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what is meant by monolithic plugin [closed]

asked 2014-10-09 08:17:12 -0500

sushma-korati gravatar image

Hi All,

I was reading about ml2 plugin ( ) and came accorss the word "monolithic plugins", can any please explain me what exactly it means?


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Closed for the following reason the question is answered, right answer was accepted by sushma-korati
close date 2014-10-27 00:26:02.237584

2 answers

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answered 2014-10-09 13:06:02 -0500

darragh-oreilly gravatar image

All plugins except the ML2 plugin are "monolithic plugins".

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Thanks darragh.

sushma-korati gravatar imagesushma-korati ( 2014-10-10 05:20:59 -0500 )edit

answered 2014-10-09 13:55:14 -0500

sgordon gravatar image

updated 2014-10-09 17:25:53 -0500

All plugins implemented prior to the creation of the Modular Layer 2 framework were "monolithic" in that they took an all or nothing approach to handling the Layer-2 networking within the OpenStack environment. ML2 allows for a thinner, simpler to implement approach to adding Layer-2 technologies by implementing so called "mechanism drivers", and allows users to mix Layer-2 technologies within the same neutron deployment.

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Thank you sgordon. when you say "mix L2 technologies" does that mean we can use mutilple mechanism drivers in the same deployment, like I can create a port using opensvswitch and another port using linux bridge with-in the same subnet, in single openstack deployment??
Thanks in advance.

sushma-korati gravatar imagesushma-korati ( 2014-10-10 06:19:46 -0500 )edit

Yes, you can have multiple mechanism drivers. OpenVSwitch and LinuxBridge are commonly used together, but they don't work the way you seem to suggest [some ports created by OVS, some by LB].

vthapar gravatar imagevthapar ( 2014-10-20 06:03:45 -0500 )edit

Thanks vthapar. I have seen this sentence in ML2 wiki page "Unlike with the metaplugin, multiple mechanisms can be used simultaneously to access different ports of the same virtual network." so I got the doubt. Can you please explain this statement?

sushma-korati gravatar imagesushma-korati ( 2014-10-20 07:43:24 -0500 )edit

What it means is that you can use multiple mech drivers at same time. The way ML2 code works is it calls every mechanism driver configured for every method. So, lets say you have openvswitch and linuxbridge configured as mechanism driver, they both will get called for every port-create.

vthapar gravatar imagevthapar ( 2014-10-20 13:58:58 -0500 )edit

Thanks for explaining vthapar.

sushma-korati gravatar imagesushma-korati ( 2014-10-21 02:19:02 -0500 )edit

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Asked: 2014-10-09 08:17:12 -0500

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Last updated: Oct 09 '14