Changeset 42444 for trunk/tools

Timestamp:

Apr 6, 2023, 6:00:06 PM (3 years ago)

Author:

eugene

Message:

big re-work to allow repeat, iterated fixes

Location:

trunk/tools/eam/rawfix.20230221/src

Files:

• check_chip_locations.pl (modified) (5 diffs)
• check_chip_locations.v0.pl (deleted)
• check_md5s_dateobs.pl (modified) (4 diffs)
• check_night_status.pl (modified) (5 diffs)
• fix_chip_locations.pl (modified) (11 diffs)
• fix_chip_locations_stage2.pl (deleted)
• fix_chip_locations_stage3.pl (deleted)
• get_md5s_dateobs.pl (deleted)
• get_md5s_instances.pl (modified) (7 diffs)
• get_md5s_instances_stage2.pl (deleted)
• rawfix.ckchip_s3.pt (deleted)
• rawfix.fixchip_s2.pt (deleted)
• rawfix.fixchip_s3.pt (deleted)
• rawfix.md5chk_s2.pt (deleted)
• rawfix.md5sum_s2.pt (deleted)
• rawfix.rsync_s1.pt (deleted)
• rawfix.rsync_s2.pt (deleted)

trunk/tools/eam/rawfix.20230221/src/check_chip_locations.pl

@@ -13 +13 @@
 use Getopt::Long qw( GetOptions :config auto_help auto_version );
 
-# USAGE: check_chip_locations.pl --dateobs (night) --chiplist (file) --stage (v0,v1,etc)
-# USAGE: check_chip_locations.pl --dateobs 2010/05/01 --chiplist gpc1.chips.txt --stage v0
+# USAGE: check_chip_locations.pl --dateobs (night) --chiplist (file) --stage (0,1,etc)
+# USAGE: check_chip_locations.pl --dateobs 2010/05/01 --chiplist gpc1.chips.txt --stage 0
 
 my ($fulldate, $dateword, $chiplist, $stage, $topdir) = &parse_cmdopts;
@@ -31 +31 @@
 # output files: 
 # instance lists by host: YYYYMMDD/HOSTNAME.inst.STAGE.txt
-# chip states by chip: YYYYMMDD/CHIPNAME.uris.txt 
+# chip states by chip: YYYYMMDD/CHIPNAME.uris.STAGE.txt 
 
 foreach my $chip_id (@chip_ids) {
 
     my $outfh;
-    open ($outfh, ">$topdir/$dateword/$chip_id.uris.txt");
+    open ($outfh, ">$topdir/$dateword/$chip_id.uris.$stage.txt");
 
     # get the list of chip neb paths for one chip
@@ -182 +182 @@
     my $sql_chip_instances = "SELECT uri, host, available, xattr, cab_id from instance join storage_object using (so_id) join volume using (vol_id) where ext_id = '$ext_id'";
     my $rowref   = $neb_dbh->selectall_arrayref( $sql_chip_instances );
-  
+    
     return ($rowref, $ext_id);
 }
@@ -338 +338 @@
     pod2usage( -msg => "Specify the top-level output directory with --topdir", -exitval => 2) unless defined $topdir;
     
+    # check that stage is an integer
+    unless (&is_integer ($stage)) { die "stage must be a non-negative integer\n"; }
+    unless ($stage >= 0) { die "stage must be a non-negative integer\n"; }
+
     # check the date format (require YYYY/MM/DD and use that from 00:00:00 to 23:59:59 or take start and end?)
 
@@ -405 +409 @@
 }
 
-    
+sub is_integer {
+    defined $_[0] && $_[0] =~ /^[+-]?\d+$/;
+}
+
 # example of using the return value of arrayref:
 

trunk/tools/eam/rawfix.20230221/src/check_md5s_dateobs.pl

@@ -20 +20 @@
 
 my $Nfail = 0;
+my %failchips;
+my %goodchips;
 
 foreach my $instfile (@instlist) {
@@ -80 +82 @@
 
         if ($md5tru ne $md5obs) {
-            print STDOUT "FAIL: $inst $state $md5tru $md5obs\n";
-            $Nfail ++;
+            &save_failure ($inst);
+            if ($DEBUG > 2) { print STDOUT "FAIL: $inst $state $md5tru $md5obs\n"; }
         } else {
-            if ($DEBUG > 2) {
-                print STDOUT "$inst $state $md5tru = $md5obs\n";
-            }
+            &save_goodchip ($inst);
+            if ($DEBUG > 2) { print STDOUT "$inst $state $md5tru = $md5obs\n"; }
         }
     }
 }
 
