Strange mnesia behaviour
Mon Aug 25 09:42:26 CEST 2003
flush_downs cleans the msg queue, with alot msgs in it, it takes some
Can you email me the test program?
Anders Nygren writes:
> I have found a strange thing in mnesia. I was trying
> to do some throughput measurement on a process.
> My process does the following:
> 1, receive one message
> 2, make one mnesia:select
> 3, send one message
> My test was to send N identicat messages to my process
> and measure the time it took to process all messages.
> To my suprise the times grew non-linearly with N.
> eprof shows that
> N = 10 - > mnesia:flush_downs/0 is called 55 times
> N = 100 -> mnesia:flush_downs/0 is called 5000 times
> N = 4000 -> a whopping 4 million times.
> Also if I run the test twice with 50 messages I get
> 2500 mnesia:flush_downs, but when I run one test with
> 100 messages there are 5000.
> I the mnesia table has one record.
> I am using a single node -> no distribution.
> The table is type bag, disc_copy.
> I am using R9C on Suse 8.2.
> Is there something wrong with mnesia or is there
> something I dont understand?
> Yahoo! Mail - Gratis: 6 MB lagringsutrymme, spamfilter och virusscan. Se mer på http://se.mail.yahoo.com
More information about the erlang-questions