option to skip CYCLE sequences in action sequence

moench-tegeder · moench-tegeder · commit d2962dee0830 · 2017-12-03T18:40:24.000+01:00
This adds a new option "--skipcycled" which forces sequences
with the CYCLE option to be reported at 0% usage, thus not creating
WARNINGs and CRITICALs for these sequences. The default is still
the old behaviour (no special treatment for CYCLE sequences).
diff --git a/check_postgres.pl b/check_postgres.pl
@@ -1270,7 +1270,8 @@ package check_postgres;
     'filter=s@',   ## used by same_schema only
     'suffix=s',    ## used by same_schema only
     'replace',     ## used by same_schema only
-    'lsfunc=s',    ## used by wal_files and archive_ready
+    'lsfunc=s',    ## used by wal_fles and archive_ready
+    'skipcycled',  ## used by sequence only
 );
 
 die $USAGE if ! keys %opt and ! @ARGV;
@@ -7665,6 +7666,12 @@ sub check_sequence {
     ## Warning and critical are percentages
     ## Can exclude and include sequences
 
+    my $skipcycled = $opt{'skipcycled'} || 0;
+    my $percsql = 'ROUND(used/slots*100)';
+    if($skipcycled) {
+      $percsql = 'CASE WHEN cycle THEN 0 ELSE ' . $percsql . ' END';
+    }
+
     my ($warning, $critical) = validate_range
         ({
           type              => 'percent',
@@ -7719,13 +7726,14 @@ sub check_sequence {
 WHERE nspname !~ '^pg_temp.*'
 ORDER BY nspname, seqname, typname
 };
-    my $SQL10 = q{
-SELECT seqname, last_value, slots, used, ROUND(used/slots*100) AS percent,
+    my $SQL10 = qq{
+SELECT seqname, last_value, slots, used, $percsql AS percent,
   CASE WHEN slots < used THEN 0 ELSE slots - used END AS numleft
 FROM (
  SELECT quote_ident(schemaname)||'.'||quote_ident(sequencename) AS seqname, COALESCE(last_value,min_value) AS last_value,
-  CEIL((max_value-min_value::numeric+1)/increment_by::NUMERIC) AS slots,
-  CEIL((COALESCE(last_value,min_value)-min_value::numeric+1)/increment_by::NUMERIC) AS used
+  cycle,
+  CEIL((max_value-min_value::NUMERIC+1)/increment_by::NUMERIC) AS slots,
+  CEIL((COALESCE(last_value,min_value)-min_value::NUMERIC+1)/increment_by::NUMERIC) AS used
 FROM pg_sequences) foo};
     ## use critic
 
@@ -7752,12 +7760,13 @@ sub check_sequence {
             my $seqname_l = $seqname;
             $seqname_l =~ s/'/''/g; # SQL literal quoting (name is already identifier-quoted)
             push @seq_sql, qq{
-SELECT '$seqname_l' AS seqname, last_value, slots, used, ROUND(used/slots*100) AS percent,
+SELECT '$seqname_l' AS seqname, last_value, slots, used, $percsql AS percent,
   CASE WHEN slots < used THEN 0 ELSE slots - used END AS numleft
 FROM (
  SELECT last_value,
-  CEIL((LEAST(max_value, $maxValue)-min_value::numeric+1)/increment_by::NUMERIC) AS slots,
-  CEIL((last_value-min_value::numeric+1)/increment_by::NUMERIC) AS used
+  is_cycled AS cycle,
+  CEIL((LEAST(max_value, $maxValue)-min_value::NUMERIC+1)/increment_by::NUMERIC) AS slots,
+  CEIL((last_value-min_value::NUMERIC+1)/increment_by::NUMERIC) AS used
 FROM $seqname) foo
 };
         }
@@ -9967,7 +9976,8 @@ =head2 B<sequence>
 The I<--warning> and I<--critical> options should be expressed as percentages. The default values 
 are B<85%> for the warning and B<95%> for the critical. You may use --include and --exclude to 
 control which sequences are to be checked. Note that this check does account for unusual B<minvalue> 
-and B<increment by> values, but does not care if the sequence is set to cycle or not.
+and B<increment by> values. By default it does not care if the sequence is set to cycle or not,
+and by passing I<--skipcycled> sequenced set to cycle are reported with 0% usage.
 
 The output for Nagios gives the name of the sequence, the percentage used, and the number of 'calls' 
 left, indicating how many more times nextval can be called on that sequence before running into 
diff --git a/t/02_sequence.t b/t/02_sequence.t
@@ -6,7 +6,7 @@ use 5.006;
 use strict;
 use warnings;
 use Data::Dumper;
-use Test::More tests => 14;
+use Test::More tests => 16;
 use lib 't','.';
 use CP_Testing;
 
@@ -47,6 +47,7 @@ my $testtbl = 'sequence_test';
 $cp->drop_sequence_if_exists($seqname);
 $cp->drop_sequence_if_exists("${seqname}2");
 $cp->drop_sequence_if_exists("${seqname}'\"evil");
+$cp->drop_sequence_if_exists("${seqname}_cycle");
 $cp->drop_table_if_exists("$testtbl");
 
 $t=qq{$S works when no sequences exist};
@@ -100,8 +101,16 @@ $dbh->commit();
 $t=qq{$S handles SQL quoting};
 like ($cp->run(''), qr{OK:.+'public."${seqname}''""evil"'}, $t); # extra " and ' because name is both identifier+literal quoted
 
+# test CYCLE sequence skipping
+$dbh->do(qq{CREATE SEQUENCE ${seqname}_cycle MAXVALUE 5 CYCLE});
+$dbh->commit();
+$dbh->do("SELECT setval('${seqname}_cycle',5)");
+like ($cp->run('--skipcycled'), qr{OK:.+public.cp_test_sequence_cycle=0%;85%;95% }, $t);
+like ($cp->run(''), qr{CRITICAL:.+public.cp_test_sequence_cycle=100% \(calls left=0\) }, $t);
+
 $dbh->do("DROP SEQUENCE ${seqname}");
 $dbh->do("DROP SEQUENCE ${seqname}2");
+$dbh->do("DROP SEQUENCE ${seqname}_cycle");
 $dbh->do(qq{DROP SEQUENCE "${seqname}'""evil"});
 
 # test integer column where the datatype range is smaller than the serial range