+# save both good and fail chip lists
+open (OUTFILE, ">$topdir/$dateword/goodchips.$stage.txt");
+my @goodchipURIs = keys %goodchips;
+foreach my $uri (@goodchipURIs) {
+    print OUTFILE "$uri\n";
+}
+close (OUTFILE);
+
+open (OUTFILE, ">$topdir/$dateword/failchips.$stage.txt");
+my @failchipURIs = keys %failchips;
+foreach my $uri (@failchipURIs) {
+    print OUTFILE "$uri\n";
+}
+close (OUTFILE);
+
+
+## we only report an error if we could not find the md5sum files or if the inst and md5s 
+## files are inconsistent.  In that case, we cannot check the md5s for all instances
+## if the md5sum is wrong for a chip, mark that chip and save it.  It will be skipped in fix_chip_locations
 if ($Nfail) { 
     print STDOUT "ERROR: $Nfail errors\n";
@@ -105 +125 @@
     pod2usage( -msg => "Cannot determine target date, use --dateobs YYYY/MM/DD", -exitval => 2) unless defined $dateobs;
     pod2usage( -msg => "Specify the top-level output directory with --topdir", -exitval => 2) unless defined $topdir;
-    pod2usage( -msg => "Define the stage (v0, v1, etc) with --stage", -exitval => 2) unless defined $stage;
+    pod2usage( -msg => "Define the stage (0, 1, etc) with --stage", -exitval => 2) unless defined $stage;
+    
+    # check that stage is an integer
+    unless (is_integer ($stage)) { die "stage must be a non-negative integer\n"; }
+    unless ($stage >= 0) { die "stage must be a non-negative integer\n"; }
     
     # check the date format (require YYYY/MM/DD and use that from 00:00:00 to 23:59:59 or take start and end?)
@@ -126 +150 @@
     return $status;
 }
+
+sub neb_reverse {
+
+    my (@neb_path) = split /\//, $_[0];
+    my $neb_key = $neb_path[-1];
+
+    # Remove ins_id
+    $neb_key =~ s/^\d+\.//;
+
+    # Convert colons to slashes.
+    $neb_key =~ s%:%/%g;
+
+    # strip ending .fz added for compressed .fits images
+    $neb_key =~ s%.fz$%%;
+    return $neb_key;
+}
+
+sub save_failure {
+    my $nebfile = &neb_reverse($_[0]);
+    if (defined $failchips{$nebfile}) {
+        $failchips{$nebfile} ++;
+    } else {
+        $failchips{$nebfile} = 1;
+    }
+    return;
+}
+
+sub save_goodchip {
+    my $nebfile = &neb_reverse($_[0]);
+    if (defined $goodchips{$nebfile}) {
+        $goodchips{$nebfile} ++;
+    } else {
+        $goodchips{$nebfile} = 1;
+    }
+    return;
+}
+
+sub is_integer {
+   defined $_[0] && $_[0] =~ /^[+-]?\d+$/;
+}

trunk/tools/eam/rawfix.20230221/src/check_night_status.pl

@@ -11 +11 @@
 use Getopt::Long qw( GetOptions :config auto_help auto_version );
 
-# USAGE: check_night_status.pl --dateobs (night) --chiplist (file)
+# USAGE: check_night_status.pl --dateobs (night) --chiplist (file) --stage (0,1,etc)
 
 # we need to select targets for ITC copies of files currently only at ATRC:
@@ -17 +17 @@
 # for each chip, target a single host?
 
-my ($fulldate, $dateword, $chiplist) = &parse_cmdopts;
+my ($fulldate, $dateword, $chiplist, $stage) = &parse_cmdopts;
 
 # read the list of chip_ids:
@@ -36 +36 @@
 foreach my $chip_id (@chip_ids) {
 
-    my $urifile = "$dateword/$chip_id.uris.txt";
+    my $urifile = "$dateword/$chip_id.uris.$stage.txt";
     open (FILE, "$urifile");
     my @lines = <FILE>;
@@ -110 +110 @@
 sub parse_cmdopts {
 
