R11B multiple processes starting

Michael McDaniel <>
Sat Jul 8 01:18:06 CEST 2006


SHORT VERSION:

After installing R11B-0, my application starts multiple OS processes
where before it only started a single OS process.
-----------


LONG VERSION:

I have just installed R11B-0 on one of my servers (formerly at R10B-8).

$ uname -a
Linux xq02 2.4.21-99-default #1 Wed Sep 24 13:30:51 UTC 2003 i686 i686 i386 GNU/Linux


An application that I start thusly:

$ /bin/su mmcdanie -c "cd /home/erl ; /usr/local/bin/erl -sname   \
   ${HOST}_block -home /home/erl -setcookie fake -heart -detached \
   -config /home/erl/sys.config  -s block start"

is still working fine.  However, now when I start it, three OS 
processes are running rather than as with R10B-8 where only a 
single OS process would run when application started.

$ ps xuaw | egrep block | egrep -v grep
mmcdanie 14771  0.1  1.2 12964 6440 pts/1    S    15:59   0:00 /usr/local/lib/erlang/erts-5.5/bin/beam -- -root /usr/local/lib/erlang -progname erl -- -home /home/mmcdanie -sname xq02_block -home /home/erl -setcookie fake -heart -noshell -noinput -config /home/erl/sys.config -s block start
mmcdanie 14774  0.0  1.2 12964 6440 pts/1    S    15:59   0:00 /usr/local/lib/erlang/erts-5.5/bin/beam -- -root /usr/local/lib/erlang -progname erl -- -home /home/mmcdanie -sname xq02_block -home /home/erl -setcookie fake -heart -noshell -noinput -config /home/erl/sys.config -s block start
mmcdanie 14775  0.0  1.2 12964 6440 pts/1    S    15:59   0:00 /usr/local/lib/erlang/erts-5.5/bin/beam -- -root /usr/local/lib/erlang -progname erl -- -home /home/mmcdanie -sname xq02_block -home /home/erl -setcookie fake -heart -noshell -noinput -config /home/erl/sys.config -s block start

(apologies for line wraps)

I am not understanding why multiple OS processes are running now when
I start the application.  I have changed nothing on the machine other
than installing the new R11B-0  (and the way I did that was to move
the old /usr/local/lib/erlang directory before doing the install, so
the new /usr/local/lib/erlang is completely fresh, not an
install-over-old).

As I mention above, the application is working fine.

The contents of /home/erl/sys.config are:
[{mnesia, [{dir, "/home/erl/Mnesia.block"}  ,
%%           {debug, trace}                   ,
           {schema_location, disc}]}].

and mnesia is getting updated just fine.

I compiled *without* --enable-smp-support since the native POSIX threads
library is not installed (it is not an SMP machine).


Does anyone have any tips on how to figure out why multiple OS processes
are now starting?  Or perhaps already knows the answer to the question?

thanks,

~Michael






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