On Wed, May 21, 2014 at 03:31:22PM -0400, Dmitri Pal wrote:
On 05/19/2014 01:36 PM, Nikolai Kondrashov wrote:
>On 05/19/2014 08:28 PM, Jakub Hrozek wrote:
>>On Mon, May 19, 2014 at 05:55:45PM +0300, Nikolai Kondrashov wrote:
>>>>"ramdisk" is 58x faster then HDD.
>>>>"ramdisk" is 26x faster then HDD.
>>>
>>>Out of curiosity: why is it so much faster? Does the code sync
>>>to disc often?
>>
>>Every sysdb_transaction_commit or ldb_transaction_commit if we rely on
>>ldb's autotransaction is several fsyncs (4 I think). That's the reason
>>we try to collect all the data first in the daemon and write larger
>>chunks of data in a single transaction.
>
>Ah, as I suspected, thanks!
>I should have probably just run the tests under strace, instead of
>asking.
I wonder if tdb is really what we should use in the long run.
May be there is a way to shard it internally so that you do not need
to lock the whole database but only a portion of it?
I was working on mdb backend for ldb in my spare time:
https://github.com/jhrozek/samba-ldb-mdb/tree/mdb
So far the performance seems to be really nice, but given this is a
spare time project, the progress wasn't as rapid as I would like.
I'd like to finish the backend before I go for vacation in early June,
although I suspect indexing wouldn't be finished.