Db- open() hangs on a machine (64bit), its working on another (32bit)

Question

Hi,
my app hangs when opening a db. This occurs on a 64bit linux server, it's working on a 32bit linux desktop. The code snippet is:
u_int32_t flags = DB_CREATE; /* database open flags */
ret = this->dbp->open(this->dbp,
NULL,
file,
NULL,
DB_HASH,
flags,
0);
It hangs when fsync'ing the db file. Following is the stacktrace after attaching to the hanging process via gdb:
(gdb)
#0 0x00007f2ce2820a90 in fdatasync () from /lib/libc.so.6
#1 0x00007f2ce3382b4d in __os_fsync () from /usr/lib/libdb-4.7.so
#2 0x00007f2ce333db7e in __db_new_file () from /usr/lib/libdb-4.7.so
#3 0x00007f2ce33650ea in __fop_file_setup () from /usr/lib/libdb-4.7.so
#4 0x00007f2ce333e042 in __db_open () from /usr/lib/libdb-4.7.so
#5 0x00007f2ce3336a2f in __db_open_pp () from /usr/lib/libdb-4.7.so
#6 0x0000000000403647 in DBD::openDB (this=0x7fffebb40b40) at DBD.cpp:43
#7 0x000000000040248e in DBD (this=0x7fffebb40b40, filename=
{static npos = 18446744073709551615, _M_dataplus = {<std::allocator<char>> = {<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No data fields>}, Mp = 0x7fffebb40ab0 "\210"}}) at DBD.h:29
#8 0x00000000004024eb in OffsetIndex (this=0x7fffebb40b40, filename=
{static npos = 18446744073709551615, _M_dataplus = {<std::allocator<char>> = {<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No data fields>}, Mp = 0x7fffebb40b80 "\210"}}) at OffsetIndex.h:22
#9 0x0000000000402107 in main (argc=2, argv=0x7fffebb40ca8) at osmindexer.cpp:30
(gdb)
Anyone can give a hint how to solve the problem?
Thx,
Chris

Answer 1

Hi,
Could you please answer a few questions to help isolate the problem:
1) Does the database you are opening already exist?
2) If it already exists, was it created on the same machine?
3) Can you reproduce the same hang when creating a DB_BTREE database, instead of DB_HASH?
4) Is the application actually hung in the fsync call, or is does it appear to be in an infinite loop (ie: can you make progress by stepping through the application in gdb)?
Thanks,
Alex Gorrod,
Oracle Berkeley DB