在Scrapy中，对回调函数的调用导致收益请求失败

Question

class DmozSpider(Spider):
global requests
name = "drugtrials"
dt = import_config()
allowed_domains = ['chinadrugtrials.org.cn']
start_urls = [
    'http://www.chinadrugtrials.org.cn/eap/clinicaltrials.searchlist'
]

def parse(self, response):
    print 'drugtrials start time :', datetime.datetime.now()
    f = open('/var/www/html/cde/drugtrials.txt', 'a+')
    f.write("drugtrials start time" + str(datetime.datetime.now()) + '\n')
    f.close()
    dt = import_config()
    notneedwords_str = dt['not_need_words']
    NOTNEEDWORDS = notneedwords_str.split('，')
    print "NOTNEEDWORDS:", NOTNEEDWORDS
    db = cx_Oracle.connect(ORACLE_USER, ORACLE_PASSWD, ORACLE_DSN)
    cursor = db.cursor()
    sql = """SELECT "id","name","company" FROM "cde" where "sfda_status">=8""" # **There are 116589 data sets here.**
    cursor.execute(sql)
    result = cursor.fetchall()
    length = len(result)
    requests = []
    zhPattern = re.compile(u'[\u4e00-\u9fa5]+')
    for i in range(0, length):
        namearr = result[i][1].split(" ")
        companyarr = result[i][2].split(" ")
        arr = namearr + companyarr
        for m in arr:
            if not len(m) == 1 and m not in NOTNEEDWORDS:
                if m in namearr:
                    # 药物别名查询
                    cursor.execute(
                        """SELECT "cde_usedname","cde_usedname2","cde_usedname3","cde_usedname4","cde_usedname5" from "cde_usedname" where "cde_name"=:cde_name """,
                        {'cde_name': m})
                    all_bieming1 = cursor.fetchone()
                    all_bieming = []
                    if all_bieming1:
                        for iva in all_bieming1:
                            if iva is not None:
                                all_bieming.append(iva)
                        print all_bieming
                        all_drug_name = ' '.join(all_bieming)
                        m2 = m + ' ' + all_drug_name
                    else:
                        m2 = m
                    request = FormRequest(dt['drug_url'],
                                          formdata={
                                              'drugs_name': m2
                                          },
                                          dont_filter=True,
                                          callback=self.parse_page,
                                          meta={'code': result[i][0], 'keyword': m2, 'keyword_type': 'drugs_name'}
                                          )
                    requests.append(request)
                else:
                    match = zhPattern.search(unicode(m))
                    if match:
                        request = FormRequest(dt['drug_url'],
                                              formdata={
                                                  'appliers': m
                                              },
                                              dont_filter=True,
                                              callback=self.parse_page,
                                              meta={'code': result[i][0], 'keyword': m, 'keyword_type': 'appliers'}
                                              )
                        requests.append(request)
                    else:
                        print'没中文{}'.format(m)

    length1 = len(requests)
    print "length1:",length1
    for request in requests:
        yield request

def parse_page(self, response):
    pass

我发现，当请求中的数据量太大（116,589）时，程序将不执行yield请求的代码。 我确定问题的原因是由于大量请求而导致无法调用回调函数。但是我没有找到解决问题的方法，请帮助我回答。谢谢！