Re: SNMP Table Handling

On Thu, May 30, 2019 at 2:51 PM Krishna Chaitanya
<[email protected]> wrote:
>
> Hi,
>
> I am just starting on SNMP and have a query on how to implement tables.
>
> I did go through forum messages and examples found below to be
> helpful, but still, have doubts.
>
> https://sourceforge.net/p/net-snmp/mailman/message/33480025/ (This was helpful)
> examples/mibgroup/netSnmpHostsTable.c
>
> I have a single API which will get 3 different types of stats (A, B, C) and each
> stats can have multiple instances, so I have made 3 different tables (A, B, C).
>
> a) providing complete row
> I want to provide the latest stats every time a request is made
> (snmpwalk/snmptable). For that
> I have registered a handler for each table and inside the handler,
> fetching the stats.
> But the problem is that the handler is called for every column? So,
> for efficiency sake
> I need to run a separate thread to fetch and fill only the column
> asked in the handler? Is there a better approach? Like can I submit
> the entire row at once?
>
> b) replace row asserts
> FYI, I am using data_set tables it already has a handler but as I want
> to update the table
> with new values, I am doing a replace row (it causes duplicate warnings).
>
> Any help is appreciated. Thanks.
>
After spending some more time, able to get below optimizations:
FYI, I am using table_data_set tables. In my custom table handler,
I am doing below pseudo code: Is this the preferred approach?

for (requests)
   //Try to update full row at once.
   if table->colnum != LAST_COL
      continue;
   //fetch existing row
   for (rows)
          row->index == table_info->index
          old_row = row
          break;
   row = fetch_and_prepare_data()
   replace (old_row, row)