django-query-tracer

A simplified version of django-devserver limited to SQL tracing and Ajax dump.

Motivations

django-devserver is a very nice and usefull package, but the project isn't very active, and occasional problems related to new Django versions stay unfixed for long time even when a solution is available as PR.

Being mostly interested in tracing db queries, I finally decided to package a stripped down version of the project.

Screenshots

Quickstart

Install django-query-tracer:

pip install django-query-tracer

Add it to your INSTALLED_APPS:

INSTALLED_APPS = (
    ...
    'query_tracer',
    ...
)

Add django-query-tracer's middleware:

MIDDLEWARE_CLASSES = [
    ...
    'query_tracer.middleware.QueryTracerMiddleware',
    ...
]

Settings

QUERYTRACER_MODULES

Selects active modules.

Default: []

Example:

QUERYTRACER_MODULES = [
    'query_tracer.modules.sql.SQLRealTimeModule',
    'query_tracer.modules.sql.SQLSummaryModule',
    'query_tracer.modules.ajax.AjaxDumpModule',
    'query_tracer.modules.time.TimeModule',
]

QUERYTRACER_FILTER_OUT_SQL

A list of regex patterns to filter out SQL queries.

Queries matching any of the given patterns will be excluded from log.

Example:

QUERYTRACER_FILTER_OUT_SQL [
    re.compile('djkombu_\w+'),  # Filter all queries related to Celery
]

QUERYTRACER_FILTER_IN_SQL

A list of regex patterns to filter in SQL queries.

Only queries matching all patterns will be included in the log.

Example:

QUERYTRACER_FILTER_IN_SQL = [
    re.compile('sync_logs'),
    re.compile('date_created'),
]

DEVSERVER_TRUNCATE_SQL

Disable SQL query truncation (used in SQLRealTimeModule) setting this to False

QUERYTRACER_AJAX_CONTENT_LENGTH

Ajax responses longer than this will not be logged.

Default: 300

QUERYTRACER_AJAX_PRETTY_PRINT

If set, try to format ajax requests and responses as intented JSON

QUERYTRACER_SQL_MIN_DURATION

Minimum time a query must execute to be shown, value is in MS

Default: None

Sample local setup for development

# Install query_tracer

INSTALLED_APPS.append('query_tracer')

MIDDLEWARE_CLASSES += [
    'query_tracer.middleware.QueryTracerMiddleware',
]

QUERYTRACER_MODULES = (
    'query_tracer.modules.sql.SQLRealTimeModule',
    'query_tracer.modules.sql.SQLSummaryModule',
    'query_tracer.modules.ajax.AjaxDumpModule',
    'query_tracer.modules.time.TimeModule',
)

#QUERYTRACER_AJAX_CONTENT_LENGTH = 10000
QUERYTRACER_AJAX_PRETTY_PRINT = True
QUERYTRACER_TRUNCATE_SQL = False

QUERYTRACER_FILTER_IN_SQL = [
    re.compile('sync_logs'),
    re.compile('date_created'),
]

Features

See file "query_tracer/settings.py" for available options, and refer to django-devserver doc for usage/

Time module

A simple TimeModule module has been added to display the time required to process each Django view.

Utility functions

query_traces.utils.trace.trace

Prints a text message or list, optionally prettified

query_traces.utils.trace.prettyprint_query

Format and print a generic SQL query

query_traces.utils.trace.prettyprint_queryset

Format and print a queryset's query

query_traces.utils.trace.trace_func

Prints function calls, showing actual parameters; to be used as decorator

query_traces.utils.time.ms_from_timedelta

Returns timedelta in milliseconds

Credits

This project is a stripped down version of:

• django-devserver

Tools used in rendering this package:

• Cookiecutter
• cookiecutter-djangopackage