Topic: Clipper-based Application (dbf) and Ibays - slow performance

[the-heck]

Hi.  I have seen most of the post and other sites info regarding this one.

I have manage to get the clipper-based application running from an ibay.  However, when a Re-Index command was issued from a workstation to the server, a long, long duration for completing the job occurred.
The .dbf files are known to have problem with samba.  Is there anyone who could give me workarounds with this issues?

Anyone's expertise on samba share would be very much appreciated.

[thomasch]

the-heck,

Try to turn off samba oplocks

Code: [Select]

db configuration setprop smb oplocks disabled
signal-event ibay-modify

Please report back here if it works.

Thanks

[the-heck]

Thanks. Yes, i did turn off the oplocks, as per recommendations of some samba sites. problem persist.

Actually, the application is running normal operations.  However, .dbf is known for index corruption (oplocking something to do with this also), and so the application have a re-indexing process.  Here, the application is deleting all indexes, and start an update process.  Here many small .dbf files are being read.  If the databases are in the workstation, and issue the update command, the whole process takes only 5-10mins.  But when it is in the ibay (smb), it took almost 30-45 minutes to finish.

I checked with ext2, ext3 and reiserfs filesystem, if there are any issues. Reiserfs is known to be speedy in small files.  Could this be a filesystem issue?  Or Samba still have solve .dbf bugs?

Any help would be appreciated.

[pfloor]

If the application is on a workstation and the .dbf files are on the server then you might be experiencing network trafic issues.

Is the network 100 or 1000?

Are there a lot of clients on the network?

[thomasch]

I don't think clipper reindexing will hog even 100mbps pipe.

suspect :
- RAID1 is slow in high-disk-writing tasks. <-- use high rpm 7200-10000rpm high buffer 32MB harddisk
- Samba needs tune-up (search google for samba tune-up (so_sndbuff stuff))
- MSWindows TCP/IP setting (MTU, etc) needs tune up

What is MS Windows version you use?

Do you see any funny error stuff in you samba log file during reindexing?

[brianr]

Also you might want to consider whether a local "on access" anti virus scanner is running on the PC, such as Norton or Macafee.  if so, make sure it is NOT scanning dbf files.

[the-heck]

Thomasch

- Samba needs tune-up (search google for samba tune-up (so_sndbuff stuff))

I cant seem to find a clear explanation of the so_sndbuff.  But as one of the sites I've been, they provided these oplocks and fine tuning of MTU, etc...  I will paste the link later, it somewhere in my history pages.

Anyway, the computer configuration is ok.  Actually same computer was tested with Win2003 server, and the application is working smoothly, even the updating problem that I have with sme server.  Do samba still have a bug with .dbf? or is it a known limitation?

Also, I did the recommendation of skipping the .dbf files for scanning.  However, no noticeable change occurred.

Anyone who is running the same problem with clipper?  I know its an old language, but is very effective, and we can't throw away the useful application we have.

Thanks for the assistance. Cheers!

[mmccarn]

How long does the reindex take if you put the files in a windows share on one XP system, then run the re-index from another XP system over the network?  This should be a more realistic comparison time than the one you get from re-indexing the data locally.

The time required to reindex a .dbf file will depend on the .dbf file size, the index file size, the data transfer speed (network vs. local disk), and the location of the temporary files.

If you are reindexing files that are on a server you will also be impacted by the transaction processing speed of the server, the disk subsystem of the server, other load factors on the server, etc.

I haven't used clipper for >15 years, but I think it used to be possible to configure it to create temporary files on the local workstation while leaving data files and indexes on the server - a great speed boost back in the 10Mbit (or even the 2Mbit - for anyone who remembers Arcnet) days.

I use Foxpro daily.  The .dbf I use most often is a little over 100MB.  Reindexing this file from a medium-speed workstation over a 100Mbit network takes about 20 minutes.  Reindexing the same file from a high-speed system over Gigabit networking takes about 5 minutes.

[the-heck]

The .dbf files are less than 100Mb total. Very small databases but many. The server-desktop is having SATA2 Baracuda 7200rpm 16mb on raid1, 2GB RAM, Pentium D, running on Server mode only at 100Mb network.

Update Process on Windows XP:
Connected to windows2003 server, the update process took aroung 5-7mins.  While connected to sme server, it took around 30-45mins. Sometimes, even longer, up to 50mins.  The thing is, using the application is like normal operation on fileserver environment.

Could you please point me to the direction of having the templates on local?  How do I go about it?  This may really help me.

Thank you very much in advance.

[thomasch]

the heck,
Search samba performance tuning in google.

Also please check if there is Novell Netware Client/driver left in the client machine.
This can slow down samba too.

I suspect there is hardware setting related problem.
What is your NIC card/chipset?
Maybe you should check Full/Half duplex NIC setting.
Don't force to 100mb.. as this can slow down the network too.
Choose Auto Negotiation.

thomas