Metadata-Version: 1.2
Name: django-dbconn-retry-coreteam
Version: 0.1.7
Summary: Patch Django to retry a database connection first before failing.
Home-page: https://github.com/jdelic/django-dbconn-retry/
Author: Jonas Maurus (@jdelic)
Author-email: jonas-dbconn-retry@gopythongo.com
Maintainer: GoPythonGo.com
Maintainer-email: info@gopythongo.com
License: UNKNOWN
Description: Django Database Connection Autoreconnect
        ========================================
        
        .. image:: https://coveralls.io/repos/github/jdelic/django-dbconn-retry/badge.svg?branch=HEAD
            :target: https://coveralls.io/github/jdelic/django-dbconn-retry?branch=HEAD
        
        .. image:: https://travis-ci.org/jdelic/django-dbconn-retry.svg?branch=master
            :target: https://travis-ci.org/jdelic/django-dbconn-retry
        
        This library monkeypatches ``django.db.backends.base.BaseDatabaseWrapper`` so
        that when a database operation fails because the underlying TCP connection was
        already closed, it first tried to reconnect, instead of immediately raising
        an ``OperationException``.
        
        
        Why is this useful?
        -------------------
        I use `HAProxy`_ as a load-balancer in front of my PostgreSQL databases all
        the time, sometimes in addition to ``pgbouncer``. Even though you can mostly
        prevent surprises by enabling TCP keep-alive packets through `tcpka`_,
        `clitcpka`_ and `srvtcpka`_, I still encounter situations where the
        underlying TCP connection has been closed through the load-balancer. Most often
        this results in
        
        .. code-block::
        
            django.db.utils.OperationalError: server closed the connection unexpectedly
            This probably means the server terminated abnormally before or while
            processing the request.
        
        This library patches Django such that it try to reconnect once before failing.
        
        Another application of this is when using `Hashicorp Vault`_, where
        credentials for a database connection can expire at any time and then need to
        be refreshed from Vault.
        
        
        How to install?
        ---------------
        Just pull the library in using ``pip install django-dbconn-retry``. Then add
        ``django_dbconn_retry`` to ``INSTALLED_APPS`` in your ``settings.py``.
        
        
        Signals
        -------
        The library provides an interface for other code to plug into the process to,
        for example, allow `12factor-vault`_ to refresh the database credentials
        before the code tries to reestablish the database connection. These are
        implemented using `Django Signals`_.
        
        ===========================  ==================================================
        Signal                       Description
        ===========================  ==================================================
        ``pre_reconnect``            Installs a hook of the type
                                     ``Callable[[type, BaseDatabaseWrapper], None]``
                                     that will be called before the library tries to
                                     reestablish a connection. 12factor-vault uses this
                                     to refresh the database credentials from Vault.
        ``post_reconnect``           Installs a hook of the type
                                     ``Callable[[type, BaseDatabaseWrapper], None]``
                                     that will be called after the library tried to
                                     reestablish the connection. Success or failure has
                                     not been tested at this point. So the connection
                                     may be in any state.
        ===========================  ==================================================
        
        
        License
        =======
        
        Copyright (c) 2018, Jonas Maurus
        All rights reserved.
        
        Redistribution and use in source and binary forms, with or without
        modification, are permitted provided that the following conditions are met:
        
        1. Redistributions of source code must retain the above copyright notice, this
           list of conditions and the following disclaimer.
        
        2. Redistributions in binary form must reproduce the above copyright notice,
           this list of conditions and the following disclaimer in the documentation
           and/or other materials provided with the distribution.
        
        3. Neither the name of the copyright holder nor the names of its contributors
           may be used to endorse or promote products derived from this software
           without specific prior written permission.
        
        THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
        ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
        WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
        DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
        FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
        DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
        SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
        CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
        OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
        OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
        
        
        .. _12factor-vault: https://github.com/jdelic/12factor-vault/
        .. _Django Signals: https://docs.djangoproject.com/en/dev/topics/signals/
        .. _HAProxy: http://www.haproxy.org/
        .. _tcpka:
           https://cbonte.github.io/haproxy-dconv/1.8/configuration.html#option%20tcpka
        .. _clitcpka:
           https://cbonte.github.io/haproxy-dconv/1.8/configuration.html#4-option%20clitcpka
        .. _srvtcpka:
           https://cbonte.github.io/haproxy-dconv/1.8/configuration.html#option%20srvtcpka
        .. _Hashicorp Vault: https://vaultproject.io/
        
Platform: UNKNOWN
Classifier: Development Status :: 4 - Beta
Classifier: Intended Audience :: Developers
Classifier: Intended Audience :: System Administrators
Classifier: Programming Language :: Python :: 3 :: Only
Classifier: License :: OSI Approved :: BSD License
Classifier: Operating System :: POSIX
