Merge branch 'sh/collectd-4.5' into sh/collectd-4.6
[collectd.git] / src / rrdtool.c
index 7cf2436..b80e110 100644 (file)
@@ -23,6 +23,7 @@
 #include "plugin.h"
 #include "common.h"
 #include "utils_avltree.h"
+#include "utils_rrdcreate.h"
 
 #include <rrd.h>
 
@@ -42,7 +43,8 @@ struct rrd_cache_s
        enum
        {
                FLAG_NONE   = 0x00,
-               FLAG_QUEUED = 0x01
+               FLAG_QUEUED = 0x01,
+               FLAG_FLUSHQ = 0x02
        } flags;
 };
 typedef struct rrd_cache_s rrd_cache_t;
@@ -64,27 +66,6 @@ typedef struct rrd_queue_s rrd_queue_t;
 /*
  * Private variables
  */
-static int rra_timespans[] =
-{
-       3600,
-       86400,
-       604800,
-       2678400,
-       31622400
-};
-static int rra_timespans_num = STATIC_ARRAY_SIZE (rra_timespans);
-
-static int *rra_timespans_custom = NULL;
-static int rra_timespans_custom_num = 0;
-
-static char *rra_types[] =
-{
-       "AVERAGE",
-       "MIN",
-       "MAX"
-};
-static int rra_types_num = STATIC_ARRAY_SIZE (rra_types);
-
 static const char *config_keys[] =
 {
        "CacheTimeout",
@@ -94,18 +75,29 @@ static const char *config_keys[] =
        "HeartBeat",
        "RRARows",
        "RRATimespan",
-       "XFF"
+       "XFF",
+       "WritesPerSecond"
 };
 static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
 
 /* If datadir is zero, the daemon's basedir is used. If stepsize or heartbeat
  * is zero a default, depending on the `interval' member of the value list is
  * being used. */
-static char   *datadir   = NULL;
-static int     stepsize  = 0;
-static int     heartbeat = 0;
-static int     rrarows   = 1200;
-static double  xff       = 0.1;
+static char *datadir   = NULL;
+static double write_rate = 0.0;
+static rrdcreate_config_t rrdcreate_config =
+{
+       /* stepsize = */ 0,
+       /* heartbeat = */ 0,
+       /* rrarows = */ 1200,
+       /* xff = */ 0.1,
+
+       /* timespans = */ NULL,
+       /* timespans_num = */ 0,
+
+       /* consolidation_functions = */ NULL,
+       /* consolidation_functions_num = */ 0
+};
 
 /* XXX: If you need to lock both, cache_lock and queue_lock, at the same time,
  * ALWAYS lock `cache_lock' first! */
@@ -117,6 +109,8 @@ static pthread_mutex_t cache_lock = PTHREAD_MUTEX_INITIALIZER;
 
 static rrd_queue_t    *queue_head = NULL;
 static rrd_queue_t    *queue_tail = NULL;
+static rrd_queue_t    *flushq_head = NULL;
+static rrd_queue_t    *flushq_tail = NULL;
 static pthread_t       queue_thread = 0;
 static pthread_mutex_t queue_lock = PTHREAD_MUTEX_INITIALIZER;
 static pthread_cond_t  queue_cond = PTHREAD_COND_INITIALIZER;
@@ -127,233 +121,7 @@ static pthread_mutex_t librrd_lock = PTHREAD_MUTEX_INITIALIZER;
 
 static int do_shutdown = 0;
 
