> Ivan Shmakov writes:
[BTW, I've found that the issue exists down at the nc_open ()
call level, so this report should probably be reassigned to
libnetcdf6 and retitled appropriately.]
[…]
> On the other hand, the URI's of 55 characters and less are handled
> differently, and the requests are being made:
[…]
While checking strace(1) and ltrace(1) output, I've found that
the correct behavior coincides with a single DNS request, while
the buggy one coincides with three.
Thus, I've breakpointed GDB at recvfrom () and got the
backtraces MIME'd. As far as I can see, the URL is correctly
passed down to the ocfetchurl () NetCDF internal function.
Unfortunately, even though libcurl3-dbg is installed, the
arguments to the Curl_* functions aren't shown.
Any hints?
$ dpkg -l \*-dbg | grep -E ^i
ii libcurl3-dbg 7.21.0-1 libcurl compiled with debug symbols
ii netcdf-dbg1:4.1.1-5 debugging symbols for NetCDF
$
--
FSF associate member #7257
(gdb) r
Starting program: /usr/bin/ncdump -k
http://nomads.ncep.noaa.gov:9090/dods/gfs_hd/gfs_hd2011 # 128/gfs_hd_00z
[Thread debugging using libthread_db enabled]
Breakpoint 5, 0x76934e20 in recvfrom () from /lib/libc.so.6
(gdb) bt
#0 0x76934e20 in recvfrom () from /lib/libc.so.6
#1 0x75459b09 in ?? () from /lib/libresolv.so.2
#2 0x75457a75 in __libc_res_nquery () from /lib/libresolv.so.2
#3 0x75458031 in ?? () from /lib/libresolv.so.2
#4 0x7545843d in __libc_res_nsearch () from /lib/libresolv.so.2
#5 0x73d15c37 in _nss_dns_gethostbyname4_r ()
from /lib/libnss_dns.so.2
#6 0x7691048c in ?? () from /lib/libc.so.6
#7 0x76912782 in getaddrinfo () from /lib/libc.so.6
#8 0x77bc8af2 in Curl_getaddrinfo_ex ()
from /usr/lib/libcurl-gnutls.so.4
#9 0x77bc2818 in Curl_getaddrinfo () from /usr/lib/libcurl-gnutls.so.4
#10 0x77b9976c in Curl_resolv () from /usr/lib/libcurl-gnutls.so.4
#11 0x77b99897 in Curl_resolv_timeout ()
from /usr/lib/libcurl-gnutls.so.4
#12 0x77babcb6 in ?? () from /usr/lib/libcurl-gnutls.so.4
#13 0x77babd83 in Curl_connect () from /usr/lib/libcurl-gnutls.so.4
#14 0x77bb646f in ?? () from /usr/lib/libcurl-gnutls.so.4
#15 0x77650c61 in ocfetchurl (curl=0x665270,
url=0x66e050 "http://nomads.ncep.noaa.gov:9090/dods/gfs_hd/gfs_hd2011.dds";,
buf=0x64f1b0, filetime=0x7fffe038) at http.c:110
#16 0x77658a75 in readpacket (curl=0x665270,
url=, packet=0x64f1b0, dxd=,
lastmodified=0x7fffb8c0) at read.c:76
#17 0x77658bf9 in readDDS (state=0x66df50, tree=)
at read.c:31
#18 0x7764fdeb in ocfetch (state=0x66df50, constraint=0x0, kind=0,
rootp=0x7fffe0d8) at ocinternal.c:255
#19 0x7764ba3a in oc_fetch (conn=7, constraint=0x7fffc5c0 "\001",
dxdkind=0, rootp=0x7fffe158) at oc.c:593
#20 0x77655c65 in dap_oc_fetch (drno=0x648000, conn=6741840, ce=0x0,
dxd=0, rootp=0x7fffe158) at daputil.c:958
#21 0x7764d51b in fetchtemplatemetadata3 (drno=0x648000)
at ncdap3.c:1323
#22 0x7764e89f in nc3d_open (path=,
mode=, ncidp=0x647f50) at ncdap3.c:199
#23 0x77612b19 in l4nc_open_file (
path=0x613040 "http://nomads.ncep.noaa.gov:9090/dods/gfs_hd/gfs_hd2011";,
mode=0, basepe=0, chunksizehintp=0x0, use_parallel=,
comm=, info=0, ncidp=0x7fffe3ec) at nc4file.c:2338
#24 0x7765f008 in nc4d_open_file (
path=0x613040 "http://nomads.ncep.noaa.gov:9090/dods/gfs_hd/gfs_hd2011";,
mode=0, basepe=,
chunksizehintp=, use_parallel=0, comm=0, info=0,
ncidp=0x7fffe48c) at ncdap4.c:122
#25 0x776103bf in nc_open (path=0x7 ,
mode=-14912, ncidp=) at nc4file.c:2400
#26 0x00405d39 in main (argc=, argv=0x613160)
at ncdump.c:2127
(gdb)
(gdb) r
Starting program: /usr/bin/ncdump -k
http://nomads.ncep.noaa.gov:9090/dods/gfs_hd/gfs_hd2011128/gfs_hd_00z
[Thread debugging using libthread_db enabled]
Breakpoint 5, 0x76934e20 in recvfrom () from /lib/libc.so.6
(gdb) bt
#0 0x76934e20 in recvfrom () from /lib/libc.so.6
#1 0x75459b09 in ?? () from /lib/libresolv.so.2
#2 0x75457a75 in __libc_res_nquery () from /lib/libresolv.so.2
#3 0x75458031 in ?? () from /lib/libresolv.so.2
#4 0x7545843d in __libc_res_nsearch () from /lib/libresolv.so.2
#5 0x73d15c37 in _nss_dns_gethostbyname4_r ()
from /lib/libnss_dns.so.2
#6 0x7691048c in ?? () from /lib/libc.so.6
#7 0x76912782 in getaddrinfo () from /lib/libc.so.6
#8 0x77bc8af2 in Curl_getaddrinfo_ex ()
from /usr/lib/libcurl-gnutls.so.4
#9 0x77bc2818 in Curl_getaddrinfo () from /usr/lib/libcurl-gnutls.so.4
#10 0x77b9976c in Curl_resolv () from /usr/lib/libc
