X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/6386f2aca83b477210bda19a3284ea31463d2efc..1fa1006e5b21cfc30e694890db969c20864af8c6:/sdk/python/arvados/keep.py diff --git a/sdk/python/arvados/keep.py b/sdk/python/arvados/keep.py index f0a872417a..d92758062d 100644 --- a/sdk/python/arvados/keep.py +++ b/sdk/python/arvados/keep.py @@ -1,6 +1,4 @@ import gflags -import httplib -import httplib2 import logging import os import pprint @@ -21,6 +19,7 @@ import timer import datetime import ssl import socket +import requests _logger = logging.getLogger('arvados.keep') global_client_object = None @@ -143,8 +142,81 @@ class Keep(object): 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): + 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''' + self._cache_lock.acquire() + try: + # 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]) + finally: + self._cache_lock.release() + + def reserve_cache(self, locator): + '''Reserve a cache slot for the specified locator, + or return the existing slot.''' + self._cache_lock.acquire() + try: + # 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, False + + # Add a new cache slot for the locator + n = KeepBlockCache.CacheSlot(locator) + self._cache.insert(0, n) + return n, True + finally: + self._cache_lock.release() class KeepClient(object): + + # Default Keep server connection timeout: 3 seconds + # Default Keep server read timeout: 30 seconds + # Default Keep proxy connection timeout: 20 seconds + # Default Keep proxy read timeout: 60 seconds + DEFAULT_TIMEOUT = (3, 30) + DEFAULT_PROXY_TIMEOUT = (20, 60) + class ThreadLimiter(object): """ Limit the number of threads running at a given time to @@ -204,10 +276,10 @@ class KeepClient(object): class KeepService(object): # Make requests to a single Keep service, and track results. - HTTP_ERRORS = (httplib2.HttpLib2Error, httplib.HTTPException, + HTTP_ERRORS = (requests.exceptions.RequestException, socket.error, ssl.SSLError) - def __init__(self, root, **headers): + def __init__(self, root, timeout=None, **headers): self.root = root self.last_result = None self.success_flag = None @@ -223,19 +295,19 @@ class KeepClient(object): def last_status(self): try: - return int(self.last_result[0].status) + return self.last_result.status_code except (AttributeError, IndexError, ValueError): return None - def get(self, http, locator): - # http is an httplib2.Http object. + def get(self, locator, timeout=None): # locator is a KeepLocator object. url = self.root + str(locator) _logger.debug("Request: GET %s", url) try: with timer.Timer() as t: - result = http.request(url.encode('utf-8'), 'GET', - headers=self.get_headers) + result = requests.get(url.encode('utf-8'), + headers=self.get_headers, + timeout=timeout) except self.HTTP_ERRORS as e: _logger.debug("Request fail: GET %s => %s: %s", url, type(e), str(e)) @@ -243,7 +315,7 @@ class KeepClient(object): else: self.last_result = result self.success_flag = retry.check_http_response_success(result) - content = result[1] + content = result.content _logger.info("%s response: %s bytes in %s msec (%.3f MiB/sec)", self.last_status(), len(content), t.msecs, (len(content)/(1024.0*1024))/t.secs) @@ -251,15 +323,18 @@ class KeepClient(object): resp_md5 = hashlib.md5(content).hexdigest() if resp_md5 == locator.md5sum: return content - _logger.warning("Checksum fail: md5(%s) = %s", url, md5) + _logger.warning("Checksum fail: md5(%s) = %s", + url, resp_md5) return None - def put(self, http, hash_s, body): + def put(self, hash_s, body, timeout=None): url = self.root + hash_s _logger.debug("Request: PUT %s", url) try: - result = http.request(url.encode('utf-8'), 'PUT', - headers=self.put_headers, body=body) + result = requests.put(url.encode('utf-8'), + data=body, + headers=self.put_headers, + timeout=timeout) except self.HTTP_ERRORS as e: _logger.debug("Request fail: PUT %s => %s: %s", url, type(e), str(e)) @@ -300,12 +375,13 @@ class KeepClient(object): str(threading.current_thread()), self.args['data_hash'], self.args['service_root']) - h = httplib2.Http(timeout=self.args.get('timeout', None)) self._success = bool(self.service.put( - h, self.args['data_hash'], self.args['data'])) + self.args['data_hash'], + self.args['data'], + timeout=self.args.get('timeout', None))) status = self.service.last_status() if self._success: - resp, body = self.service.last_result + result = self.service.last_result _logger.debug("KeepWriterThread %s succeeded %s %s", str(threading.current_thread()), self.args['data_hash'], @@ -315,18 +391,20 @@ class KeepClient(object): # we're talking to a proxy or other backend that # stores to multiple copies for us. try: - replicas_stored = int(resp['x-keep-replicas-stored']) + replicas_stored = int(result.headers['x-keep-replicas-stored']) except (KeyError, ValueError): replicas_stored = 1 - limiter.save_response(body.strip(), replicas_stored) + limiter.save_response(result.text.strip(), replicas_stored) elif status is not None: _logger.debug("Request fail: PUT %s => %s %s", self.args['data_hash'], status, - self.service.last_result[1]) + self.service.last_result.text) - def __init__(self, api_client=None, proxy=None, timeout=300, - api_token=None, local_store=None): + 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): """Initialize a new KeepClient. Arguments: @@ -337,8 +415,14 @@ class KeepClient(object): Keep proxy. Otherwise, KeepClient will fall back to the setting of the ARVADOS_KEEP_PROXY configuration setting. If you want to ensure KeepClient does not use a proxy, pass in an empty string. - * timeout: The timeout for all HTTP requests, in seconds. Default - 300. + * timeout: The timeout (in seconds) for HTTP requests to Keep + non-proxy servers. A tuple of two floats