Another, slightly more advanced script is memcached-keytrace.d:
:memcached::command-set,command-add,command-delete,command-get
/pid == $target && copyinstr(arg1) == "123456789"/
{
trace(copyinstr(arg1));
}
END
{
}
This one will trace set, add, delete and get commands applied to one
specific key:
Invoke as:
dtrace -s ~/memcached/dtrace/memcached-trace.d -p 24167
Then run a telnet session:
telnet system 11211
Trying 9.9.9.9...
Connected to system.
Escape character is '^]'.
abcdefghij
ERROR
set 123456789 0 0 10
abcdefghij
STORED
delete 123456789 0 0
DELETED
get 123456789 0 0 0
END
And the dtrace script reports:
CPU ID FUNCTION:NAME
1 54165 complete_nread:command-set 123456789
0 54159 process_delete_command:command-delete 123456789
1 54160 process_get_command:command-get 123456789
Useful? Maybe...
Roy
Dustin Sallings wrote:
For those of us who haven't truly unleashed the power of dtrace, can
you describe the kinds of things we can learn from this (perhaps with
scripts)?
--Dustin Sallings (mobile)
On Mar 6, 2008, at 4:48, Trond Norbye <[EMAIL PROTECTED]> wrote:
On Mar 5, 2008, at 3:52 PM, Trond Norbye wrote:
The following patch adds a new configure-option (--enable-dtrace)
that adds DTrace probes to various parts of memcached.
Please comment.
Trond
I discovered that I had some "leftovers" in this patch from before I
fixed the comments regarding the large page support..
The attached version is replacement for the original patch.
Trond
<dtrace.patch.gz>
