[Samba] Slower performance on oplock - Samba

This is a discussion on [Samba] Slower performance on oplock - Samba ; Hello, We are running into the problem in slower performance on oplock. Here is the oplock scenario. - We are using 3.0.22. - Kernel oplock has been implemented on hp-ux 11v3. - smb.conf kernel oplocks = Yes oplock break wait ...

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Thread: [Samba] Slower performance on oplock

  1. [Samba] Slower performance on oplock

    Hello,

    We are running into the problem in slower performance on oplock.
    Here is the oplock scenario.

    - We are using 3.0.22.
    - Kernel oplock has been implemented on hp-ux 11v3.
    - smb.conf
    kernel oplocks = Yes
    oplock break wait time = 0
    fake oplocks = No
    locking = Yes
    oplocks = Yes
    level2 oplocks = Yes
    oplock contention limit = 2
    posix locking = Yes
    - Running a Windows application that have to access to data on Samba share.
    - Read data is ok.
    - A single user to write data is ok.
    - Multiple users to write data experience oplock delay. For example, two clients tried to edit data at the same time in the application, there are following processing from my observation:
    * The first open on a file with an exclusive oplock.
    * The second open on the same file needs to call defer_open() and send oplock break msg to itself.
    * Most of time, the msg can be received. Performance is OK. But sometimesfor some reason, the msg couldn't be received. I don't know why. So there was a delay(probably 60s) after open_was_deferred(). After this, Windows client tried to send SMBntcreate to open it again. This time still failed. Since we have "Trying to delay for oplocks twice" in open_file_ntcreate(), itleaded to close the connection.

    - Whether IS the defer_open on the second open necessary? Because this is the same process, and the same file.
    - What kind of reasons to cause the smbd did not receive the break msg?
    - Is there any way to remove the delay, or a specific fix around this?

    Any help greatly appreciated.

    Thanks very much.
    -Ying
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  2. Re: [Samba] Slower performance on oplock

    On Sat, Feb 16, 2008 at 12:33:38AM +0000, Li, Ying (ESG) wrote:
    > - Whether IS the defer_open on the second open necessary?
    > Because this is the same process, and the same file.
    > - What kind of reasons to cause the smbd did not receive the break msg?


    No idea. A signal sometimes not delivered? Does the message
    end up in messages.tdb? As this is a message to the process
    itself, you could implement a shortcut in messages.c if
    signals on HP/UX are unreliable. But this will not help
    with oplocks to other processes.

    Volker

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