我正在抓取从网站上获取数据到rails中的数据库。我使用此脚本获取32000记录没有任何问题，但我想更快地获取数据，所以我在我的网站中应用了线程rake任务但是在运行rake任务时出现问题，一些数据正在获取，然后rake任务被中止。
如果可以提供任何帮助，我不知道该怎么做我真的很感激。这是我的rake任务代码。
task scratch_to_database: :environment do
time2 = Time.now
puts "Current Time : " + time2.inspect
client = Mechanize.new
giftcard_types=Giftcard.card_types
find_all_merchant=Merchant.all.pluck(:id, :name).to_h
#first index page of the merchant
index_page = client.get('https://www.twitter.com//')
document_page_index = Nokogiri::HTML::Document.parse(index_page.body)
#set all merchant is deteled true
# set_merchant_as_deleted = Merchant.update_all(is_deleted: true) if Merchant.exists?
# set_giftcard_as_deleted = Giftcard.update_all(is_deleted: true) if Giftcard.exists?
update_all_merchant_record = []
update_all_giftcard_record = []
threads = []
#Merchant inner page pagination loop
page_no_merchant = document_page_index.css('.pagination.pagination-centered ul li:nth-last-child(2) a').text.to_i
1.upto(page_no_merchant) do |page_number|
threads << Thread.new do
client.get("https://www.twitter.com/buy-gift-cards?page=#{page_number}") do |page|
document = Nokogiri::HTML::Document.parse(page.body)
#Generate the name of the merchant and image of the merchant loop
document.css('.product-source').each do |item|
merchant_name= item.children.css('.name').text.gsub("Gift Cards", "")
href = item.css('a').first.attr('href')
image_url=item.children.css('.img img').attr('data-src').text.strip
#image url to parse the url of the image
image_url=URI.parse(image_url)
#saving the record of the merchant
# @merchant=Merchant.create(name: merchant_name , image_url:image_url)
if find_all_merchant.has_value?(merchant_name)
puts "this if"
merchant_id=find_all_merchant.key(merchant_name)
puts merchant_id
else
@merchant= Merchant.create(name: merchant_name , image_url:image_url)
update_all_merchant_record << @merchant.id
merchant_id=@merchant.id
end
# @merchant.update_attribute(:is_deleted, false)
#set all giftcard is deteled true
# set_giftcard_as_deleted = Giftcard.where(merchant_id: @merchant.id).update_all(is_deleted: true) if Giftcard.where(merchant_id: @merchant.id).exists?
#first page of the giftcard details page
first_page = client.get("https://www.twitter.com#{href}")
document_page = Nokogiri::HTML::Document.parse(first_page.body)
page_no = document_page.css('.pagination.pagination-centered ul li:nth-last-child(2) a').text.to_i
hrefextra =document_page.css('.dropdown-menu li a').last.attr('href')
#generate the giftcard details loop with the pagination
# update_all_record = []
find_all_giftcard=Giftcard.where(merchant_id:merchant_id).pluck(:row_id)
puts merchant_name
# puts find_all_giftcard.inspect
card_page = client.get("https://www.twitter.com#{hrefextra}")
document_page = Nokogiri::HTML::Document.parse(card_page.body)
#table details to generate the details of the giftcard with price ,per_off and final value of the giftcard
document_page.xpath('//table/tbody/tr[@class="toggle-details"]').collect do |row|
type1=[]
row_id = row.attr("id").to_i
row.at("td[2] ul").children.each do |typeli|
type = typeli.text.strip if typeli.text.strip.length != 0
type1 << type if typeli.text.strip.length != 0
end
value = row.at('td[3]').text.strip
value = value.to_s.tr('$', '').to_f
per_discount = row.at('td[4]').text.strip
per_discount = per_discount.to_s.tr('%', '').to_f
final_price = row.at('td[5] strong').text.strip
final_price = final_price.to_s.tr('$', '').to_f
type1.each do |type|
if find_all_giftcard.include?(row_id)
update_all_giftcard_record<<row_id
puts "exists"
else
puts "new"
@giftcard= Giftcard.create(card_type: giftcard_types.values_at(type.to_sym)[0], card_value:value, per_off:per_discount, card_price: final_price, merchant_id: merchant_id , row_id: row_id )
update_all_giftcard_record << @giftcard.row_id
end
end
#saving the record of the giftcard
# @giftcard=Giftcard.create(card_type:1, card_value:value, per_off:per_discount, card_price: final_price, merchant_id: @merchant.id , gift_card_type: type1)
end
# Giftcard.where(:id =>update_all_record).update_all(:is_deleted => false)
#delete all giftcard which is not present
# giftcard_deleted = Giftcard.where(:is_deleted => true,:merchant_id => @merchant.id).destroy_all if Giftcard.where(merchant_id: @merchant.id).exists?
time2 = Time.now
puts "Current Time : " + time2.inspect
end
end
end
end
threads.each(&:join)
puts "-------"
puts threads
# merchant_deleted = Merchant.where(:is_deleted => true).destroy_all if Merchant.exists?
merchant_deleted = Merchant.where('id NOT IN (?)',update_all_merchant_record).destroy_all if Merchant.exists?
giftcard_deleted = Giftcard.where('row_id NOT IN (?)',update_all_giftcard_record).destroy_all if Giftcard.exists?
end
端
我收到的错误： ActiveRecord :: ConnectionTimeoutError：无法在5.000秒内从池中获取连接（等待5.001秒）;所有汇集的连接都在使用中
答案 0 :(得分：0)
每个线程都需要单独连接到您的数据库。您需要增加应用程序可以在database.yml文件中使用的连接池大小。
但是您的数据库也应该能够处理传入的连接。如果您使用的是mysql，可以通过在控制台上运行select @@MAX_CONNECTIONS来检查这一点。