TriDent (was: Safe and stable)

David Collier-Brown davecb at canada.sun.com
Thu Mar 2 19:23:15 GMT 2000


You wrote:
| I have now moved the database over to Samba from its situation on a
Win98
| peer and BTW noted by wishful thinking or imagination a significant
| improvement in the speed at which the data arrives at the client (in
the
| case of TriDent).

	Spiffy!

| I *am* using log level 3, and my question remains "what errors am I
| looking for?" - I have only seen one oplock error so far and that
was
| related to a M$ Excel document!

	The things I'd watch out for are:
	1) oplock breaks on the samba side
	2) diagnosis of locking failure on the client side,
	   such as "can't access/lock xxx" -type messages
	3) actual data overwrite errors in the trivial test:
	   have two folks update the exact same field.

	Once you've tried the trivial test, turn your logging
	back down: log level = 3 slows down Samba a lot!

|  Now I don't really want to turn oplocks off since I understand that 
| this would lead to a significant drop in performance but would
really 
| like to know what effect it could have in this situation 


	Sure: in the case of exactly one user using the database's
	data files, they would be cached locally on that person's
	client.  This causes a performance improvement.

	In the normal multi-user case, the first client gets an oplock,
	caches the file, and as soon as the second user comes along,
	gets an oplock break and has to write-back the cache, wasting
	time.  After that, the two (or more) users access individual
	chunks of the file from the server, with no caching, but under
	control of windows byte-range locks.

	I'd mildly recommend making just the share that the database
	is on non-cached (oplocks = no), as it will save on wasted
	attempts to cache, and not hurt performance if you have
	more than one user.

--dave
-- 
David Collier-Brown,  | Always do right. This will gratify some people
185 Ellerslie Ave.,   | and astonish the rest.        -- Mark Twain
Willowdale, Ontario   | //www.oreilly.com/catalog/samba/author.html
Work: (905) 415-2849 Home: (416) 223-8968 Email: davecb at canada.sun.com


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