spider2

spider2

A 2nd generation spider to crawl any article site, automatic reading title and content.

Performance

In my case, the speed of spider is about 700 thousands documents per day, 22 million per month, and the maximize crawling speed is 450 per minute, avg 80 per minute, the memory cost are about 200 megabytes on each spider kernel, and the accuracy is about 90%, the rest 10% can be fixed by customizing Score Rules or Selectors. it's better than any other readability modules.

Server infos:

• 20M bandwidth of fibre-optical
• 8 Intel(R) Xeon(R) CPU E5-2650 v2 @ 2.60GHz cpus
• 32G memory

Features

Multi-core crawling

It is not a single spider runs in a single thread. To take advantage of multi-core systems we maybe wanna launch a cluster of processes to handle the load, this is exactly what spider2 does - Crawling fast and in order to maximum performance.

Concurrency

Multi-core crawling feature is just make spiders work in a fork mode, but concurrency makes them work together in a same thread and at a same time!!!

Automatic

The old school crawls links/articles in a manual mode, e.g.: request to server and get the response(HTML), then using jQuery or something else to analyze links/articles by hard code, this feels sucks, currently, we just need to make a list of websites that you wanna scrape, spider2 will handle anything else, take a cup of coffee, and wait to harvest the fruit.

Queue

All the jobs are managed by async queue, so you can keep pushing the urls which to be crawled/read.

More features

• Automatic User-Agent (actually I am a browser, not a spider).
• Proxy supports (avoid being blocked by server).
• Blazing fast with Cheerio & Cluster Fork Mode.
• Automatic Decode encodings (especially useful with non-english language).
• ...

Installation

npm install spider2 --production

Programmatic

Require

var Spider = require('spider2');

Usage

var spider = Spider({
  timeout: 5000,
  debug: true,
  domain: true,
  workers: 7,
  concurrency: 1
});

Options

The options including:

• timeout Set a timeout (in milliseconds) for the request, 10000 by default.
• debug A value indicating whether show the debug log or not, false by default, also it could be set with process.env.SP_DEBUG.
• domain A value indicating whether the links being crawled should in a same domain with the base url or not, true by default.
• workers Number of multi-core, can not greater than number of CPUs.
• concurrency number of concurrency per worker, 1 by default.

Events

error

This event is emitted when an error has been caught, the arguments including:

• err Error object
• req Request data, if req.worker is defined an it is a number, means error is from the worker, req.worker is the id of a worker, otherwise it is a normal error. Example:

spider.on('error', function (err, req) {
  if (req.worker) {
    console.error('worker #', req.worker, 'has an error:', err.message);
  } else {
    console.error(req.uri, err.message);
  }
});

data

Data send by spider are obtained using this event, arguments including:

• req Request data.
• res Response data, if req._type equals Spider.type.LINK, res should be an array, including key-value pairs like {title: [ANCHOR_TITLE], uri: [ANCHOR_HREF]}, and if equals Spider.type.ARTICLE, res should be an object, keys including title and content. Example:

spider.on('data', function (req, res) {
  if (req._type == Spider.type.LINK) {
    spider.read(_.filter(res, validLink));
  } else if (req._type == Spider.type.ARTICLE) {
    console.log(req.uri, res.title);
  }
});

end

This event is emitted after all the spiders terminated abnormally, e.g.:

spider.on('end', function () {
  console.log('[END]');
});

Methods

crawl

Crawl links, OPTION could be one of below:

• String Url
• Array Array of urls, both [String, String, ...] and [Object, Object, ...] will be fine.
• Object Must including uri property.

e.g.:

spider.crawl([OPTION]);

read

Read title and content of article, OPTION is same as above, e.g.:

spider.read([OPTION]);

destroy

Peaceful quit, e.g.:

spider.destroy();

ping

Ping the spider and returns workers' status Array, e.g.:

var pong = spider.ping();
console.log(pong);

pong will be printed like:

[
  {id: 1, count: 12},
  {id: 2, count: 90},
  ...
]

id is the id of worker, and count is the count of remaining jobs.

Test

npm test

Examples

Head over to test/ or /examples directory.

TODO

• fix typo bug
• more tests

License

Copyright 2014 Tjatse

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.