-    my ($dateobs, $chiplist);
-    GetOptions( 'dateobs=s' => \$dateobs, 'chiplist=s' => \$chiplist) || pod2usage(2);
+    my ($dateobs, $chiplist, $stage);
+    GetOptions( 'dateobs=s' => \$dateobs, 'chiplist=s' => \$chiplist, 'stage=s' => \$stage) || pod2usage(2);
     
     pod2usage( -msg => "Cannot determine target date, use --dateobs YYYY/MM/DD", -exitval => 2) unless defined $dateobs;
     pod2usage( -msg => "Provide a list of chips with --chiplist", -exitval => 2) unless defined $chiplist;
+    pod2usage( -msg => "Define the stage (0, 1, etc) with --stage", -exitval => 2) unless defined $stage;
+    
+    # check that stage is an integer
+    unless (is_integer ($stage)) { die "stage must be a non-negative integer\n"; }
+    unless ($stage >= 0) { die "stage must be a non-negative integer\n"; }
+
     
     # check the date format (require YYYY/MM/DD and use that from 00:00:00 to 23:59:59 or take start and end?)
@@ -127 +133 @@
     my $dateword = sprintf ("%4d%02d%02d", $date_year, $date_month, $date_day);
 
-    return ($fulldate, $dateword, $chiplist);
+    return ($fulldate, $dateword, $chiplist, $stage);
 }
 
+
+sub is_integer {
+   defined $_[0] && $_[0] =~ /^[+-]?\d+$/;
+}
+    

trunk/tools/eam/rawfix.20230221/src/fix_chip_locations.pl

@@ -12 +12 @@
 use Getopt::Long qw( GetOptions :config auto_help auto_version );
 
-# USAGE: fix_chip_locations.pl --dateobs (night) --chiplist (file) --stage (v0,v1,etc)
+# USAGE: fix_chip_locations.pl --dateobs (night) --chiplist (file) --stage (0,1,etc)
 
 # we need to select targets for ITC copies of files currently only at ATRC:
@@ -25 +25 @@
 
 # choose ITC machines on which to place backup copies:
-my @volarray = &get_neb_volumes;
+my @vol_copy = &get_neb_volumes_copy; # array of neb hosts to copy data to at ITC
+my %vol_good = &get_neb_volumes_good; # hash of valid neb hosts
 my $volnum = 0;
 
 my $Ngood = 0;
+my $Ndead = 0;
 my $Ngone = 0;
-my $Ndead = 0;
 my $Nsing = 0;
 my $Ndups = 0;
@@ -40 +41 @@
 my $Ncul3 = 0;
 
+# load the lists of good and fail chips
+my $prev = $stage - 1;
+my $goodfile = "$topdir/$dateword/goodchips.$prev.txt";
+my %goodchips;
+if (-e $goodfile) {
+    open (GOODFILE,  $goodfile);
+    my @lines = <GOODFILE>;
+    close (GOODFILE);
+    
+    foreach my $line (@lines) {
+        chomp $line;
+        $goodchips{$line} = 1;
+    }
+}
+my $failfile = "$topdir/$dateword/failchips.$prev.txt";
+my %failchips;
+if (-e $failfile) {
+    open (FAILFILE,  $failfile);
+    my @lines = <FAILFILE>;
+    close (FAILFILE);
+    
+    foreach my $line (@lines) {
+        chomp $line;
+        $failchips{$line} = 1;
+    }
+}
+
 foreach my $chip_id (@chip_ids) {
 
-    my $urifile = "$topdir/$dateword/$chip_id.uris.txt";
-    open (FILE,  $urifile);
-    my @lines = <FILE>;
-    close (FILE);
+    # read from chip_id file, update to next stage number
+    my $urifile = "$topdir/$dateword/$chip_id.uris.$stage.txt";
+    if (! -e $urifile) { die "missing file $urifile\n"; }
+    open (URIFILE,  $urifile);
+    my @lines = <URIFILE>;
+    close (URIFILE);
 
     foreach my $line (@lines) {
@@ -61 +91 @@
         my $md5sum = $words[3];
 
+        my $haveMD5 = 0;
+        my $goodMD5 = 0;
+        if ($goodchips{$ext_id}) { $haveMD5 = 1; $goodMD5 = 1; }
+        if ($failchips{$ext_id}) { $haveMD5 = 1; }
+
+
+        # nothing to be done, or need be done for these:
         if ($state eq "GOOD:") { $Ngood++; next; }
         if ($state eq "DEAD:") { $Ndead++; next; }
@@ -66 +103 @@
 