-/* * * * * * * * * *
- * WARNING:  Magic *
- * * * * * * * * * */
-
-static void rra_free (int rra_num, char **rra_def)
-{
-       int i;
-
-       for (i = 0; i < rra_num; i++)
-       {
-               sfree (rra_def[i]);
-       }
-       sfree (rra_def);
-} /* void rra_free */
-
-static int rra_get (char ***ret, const value_list_t *vl)
-{
-       char **rra_def;
-       int rra_num;
-
-       int *rts;
-       int  rts_num;
-
-       int rra_max;
-
-       int span;
-
-       int cdp_num;
-       int cdp_len;
-       int i, j;
-
-       char buffer[64];
-
-       /* The stepsize we use here: If it is user-set, use it. If not, use the
-        * interval of the value-list. */
-       int ss;
-
-       if (rrarows <= 0)
-       {
-               *ret = NULL;
-               return (-1);
-       }
-
-       ss = (stepsize > 0) ? stepsize : vl->interval;
-       if (ss <= 0)
-       {
-               *ret = NULL;
-               return (-1);
-       }
-
-       /* Use the configured timespans or fall back to the built-in defaults */
-       if (rra_timespans_custom_num != 0)
-       {
-               rts = rra_timespans_custom;
-               rts_num = rra_timespans_custom_num;
-       }
-       else
-       {
-               rts = rra_timespans;
-               rts_num = rra_timespans_num;
-       }
-
-       rra_max = rts_num * rra_types_num;
-
-       if ((rra_def = (char **) malloc ((rra_max + 1) * sizeof (char *))) == NULL)
-               return (-1);
-       memset (rra_def, '\0', (rra_max + 1) * sizeof (char *));
-       rra_num = 0;
-
-       cdp_len = 0;
-       for (i = 0; i < rts_num; i++)
-       {
-               span = rts[i];
-
-               if ((span / ss) < rrarows)
-                       span = ss * rrarows;
-
-               if (cdp_len == 0)
-                       cdp_len = 1;
-               else
-                       cdp_len = (int) floor (((double) span)
-                                       / ((double) (rrarows * ss)));
-
-               cdp_num = (int) ceil (((double) span)
-                               / ((double) (cdp_len * ss)));
-
-               for (j = 0; j < rra_types_num; j++)
-               {
-                       if (rra_num >= rra_max)
-                               break;
-
-                       if (ssnprintf (buffer, sizeof (buffer), "RRA:%s:%3.1f:%u:%u",
-                                               rra_types[j], xff,
-                                               cdp_len, cdp_num) >= sizeof (buffer))
-                       {
-                               ERROR ("rra_get: Buffer would have been truncated.");
-                               continue;
-                       }
-
-                       rra_def[rra_num++] = sstrdup (buffer);
-               }
-       }
-
-#if COLLECT_DEBUG
-       DEBUG ("rra_num = %i", rra_num);
-       for (i = 0; i < rra_num; i++)
-               DEBUG ("  %s", rra_def[i]);
-#endif
-
-       *ret = rra_def;
-       return (rra_num);
-} /* int rra_get */
-
-static void ds_free (int ds_num, char **ds_def)
-{
-       int i;
-
-       for (i = 0; i < ds_num; i++)
-               if (ds_def[i] != NULL)
-                       free (ds_def[i]);
-       free (ds_def);
-}
-
-static int ds_get (char ***ret, const data_set_t *ds, const value_list_t *vl)
-{
-       char **ds_def;
-       int ds_num;
-
-       char min[32];
-       char max[32];
-       char buffer[128];
-
-       DEBUG ("ds->ds_num = %i", ds->ds_num);
-
-       ds_def = (char **) malloc (ds->ds_num * sizeof (char *));
-       if (ds_def == NULL)
-       {
-               char errbuf[1024];
-               ERROR ("rrdtool plugin: malloc failed: %s",
-                               sstrerror (errno, errbuf, sizeof (errbuf)));
-               return (-1);
-       }
-       memset (ds_def, '\0', ds->ds_num * sizeof (char *));
-
-       for (ds_num = 0; ds_num < ds->ds_num; ds_num++)
-       {
-               data_source_t *d = ds->ds + ds_num;
-               char *type;
-               int status;
-
-               ds_def[ds_num] = NULL;
-
-               if (d->type == DS_TYPE_COUNTER)
-                       type = "COUNTER";
-               else if (d->type == DS_TYPE_GAUGE)
-                       type = "GAUGE";
-               else
-               {
-                       ERROR ("rrdtool plugin: Unknown DS type: %i",
-                                       d->type);
-                       break;
-               }
-
-               if (isnan (d->min))
-               {
-                       sstrncpy (min, "U", sizeof (min));
-               }
-               else
-                       ssnprintf (min, sizeof (min), "%lf", d->min);
-
-               if (isnan (d->max))
-               {
-                       sstrncpy (max, "U", sizeof (max));
-               }
-               else
-                       ssnprintf (max, sizeof (max), "%lf", d->max);
-
-               status = ssnprintf (buffer, sizeof (buffer),
-                               "DS:%s:%s:%i:%s:%s",
-                               d->name, type,
-                               (heartbeat > 0) ? heartbeat : (2 * vl->interval),
-                               min, max);
-               if ((status < 1) || (status >= sizeof (buffer)))
-                       break;
-
-               ds_def[ds_num] = sstrdup (buffer);
-       } /* for ds_num = 0 .. ds->ds_num */
-
-#if COLLECT_DEBUG
-{
-       int i;
-       DEBUG ("ds_num = %i", ds_num);
-       for (i = 0; i < ds_num; i++)
-               DEBUG ("  %s", ds_def[i]);
-}
-#endif
-
-       if (ds_num != ds->ds_num)
-       {
-               ds_free (ds_num, ds_def);
-               return (-1);
-       }
-
-       *ret = ds_def;
-       return (ds_num);
-}
-
 #if HAVE_THREADSAFE_LIBRRD
-static int srrd_create (char *filename, unsigned long pdp_step, time_t last_up,
-               int argc, const char **argv)
-{
-       int status;
-
-       optind = 0; /* bug in librrd? */
-       rrd_clear_error ();
-
-       status = rrd_create_r (filename, pdp_step, last_up, argc, (void *) argv);
-
-       if (status != 0)
-       {
-               WARNING ("rrdtool plugin: rrd_create_r (%s) failed: %s",
-                               filename, rrd_get_error ());
-       }
-
-       return (status);
-} /* int srrd_create */
-
 static int srrd_update (char *filename, char *template,
                int argc, const char **argv)
 {
@@ -375,59 +143,6 @@ static int srrd_update (char *filename, char *template,
 /* #endif HAVE_THREADSAFE_LIBRRD */
 
