Dotter

Dotter is a high performance module which allows your application to send data to the outside world without any dependency but a small file.

Here is how it works.

+---------------+      +-------------------+
|  Application  |      |     Displayer     |
|               |      |                   |
|  +---------+  |      |  +-------------+  |
|  |Publisher|  |      |  |    Plot     |  |
|  +---------+  |      |  +-------------+  |
|      | |      |      |                   |
+------|-|------+      +-------------------+
       | |                      ^
       \ /                     / \
        v                      | |
+--------------+      +--------|-|--------+
|  Filesystem  |      | Broker | |        |
|              |      |        | |        |
|  +--------+  |      |   +-----------+   |
|  |  mmap  |--|------|-->| Collector |   |
|  +--------+  |      |   +-----------+   |
|              |      |                   |
+--------------+      +-------------------+

Demo Time

• Get ready

    $ pip install redis

• Start a Redis server to data storage

    $ redis-server &

• Start Publisher

    $ python -m dotter.publisher /tmp/data.mmap 1000 &

• Start Borker to transfer data to Displayer

    $ python -m dotter.broker /tmp/data.mmap 0.1 http://localhost:8000/data &

• Start Collector receive from Broker

    $ python app.py

• Go to Displayer to view time series

    $ open http://localhost:8000/static/index.html

Benchmark

Dotter basically won't affect the performance of your application.

It uses mmap to avoid network overhead, and also benefits from mmap's lazy flush.

The following benchmark is run on my Macbook Pro Retina:

$ python -m dotter.dotter benchmark ./dotter.mmap 10000
Speed: 257752.541081 dots per second

And also run on a server with a normal disk:

$ python -m dotter.dotter benchmark ./dotter.mmap 10000
Speed: 158639.595752 dots per second