> I need to receive SNMP-Traps in one of my apps. While I have
> successfully used Synapse to send SNMP-Traps I'm not sure I understand
> how to receive Traps without missing data.
> As Synapse uses blocking sockets I guess I should put the calls to
> RecvTrap() into a thread of its own. So far so good. What puzzles me is
> that inside the classless RecvTrap() function a TSNMPSend object is
> created and as soon as it has received a trap data packet this object is
> destroyed again. The classless function returns the trap data.
> So while I handle the trap data in my app any incoming SNMP traps are
> not handled because noone is listening on UDP port 162. Even if I do a
> new call to RecvTrap() as soon as possible there is still a small
> timeframe where a SNMP packet could arrive without being handled.
>
> Is it just me who doesn't see the forest for the trees or is this a
> faulty design in Synapse? Any comments are welcome. Thanks.
Maybe this is the place where asynchronous socket would help, such as ICS
http://www.overbyte.be.
Even using async socket, you have to be very careful about the design of
your application because UDP is a connectionless protocol, you are likely to
easily loose packets ! You should have a thread with highest possible
priority to accept incomming UDP datagrams (SNMP traps in your case) and put
those datagram into a queue for processing by another thread with lower
priority. Pay attention to DOS attack: always check you queue size and do
not accept datagram if the queue ever became too large. It is either that
the computer you are using is too slow for the load, or there is a DOS
attack occuring, flooding your application with tons of datagrams.
Contribute to the SSL Effort. Visit http://www.overbyte.be/eng/ssl.html
--
francois.piette@overbyte.be
Author of ICS (Internet Component Suite, freeware)
Author of MidWare (Multi-tier framework, freeware)
http://www.overbyte.be
