Re: [bug] in snmp agent

As the client table is not normally kept sorted (it is a hash table), I
think there is not much of a choice other than building a temporary
table, or to create some other abstract index to the client table that
is sorted such as the hash bucket number, index.

I don't think the SNMP interface to the client table is really intended
to be walked, rather queried for the exact IP one is interested in.
Walking such a large table using SNMP is not a very nice task as the
client table can contain several thousands of entries or more..

Opinions from someone more SNMP customized than me wanted.

Regards
Henrik

Jean-Francois Dive wrote:
>
> Hi all,
>
> This is to report a bug in the snmp agent of squid. A search in bugzilla
> did not pointed me to any bug ID.
>
> When quirying the clientCacheTable, which is indexed on the IP address,
> the agent does not order the reply of getNextRequest by sorted ip
> addresses, but by appearance order. So, for example:
>
> getnext on cacheClientAddr.10.10.10.10 may return
> cacheClientAddr.20.20.20.20 . This is not RFC compliant and give problems
> with most snmpwalk which check that the previous answer is < than the new
> one.
>
> As a workaround, use -Cc option in snmpwalk. My problem is that this makes
> the table parsing in application not an easy task as standard tools
> complains.
>
> After digging in the code, the problem seems to comes from
> src/snmp_core.c::client_Inst() which takes the first entry in the
> client_table trought a call to client_entry(NULL). I dont see anyway to
> fix the problem but sort the client_table on the ip address, or use a
> temporary table which is probably not very memory friendly.
>
> I'd be interested in any input on this.
>
> JeF
Received on Fri Dec 14 2001 - 11:14:20 MST