Scrapy randomly crashing with celery in django

问题

I am running my Scrapy project within Django on a Ubuntu Server. The problem is, Scrapy randomly crash even if Its only one spider running.

Below is a snippet of the TraceBack. As a none expert, I have googled

_SIGCHLDWaker Scrappy

but couldn't comprehend the solutions found for the snippet of below:

--- <exception caught here> ---
  File "/home/b2b/virtualenvs/venv/local/lib/python2.7/site-packages/twisted/internet/posixbase.py", line 602, in _doReadOrWrite
    why = selectable.doWrite()
exceptions.AttributeError: '_SIGCHLDWaker' object has no attribute 'doWrite'

I am not familiar with twisted and it seems very unfriendly to me despite trying to understand it.

Below is the full traceback:

2015-10-10 14:17:13,652: INFO/Worker-4] Enabled downloader middlewares: HttpAuthMiddleware, DownloadTimeoutMiddleware, RandomUserAgentMiddleware, ProxyMiddleware, RetryMiddleware, DefaultHeadersMiddleware, MetaRefreshMiddleware, HttpCompressionMiddleware, RedirectMiddleware, CookiesMiddleware, ChunkedTransferMiddleware, DownloaderStats
[2015-10-10 14:17:13,655: INFO/Worker-4] Enabled spider middlewares: HttpErrorMiddleware, OffsiteMiddleware, RefererMiddleware, UrlLengthMiddleware, DepthMiddleware
[2015-10-10 14:17:13,656: INFO/Worker-4] Enabled item pipelines: MadePipeline
[2015-10-10 14:17:13,656: INFO/Worker-4] Spider opened
[2015-10-10 14:17:13,657: INFO/Worker-4] Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
Unhandled Error
Traceback (most recent call last):
  File "/home/b2b/virtualenvs/venv/local/lib/python2.7/site-packages/twisted/python/log.py", line 101, in callWithLogger
    return callWithContext({"system": lp}, func, *args, **kw)
  File "/home/b2b/virtualenvs/venv/local/lib/python2.7/site-packages/twisted/python/log.py", line 84, in callWithContext
    return context.call({ILogContext: newCtx}, func, *args, **kw)
  File "/home/b2b/virtualenvs/venv/local/lib/python2.7/site-packages/twisted/python/context.py", line 118, in callWithContext
    return self.currentContext().callWithContext(ctx, func, *args, **kw)
  File "/home/b2b/virtualenvs/venv/local/lib/python2.7/site-packages/twisted/python/context.py", line 81, in callWithContext
    return func(*args,**kw)
--- <exception caught here> ---
  File "/home/b2b/virtualenvs/venv/local/lib/python2.7/site-packages/twisted/internet/posixbase.py", line 602, in _doReadOrWrite
    why = selectable.doWrite()
exceptions.AttributeError: '_SIGCHLDWaker' object has no attribute 'doWrite'

Here is how I have implemented my task per documentation of scrapy

from scrapy.crawler import CrawlerProcess, CrawlerRunner
from twisted.internet import reactor
from scrapy.utils.project import get_project_settings
@shared_task
def run_spider(**kwargs):
    task_id = run_spider.request.id
    status = AsyncResult(str(task_id)).status
    source = kwargs.get("source")

    pro, created = Project.objects.get_or_create(name="b2b")
    query, _ = SearchTerm.objects.get_or_create(term=kwargs['query'])
    src, _ = Source.objects.get_or_create(term=query, engine=kwargs['source'])

    b, _ = Bot.objects.get_or_create(project=pro, query=src, spiderid=str(task_id), status=status, start_time=timezone.now())

    process = CrawlerRunner(get_project_settings())

    if source == "amazon":
        d = process.crawl(ComberSpider, query=kwargs['query'], job_id=task_id)
        d.addBoth(lambda _: reactor.stop())
    else:
        d = process.crawl(MadeSpider, query=kwargs['query'], job_id=task_id)
        d.addBoth(lambda _: reactor.stop())
    reactor.run()

Also I have tried something like this tutorial but it results in a different problem which I couldn't get traceback

For completeness here is a snippet of my Spider

class ComberSpider(CrawlSpider):

    name = "amazon"
    allowed_domains = ["amazon.com"]
    rules = (Rule(LinkExtractor(allow=r'corporations/.+/-*50/[0-9]+\.html', restrict_xpaths="//a[@class='next']"),
                  callback="parse_items", follow=True),
             )

    def __init__(self, *args, **kwargs):
        super(ComberSpider, self).__init__(*args, **kwargs)
        self.query = kwargs.get('query')
        self.job_id = kwargs.get('job_id')
        SignalManager(dispatcher.Any).connect(self.closed_handler, signal=signals.spider_closed)
        self.start_urls = (
            "http://www.amazon.com/corporations/%s/------------"
            "--------50/1.html" % self.query.strip().replace(" ", "_").lower(),
        )

回答1:

This is a known Scrapy issue. See the issue report thread for details and possible workarounds.

来源：https://stackoverflow.com/questions/33060257/scrapy-randomly-crashing-with-celery-in-django