You are viewing the documentation for an older version of boto (boto2).

Boto3, the next version of Boto, is now stable and recommended for general use. It can be used side-by-side with Boto in the same project, so it is easy to start using Boto3 in your existing projects as well as new projects. Going forward, API updates and all new feature work will be focused on Boto3.

For more information, see the documentation for boto3.

An Introduction to boto’s request hook

This tutorial shows you how to use the request hook for data gathering.

It is often important to measure things we do as developers to better understand application performance and the interactions between components of the system. Boto plays a key role in some of those interactions as any client library would.

We’ll go over how to use the request hook to do some simple request logging.

Creating a connection

For this example, let’s use the EC2 interface as an example. Any connection will work (IAM, SQS, etc..):

>>> from boto import ec2
>>> conn = ec2.connect_to_region('us-west-2')

You will be using this conn object for the remainder of the tutorial to send commands to EC2.

Adding your own hook

The hook interface is defined in boto.utils.RequestHook The method signature looks like:

def handle_request_data(self, request, response, error=False):

In, there is an implementation of this interface which is written to handle multiple threads sending data to a single log writing thread. Exammining this file, you’ll see a log file, queue and thread are created, then as requests are made, the handle_request_data() method is called. It extracts data from the request and respose object to create a log message. That’s inserted into the queue and handled by the _request_log_worker thread.

One thing to note is that the boto request object has an additional value “start_time”, which is a as of the time right before the request was issued. This can be used along with the current time (after the request) to calculate the duration of the request.

To add this logger to your connection:

>>> from boto.requestlog import RequestLogger
>>> conn.set_request_hook(RequestLogger())

That’s all you need to do! Now, if you make a request, like:

>>> conn.get_all_volumes()

The log message produced might look something like this:

'2014-02-26 21:38:27', '200', '0.791542', '592', 'DescribeVolumes'