def check_for_finished_scrapers():
"""Checks for any finished scrapers and kicks off next processes."""
next_phase = scrape_phase.next_phase(request.endpoint)
next_phase_url = url_for(next_phase) if next_phase else None
cloud_task_manager = ScraperCloudTaskManager()
@monitoring.with_region_tag
def _check_finished(region_code: str):
# If there are no sessions currently scraping, nothing to check.
session = sessions.get_current_session(
ScrapeKey(region_code, constants.ScrapeType.BACKGROUND)
)
if not session or not session.phase.is_actively_scraping():
return
if is_scraper_finished(region_code, cloud_task_manager):
logging.info("Region [%s] has finished scraping.", region_code)
if next_phase:
logging.info(
"Enqueueing [%s] for region [%s].", next_phase, region_code
)
ScraperCloudTaskManager().create_scraper_phase_task(
region_code=region_code, url=next_phase_url
)
region_codes = ingest_utils.validate_regions(
get_str_param_values("region", request.args)
)
failed_regions = []
with futures.ThreadPoolExecutor() as executor:
future_to_region = {
executor.submit(
structured_logging.with_context(_check_finished), region_code
): region_code
for region_code in region_codes
}
for future in futures.as_completed(future_to_region):
region_code = future_to_region[future]
with monitoring.push_tags({monitoring.TagKey.REGION: region_code}):
try:
future.result()
except Exception:
logging.exception(
"An exception occured when checking region [%s]", region_code
)
failed_regions.append(region_code)
if failed_regions:
return (
"Failed to check regions: {}".format(failed_regions),
HTTPStatus.INTERNAL_SERVER_ERROR,
)
return ("", HTTPStatus.OK)
def read_and_persist() -> Tuple[str, HTTPStatus]:
"""Reads all of the messages from Datastore for a region and persists
them to the database.
"""
region = request.args.get("region")
if not isinstance(region, str):
raise ValueError(f"Expected string region, found [{region}]")
batch_tags = {
monitoring.TagKey.STATUS: "COMPLETED",
monitoring.TagKey.PERSISTED: False,
}
# Note: measurements must be second so it receives the region tag.
with monitoring.push_tags(
{monitoring.TagKey.REGION: region}
), monitoring.measurements(batch_tags) as measurements:
measurements.measure_int_put(m_batch_count, 1)
session = sessions.get_most_recent_completed_session(
region, ScrapeType.BACKGROUND
)
if not session:
raise ValueError(
f"Most recent session for region [{region}] is unexpectedly None"
)
scrape_type = session.scrape_type
try:
did_persist = persist_to_database(region, session.start)
batch_tags[monitoring.TagKey.PERSISTED] = did_persist
except Exception as e:
logging.exception(
"An exception occurred in read and persist: %s", type(e).__name__
)
batch_tags[monitoring.TagKey.STATUS] = "ERROR: {}".format(type(e).__name__)
sessions.update_phase(session, scrape_phase.ScrapePhase.DONE)
raise BatchPersistError(region, scrape_type) from e
if did_persist:
next_phase = scrape_phase.next_phase(request.endpoint)
sessions.update_phase(session, scrape_phase.ScrapePhase.RELEASE)
if next_phase:
logging.info("Enqueueing %s for region %s.", next_phase, region)
ScraperCloudTaskManager().create_scraper_phase_task(
region_code=region, url=url_for(next_phase)
)
return "", HTTPStatus.OK
sessions.update_phase(session, scrape_phase.ScrapePhase.DONE)
return "", HTTPStatus.ACCEPTED
def read_and_persist():
"""Reads all of the messages from Datastore for a region and persists
them to the database.
"""
region = request.args.get('region')