         # one copy at ITC: neb-replicate will create a copy at ATRC
+        # does not depend on existence of MD5sum
         if ($state eq "SING:") { 
             my $status = &vsystem ("neb-replicate $ext_id");
@@ -79 +117 @@
 
         # one copy at ATRC: neb-replicate will create a copy at ITC iff we supply the target volume
+        # does not depend on existence of MD5sum
         if ($state eq "SBCK:") { 
-            my $tgtvol = $volarray[$volnum];
+            my $tgtvol = $vol_copy[$volnum];
             my $status = &vsystem ("neb-replicate --volume $tgtvol $ext_id");
             if ($status) { print STDERR "FAIL SBCK: neb-replicate : $ext_id on $tgtvol\n"; next; }
@@ -92 +131 @@
         }
 
-        # these are done in stage 2:
-        if ($state eq "DUPS:") { $Ndups++; next; }
-        if ($state eq "XBCK:") { $Nxbck++; next; }
-
-        # these are done in stage 3:
-        if ($state eq "CUL1:") { $Ncul1++; next; }
-        if ($state eq "CUL2:") { $Ncul2++; next; }
-        if ($state eq "CUL3:") { $Ncul3++; next; }
+        # multiple copies @ ITC, but none at ATRC. use neb-replicate to make copies
+        # skip if we do not know the state of the md5sum
+        if ($state eq "DUPS:") { 
+            if ($haveMD5 && $goodMD5) { 
+                my $status = &vsystem ("neb-replicate $ext_id");
+                if ($status) { print STDERR "FAIL DUPS: neb-replicate : $ext_id\n"; next; }
+                my ($newfile, $newhost, $newxattr) = &get_new_instance ($ext_id);
+                unless ($newxattr == 1) { die "new instance is not at ATRC? $ext_id : $newfile : $newhost : $newxattr\n"; }
+                open (OUTFILE, ">>$topdir/$dateword/$newhost.inst.$stage.txt");
+                print OUTFILE "$newfile $datast $md5sum\n";
+                close (OUTFILE);
+            }
+            $Ndups++; 
+            next; 
+        }
+
+        # multiple copies @ ATRC, but none @ ITC: neb-replicate will create a copy at ITC iff we supply the target volume
+        # skip if we do not know the state of the md5sum
+        if ($state eq "XBCK:") { 
+            if ($haveMD5 && $goodMD5) {
+                my $tgtvol = $vol_copy[$volnum];
+                my $status = &vsystem ("neb-replicate --volume $tgtvol $ext_id");
+                if ($status) { print STDERR "FAIL XBCK: neb-replicate : $ext_id on $tgtvol\n"; next; }
+                my ($newfile, $newhost, $newxattr) = &get_new_instance ($ext_id);
+                unless ($newxattr == 0) { die "new instance is not at ITC? $ext_id : $newfile : $newhost : $newxattr\n"; }
+                open (OUTFILE, ">>$topdir/$dateword/$newhost.inst.$stage.txt");
+                print OUTFILE "$newfile $datast $md5sum\n";
+                close (OUTFILE);
+            }
+            $Nxbck++; 
+            next; 
+        }
+
+        # one copy at ITC: neb-replicate will create a copy at ATRC
+        # skip if we do not know the state of the md5sum
+        if (($state eq "CUL1:") || ($state eq "CUL2:") || ($state eq "CUL3:")) { 
+
+            if ($haveMD5 && $goodMD5) {
+                # get info for all instances of this chip
+                # returns a reference to the array of instance data
+                # also strips neb://hostname.volnum/ from nebname and returns as ext_id
+                my ($inforows, $ext_id) =  &get_chip_instances ($ext_id);
+
+                my ($main_keep, $back_keep, $cull_list_r) = &check_instance_xattr ($inforows, $ext_id);
+
+                if ($main_keep eq "") { print STDERR "FAIL $state: missing ITC copy for $ext_id\n";  next; }
+                if ($back_keep eq "") { print STDERR "FAIL $state: missing ATRC copy for $ext_id\n"; next; }
+
+                my $NcullTotal = @$cull_list_r;
+                foreach my $instance (@$cull_list_r) {
+                    my ($volname) = $instance =~ m|file:///data/([0-9a-zA-Z]*\.[0-9])/\S*|;
+                    unless (defined $vol_good{$volname}) { die "ERROR: invalid volume name $volname\n"; }
+                    # print STDERR "neb-cull $state: $ext_id $volname ($main_keep $back_keep)\n";
+                    my $status = &vsystem ("neb-cull --volume $volname $ext_id");
+                    if ($status) { print STDERR "FAIL CULL: neb-replicate : $ext_id\n"; next; }
+                }
+                # print STDERR "Ncull Total $NcullTotal\n";
+            }
+
+            # these are done in stage 3:
+            if ($state eq "CUL1:") { $Ncul1++; next; }
+            if ($state eq "CUL2:") { $Ncul2++; next; }
+            if ($state eq "CUL3:") { $Ncul3++; next; }
+        }
     }
     $volnum ++;
@@ -136 +231 @@
 }
 
