match_empty_counter plugin: Match for zero counter values.

diff --git a/README b/README
index 83eede2..1cfa643 100644 (file)
--- a/README
+++ b/README
@@ -340,6 +340,9 @@ Features
   * Value processing can be controlled using the "filter chain" infrastructure
     and "matches" and "targets". The following plugins are available:
 
+    - match_empty_counter
+      Match counter values which are currently zero.
+
     - match_regex
       Match values by their identifier based on regular expressions.
 

diff --git a/configure.in b/configure.in
index 4ef308e..65e296a 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -3717,6 +3717,7 @@ AC_PLUGIN([java],        [$with_java],         [Embed the Java Virtual Machine])
 AC_PLUGIN([libvirt],     [$plugin_libvirt],    [Virtual machine statistics])
 AC_PLUGIN([load],        [$plugin_load],       [System load])
 AC_PLUGIN([logfile],     [yes],                [File logging plugin])
+AC_PLUGIN([match_empty_counter], [yes],        [The empty counter match])
 AC_PLUGIN([match_regex], [yes],                [The regex match])
 AC_PLUGIN([match_timediff], [yes],             [The timediff match])
 AC_PLUGIN([match_value], [yes],                [The value match])
@@ -4013,6 +4014,7 @@ Configuration:
     libvirt . . . . . . . $enable_libvirt
     load  . . . . . . . . $enable_load
     logfile . . . . . . . $enable_logfile
+    match_empty_counter . $enable_match_empty_counter
     match_regex . . . . . $enable_match_regex
     match_timediff  . . . $enable_match_timediff
     match_value . . . . . $enable_match_value

diff --git a/src/Makefile.am b/src/Makefile.am
index e6d9073..d7d92c4 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -453,6 +453,14 @@ collectd_LDADD += "-dlopen" logfile.la
 collectd_DEPENDENCIES += logfile.la
 endif
 
+if BUILD_PLUGIN_MATCH_EMPTY_COUNTER
+pkglib_LTLIBRARIES += match_empty_counter.la
+match_empty_counter_la_SOURCES = match_empty_counter.c
+match_empty_counter_la_LDFLAGS = -module -avoid-version
+collectd_LDADD += "-dlopen" match_empty_counter.la
+collectd_DEPENDENCIES += match_empty_counter.la
+endif
+
 if BUILD_PLUGIN_MATCH_REGEX
 pkglib_LTLIBRARIES += match_regex.la
 match_regex_la_SOURCES = match_regex.c

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index e401d42..8a5f6fd 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -4057,6 +4057,19 @@ Example:
    Satisfy "Any"
  </Match>
 
+=item B<empty_counter>
+
+Matches all values with one or more data sources of type B<COUNTER> and where
+all counter values are zero. These counters usually I<never> increased since
+they started existing (and are therefore uninteresting), or got reset recently
+or overflowed and you had really, I<really> bad luck.
+
+Please keep in mind that ignoring such counters can result in confusing
+behavior: Counters which hardly ever increase will be zero for long periods of
+time. If the counter is reset for some reason (machine or service restarted,
+usually), the graph will be empty (NAN) for a long time. People may not
+understand why.
+
 =back
 
 =head2 Available targets

diff --git a/src/match_empty_counter.c b/src/match_empty_counter.c
new file mode 100644 (file)
index 0000000..b9afd81
--- /dev/null
+++ b/src/match_empty_counter.c
@@ -0,0 +1,118 @@
+/**
+ * collectd - src/match_empty_counter.c
+ * Copyright (C) 2009  Florian Forster
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * Authors:
+ *   Florian Forster <octo at verplant.org>
+ **/
+
+#include "collectd.h"
+#include "common.h"
+#include "utils_cache.h"
+#include "filter_chain.h"
+
+/*
+ * private data types
+ */
+struct mec_match_s;
+typedef struct mec_match_s mec_match_t;
+struct mec_match_s
+{
+  int dummy;
+};
+
+/*
+ * internal helper functions
+ */
+static int mec_create (const oconfig_item_t *ci, void **user_data) /* {{{ */
+{
+  mec_match_t *m;
+
+  m = (mec_match_t *) malloc (sizeof (*m));
+  if (m == NULL)
+  {
+    ERROR ("mec_create: malloc failed.");
+    return (-ENOMEM);
+  }
+  memset (m, 0, sizeof (*m));
+
+  if (ci->children_num != 0)
+  {
+    ERROR ("empty_counter match: This match does not take any additional "
+        "configuration.");
+  }
+
+  *user_data = m;
+  return (0);
+} /* }}} int mec_create */
+
+static int mec_destroy (void **user_data) /* {{{ */
+{
+  if (user_data != NULL)
+  {
+    sfree (*user_data);
+  }
+
+  return (0);
+} /* }}} int mec_destroy */
+
+static int mec_match (const data_set_t __attribute__((unused)) *ds, /* {{{ */
+    const value_list_t *vl,
+    notification_meta_t __attribute__((unused)) **meta, void **user_data)
+{
+  mec_match_t *m;
+  int num_counters;
+  int num_empty;
+  int i;
+
+  if ((user_data == NULL) || (*user_data == NULL))
+    return (-1);
+
+  m = *user_data;
+
+  num_counters = 0;
+  num_empty = 0;
+
+  for (i = 0; i < ds->ds_num; i++)
+  {
+    if (ds->ds[i].type != DS_TYPE_COUNTER)
+      continue;
+
+    num_counters++;
+    if (vl->values[i].counter == 0)
+      num_empty++;
+  }
+
+  if (num_counters == 0)
+    return (FC_MATCH_NO_MATCH);
+  else if (num_counters == num_empty)
+    return (FC_MATCH_MATCHES);
+  else
+    return (FC_MATCH_NO_MATCH);
+} /* }}} int mec_match */
+
+void module_register (void)
+{
+  match_proc_t mproc;
+
+  memset (&mproc, 0, sizeof (mproc));
+  mproc.create  = mec_create;
+  mproc.destroy = mec_destroy;
+  mproc.match   = mec_match;
+  fc_register_match ("empty_counter", mproc);
+} /* module_register */
+
+/* vim: set sw=2 sts=2 tw=78 et fdm=marker : */