batch_tags = {
monitoring.TagKey.STATUS: 'COMPLETED',
monitoring.TagKey.PERSISTED: False
}
# Note: measurements must be second so it receives the region tag.
with monitoring.push_tags({monitoring.TagKey.REGION: region}), \
monitoring.measurements(batch_tags) as measurements:
measurements.measure_int_put(m_batch_count, 1)
session = sessions.get_most_recent_completed_session(
region, ScrapeType.BACKGROUND)
scrape_type = session.scrape_type
try:
did_persist = persist_to_database(region, session.start)
batch_tags[monitoring.TagKey.PERSISTED] = did_persist
except Exception as e:
logging.exception("An exception occurred in read and persist: %s",
type(e).__name__)
batch_tags[monitoring.TagKey.STATUS] = 'ERROR: {}' \
.format(type(e).__name__)
sessions.update_phase(session, scrape_phase.ScrapePhase.DONE)
raise BatchPersistError(region, scrape_type)
if did_persist:
next_phase = scrape_phase.next_phase(request.endpoint)
sessions.update_phase(session, scrape_phase.ScrapePhase.RELEASE)
if next_phase:
logging.info("Enqueueing %s for region %s.", region,
next_phase)
queues.enqueue_scraper_phase(region_code=region,
url=url_for(next_phase))
return '', HTTPStatus.OK
sessions.update_phase(session, scrape_phase.ScrapePhase.DONE)
return '', HTTPStatus.ACCEPTED
def scraper_stop():
"""Request handler to stop one or several running scrapers.
Note: Stopping any scrape type for a region involves purging the
scraping task queue for that region, necessarily killing any other
in-progress scrape types. Untargeted scrapes killed by this request
handler will be noted and resumed a moment or two later.
Unlike the other Scraper action methods, stop_scrape doesn't call
individually for each scrape type. That could create a race condition,
as each call noticed the other scrape type was running at the same
time, kicked off a resume effort with a delay, and then our second
call came to kill the other type and missed the (delayed / not yet
in taskqueue) call - effectively not stopping the scrape.
Instead, we send the full list of scrape_types to stop, and
Scraper.stop_scrape is responsible for fan-out.
Example query:
/scraper_control/stop?region=us_ny&scrape_type=background
URL parameters:
region: (string) Region to take action for, or 'all'
scrape_type: (string) Type of scrape to take action for, or 'all'
Args:
N/A
Returns:
N/A
"""
timezone = ingest_utils.lookup_timezone(request.args.get("timezone"))
respect_is_stoppable = get_str_param_value("respect_is_stoppable",
request.args)
# If a timezone wasn't provided stop all regions. If it was only stop
# regions that match the timezone.
scrape_regions = ingest_utils.validate_regions(
get_str_param_values("region", request.args), timezone=timezone)
scrape_types = ingest_utils.validate_scrape_types(
get_str_param_values("scrape_type", request.args))
next_phase = scrape_phase.next_phase(request.endpoint)
next_phase_url = url_for(next_phase) if next_phase else None
@structured_logging.copy_trace_id_to_thread
@monitoring.with_region_tag
def _stop_scraper(region: str):
closed_sessions = []
for scrape_type in scrape_types:
closed_sessions.extend(
sessions.close_session(ScrapeKey(region, scrape_type)))
for session in closed_sessions:
sessions.update_phase(session, scrape_phase.ScrapePhase.PERSIST)
if not closed_sessions:
return
was_stopped = False
try:
logging.info("Stopping scraper for region [%s].", region)
region_scraper = regions.get_region(region).get_ingestor()
was_stopped = region_scraper.stop_scrape(scrape_types,
respect_is_stoppable)
finally:
if next_phase and was_stopped:
logging.info("Enqueueing %s for region [%s].",
next_phase, region)
queues.enqueue_scraper_phase(region_code=region,
url=next_phase_url)
if not scrape_regions or not scrape_types:
return ('Missing or invalid parameters, see service logs.',
HTTPStatus.BAD_REQUEST)
failed_stops = []
with futures.ThreadPoolExecutor() as executor:
# Start all of the calls.
future_to_regions = \
{executor.submit(_stop_scraper, region_code): region_code
for region_code in scrape_regions}
# Wait for all the calls to finish.
for future in futures.as_completed(future_to_regions):
region_code = future_to_regions[future]
with monitoring.push_tags({monitoring.TagKey.REGION: region_code}):
try:
future.result()
except Exception:
logging.exception(
'An exception occured when stopping region [%s] for '
'[%s]',
region_code, scrape_types)
failed_stops.append(region_code)
else:
logging.info('Finished stopping region [%s] for [%s].',
region_code, scrape_types)
if failed_stops:
# This causes the whole request to be retried. Any regions whose session
# was closed during this call will be immediately skipped in the next
# call as we won't find any sessions to close. Any regions we failed to
# start likely still had their sessions closed and thus will be skipped,
# but it is worth retrying anyway.
return ('Failed to stop regions: {}'.format(failed_stops),
HTTPStatus.INTERNAL_SERVER_ERROR)
return ('', HTTPStatus.OK)