-# get the list of chip neb paths for one chip
-sub get_neb_volumes {
+sub get_chip_instances {
+
+    my $ext_id = $_[0];
+    
+    my $sql_chip_instances = "SELECT uri, host, available, xattr, cab_id from instance join storage_object using (so_id) join volume using (vol_id) where ext_id = '$ext_id'";
+    my $rowref   = $neb_dbh->selectall_arrayref( $sql_chip_instances );
+    
+    return ($rowref, $ext_id);
+}
+
+# select 1 instance with xattr = 0, 1 with xattr = 1.
+# the rest should be culled.
+
+sub check_instance_xattr {
+
+    my $rowref  = $_[0];
+    my $ext_id  = $_[1];
+
+    my @inforows = @$rowref;
+    my $Nrows    = @inforows;
+
+    if ($DEBUG > 5) { print "found $Nrows instances\n"; }
+
+    # get user_copies for this storage_object
+    my $main_keep = "";
+    my $back_keep = "";
+    my @cull_list = ();
+
+    # xattr = 0 means instance @ ITC  (main)
+    # xattr = 1 means instance @ ATRC (back)
+    for (my $j = 0; $j < $Nrows; $j ++) {
+        my $valref = $inforows[$j];
+        my @values = @$valref;
+        
+        # the number of returned values per row must match the query above (in get_chip_instances)
+        my $Nvalue = @values;
+        if ($Nvalue != 5) {
+            print STDERR "ERROR : INVALID DB XATTR RESPONSE: $ext_id\n";
+            next;
+        }
+
+        my $instance = $values[0];
+        my $hostname = $values[1];
+        my $xattr    = $values[3];
+        
+        if (($xattr == 0) && ($main_keep eq "")) { $main_keep = $instance; next; }
+        if (($xattr == 1) && ($back_keep eq "")) { $back_keep = $instance; next; }
+
+        # if we make it here, we already have an instance at this location
+        push (@cull_list, $instance);
+    }
+    return ($main_keep, $back_keep, \@cull_list);
+}
+
+# get the list of neb hosts to copy data to at ITC
+sub get_neb_volumes_copy {
 
     my @volarray;
@@ -164 +313 @@
 }
 
+# get the list of valid neb hosts (ITC or ATRC)
+sub get_neb_volumes_good {
+
+    my %volarray;
+
+    my $sql_neb_volumes = "select name from mountedvol where ((xattr = 0) or (xattr = 1))";
+    if ($DEBUG > 4) { print "sql: $sql_neb_volumes\n"; }
+
+    my $rowref   = $neb_dbh->selectall_arrayref( $sql_neb_volumes );
+    my @tmparray = @$rowref;
+    my $Nrows    = @tmparray;
+
+    if ($DEBUG > 4) { print "found $Nrows possible volumes\n"; }
+
+    foreach my $valref (@tmparray) {
+        my @values = @$valref;
+        # there should only be a single value (only name selected above)
+        my $Nvalues = @values;
+        if ($Nvalues == 0) { print "ERROR: missing uri\n"; next; }
+        if ($Nvalues  > 1) { print "ERROR: too many uri entries?\n"; next; }
+        
+        $volarray{$values[0]} = 1;
+        if ($DEBUG > 4) { print "$values[0]\n"; }
+    }
+    
+    return %volarray;
+}
+
 # read the list of chip_ids:
 sub load_chip_list {
@@ -194 +371 @@
     pod2usage( -msg => "Cannot determine target date, use --dateobs YYYY/MM/DD", -exitval => 2) unless defined $dateobs;
     pod2usage( -msg => "Provide a list of chips with --chiplist", -exitval => 2) unless defined $chiplist;
-    pod2usage( -msg => "Define the stage (v0, v1, etc) with --stage", -exitval => 2) unless defined $stage;
+    pod2usage( -msg => "Define the stage (0, 1, etc) with --stage", -exitval => 2) unless defined $stage;
     pod2usage( -msg => "Specify the top-level output directory with --topdir", -exitval => 2) unless defined $topdir;
     
