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Telnet Console

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.. module:: scrapy.extensions.telnet
   :synopsis: The Telnet Console

Scrapy comes with a built-in telnet console for inspecting and controlling a Scrapy running process. The telnet console is just a regular python shell running inside the Scrapy process, so you can do literally anything from it.

The telnet console is a :ref:`built-in Scrapy extension <topics-extensions-ref>` which comes enabled by default, but you can also disable it if you want. For more information about the extension itself see :ref:`topics-extensions-ref-telnetconsole`.

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.. highlight:: none

How to access the telnet console

The telnet console listens in the TCP port defined in the :setting:`TELNETCONSOLE_PORT` setting, which defaults to 6023. To access the console you need to type:

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telnet localhost 6023
>>>

You need the telnet program which comes installed by default in Windows, and most Linux distros.

Available variables in the telnet console

The telnet console is like a regular Python shell running inside the Scrapy process, so you can do anything from it including importing new modules, etc.

However, the telnet console comes with some default variables defined for convenience:

Shortcut	Description
`crawler`	the Scrapy Crawler (:class:`scrapy.crawler.Crawler` object) System Message: ERROR/3 (`<stdin>`, line 47); backlink Unknown interpreted text role "class".
`engine`	Crawler.engine attribute
`spider`	the active spider
`slot`	the engine slot
`extensions`	the Extension Manager (Crawler.extensions attribute)
`stats`	the Stats Collector (Crawler.stats attribute)
`settings`	the Scrapy settings object (Crawler.settings attribute)
`est`	print a report of the engine status
`prefs`	for memory debugging (see :ref:`topics-leaks`) System Message: ERROR/3 (`<stdin>`, line 63); backlink Unknown interpreted text role "ref".
`p`	a shortcut to the pprint.pprint function
`hpy`	for memory debugging (see :ref:`topics-leaks`) System Message: ERROR/3 (`<stdin>`, line 67); backlink Unknown interpreted text role "ref".

Telnet console usage examples

Here are some example tasks you can do with the telnet console:

View engine status

You can use the est() method of the Scrapy engine to quickly show its state using the telnet console:

telnet localhost 6023
>>> est()
Execution engine status

time()-engine.start_time                        : 8.62972998619
engine.has_capacity()                           : False
len(engine.downloader.active)                   : 16
engine.scraper.is_idle()                        : False
engine.spider.name                              : followall
engine.spider_is_idle(engine.spider)            : False
engine.slot.closing                             : False
len(engine.slot.inprogress)                     : 16
len(engine.slot.scheduler.dqs or [])            : 0
len(engine.slot.scheduler.mqs)                  : 92
len(engine.scraper.slot.queue)                  : 0
len(engine.scraper.slot.active)                 : 0
engine.scraper.slot.active_size                 : 0
engine.scraper.slot.itemproc_size               : 0
engine.scraper.slot.needs_backout()             : False

Pause, resume and stop the Scrapy engine

To pause:

telnet localhost 6023
>>> engine.pause()
>>>

To resume:

telnet localhost 6023
>>> engine.unpause()
>>>

To stop:

telnet localhost 6023
>>> engine.stop()
Connection closed by foreign host.

Telnet Console signals

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.. signal:: update_telnet_vars

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.. function:: update_telnet_vars(telnet_vars)

    Sent just before the telnet console is opened. You can hook up to this
    signal to add, remove or update the variables that will be available in the
    telnet local namespace. In order to do that, you need to update the
    ``telnet_vars`` dict in your handler.

    :param telnet_vars: the dict of telnet variables
    :type telnet_vars: dict

Telnet settings

These are the settings that control the telnet console's behaviour:

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.. setting:: TELNETCONSOLE_PORT

TELNETCONSOLE_PORT

Default: [6023, 6073]

The port range to use for the telnet console. If set to None or 0, a dynamically assigned port is used.

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