25 Jan
2010
25 Jan
'10
11:45 a.m.
Daniel-Constantin Mierla wrote:
Hello,
On 1/22/10 3:31 PM, Ovidiu Sas wrote:
Hello,
I saw the pipelimit commit, and I am going to have a look to better
understand the design. The first question is about the new pipelimit
module...
Does it require(as in it's a must) a working DB connection to get the
pipe configuration ? Because this could be a problem for some systems,
(like a light stateless proxy in front of other machines) because this
will mean the requirement of loading a DB module.
If there is indeed the need for a database, than I suggest that we still
allow cfg configuration , will the limitation that runtime changes
aren't permanent and are lost in case of a restart.
Regarding the static indexing versus dynamic allocation of pipes, I was
thinking that most setups only need a few pipes and that number doesn't
change very often. With this in mind I was thinking about combining the
two approaches: start to a low number of pipes (16 for example which is
basicaly an array on the stack or continuous allocation on the heap). In
case of need of a 17th pipe double the capacity (allocate a 32
continuous array on the heap ) and deep copy the old 16 pipes (something
that std::vector in c++ does when we alter its capacity). This will add
the advantage on using static indexing but still provide with the new
functionality of a variable number of pipes.
What do you think?
Greetings,
Marius
The way that the original module was written did
not allow dynamic
numbers of queues and pipes.
I am using the ratelimit module to control incoming/outgoing traffic
on specific trunks by invoking rate limitation based on pipes (by
forcing a specific pipe).
Choosing a specific pipe is up to the kamailio config designer (any
type of operations ca be applied to the pvar before choosing a
specific pipe, so IMHO it is pretty flexible as is right now - one can
apply any regex operations to a pvar).
Pipes and queues can be dynamically modified via mi commands.
The major limitation of the module is the hard coded number of queues
and pipes and the fact that dynamic changes to pipes and queues are
not saved on restart.
Loading the queues and pipes from a db will require a redesign of how
the pipes and queues are stored internally.
yes, it is a hash table. A benefit of dynamic/dynamic names is you can
simply use ip address as pipe name. Also strings tend to look more
meaningful when coming back to a config after some time :-) .
IIRC, one issue with the old design is using single lock for all
pipes. The advantage was using static indexing, therefore faster
access (still under one lock). The new one has a lock per slot, so
there can be quite some parallelism of updates/checks, therefore
overall could be same results, tending to be faster with old for low
number of pipes and not so heavy traffic, better with lot of pipes and
lot of traffic.
On the other hand, I find useful what Marius proposed as new features.
Cheers,
Daniel