diff --git a/perl-xCAT/xCAT/Table.pm b/perl-xCAT/xCAT/Table.pm
index 474e4c8d0..706c08e77 100644
--- a/perl-xCAT/xCAT/Table.pm
+++ b/perl-xCAT/xCAT/Table.pm
@@ -179,6 +179,10 @@ sub init_dbworker {
         #setup signal in NotifHandler so that the cache can be updated
         xCAT::NotifHandler::setup($$, 0);
 
+        # NOTE: There's a bug that sometimes the %SIG is cleaned up by accident, but we cannot figure out when and why
+        # this happens. The temporary fix is to backup the %SIG and recover it when necessary.
+        my %SIGbakup = %SIG;
+
         while (not $exitdbthread) {
             eval {
                 my @ready_socks = $clientset->can_read;
@@ -191,6 +195,7 @@ sub init_dbworker {
                     } else {
                         eval {
                             handle_dbc_conn($currcon,$clientset);
+                            unless (%SIG && defined ($SIG{USR1})) { %SIG = %SIGbakup; }
                         };
                         if ($@) { 
                             my $err=$@;