FEATURE REQUEST: option to limit size of network creation; batch/transaction creation

[freakalad]

I'm not sure is this is strictly-speaking the right place to file this, but will do so for want of a better alternative for now.

I recently made use of the RackSpace OpenStack Private Cloud installer/ISO, Alamo v.1.0.1
During the install process, I was promptes for my [private] network block, and I provided it as 192.168.0.0/8

The install process proceeded (overnight), but was getting nowhere.
Upon closer inspection of the process list (`top` & `ps aux`), I found the following to explain the crazy load on the system:
"/usr/bin/python /usr/bin/nova-manage network create --multi_host=T --label=public --fixed_range_v4=192.168.0.0/8 --num_networks=1 --network_size=16777214 --bridge=br0 --bridge_interface=eth1 --dns1=8.8.8.8 --dns2=8.8.4.4"
note: trying to fill up the *entire* network range of 16+ *MILLION* addresses

Found this issue with the help of a very nice RS tech @ IRC.

The prevailing consensus is that there should probably be a little bit more smarts in this subsystem - either get verification for networks larger than 1,000 or 10,000 adresses (anything that'll take more than, say, an hour to process; probably not really a possibility for a batch process), or batch the DB process into a transaction to run more efficiently.

[Michael Still (mikal)]

What version of openstack is the rackspace installer setting up? The performance of network creation was improved in folsom, so this shouldn't be horrendously slow any more.

Either way, this is probably a wishlist where we at least warn people that an operation like this would be very slow.

[Thierry Carrez (ttx)]

We cannot solve the issue you reported without more information. Could you please provide the requested information ?

[Justin Shepherd (jshepher)]

RAX Alamo-v1.0.1 used Essex.. Alamo-v2.0 uses folsom.. per @mikalstill above this should have been resolved.

[Aaron Rosen (arosen)]

The issue is that nova-network will create an ip entry for for each ip in that /8 i.e 16,777,216 inserts. Fwiw, If using quantum this is avoided.

[Markus Zoeller (markus_z) (mzoeller)]

This wishlist bug has been open a year without any activity. I'm going to move it to "Opinion / Wishlist", which is an easily-obtainable queue of older requests that have come on. If you decide to work on this
consider using a blueprint [1] (with spec [2]). I'll recommend to
read [3] if not yet done.

If there are any questions left, feel free to contact me (markus_z)
in the IRC channel #openstack-nova

References:
[1] https://blueprints.launchpad.net/nova/
[2] https://github.com/openstack/nova-specs
[3] https://wiki.openstack.org/wiki/Blueprints