Source code for biothings.web.query.pipeline


import asyncio
import logging
from collections import Counter
from dataclasses import dataclass

import elasticsearch
from biothings.web.query.builder import RawQueryInterrupt
from biothings.web.query.engine import EndScrollInterrupt, RawResultInterrupt

# here this module defines two types of operations supported in
# each query pipeline class, one called "search" which corresponds to
# a key-value pair search, with the sometimes optional parameter "scopes"
# being a list of keys to look for the value, named as parameter "q".
# the other type of query is called "fetch", that looks up documents
# basing on pre-defined fields that function as their mostly unique
# identifiers, it is a special type of "search" that ususally returns
# only one document. in this type of query, "scopes" are absolutely NOT
# provided, and the query term is called "id" in the parameter list.

# this module is called pipeline because
# a) it is a combination of individual query processing stages
# b) during async operations, it functions like the CPU pipeline,
#    more than 1 stage can be busy at a single point in time.

logger = logging.getLogger(__name__)


[docs]@dataclass(frozen=True) class QueryPipelineException(Exception): code: int = 500 summary: str = "" details: object = None
# use code here to indicate error types instead of # exception types, this reduces the number of potential # exception types this module needs to create. # furthermore, consider using a superset of HTTP codes, # so that error translation from the upper layers # is also convenient and straightforward.
[docs]class QueryPipelineInterrupt(QueryPipelineException): def __init__(self, data): super().__init__(200, None, data)
[docs]class QueryPipeline(): def __init__(self, builder, backend, formatter, **settings): self.builder = builder self.backend = backend self.formatter = formatter self.settings = settings
[docs] def search(self, q, **options): query = self.builder.build(q, **options) result = self.backend.execute(query, **options) return self.formatter.transform(result, **options)
[docs] def fetch(self, id, **options): assert options.get('scopes') is None result = self.search(id, **options) return result
def _simplify_ES_exception(exc, debug=False): result = {} try: root_cause = exc.info.get('error', exc.info) root_cause = root_cause['root_cause'][0]['reason'] root_cause = root_cause.replace('\"', '\'').split('\n') for index, cause in enumerate(root_cause): result['root_cuase_line_'+f'{index:02}'] = cause except IndexError: pass # no root cause except Exception: logger.exception(' '.join(( "Unexpected error in _simplify_ES_exception.", "Caused by incompatible version, build, etc.", "Update ES exception parsing logic here." ))) if debug: # raw ES error response result["debug"] = exc.info return exc.error, result
[docs]def capturesESExceptions(func): async def _(*args, **kwargs): try: return await func(*args, **kwargs) except( RawQueryInterrupt, # correspond to 'rawquery' option RawResultInterrupt, # correspond to 'raw' option EndScrollInterrupt ) as exc: raise QueryPipelineInterrupt(exc.data) except AssertionError as exc: # in our application, AssertionError should be internal # the individual components raising the error should instead # rasie exceptions like ValueError and TypeError for bad input logging.error("FIXME: Unexpected Assertion Error.") raise QueryPipelineException(500, str(exc) or "N/A") except (ValueError, TypeError) as exc: raise QueryPipelineException(400, type(exc).__name__, str(exc)) except elasticsearch.ConnectionError: # like timeouts.. raise QueryPipelineException(503) except elasticsearch.RequestError as exc: # 400s raise QueryPipelineException(400, *_simplify_ES_exception(exc)) # it seems like the managed Elasticsearch service by AWS # may provide slightly different exceptions when the server # is overloaded comparing to that of self-managed ES. # this case and most of the handling below can be further studied. # most of the exception handlings from this point on are based on # experience. further documentation in details will be helpful. except elasticsearch.TransportError as exc: # >400 if exc.error == 'search_phase_execution_exception': reason = exc.info.get("caused_by", {}).get("reason", "") if "rejected execution" in reason: raise QueryPipelineException(503) else: # unexpected, provide additional information for debug raise QueryPipelineException(500, *_simplify_ES_exception(exc, True)) elif exc.error == 'index_not_found_exception': raise QueryPipelineException(500, exc.error) elif exc.status_code in (429, 'N/A'): raise QueryPipelineException(503) else: # unexpected raise return _
[docs]class AsyncESQueryPipeline(QueryPipeline):
[docs] @capturesESExceptions async def search(self, q, **options): if isinstance(q, list): # multisearch options['templates'] = (dict(query=_q) for _q in q) options['template_miss'] = dict(notfound=True) options['template_hit'] = dict() query = self.builder.build(q, **options) response = await self.backend.execute(query, **options) result = self.formatter.transform(response, **options) return result
[docs] @capturesESExceptions async def fetch(self, id, **options): if options.get('scopes'): raise ValueError("Scopes Not Allowed.") # for builder options['autoscope'] = True # for formatter options['version'] = True options['score'] = False options['one'] = True # annotation endpoint should work on fields with reasonable # uniqueness of values, like id and symbol fields. because # we do not provide pagination for this endpoint, as it is # largely unncessary, in the case of matching too many docs # for one request, raise an exception instead of providing # the user incomplete matches. usually, when this happends, # it indicates bad choices of values as the default fields. MAX_MATCH = self.settings.get("fetch_max_match", 1000) options['size'] = MAX_MATCH + 1 # err when len(res) > MAX # "fetch" is a wrapper over "search". #---------------------------------------- result = await self.search(id, **options) #---------------------------------------- if isinstance(id, list): # batch counter = Counter(x["query"] for x in result) if counter.most_common(1)[0][1] > MAX_MATCH: raise QueryPipelineException(500, "Too Many Matches.") else: # single if result is None: raise QueryPipelineException(404, "Not Found.") if isinstance(result, list) and len(result) > MAX_MATCH: raise QueryPipelineException(500, "Too Many Matches.") return result
[docs]class ESQueryPipeline(QueryPipeline): # over async client # These implementations may not be performance optimized # It is used as a proof of concept and helps the design # of upper layer constructs, it also simplifies testing # by providing ioloop management, enabling sync access. # >>> from biothings.web.query.pipeline import ESQueryPipeline # >>> pipeline = ESQueryPipeline() # # >>> pipeline.fetch("1017", _source=["symbol"]) # {'_id': '1017', '_version': 1, 'symbol': 'CDK2'} # # >>> pipeline.search("1017", _source=["symbol"]) # { # 'took': 11, # 'total': 1, # 'max_score': 4.0133753, # 'hits': [ # { # '_id': '1017', # '_score': 4.0133753, # 'symbol': 'CDK2' # } # ] # } def __init__( self, builder=None, backend=None, formatter=None, *args, **kwargs ): if not builder: from biothings.web.query.builder import ESQueryBuilder builder = ESQueryBuilder() if not backend: from biothings.web.connections import get_es_client from biothings.web.query.engine import ESQueryBackend client = get_es_client(async_=True) backend = ESQueryBackend(client) if not formatter: from biothings.web.query.formatter import ESResultFormatter formatter = ESResultFormatter() super().__init__(builder, backend, formatter, *args, **kwargs) def _run_coroutine(self, coro, *args, **kwargs): loop = asyncio.get_event_loop() pipeline = AsyncESQueryPipeline( self.builder, self.backend, self.formatter) return loop.run_until_complete( coro(pipeline, *args, **kwargs))
[docs] def search(self, q, **options): return self._run_coroutine( AsyncESQueryPipeline.search, q, **options)
[docs] def fetch(self, id, **options): return self._run_coroutine( AsyncESQueryPipeline.fetch, id, **options)
[docs]class MongoQueryPipeline(QueryPipeline): pass
[docs]class SQLQueryPipeline(QueryPipeline): pass