Re: Poor performance on Solaris

Brett @Google wrote:

On Fri, Feb 25, 2011 at 10:25 AM, Howard Chu <hyc@symas.com mailto:hyc@symas.com> wrote:

    I will note that if you are going to use slowaris, I highly advise you set
    a memory key rather than using on disk cache for BDB if your DB is any
    size
    over about 4 GB.  Other than that, you'll generally just have to deal with
    the fact it will be significantly slower than Linux.



Actually, you should always use a shared memory key on Solaris. Using
mmap'd files is just too slow on that OS.

Incidentlly, What is the uniqueness of a shared memory key, is it unique amoung all instances on a single server ?

The significance of a shared memory key depends entirely on your operating system. But by its nature, shared memory is global to a machine, so you can assume that all keys must be unique on a particular machine.

I have personally only ever needed a shared memory key on one of a group of ldap servers.

But i noticed that the bdb logs are not written to disk when shared memory is configured, is this a good or bad thing ?

The use of shared memory has no bearing on how the BDB library writes its transaction logs.