[Monetdb-developers] Not descriptive error message
Hello all, that is my first mail to this list, so please apologize if I do mistakes. I recently compiled MonetDB on a NFS-home-directory (stupid, now that I think of it). The error message I got was: !FATAL: GDKlockHome: Database lock '.gdk_lock' denied After some investigations I found out that in /cvsroot/monetdb/MonetDB/src/gdk/gdk_posix.mx the original OS-error message was discarded and a simple error-return-value was choosen. I suggest to change it to something like what is attached to this mail. Best regards, Robin -- Robin Aly (PhD student, University Twente) Phone: +31 (53) 489 4520 Fax: +31 (53) 489 2927 email: r.aly@ewi.utwente.nl
Hi Robin, Thanks for your patch! On 17-11-2006 13:36:39 +0100, Robin Aly wrote:
I recently compiled MonetDB on a NFS-home-directory (stupid, now that I think of it). The error message I got was: !FATAL: GDKlockHome: Database lock '.gdk_lock' denied
After some investigations I found out that in /cvsroot/monetdb/MonetDB/src/gdk/gdk_posix.mx the original OS-error message was discarded and a simple error-return-value was choosen. I suggest to change it to something like what is attached to this mail.
What was the actual problem in your case? lockd not running?
Index: gdk_posix.mx =================================================================== RCS file: /cvsroot/monetdb/MonetDB/src/gdk/gdk_posix.mx,v retrieving revision 1.119 diff -r1.119 gdk_posix.mx 1765c1765,1766 < if (fd < 0) ---
if (fd < 0) { perror("MonetDB (open): "); 1767,1768c1768,1782 < if (lseek(fd, off, SEEK_SET) == off) < ret = (lockf(fd, mode, len) == 0) ? 1 : -1;
}
With this change you actually change the behaviour of the function (and it's contract). These kind of diffs are extremely hard to read, so I might be wrong. In any case, perror is not the solution here, and as far as I know the current behaviour is used consistently within MonetDB at the moment. It probably is better to try and fix this better at the caller of this function using errno and strerror.
if (lseek(fd, off, SEEK_SET) == off) { ret = lockf(fd, mode, len); if (ret==0) { ret=1;
} else { perror("MonetDB (lockf): "); ret=-1; } } else { perror("MonetDB (lseek):"); }
Hi Fabian,
I recently compiled MonetDB on a NFS-home-directory (stupid, now that I think of it). The error message I got was: !FATAL: GDKlockHome: Database lock '.gdk_lock' denied
After some investigations I found out that in /cvsroot/monetdb/MonetDB/src/gdk/gdk_posix.mx the original OS-error message was discarded and a simple error-return-value was choosen. I suggest to change it to something like what is attached to this mail.
What was the actual problem in your case? lockd not running?
The problem was that the dbfarm directory resided on a NFS-directory which didn't support locking (I don't know anything more specific, as I don't maintain the server) But there is a process lockd running.
Index: gdk_posix.mx =================================================================== RCS file: /cvsroot/monetdb/MonetDB/src/gdk/gdk_posix.mx,v retrieving revision 1.119 diff -r1.119 gdk_posix.mx 1765c1765,1766 < if (fd < 0) ---
if (fd < 0) { perror("MonetDB (open): ");
1767,1768c1768,1782 < if (lseek(fd, off, SEEK_SET) == off) < ret = (lockf(fd, mode, len) == 0) ? 1 : -1; ---
}
With this change you actually change the behaviour of the function (and it's contract). These kind of diffs are extremely hard to read, so I might be wrong.
I am pretty sure that I didn't change the semantic of the function. Except that it outputted something stderr of course.
In any case, perror is not the solution here, and as far as I know the current behaviour is used consistently within MonetDB at the moment. It probably is better to try and fix this better at the caller of this function using errno and strerror.
Ups, sorry, I didn't mean this "hack" to be meant a proper solution it only served as a trace to the problem. Maybe a stack of (errorno,strerror) would be good - because the error-handling function could also be calling this function indirectly. Cheers Robin -- Robin Aly (PhD student, University Twente) Phone: +31 (53) 489 4520 Fax: +31 (53) 489 2927 email: r.aly@ewi.utwente.nl
participants (2)
-
Fabian Groffen -
Robin Aly