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simba
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lock fileset by storing the pid in the table. Somewhat ugly but should 

work.
This commit is contained in:
hjp 2010-09-02 12:05:59 +00:00
parent 3a2570be8e
commit ea76362546
1 changed files with 27 additions and 7 deletions
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34
lib/Simba/CA.pm
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@ -153,13 +153,7 @@ sub run {
sub backup2disk {
my ($self, $target) = @_;
# XXX - lock fileset here, we don't want to backup the same fileset twice concurrently.
# theoretically something like
$self->{dbh}->selectall_arrayref(q{select * from filesets where id = ? for update}, {}, $target->{id});
# should suffice, but I'm not sure if that blocks too much (does that block reads? block the whole table?)
# Just try it and we will see ...
# According to the manual this only works if autocommit is off, so it probably doesn't work on MyISAM
# anyway.
$self->reserve_fileset($target);
$self->log(3, "starting backup for target host " . $target->{host} . " dir " . $target->{dir});
$self->{target} = $target;
@ -215,10 +209,36 @@ sub backup2disk {
}
$self->flush_insert_instances();
$self->close_session();
$self->reserve_fileset($target);
$self->log(3, "finished backup for target host " . $target->{host} . " dir " . $target->{dir} . ": $count files");
$self->{counts}{objects} += $count;
}
sub reserve_fileset {
my ($self, $target) = @_;
for (;;) {
my $rows = $self->{dbh}->do(q{update filesets set pid=? where id = ? and pid is null}, {}, $$, $target->{id});
return if $rows == 1;
my $pid = $self->{dbh}->selectrow_array(q{select pid from filesets where id = ?}, {}, $target->{id});
$self->log(3, "fileset $target->{id} appears to be in use by my pid $pid");
if (!kill(0, $pid) && $!{ESRCH}) {
$self->log(3, "pid $pid doesn't exist, trying to release fileset $target->{id}");
$self->{dbh}->do(q{update filesets set pid=null where id = ? and pid=?}, {}, $target->{id}, $pid);
}
sleep 60;
}
}
sub release_fileset {
my ($self, $target) = @_;
$self->log(3, "releasing fileset $target->{id}");
$self->{dbh}->do(q{update filesets set pid=null where id=? and pid=?}, {}, $target->{id}, $$);
}
sub parse {
my ($self, $s) = @_;