Streaming Solutions

In the streaming solutions space, it all begins with the event driven architecture. This basically includes events (what triggers everything), the handlers (responsible for taking action) & the event loop (for coordinating). When things get more involved & complicated with multiple event streams/ sources, etc. solutions move into the cep space.

Another very popular programming methodology in recent times is Reactive programming. This in some senses is a special case of event driven programming with the focus on data change (as the event) & the reactive step to do other downstream data changes (as the handlers).

A whole bunch of frameworks for streaming solutions have emerged from the Big Data ecosystem such as Storm, Spark Streaming, Flink, etc. These allow for quick development of streaming solutions using high level abstractions. Even Solr has a streaming expression support now for building distributed streaming search solutions.

Outside of these frameworks, Akka Streams seems promising. It's built on top of Akka's robus Actor model & the Reactive Streams api. Solutions such as Gear Pump can provide a sense of the ground up solutions possible with Akka Streams. 

Installing Canon LBP2900 Printer on Ubuntu 16.04

Capturing notes on installation of Canon LBP2900 printer on a 64-bit Ubuntu 16.04 (a first for this version) locally (usb). These are essentially a mix and match of instructions from the pages Canon CAPT Driver, installing canon printer on debian systems, & Canon CAPT driver in a sequence that works.

=> Pre-requisites:

 

- Cups installation:

(Note: These instructions are from the alternate open source foo2capt library library. I have retained the installs for now, did not apt-remove. Not sure if all of them are actually needed.

As such, the foo2capt code failed to build & install with a whole lot of other missing/ invalid dependency issues. The foo2capt project rewrite seems to be on, so for now dropped the idea of experimenting with it any further.)

- Work around to known CAPT 64-bit OS issues linking to 32-bit libraries:

=> Download & install the Linux CAPT printer driver:

Download Linux_CAPT_PrinterDriver_V260_uk_EN.tar.gz, also linked here.

- Untar & install the 64-bit > Debian packages: 

=> Add printer to system:

- Start/ Restart cups service:

 

 - Can be done via the command line using lpadmin:

  

- Alternatively can be done via System Settings > Printer:

Either type on terminal: 

Or via System Tools > System Settings & Search for Printer

At this point a new printer gets created in my system with the name "Canon-LBP2900-CAPT-English".

(NOTE: Important to use the port 59787 (and not 59687). Also note that in the /etc/ccpd.conf, port 59787 is mentioned as UI_Port (& used by the captstatusui to communicate), while port 59687 as PDATA_Port files. Once ccpd services have been started, you can telnet to check that these ports are listening. )

 

=>  Add printer to ccpadmin:

- Add "Canon-LBP2900-CAPT-English" to ccpadmin: (will override any existing/ old entry)

- Now there should be a proper entry corresponding to the printer "Canon-LBP2900-CAPT-English":

=> Restart ccpd services:

The ccpd services need to be restarted since they don't start up automatically, there could also be the one ccpd process issue.

 

=> View status of printer on captstatusui:

- In case you see a communication error, unplug your printer & plug it in again. On my system this works & the printer status changes to:
 "Ready to Print"

(Note: Steps for setting up capt rules for usb add/remove could also be tried out.)

=> Print test page:

 Next print a test page on "Canon-LBP2900-CAPT-English" & that's it for the set-up.