The google.appengine.api.logservice package provides functions allowing applications to periodically flush logs during long-running requests and to examine an application's request logs and application logs.

This package has the following functions:

fetch ( start_time = None , end_time = None , offset = None , minimum_log_level = None , include_incomplete = False , include_app_logs = False , version_ids = None , request_ids = None )

Fetches an application's request and application logs. (An application can only retrieve its own application logs.) Returns an iterator that returns RequestLog objects, each of which contains the full log data for a request, both the request logs and any application logs for that request. Raises an InvalidArgumentError if any of the input parameters are not of the correct type.

Arguments

start_time

The earliest request completion or last-update time that results should be fetched for, in seconds since the Unix epoch.

end_time

The latest request completion or last-update time that results should be fetched for, in seconds since the Unix epoch.

offset

An offset value from a RequestLog object returned in a previous fetch call. May be used to continue a fetch() across multiple HTTP requests, for instance to display pages of results. Subsequent fetch() calls made with the same parameters plus an offset will continue immediately after the RequestLog from which the offset was retrieved.

minimum_log_level

An application log level that serves as a filter on the requests returned. Requests with no application log at or above the specified level will be omitted. This argument takes effect even if include_app_logs is not set to True. In ascending order, the available log levels are:

• logservice.LOG_LEVEL_DEBUG
• logservice.LOG_LEVEL_INFO
• logservice.LOG_LEVEL_WARNING
• logservice.LOG_LEVEL_ERROR
• logservice.LOG_LEVEL_CRITICAL

include_incomplete

Specifies whether to include requests that have started but are not yet finished, as a boolean.

include_app_logs

Specifies whether to include application logs, as a boolean. By default, application logs are not returned by logservice.fetch() ; you have to invoke it with its include_app_logs parameter set to True .

version_ids

A list of strings specifying the version IDs of the application to be queried in the fetch call. If you specify the request_ids parameter, version_ids is ignored.

request_ids

A list of strings containing the request IDs whose logs you are retrieving in the fetch call. You must supply a non-empty list containing no duplicate request IDs. You cannot use this parameter together with any other filtering option such as start_time , end_time , offset , or minimum_log_level .

Any request ID that does not correspond to a request log is ignored. Any malformed request IDs will cause the entire fetch() call to fail.

flush ()

For the current request, flushes log lines that are currently buffered.

flush_time ()

Returns the last time that the log buffer was flushed.

log_buffer_contents ()

Returns the contents of the logs buffer.

log_buffer_bytes ()

Returns the size of the log buffer, in bytes.

log_buffer_lines ()

Returns the number of log lines currently buffered.

auto_flush ()

This method is invoked automatically to flush logs in the background. You can tune the autoflush function with the following constants:

• logservice.AUTOFLUSH_ENABLED – Controls whether the in-process logs buffer is automatically flushed during a request. If false, logs are flushed at the end of each request. If true, automatically flushes the log buffer in the background.
• logservice.AUTOFLUSH_EVERY_SECONDS – If auto_flush() is enabled, flushes the logs buffer after this many seconds.
• logservice.AUTOFLUSH_EVERY_BYTES – If auto_flush() is enabled, flushes the logs buffer once this many bytes have been logged.
• logservice.AUTOFLUSH_EVERY_LINES – If auto_flush() is enabled, flushes the logs buffer once this many lines have been logged.

These are module-level variables that apps can change directly. For example, you can disable autoflush entirely as follows:

from google.appengine.api import logservice
logservice.AUTOFLUSH_ENABLED = False

# When you want to flush manually, do this
logservice.flush()

To flush every 20 lines, with no limit on time or bytes:

from google.appengine.api import logservice
logservice.AUTOFLUSH_EVERY_SECONDS = None
logservice.AUTOFLUSH_EVERY_BYTES = None
logservice.AUTOFLUSH_EVERY_LINES = 20 # The default, but set here for clarity