rrdtool plugin: Implemented the settings `StepSize', `HeartBeat', `RRARows', and...

The documentation has been updated, too.

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index 3d387079b4134c5e115636b6b6fa6e0edf04e9b2..3c34905f726195e313ce5a471a3100fc36f85087 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -337,8 +337,49 @@ Sets the Time-To-Live of generated ICMP packets.
 
 =head2 Plugin C<rrdtool>
 
+You can use the settings B<StepSize>, B<HeartBeat>, B<RRARows>, and B<XFF> to
+finetune your RRD-files. Please read L<rrdcreate(1)> if you encounter problems
+using these settings. If you don't want to dive into the depths of RRDTool, you
+can savely ignore these settings.
+
 =over 4
 
+=item B<DataDir> I<Directory>
+
+Set the directory to store RRD-files under. Per default RRD-files are generated
+beneath the daemon's working directory, i.E<nbsp>e. the B<BaseDir>.
+
+=item B<StepSize> I<Seconds>
+
+Sets the stepsize of newly created RRD-files. Ideally (and per default) this
+setting is identical to the global B<Interval>-option and should not be
+smaller. If unsure, don't set this option.
+
+=item B<HeartBeat> I<Seconds>
+
+Sets the heartbeat of newly created RRD-files. Ideally (and per default) this
+setting is bigger than the B<Interval>-setting. If unsure, don't set this
+option.
+
+=item B<RRARows> I<NumRows>
+
+The C<rrdtool plugin> calculates the number of PDPs per CDP based on the
+B<StepSize>, this setting and a timespan. This plugin creates RRD-files with
+three times five RRAs, i. e. five RRAs with the CFs B<MIN>, B<AVERAGE>, and
+B<MAX>. The five RRAs are optimized for graphs covering one hour, one day, one
+week, one month, and one year.
+
+So for each timespan, it calculates how many PDPs need to be consolidated into
+one CDP by calculating:
+  number of PDPs = timespan / (stepsize * rrarows)
+
+Bottom line is, set this no smaller than the width of you graphs in pixels.
+
+=item B<XFF> I<Factor>
+
+Set the "XFiles Factor". This is mostly interesting if you set B<StepSize>
+bigger than B<Interval>. If unsure, don't set this option.
+
 =item B<CacheFlush> I<Seconds>
 
 When the C<rrdtool plugin> uses a cache (by setting B<CacheTimeout>, see below)
@@ -360,11 +401,6 @@ reduces IO-operations and thus lessens the load produced by updating the files.
 The tradeoff is that the graphs kind of "drag behind" and that more memory is
 used.
 
-=item B<DataDir> I<Directory>
-
-Set the directory to store RRD-files under. Per default RRD-files are generated
-beneath the daemon's working directory, i.E<nbsp>e. the B<BaseDir>.
-
 =back
 
 =head2 Plugin C<sensors>

diff --git a/src/rrdtool.c b/src/rrdtool.c
index 8154df9d8d53d5d6d4c2620b68f72d431781dd1e..80fc7671c32939d19ace90e93e3ab15538b3992d 100644 (file)
--- a/src/rrdtool.c
+++ b/src/rrdtool.c
@@ -59,30 +59,35 @@ static int rra_timespans[] =
        86400,
        604800,
        2678400,
-       31622400,
-       0
+       31622400
 };
-static int rra_timespans_num = 5;
+static int rra_timespans_num = STATIC_ARRAY_SIZE (rra_timespans);
 
 static char *rra_types[] =
 {
        "AVERAGE",
        "MIN",
-       "MAX",
-       NULL
+       "MAX"
 };
-static int rra_types_num = 3;
+static int rra_types_num = STATIC_ARRAY_SIZE (rra_types);
 
 static const char *config_keys[] =
 {
        "CacheTimeout",
        "CacheFlush",
        "DataDir",
-       NULL
+       "StepSize",
+       "HeartBeat",
+       "RRARows",
+       "XFF"
 };
-static int config_keys_num = 3;
+static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
 
