Hi Daniel,
the patch is actually very simple ...
--- branches/1.3/program/src/rrd_fetch.c (revision 1684)
+++ branches/1.3/program/src/rrd_fetch.c (working copy)
@@ -359,6 +359,8 @@
/* fill the gap at the start if needs be */
+ if (*start <= rra_end_time && *end >= rra_start_time - *step){
+
if (start_offset <= 0)
rra_pointer = rrd.rra_ptr[chosen_rra].cur_row + 1;
else
@@ -374,6 +376,8 @@
fprintf(stderr, "First Seek: rra_base %lu rra_pointer %lu\n",
rra_base, rra_pointer);
#endif
+ }
+
/* step trough the array */
for (i = start_offset;
the problem has been present in rrdtool forever it seems ... I have applied the
fix in 1.2,1.3 and trunk
thanks for finding this
tobi
Thursday [EMAIL PROTECTED] wrote:
>
>
> > -----Original Message-----
> > From: Tobias Oetiker [mailto:[EMAIL PROTECTED]
> > Sent: 27 November 2008 10:57
> > To: Pocock, Daniel: IT (LDN)
> > Cc: [email protected]
> > Subject: Re: [rrd-developers] rrd_fetch seek issue
> >
> > Hi Daniel,
> >
> > (I have not yet looked at the code).
> >
> > I just tried to reproduce the problem here and it did not work.
> >
> > I guess you are hitting some sort of a corner case ... can
> > you create a little demo script ...
>
>
> I encountered the problem in my patched version of trunk, so I decided
> to explore it with an unpatched version of 1.2.15, as that is an
> unpatched version I already have on a box.
>
> My patched code is quite unforgiving - there is an assert() for bad
> seeks. That's how I discovered the problem.
>
> Testing with 1.2.15, there is also a seek beyond the end of the file,
> and NaN data is returned by rrd_fetch.
>
> NOW=`date +%s`
> START_T=`expr $NOW - 3600`
> TS2=`expr $START_T + 10`
> TS3=`expr $START_T + 20`
>
> rrdtool create /tmp/test1.rrd \
> --start ${START_T} \
> --step 10 \
> DS:ds0:COUNTER:900:U:U \
> RRA:AVERAGE:0.8:1:180
>
> $ ls -l /tmp/test1.rrd
> -rw-r--r-- 1 daniel daniel 1984 Nov 27 16:28 /tmp/test1.rrd
>
> # notice the file size is 1984 bytes, consistent with 180 rows in the
> RRA
> # put in a couple of updates with old time stamps:
>
> rrdtool update /tmp/test1.rrd ${TS2}:1000
> rrdtool update /tmp/test1.rrd ${TS3}:2000
>
>
> # Notice that last_update is over 1 hour ago
> # There can only be data for 30 minutes (180 rows)
> $ rrdtool info /tmp/test1.rrd |grep last_upd
> last_update = 1227799751
> $ date +%s
> 1227804688
>
> # Now I inspect the fetch code, notice how the seek is for
> # 544 + (569 * 1 * 8) = 5096
> # which is beyond the end of the file
>
> $ gdb rrdtool
>
> set args fetch /tmp/test1.rrd AVERAGE -r 10 -s -60s
>
> Breakpoint 3, rrd_fetch_fn (
> filename=0xfffffe76 <Address 0xfffffe76 out of bounds>,
> cf_idx=CF_AVERAGE,
> start=0xbffb8868, end=0xbffb886c, step=0xbffb8870,
> ds_cnt=0xbffb8874,
> ds_namv=0xbffb8878, data=0xbffb887c) at rrd_fetch.c:346
> 346 if (start_offset <= 0)
> (gdb) next
> 338 end_offset = (long)(rra_end_time - *end ) / (long)*step;
> (gdb) next
> 346 if (start_offset <= 0)
> (gdb)
> 349 rra_pointer =
> rrd.rra_ptr[chosen_rra].cur_row+1+start_offset;
> (gdb)
> 351 if(fseek(in_file,(rra_base
> (gdb) print rra_base
> $1 = 544
> (gdb) print rra_pointer
> $2 = 569
> (gdb) print *ds_cnt
> $3 = 1
> (gdb) next
> 372 for (i=start_offset;
> (gdb) print ftell(in_file)
> $4 = 5096
> _______________________________________________
>
> This e-mail may contain information that is confidential, privileged or
> otherwise protected from disclosure. If you are not an intended recipient of
> this e-mail, do not duplicate or redistribute it by any means. Please delete
> it and any attachments and notify the sender that you have received it in
> error. Unless specifically indicated, this e-mail is not an offer to buy or
> sell or a solicitation to buy or sell any securities, investment products or
> other financial product or service, an official confirmation of any
> transaction, or an official statement of Barclays. Any views or opinions
> presented are solely those of the author and do not necessarily represent
> those of Barclays. This e-mail is subject to terms available at the following
> link: www.barcap.com/emaildisclaimer. By messaging with Barclays you consent
> to the foregoing. Barclays Capital is the investment banking division of
> Barclays Bank PLC, a company registered in England (number 1026167) with its
> registered office at 1 Churchill Place, London, E14 5HP. This email may
> relate to or be sent from other members of the Barclays Group.
> _______________________________________________
>
>
--
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch [EMAIL PROTECTED] ++41 62 775 9902 / sb: -9900_______________________________________________
rrd-developers mailing list
[email protected]
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-developers
