def _start_scraper(region, scrape_type):
scrape_key = ScrapeKey(region, scrape_type)
most_recent_session = next(
sessions.get_sessions(
region_code=scrape_key.region_code,
include_closed=True,
most_recent_only=True,
scrape_type=scrape_key.scrape_type,
),
None,
)
if most_recent_session and not most_recent_session.phase.has_persisted(
):
raise Exception("Session already running for region [%s]. Could "
"not start a new session" % region)
logging.info(
"Purging pubsub queue for scrape_key: [%s] and pubsub_type: [%s]",
scrape_key,
BATCH_PUBSUB_TYPE,
)
pubsub_helper.purge(scrape_key, BATCH_PUBSUB_TYPE)
logging.info("Starting new scraper for: [%s]", scrape_key)
scraper = regions.get_region(region).get_scraper()
current_session = sessions.create_session(scrape_key)
# Help avoid race condition with new session info
# vs updating that w/first task.
time.sleep(1)
# Clear prior query docket for this scrape type and start adding new
# items in a background thread. In the case that there is a large
# names list, loading it can take some time. Loading it in the
# background allows us to start the scraper before it is fully
# loaded.
tracker.purge_docket_and_session(scrape_key)
# Note, the request context isn't copied when launching this thread, so
# any logs from within `load_target_list` will not be associated with
# the start scraper request.
load_docket_thread = threading.Thread(
target=structured_logging.with_context(docket.load_target_list),
args=(scrape_key, given_names, surname),
)
load_docket_thread.start()
# Start scraper, if the docket is empty this will wait for a bounded
# period of time for an item to be published (~90 seconds).
logging.info("Starting [%s]/[%s] scrape...", region, scrape_type)
scraper.start_scrape(scrape_type)
sessions.update_phase(current_session, scrape_phase.ScrapePhase.SCRAPE)
# Wait for the docket to be loaded
load_docket_thread.join()
def purge_query_docket(scrape_key: ScrapeKey):
"""Purges the docket of all tasks for provided region / scrape type
This deletes our current subscription to the given docket topic. When we try
to add or pull from the topic next, we will create a new subscription. That
subscription will only receive messages that are published after it is
created.
Args:
scrape_key: (ScrapeKey) The scraper whose tasks to purge the docket of
Returns:
N/A
"""
logging.info("Purging existing query docket for scraper: [%s]", scrape_key)
pubsub_helper.purge(scrape_key, PUBSUB_TYPE)