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 built-in Scrapy extension which comes enabled by default, but you can also disable it if you want. For more information about the extension itself see Telnet console extension.
How to access the telnet console¶
The telnet console listens in the TCP port defined in the
TELNETCONSOLE_PORT setting, which defaults to 6023. To access
the console you need to type:
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 (scrapy.crawler.Crawler object) |
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 Debugging memory leaks) |
p |
a shortcut to the pprint.pprint function |
hpy |
for memory debugging (see Debugging memory leaks) |
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¶
-
scrapy.extensions.telnet.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_varsdict in your handler.Parameters: telnet_vars (dict) – the dict of telnet variables