CODEWITHSUNDEEP
csnmpnet-snmpmib
Matt
Matt

Reputation: 4989

Delayed Table Initialization

Using the net-snmp API and using mib2c to generate the skeleton code, is it possible to support delayed initialization of tables? What I mean is, the table would not be initialized until any of it's members were queried directly. The reason for this is that the member data is obtained from another server, and I'd like to be able to start the snmpd daemon without requiring the other server to be online/ready for requests. I thought of maybe initializing the table with dummy data that gets updated with the real values when a member is queried, but I'm not sure if this is the best way.

The table also has only one row of entries, so using mib2c.iterate.conf to generate table iterators and dealing with all of that just seems unnecessary. I thought of maybe just implementing the sequence defined in the MIB and not the actual table, but that's not usually how it's done in all the examples I've seen. I looked at /mibgroup/examples/delayed_instance.c, but that's not quite what I'm looking for. Using mib2c with the mib2c.create-dataset.conf config file was the closest I got to getting this to work easily, but this config file assumes the data is static and not external (both of which are not true in my case), so it won't work. If it's not easily done, I'll probably just implement the sequence and not the table, but I'm hoping there's an easy way. Thanks in advance.

Upvotes: 0

Views: 344

Answers (1)

Wes Hardaker
Wes Hardaker

Reputation: 22262

The iterator method will work just fine. It won't load any data until it calls your _first and _next routines. So it's up to you, in those routines and in the _handler routine, to request the data from the remote server. In fact, by default, it doesn't cache data at all so it'll make you query your remote server for every request. That can be slow if you have a lot of data in the table, so adding a cache to store the data for N seconds is advisable in that case.

Upvotes: 1

Related Questions