pymysqlblinker 1.2

Python MySQL Replication Blinker
================================

Features
--------

This package uses
`mysql-replication <https://github.com/noplay/python-mysql-replication>`__
to read events from MySQL's binlog and send to blinker's signal.

- binlog action level
- schema level
- table level
- row level

It will send RowsEvent only.

Whenever a binlog event come, it will be dispatched into some signals:

#. binlog\_signal: 1 signal for the binlog event.
#. schema\_signal: 1 signal for the event's schema
#. table\_signal: 1 signal for the event's table.
#. row\_signal: 1+ signals for event's rows. 1 signal per row.

Signals
-------

.. code-block::

binlog event -> binlog signal -> schema signal -> table signal --> row signals

So, suppose that an event come with schema=foo, table=bar and it updated
2 rows. Those signal will be sent:

+-----------------+--------------------------+------------------------------+
| signal | signal name | sender |
+=================+==========================+==============================+
| binlog signal | ``update`` | event (RowsEvent) |
+-----------------+--------------------------+------------------------------+
| schema signal | ``update@foo`` | event (RowsEvent) |
+-----------------+--------------------------+------------------------------+
| table signal | ``update@foo.bar`` | event.rows (list of array) |
+-----------------+--------------------------+------------------------------+
| row signal | ``update@foo.bar#row`` | row1 (array) |
+-----------------+--------------------------+------------------------------+
| row signal | ``update@foo.bar#row`` | row2 object (array) |
+-----------------+--------------------------+------------------------------+

Connect to signals
------------------

To connect to a signal, you can use the signal instance or a decorator.

Suppose that you need to connect to write signal on table
*db0.table1*:

.. code-block:: python

from pymysqlblinker import signals

tbl1_signal = signals.table_write('db0', 'table1')

def subscriber1(rows, schema, table):
pass

# use connect function
tbl1_signal.connect(subscriber1)

# or use decorator
@signals.on_table_write('db0', 'table1')
def subscriber1(rows, schema, table):
pass

Signal publishing
-----------------

To start publishing signals

.. code-block:: python

from pymysqlblinker import start_publishing

start_publishing(
'mysql://root@localhost',
)

Replication
-----------

This package support a method to replicate from mysql database. It
operates by keep memory at last binlog position. By default, it save to a file.

To make it, call:

.. code-block:: python

from pymysqlblinker import start_replication

start_replication(
'mysql://root@localhost',
'/path/to/file/that/remember/binlog/position',
)

Change logs
-----------

1.2
~~~

- Add BinlogPosMemory to allow replication: replication is publishing
with
ability to remember last binlog position. For the first run, it will
start at
the end of current binlog.

1.1.1
~~~~~

- Add connect\_timeout argument to pub.start\_publishing