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Using Google App Engine, Python 2.7, threadsafe:true, webapp2.

I would like to include all logging.XXX() messages in my API responses, so I need an efficient way to collect up all the log messages that occur during the scope of a request. I also want to operate in threadsafe:true, so I need to be careful to get only the right log messages.

Currently, my strategy is to add a logging.Handler at the start of my webapp2 dispatch method, and then remove it at the end. To collect logs only for my thread, I instantiate the logging.Handler with the name of the current thread; the handler will simply throw out log records that are from a different thread. I am using thread name and not thread ID because I was getting some unexpected results on dev_appserver when using the ID.

Questions:

  1. Is it efficient to constantly be adding/removing logging.Handler objects in this fashion? I.e., every request will add, then remove, a Handler. Is this "cheap"?

  2. Is this the best way to get only the logging messages for my request? My big assumption is that each request gets its own thread, and that thread name will actually select the right items.

  3. Am I fundamentally misunderstanding Python logging? Perhaps I should only have a single additional Handler added once at the "module-level" statically, and my dispatch should do something lighter.

Any advice is appreciated. I don't have a good understanding of what Python (and specifically App Engine Python) does under the hood with respect to logging. Obviously, this is eminently possible because the App Engine Log Viewer does exactly the same thing: it displays all the log messages for that request. In fact, if I could piggyback on that somehow, that would be even better. It absolutely needs to be super-cheap though - i.e., an RPC call is not going to cut it.

I can add some code if that will help.

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1 回答 1

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我在这里发现了很多好处：

from google.appengine.api import logservice
entries = logservice.logs_buffer().parse_logs()
于 2012-06-26T14:40:09.280 回答