['_service_root'] for hint in locator.hints if ( hint.startswith('K@') and len(hint) == 29 and self._gateway_services.get(hint[2:]) )]) # Map root URLs to their KeepService objects. roots_map = { root: self.KeepService(root, self._user_agent_pool, upload_counter=self.upload_counter, download_counter=self.download_counter) for root in hint_roots } # See #3147 for a discussion of the loop implementation. Highlights: # * Refresh the list of Keep services after each failure, in case # it's being updated. # * Retry until we succeed, we're out of retries, or every available # service has returned permanent failure. sorted_roots = [] roots_map = {} blob = None loop = retry.RetryLoop(num_retries, self._check_loop_result, backoff_start=2) for tries_left in loop: try: sorted_roots = self.map_new_services( roots_map, locator, force_rebuild=(tries_left < num_retries), need_writable=False) except Exception as error: loop.save_result(error) continue # Query KeepService objects that haven't returned # permanent failure, in our specified shuffle order. services_to_try = [roots_map[root] for root in sorted_roots if roots_map[root].usable()] for keep_service in services_to_try: blob = keep_service.get(locator, method=method, timeout=self.current_timeout(num_retries-tries_left)) if blob is not None: break loop.save_result((blob, len(services_to_try))) # Always cache the result, then return it if we succeeded. if method == "GET": slot.set(blob) self.block_cache.cap_cache() if loop.success(): if method == "HEAD": return True else: return blob # Q: Including 403 is necessary for the Keep tests to continue # passing, but maybe they should expect KeepReadError instead? not_founds = sum(1 for key in sorted_roots if roots_map[key].last_result().get('status_code', None) in {403, 404, 410}) service_errors = ((key, roots_map[key].last_result()['error']) for key in sorted_roots) if not roots_map: raise arvados.errors.KeepReadError( "failed to read {}: no Keep services available ({})".format( loc_s, loop.last_result())) elif not_founds == len(sorted_roots): raise arvados.errors.NotFoundError( "{} not found".format(loc_s), service_errors) else: raise arvados.errors.KeepReadError( "failed to read {}".format(loc_s), service_errors, label="service") @retry.retry_method def put(self, data, copies=2, num_retries=None): """Save data in Keep. This method will get a list of Keep services from the API server, and send the data to each one simultaneously in a new thread. Once the uploads are finished, if enough copies are saved, this method returns the most recent HTTP response body. If requests fail to upload enough copies, this method raises KeepWriteError. Arguments: * data: The string of data to upload. * copies: The number of copies that the user requires be saved. Default 2. * num_retries: The number of times to retry PUT requests to *each* Keep server if it returns temporary failures, with exponential backoff. The default value is set when the KeepClient is initialized. """ if isinstance(data, unicode): data = data.encode("ascii") elif not isinstance(data, str): raise arvados.errors.ArgumentError("Argument 'data' to KeepClient.put is not type 'str'") self.put_counter.add(1) data_hash = hashlib.md5(data).hexdigest() loc_s = data_hash + '+' + str(len(data)) if copies < 1: return loc_s locator = KeepLocator(loc_s) headers = {} # Tell the proxy how many copies we want it to store headers['X-Keep-Desired-Replicas'] = str(copies) roots_map = {} loop = retry.RetryLoop(num_retries, self._check_loop_result, backoff_start=2) done = 0 for tries_left in loop: try: sorted_roots = self.map_new_services( roots_map, locator, force_rebuild=(tries_left < num_retries), need_writable=True, **headers) except Exception as error: loop.save_result(error) continue writer_pool = KeepClient.KeepWriterThreadPool(data=data, data_hash=data_hash, copies=copies - done, max_service_replicas=self.max_replicas_per_service, timeout=self.current_timeout(num_retries - tries_left)) for service_root, ks in [(root, roots_map[root]) for root in sorted_roots]: if ks.finished(): continue writer_pool.add_task(ks, service_root) writer_pool.join() done += writer_pool.done() loop.save_result((done >= copies, writer_pool.total_task_nr)) if loop.success(): return writer_pool.response() if not roots_map: raise arvados.errors.KeepWriteError( "failed to write {}: no Keep services available ({})".format( data_hash, loop.last_result())) else: service_errors = ((key, roots_map[key].last_result()['error']) for key in sorted_roots if roots_map[key].last_result()['error']) raise arvados.errors.KeepWriteError( "failed to write {} (wanted {} copies but wrote {})".format( data_hash, copies, writer_pool.done()), service_errors, label="service") def local_store_put(self, data, copies=1, num_retries=None): """A stub for put(). This method is used in place of the real put() method when using local storage (see constructor's local_store argument). copies and num_retries arguments are ignored: they are here only for the sake of offering the same call signature as put(). Data stored this way can be retrieved via local_store_get(). """ md5 = hashlib.md5(data).hexdigest() locator = '%s+%d' % (md5, len(data)) with open(os.path.join(self.local_store, md5 + '.tmp'), 'w') as f: f.write(data) os.rename(os.path.join(self.local_store, md5 + '.tmp'), os.path.join(self.local_store, md5)) return locator def local_store_get(self, loc_s, num_retries=None): """Companion to local_store_put().""" try: locator = KeepLocator(loc_s) except ValueError: raise arvados.errors.NotFoundError( "Invalid data locator: '%s'" % loc_s) if locator.md5sum == config.EMPTY_BLOCK_LOCATOR.split('+')[0]: return '' with open(os.path.join(self.local_store, locator.md5sum), 'r') as f: return f.read() def is_cached(self, locator): return self.block_cache.reserve_cache(expect_hash)