Some new mnesia benchmarking results
Wed Nov 7 13:59:32 CET 2001
agree that mnesia is now getting ready for prime time as long as you have small
(Results are even more impressive on my little 1.7 GHz P4 Linux box )
I have a nasty problem that I still haven't resolved.
I you have more and larger records than you have available RAM the system will
get on its knees.
I have tried to use disk_only_copies but it after 1 hour it had only written ~1M
records so I aborted it.
This should be compared with the 15Krecords/sec i get with disk_copies.
Does anyone have a solution on how to store 10Mx2K records with mnesia without
20GB RAM ?
Sean Hinde wrote:
> Hi all,
> I just spent some time benchmarking mnesia for huge disk_copies tables with
> the latest versions. Measurements on a SPARC 400MHz with Veritas FS.
> Create a table with 1 million rows:
> R7B-1 with mnesia-3.10.0 310 secs
> R8B with mnesia-4.0 315 secs
> R8B with 10 threads 270 secs
> Beam process size afterwards
> R7B-1 167M
> R8B 160M
> R8B threads 158M
> Stop mnesia
> R7B-1 with mnesia-3.10.0 155 secs (and whole node is blocked)
> R8B with mnesia-4.1 3.7 secs
> R8B threads 15 secs
> Start mnesia and wait for 1M row table to be available
> R7B-1 25 to 50 secs
> R8B 30 secs
> R8B threads 56 secs
> Subsequent stop of mnesia
> R7B-1 1.9 secs
> R8B 12 secs
> R8B threads 25 secs
> Start up mnesia after CTRL-C CTRL-C stopping node which is writing as fast
> as possible. (Noting disk log repair of DCL file messages on startup).
> R7B-1 40 secs maximum.
> R8B 40 secs
> R8B threads 61 secs
> Apart from quite a lot of variability in timer:tc results it would appear
> that the old behaviour of mnesia where it could potentially take hours to
> rebuild tables from badly closed dets tables has been completely cured.
> Perhaps someone could confirm that this is always the case and I have not
> just been lucky in the timing of my node kills!
> I wonder also if anyone knows of any other reasons not to use mnesia for
> large databases now?
> Very impressive.
> NOTICE AND DISCLAIMER:
> This email (including attachments) is confidential. If you have received
> this email in error please notify the sender immediately and delete this
> email from your system without copying or disseminating it or placing any
> reliance upon its contents. We cannot accept liability for any breaches of
> confidence arising through use of email. Any opinions expressed in this
> email (including attachments) are those of the author and do not necessarily
> reflect our opinions. We will not accept responsibility for any commitments
> made by our employees outside the scope of our business. We do not warrant
> the accuracy or completeness of such information.
More information about the erlang-questions