On 05/13/2013 05:31 AM, Murphy McCauley wrote:
On May 12, 2013, at 11:15 PM, Karthik Sharma wrote:
I have a function called act_like_switch which uses a databased
backed architecture.If I come across a packet whose source address is
not in the database I insert the <src_packet,port_no> into the
database.Then I do a query of the destination address in the database
and retrive the port_no from the database and then send out the packet.
As you can see in the code below I measure the time taken for insert
and query.I also record the counts as well.Apparently the average
number of inserts is 30 per seconds and the average number of queries
is 700 per seconds.This is very low for my application.Are there any
ways to improve this numbers? Am I doing anything wrong?
This doesn't seem totally outlandish to me. That's like 33ms per
write... databases incur a penalty for their consistency properties
and so on.
I don't know why you're doing this, so it's hard to evaluate your
design. I'd suggest you ask yourself a bunch of questions... Do you
need to write this stuff to a database? Do you need to do it this
often (could you store this in a Python data structure temporarily and
write it to the database every few seconds)? Do you need to do it for
every exact-match flow (or could you do it for broader entries like,
for example, l2_pairs does)?
Also, instead of running a database lookup on each packet, could you
push match rules into the switch? That way, most of your packets would
avoid the overhead of being sent to the controller and waiting out the
database query.
It's kinda the whole point of having flow tables, right?