-static char *datadir = NULL;
+static char   *datadir   = NULL;
+static int     stepsize  = 0;
+static int     heartbeat = 0;
+static int     rrarows   = 1200;
+static double  xff       = 0.1;
 
 static int         cache_timeout = 0;
 static int         cache_flush_timeout = 0;
@@ -99,8 +104,6 @@ static int rra_get (char ***ret)
 
        int rra_max = rra_timespans_num * rra_types_num;
 
-       int step;
-       int rows;
        int span;
 
        int cdp_num;
@@ -119,11 +122,7 @@ static int rra_get (char ***ret)
                return (-1);
        memset (rra_def, '\0', (rra_max + 1) * sizeof (char *));
 
-       step = interval_g;
-       /* FIXME: Use config here */
-       rows = atoi (COLLECTD_ROWS);
-
-       if ((step <= 0) || (rows <= 0))
+       if ((stepsize <= 0) || (rrarows <= 0))
        {
                *ret = NULL;
                return (-1);
@@ -134,23 +133,25 @@ static int rra_get (char ***ret)
        {
                span = rra_timespans[i];
 
-               if ((span / step) < rows)
+               if ((span / stepsize) < rrarows)
                        continue;
 
                if (cdp_len == 0)
                        cdp_len = 1;
                else
-                       cdp_len = (int) floor (((double) span) / ((double) (rows * step)));
+                       cdp_len = (int) floor (((double) span)
+                                       / ((double) (rrarows * stepsize)));
 
-               cdp_num = (int) ceil (((double) span) / ((double) (cdp_len * step)));
+               cdp_num = (int) ceil (((double) span)
+                               / ((double) (cdp_len * stepsize)));
 
                for (j = 0; j < rra_types_num; j++)
                {
                        if (rra_num >= rra_max)
                                break;
 
-                       if (snprintf (buffer, sizeof(buffer), "RRA:%s:%3.1f:%u:%u",
-                                               rra_types[j], COLLECTD_XFF,
+                       if (snprintf (buffer, sizeof (buffer), "RRA:%s:%3.1f:%u:%u",
+                                               rra_types[j], xff,
                                                cdp_len, cdp_num) >= sizeof (buffer))
                        {
                                syslog (LOG_ERR, "rra_get: Buffer would have been truncated.");
@@ -241,8 +242,8 @@ static int ds_get (char ***ret, const data_set_t *ds)
                }
 
                status = snprintf (buffer, sizeof (buffer),
-                               "DS:%s:%s:%s:%s:%s",
-                               d->name, type, COLLECTD_HEARTBEAT,
+                               "DS:%s:%s:%i:%s:%s",
+                               d->name, type, heartbeat,
                                min, max);
                if ((status < 1) || (status >= sizeof (buffer)))
                        break;
@@ -278,7 +279,7 @@ static int rrd_create_file (char *filename, const data_set_t *ds)
        char **ds_def;
        int ds_num;
        int i, j;
-       char step[16];
+       char stepsize_str[16];
        int status = 0;
 
        if (check_create_dir (filename))
@@ -304,8 +305,9 @@ static int rrd_create_file (char *filename, const data_set_t *ds)
                return (-1);
        }
 
-       status = snprintf (step, sizeof (step), "%i", interval_g);
-       if ((status < 1) || (status >= sizeof (step)))
+       status = snprintf (stepsize_str, sizeof (stepsize_str),
+                       "%i", stepsize);
+       if ((status < 1) || (status >= sizeof (stepsize_str)))
        {
                syslog (LOG_ERR, "rrdtool plugin: snprintf failed.");
                return (-1);
@@ -314,7 +316,7 @@ static int rrd_create_file (char *filename, const data_set_t *ds)
        argv[0] = "create";
        argv[1] = filename;
        argv[2] = "-s";
-       argv[3] = step;
+       argv[3] = stepsize_str;
 
        j = 4;
        for (i = 0; i < ds_num; i++)
@@ -662,11 +664,11 @@ static int rrd_write (const data_set_t *ds, const value_list_t *vl)
        return (0);
 } /* int rrd_write */
 