+    # check that stage is an integer
+    unless (is_integer ($stage)) { die "stage must be a non-negative integer\n"; }
+    unless ($stage >= 0) { die "stage must be a non-negative integer\n"; }
+
     # check the date format (require YYYY/MM/DD and use that from 00:00:00 to 23:59:59 or take start and end?)
 
@@ -248 +429 @@
 sub vsystem {
     print STDERR "@_\n";
-    #return 0;
+    # return 0;
     my $status = system ("@_");
     return $status;
 }
+
+sub is_integer {
+   defined $_[0] && $_[0] =~ /^[+-]?\d+$/;
+}
+    

trunk/tools/eam/rawfix.20230221/src/get_md5s_instances.pl

@@ -11 +11 @@
 use Getopt::Long qw( GetOptions :config auto_help auto_version );
 
-# USAGE: get_md5s_instances.pl --hostname (hostname) --input (file) --stage (v0,v1,etc)
+# USAGE: get_md5s_instances.pl --hostname (hostname) --input (file) --stage (0,1,etc)
 
 my ($myhost, $input, $stage) = &parse_cmdopts;
@@ -26 +26 @@
 
 if ($output eq $input) { die "output file ($output) matches input file ($input)\n"; }
+
+# read in both instance
+my $out_hash_r;
 if (-e $output) {
-    # check that all instances are in the output file?
-    print "$output exists, skipping\n";
-    exit 0;
+    $out_hash_r = &load_output_list ($output);
 }
 
-open (OUTFILE, ">$output");
+open (OUTFILE, ">>$output");
 
 # foreach my $instance (@$ins_list_r) {
@@ -41 +42 @@
     my $md5sum_tru = $md5_list_r->[$i];
 
+    # if the instance is already in the output file, skip it
+    if (defined $out_hash_r) {
+        my $name = $out_hash_r->{$instance};
+        if (defined $name) {
+            print STDERR "skipping $instance (already in output)\n";
+            next;
+        }
+    }
+
     my $filename = $instance;
     $filename =~ s|file://||;
-    
+
     # check for the existence of the file first:
     unless (-e $filename) {
@@ -63 +73 @@
 exit 0;
 
-# read the list of chip_ids:
+# read the instance info
 sub load_instance_list {
     my $infile = $_[0];
@@ -88 +98 @@
 }
 
+# read the instance list in the output file
+sub load_output_list {
+    my $infile = $_[0];
+
+    my (%out_hash);
+
+    open(FILE,$infile) or die "cannot open file $infile\n"; 
+
+    my @lines = <FILE>;
+
+    foreach my $line (@lines) {
+        chomp $line;
+        if ($line =~ /^\s*#/) { next; } # skip lines with leading #
+        my @words = split (/\s+/,$line);
+
+        if (@words != 4) { die "error in input $infile : $line\n"; }
+        $out_hash{$words[0]} = 1;
+    }
+    close (FILE);
+
+    return (\%out_hash);
+}
+
 sub parse_cmdopts {
 
@@ -95 +128 @@
     pod2usage( -msg => "Provide the input list with --input", -exitval => 2) unless defined $input;
     pod2usage( -msg => "Define the host machine with --hostname", -exitval => 2) unless defined $myhost;
-    pod2usage( -msg => "Define the stage (v0, v1, etc) with --stage", -exitval => 2) unless defined $stage;
+    pod2usage( -msg => "Define the stage (0, 1, etc) with --stage", -exitval => 2) unless defined $stage;
+    
+    # check that stage is an integer
+    unless (is_integer ($stage)) { die "stage must be a non-negative integer\n"; }
+    unless ($stage >= 0) { die "stage must be a non-negative integer\n"; }
     
     return ($myhost, $input, $stage);
@@ -106 +143 @@
     return $status;
 }
+
+sub is_integer {
+   defined $_[0] && $_[0] =~ /^[+-]?\d+$/;
+}
+