is interpreted as + (connection_timeout, read_timeout): see + http://docs.python-requests.org/en/latest/user/advanced/#timeouts. + Default: (3, 30). + * proxy_timeout: The timeout (in seconds) for HTTP requests to + Keep proxies. A tuple of two floats is interpreted as + (connection_timeout, read_timeout). Default: (20, 60). * 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 @@ -350,33 +434,40 @@ class KeepClient(object): 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: proxy = config.get('ARVADOS_KEEP_PROXY') if api_token is None: - api_token = config.get('ARVADOS_API_TOKEN') + 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() + if local_store: self.local_store = local_store self.get = self.local_store_get self.put = self.local_store_put else: - self.timeout = timeout - self.cache_max = 256 * 1024 * 1024 # Cache is 256MiB - self._cache = [] - self._cache_lock = threading.Lock() + self.num_retries = num_retries if proxy: if not proxy.endswith('/'): proxy += '/' self.api_token = api_token self.service_roots = [proxy] self.using_proxy = True + self.timeout = proxy_timeout self.static_service_roots = True else: # It's important to avoid instantiating an API client @@ -387,6 +478,7 @@ class KeepClient(object): self.api_token = api_client.api_token self.service_roots = None self.using_proxy = None + self.timeout = timeout self.static_service_roots = False def build_service_roots(self, force_rebuild=False): @@ -403,14 +495,14 @@ class KeepClient(object): if not keep_services: raise arvados.errors.NoKeepServersError() - self.using_proxy = (keep_services[0].get('service_type') == - 'proxy') + self.using_proxy = any(ks.get('service_type') == 'proxy' + for ks in keep_services) - roots = (("http%s://%s:%d/" % - ('s' if f['service_ssl_flag'] else '', - f['service_host'], - f['service_port'])) - for f in keep_services) + roots = ("{}://[{}]:{:d}/".format( + 'https' if ks['service_ssl_flag'] else 'http', + ks['service_host'], + ks['service_port']) + for ks in keep_services) self.service_roots = sorted(set(roots)) _logger.debug(str(self.service_roots)) @@ -461,59 +553,6 @@ class KeepClient(object): _logger.debug(str(pseq)) return pseq - class CacheSlot(object): - 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 == None: - return 0 - else: - return len(self.content) - - def cap_cache(self): - '''Cap the cache size to self.cache_max''' - self._cache_lock.acquire() - try: - self._cache = filter(lambda c: not (c.ready.is_set() and c.content == None), self._cache) - sm = sum([slot.size() for slot in self._cache]) - while sm > self.cache_max: - del self._cache[-1] - sm = sum([slot.size() for a in self._cache]) - finally: - self._cache_lock.release() - - def reserve_cache(self, locator): - '''Reserve a cache slot for the specified locator, - or return the existing slot.''' - self._cache_lock.acquire() - try: - # 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, False - - # Add a new cache slot for the locator - n = KeepClient.CacheSlot(locator) - self._cache.insert(0, n) - return n, True - finally: - self._cache_lock.release() def map_new_services(self, roots_map, md5_s, force_rebuild, **headers): # roots_map is a dictionary, mapping Keep service root strings @@ -545,7 +584,8 @@ class KeepClient(object): else: return None - def get(self, loc_s, num_retries=0): + @retry.retry_method + def get(self, loc_s, num_retries=None): """Get data from Keep. This method fetches one or more blocks of data from Keep. It @@ -562,14 +602,15 @@ class KeepClient(object): *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. Default 0. + 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(',')) locator = KeepLocator(loc_s) expect_hash = locator.md5sum - slot, first = self.reserve_cache(expect_hash) + slot, first = self.block_cache.reserve_cache(expect_hash) if not first: v = slot.get() return v @@ -600,16 +641,15 @@ class KeepClient(object): services_to_try = [roots_map[root] for root in (local_roots + hint_roots) if roots_map[root].usable()] - http = httplib2.Http(timeout=self.timeout) for keep_service in services_to_try: - blob = keep_service.get(http, locator) + blob = keep_service.get(locator, timeout=self.timeout) if blob is not None: break loop.save_result((blob, len(services_to_try))) # Always cache the result, then return it if we succeeded. slot.set(blob) - self.cap_cache() + self.block_cache.cap_cache() if loop.success(): return blob @@ -625,7 +665,8 @@ class KeepClient(object): else: raise arvados.errors.KeepReadError(loc_s) - def put(self, data, copies=2, num_retries=0): + @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 @@ -640,7 +681,8 @@ class KeepClient(object): Default 2. * num_retries: The number of times to retry PUT requests to *each* Keep server if it returns temporary failures, with - exponential backoff. Default 0. + exponential backoff. The default value is set when the + KeepClient is initialized. """ data_hash = hashlib.md5(data).hexdigest() if copies < 1: @@ -686,7 +728,10 @@ class KeepClient(object): "Write fail for %s: wanted %d but wrote %d" % (data_hash, copies, thread_limiter.done())) - def local_store_put(self, data): + # Local storage methods need no-op num_retries arguments to keep + # integration tests happy. With better isolation they could + # probably be removed again. + def local_store_put(self, data, num_retries=0): md5 = hashlib.md5(data).hexdigest() locator = '%s+%d' % (md5, len(data)) with open(os.path.join(self.local_store, md5 + '.tmp'), 'w') as f: @@ -695,7 +740,7 @@ class KeepClient(object): os.path.join(self.local_store, md5)) return locator - def local_store_get(self, loc_s): + def local_store_get(self, loc_s, num_retries=0): try: locator = KeepLocator(loc_s) except ValueError: