[jcifs] jcifs-1.2.12 and DFS

Karl Wright kwright at metacarta.com
Mon Jan 8 19:08:38 GMT 2007


James,

Ok, I'll cause an appropriate -Djcifs.resolveOrder=LMHOSTS,DNS to be 
installed with the package.

Karl

Michael B Allen wrote:
> On Mon, 08 Jan 2007 13:11:16 -0500
> Karl Wright <kwright at metacarta.com> wrote:
> 
>>>Incedentially, I've noticed your ListFiles examples take 6+
>>>seconds. That's a sure indication of name service timeouts (NetBIOS
>>>name service queries are tried twice three seconds apart). Either set
>>>jcifs.netbios.wins to your WINS server or set jcifs.resolveOrder=DNS
>>>and your examples will run fast.
>>>
>>>Mike
>>>
>>
>>Mike - just a quick question - if we do not have WINS configured (e.g. 
>>set jcifs.netbios.wins), the resolution order as coded in 
>>UniAddress.java appears to be: LMHOSTS,BCAST,DNS.  Is the timeout you 
>>think we are having due to BCAST being in the resolution sequence?  If 
>>not, I really don't see what could be happening.
> 
> 
> Yes, BCAST means NetBIOS broadcast lookup. Because it's broadcasting for
> a reasponse and not querying an authority directly a negative response
> is indicated by the lack of one. Therefore there is no other choice but
> to wait a short period and retry.
> 
> 
>>The other disturbing thing that James noted is that this performance 
>>issue ONLY seems to occur for DFS lookups.  He says he is seeing good 
>>performance without DFS.  I find this unnerving since I would presume 
>>that the lookup order is the same for DFS as for normal share activity.
> 
> 
> BCAST lookups only work on the local subnet. So it could be that the
> initial target is local whereas the DFS referral is for a server on
> another subnet that cannot be reached with a broadcast packet.
> 
> If you don't have WINS just set jcifs.resolveOrder=DNS. Note that
> you cannot use NetBIOS names without WINS or BCAST. You must use
> fully qualified DNS hostnames. So instead of smb://server1/pub/ it's
> smb://server1.test.local/pub/ [1].
> 
> Mike
> 
> [1] Depending on your DNS search suffix settings you may be able to use
> the first label of the FQDN.
> 
> 
>>I've asked him to get a capture at log level 10, in hopes that there is 
>>some indication there of exact what is timing out.
> 
> 
> Verbose logs are virtually obsolete if you have captures.
> 



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