-static int rrd_config (const char *key, const char *val)
+static int rrd_config (const char *key, const char *value)
 {
        if (strcasecmp ("CacheTimeout", key) == 0)
        {
-               int tmp = atoi (val);
+               int tmp = atoi (value);
                if (tmp < 0)
                {
                        fprintf (stderr, "rrdtool: `CacheTimeout' must "
@@ -677,7 +679,7 @@ static int rrd_config (const char *key, const char *val)
        }
        else if (strcasecmp ("CacheFlush", key) == 0)
        {
-               int tmp = atoi (val);
+               int tmp = atoi (value);
                if (tmp < 0)
                {
                        fprintf (stderr, "rrdtool: `CacheFlush' must "
@@ -690,7 +692,7 @@ static int rrd_config (const char *key, const char *val)
        {
                if (datadir != NULL)
                        free (datadir);
-               datadir = strdup (val);
+               datadir = strdup (value);
                if (datadir != NULL)
                {
                        int len = strlen (datadir);
@@ -706,6 +708,50 @@ static int rrd_config (const char *key, const char *val)
                        }
                }
        }
+       else if (strcasecmp ("StepSize", key) == 0)
+       {
+               int tmp = atoi (value);
+               if (tmp <= 0)
+               {
+                       fprintf (stderr, "rrdtool: `StepSize' must "
+                                       "be greater than 0.\n");
+                       return (1);
+               }
+               stepsize = tmp;
+       }
+       else if (strcasecmp ("HeartBeat", key) == 0)
+       {
+               int tmp = atoi (value);
+               if (tmp <= 0)
+               {
+                       fprintf (stderr, "rrdtool: `HeartBeat' must "
+                                       "be greater than 0.\n");
+                       return (1);
+               }
+               heartbeat = tmp;
+       }
+       else if (strcasecmp ("RRARows", key) == 0)
+       {
+               int tmp = atoi (value);
+               if (tmp <= 0)
+               {
+                       fprintf (stderr, "rrdtool: `RRARows' must "
+                                       "be greater than 0.\n");
+                       return (1);
+               }
+               rrarows = tmp;
+       }
+       else if (strcasecmp ("XFF", key) == 0)
+       {
+               double tmp = atof (value);
+               if ((tmp < 0.0) || (tmp >= 1.0))
+               {
+                       fprintf (stderr, "rrdtool: `XFF' must "
+                                       "be in the range 0 to 1 (exclusive).");
+                       return (1);
+               }
+               xff = tmp;
+       }
        else
        {
                return (-1);
@@ -725,6 +771,20 @@ static int rrd_shutdown (void)
 
 static int rrd_init (void)
 {
+       if (stepsize <= 0)
+               stepsize = interval_g;
+       if (heartbeat <= 0)
+               heartbeat = 2 * interval_g;
+
+       if (heartbeat < interval_g)
+               syslog (LOG_WARNING, "rrdtool plugin: Your `heartbeat' is "
+                               "smaller than your `interval'. This will "
+                               "likely cause problems.");
+       else if (stepsize < interval_g)
+               syslog (LOG_WARNING, "rrdtool plugin: Your `stepsize' is "
+                               "smaller than your `interval'. This will "
+                               "create needlessly big RRD-files.");
+
        if (cache_timeout < 2)
        {
                cache_timeout = 0;
@@ -739,6 +799,11 @@ static int rrd_init (void)
                cache_flush_last = time (NULL);
                plugin_register_shutdown ("rrdtool", rrd_shutdown);
        }
+
+       DBG ("datadir = %s; stepsize = %i; heartbeat = %i; rrarows = %i; xff = %lf;",
+                       (datadir == NULL) ? "(null)" : datadir,
+                       stepsize, heartbeat, rrarows, xff);
+
        return (0);
 } /* int rrd_init */