Monks,
I am using the locking method described in the Camel book before opening my DB_File databases
use Fcntl qw(:DEFAULT :flock);
use DB_File;  # demo purposes only; any db is fine

$DBNAME  = "/path/to/database";
$LCK     = $DBNAME . ".lockfile";

# use O_RDWR if you expect to put data in the lockfile
sysopen(DBLOCK, $LCK, O_RDONLY | O_CREAT)   
    or die "can't open $LCK: $!";

# must get lock before opening database
flock(DBLOCK, LOCK_SH)
    or die "can't LOCK_SH $LCK: $!";

tie(%hash, "DB_File", $DBNAME, O_RDWR | O_CREAT)
    or die "can't tie $DBNAME: $!";

[download]

At the end of the program I call : 
untie %hash;    # must close database before lockfile
close DBLOCK;   # safe to let go of lock now

[download]


Unfortunately the lock not always released thus stopping further executions of the program (and any other programs that rely on the same lock). The only way to remedy this is to ftp the server and delete the lockfile.
I've been trying tactics around this such as timing out the operation, unlinking the lockfile, exiting immediately and asking the user (very politely) to try again. No elegant tactic, I know, but nevertheless effective.
Any suggestions esteemed ones?

In reply to pesky lockfile stays locked by traxlog

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