From 67f09e9ca1b84e2aa0fbd27122db26cc7a8baa05 Mon Sep 17 00:00:00 2001
From: Andi H <anti-mex@spin.de>
Date: Mon, 9 May 2011 14:40:56 +0200
Subject: [PATCH] Initial version

---
 plugins/other/nginx-cache-hit-rate | 97 ++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100755 plugins/other/nginx-cache-hit-rate

diff --git a/plugins/other/nginx-cache-hit-rate b/plugins/other/nginx-cache-hit-rate
new file mode 100755
index 00000000..a241a8c4
--- /dev/null
+++ b/plugins/other/nginx-cache-hit-rate
@@ -0,0 +1,97 @@
+#!/usr/bin/perl -w
+
+=head1 NAME
+
+nginx_hitmiss - Munin plugin to show hit rate of nginx proxy cache
+
+=head1 APPLICABLE SYSTEMS
+
+nginx caching proxy
+
+=head1 CONFIGURATION
+
+File::ReadBackwards is used and must be installed.
+
+You can override the log file location.
+
+  [nginx*]
+      env.logfile /var/log/nginx/cache-access.log
+
+Nginx must be configured to include "cs=$upstream_cache_status" in the
+log file. Example format:
+
+log_format cache '$remote_addr - $host [$time_local] "$request" $status '
+                 '$body_bytes_sent "$http_referer" '
+                 'rt=$request_time ut="$upstream_response_time" '
+                 'cs=$upstream_cache_status';
+
+By default the last 1000 log lines are read, you may want to change this.
+
+=head1 MAGIC MARKERS
+
+  #%# family=auto
+  #%# capabilities=autoconf
+
+=head1 LICENSE
+
+BSD
+
+=cut
+
+use File::ReadBackwards;
+my $line_counter=1000;
+
+my $LOG = exists $ENV{'logfile'} ? $ENV{'logfile'}
+                                 : "/var/log/nginx/cache-access.log";
+
+if ( exists $ARGV[0] and $ARGV[0] eq "autoconf" ) {
+    unless (-r $LOG) {
+    print "$LOG not readable\n";
+    exit 0;
+    } else {
+    print "yes\n";
+    exit 0;
+    }
+}
+
+if ( exists $ARGV[0] and $ARGV[0] eq "config" ) {
+    print "graph_title NGINX hit rates\n";
+    print "graph_args -l 0 -u 100 --rigid\n";
+    print "graph_category nginx\n";
+    print "graph_vlabel %\n";
+    print "hit.label Hits\n";
+    print "hit.draw AREA\n";
+    print "hit.min 0\n";
+    print "hit.cdef hit,$line_counter,/,100,*\n";
+    print "miss.label Misses\n";
+    print "miss.draw STACK\n";
+    print "miss.min 0\n";
+    print "miss.cdef miss,$line_counter,/,100,*\n";
+    print "expired.label Expired Objects\n";
+    print "expired.draw STACK\n";
+    print "expired.min 0\n";
+    print "expired.cdef expired,$line_counter,/,100,*\n";
+    exit 0;
+}
+
+my ($e,$h,$m) = (0,0,0);
+my $file_counter=0;
+
+FILE: while ($line_counter > 0) {
+    my $file_extension = $file_counter==0? "" : ".$file_counter";
+    my $lh= File::ReadBackwards->new( "$LOG$file_extension" )
+     or ( warn "$line_counter lines to read, but $LOG$file_extension: $!"
+          and last FILE);
+    $file_counter++;
+    while (defined ($_= $lh->readline)) {
+        $line_counter--;
+        /cs=HIT/     and $h++;
+        /cs=MISS/    and $m++;
+        /cs=EXPIRED/ and $e++;
+        last FILE if $line_counter==0;
+    }
+    $lh->close();
+}
+print "hit.value $h\n";
+print "miss.value $m\n";
+print "expired.value $e\n";