[jcifs] DFS Performance issues

[Franck Schmidlin]

Hi,

I'm hitting what seems to be a poor performance issue reading files held on a DFS file share.
The files are not particularly big, but we are currently getting a throughput of about 3.6Kb/s for files 20kb to 4673kb in size.
Opening the files directly (as opposed to programmatically through jcifs) doesn't show any performance issue.

My code is using jcifs.smb.SmbFile to open and read a file from the DFS share, is not doing anything particularly clever and is running without performance issues on other (non DFS) sites.
To run on this site I've first had to upgrade from version 1.2.13 to 1.3.17 to get rid of a 'The network name cannot be found' error.
I have not yet re-tested on other sites with the latest libraries to confirm the performance.

So now, I am a bit at a loss as to how to investigate this.

Assuming this is a jcifs/dfs issue (I'm investigating other possibilities), are there specific questions I could ask of the network owners?

All I know so far is:

> The DFS file shares are on a file server cluster.  
> The files are copied with all ACLs and managed out of a file server cluster on server-01 and from here can reside on any of 4 nodes (eg. server-01b, server-01a etc.).  > Share level changes are managed by file server administrators on the cluster but we have access to the data shares from a server server-04.  
> However, by using the DFS share below it should be irrelevant to the system where the actual file server cluster is or which server is managing the shares.


Thanks, and season greetings to everyone on the list :-)

______________________________
Franck Schmidlin
Transformation Technical Consultant - Integration
Northgate Public Services
Please consider the environment before printing this e-mail

-----------------------------------------------------------------------------------------
This email is sent on behalf of Northgate Information Solutions Limited and its associated companies ("Northgate") and is strictly confidential and intended solely for the addressee(s).  
 
If you are not the intended recipient of this email you must: (i) not disclose, copy or distribute its contents to any other person nor use its contents in any way or you may be acting unlawfully;  (ii) contact Northgate immediately on +44 (0)1442 232424 quoting the name of the sender and the addressee then delete it from your system.
 
Northgate has taken reasonable precautions to ensure that no viruses are contained in this email, but does not accept any responsibility once this email has been transmitted.  You should scan attachments (if any) for viruses.
 
Northgate Information Solutions Limited. Registered in England no. 06442582  -  Northgate Information Solutions UK Limited. Registered in England no. 968498  -  NorthgateArinso UK Limited .Registered in England no. 1587537  -  Moorepay Limited.  Registered in England no. 891686  - First Business Support Limited. Registered in England no. 3056267 -  Registered Office: Peoplebuilding 2, Peoplebuilding Estate, Maylands Avenue, Hemel Hempstead, Hertfordshire HP2 4NW 
 
Northgate Managed Services Limited (NI).  Registered in Northern Ireland no. NI032979  -  LearnServe Limited (NI).  Registered in Northern Ireland no. NI043825
Registered Office: Hillview House, 61 Church Road, Newtownabbey, Co. Antrim, BT36 7LQ 

-----------------------------------------------------------------------------------------