 #else /* !HAVE_THREADSAFE_LIBRRD */
-static int srrd_create (char *filename, unsigned long pdp_step, time_t last_up,
-               int argc, const char **argv)
-{
-       int status;
-
-       int new_argc;
-       char **new_argv;
-
-       char pdp_step_str[16];
-       char last_up_str[16];
-
-       new_argc = 6 + argc;
-       new_argv = (char **) malloc ((new_argc + 1) * sizeof (char *));
-       if (new_argv == NULL)
-       {
-               ERROR ("rrdtool plugin: malloc failed.");
-               return (-1);
-       }
-
-       if (last_up == 0)
-               last_up = time (NULL) - 10;
-
-       ssnprintf (pdp_step_str, sizeof (pdp_step_str), "%lu", pdp_step);
-       ssnprintf (last_up_str, sizeof (last_up_str), "%u", (unsigned int) last_up);
-
-       new_argv[0] = "create";
-       new_argv[1] = filename;
-       new_argv[2] = "-s";
-       new_argv[3] = pdp_step_str;
-       new_argv[4] = "-b";
-       new_argv[5] = last_up_str;
-
-       memcpy (new_argv + 6, argv, argc * sizeof (char *));
-       new_argv[new_argc] = NULL;
-       
-       pthread_mutex_lock (&librrd_lock);
-       optind = 0; /* bug in librrd? */
-       rrd_clear_error ();
-
-       status = rrd_create (new_argc, new_argv);
-       pthread_mutex_unlock (&librrd_lock);
-
-       if (status != 0)
-       {
-               WARNING ("rrdtool plugin: rrd_create (%s) failed: %s",
-                               filename, rrd_get_error ());
-       }
-
-       sfree (new_argv);
-
-       return (status);
-} /* int srrd_create */
-
 static int srrd_update (char *filename, char *template,
                int argc, const char **argv)
 {
@@ -471,58 +186,6 @@ static int srrd_update (char *filename, char *template,
 } /* int srrd_update */
 #endif /* !HAVE_THREADSAFE_LIBRRD */
 
-static int rrd_create_file (char *filename, const data_set_t *ds, const value_list_t *vl)
-{
-       char **argv;
-       int argc;
-       char **rra_def;
-       int rra_num;
-       char **ds_def;
-       int ds_num;
-       int status = 0;
-
-       if (check_create_dir (filename))
-               return (-1);
-
-       if ((rra_num = rra_get (&rra_def, vl)) < 1)
-       {
-               ERROR ("rrd_create_file failed: Could not calculate RRAs");
-               return (-1);
-       }
-
-       if ((ds_num = ds_get (&ds_def, ds, vl)) < 1)
-       {
-               ERROR ("rrd_create_file failed: Could not calculate DSes");
-               return (-1);
-       }
-
-       argc = ds_num + rra_num;
-
-       if ((argv = (char **) malloc (sizeof (char *) * (argc + 1))) == NULL)
-       {
-               char errbuf[1024];
-               ERROR ("rrd_create failed: %s",
-                               sstrerror (errno, errbuf, sizeof (errbuf)));
-               return (-1);
-       }
-
-       memcpy (argv, ds_def, ds_num * sizeof (char *));
-       memcpy (argv + ds_num, rra_def, rra_num * sizeof (char *));
-       argv[ds_num + rra_num] = NULL;
-
-       assert (vl->time > 10);
-       status = srrd_create (filename,
-                       (stepsize > 0) ? stepsize : vl->interval,
-                       vl->time - 10,
-                       argc, (const char **)argv);
-
-       free (argv);
-       ds_free (ds_num, ds_def);
-       rra_free (rra_num, rra_def);
-
-       return (status);
-}
-
 static int value_list_to_string (char *buffer, int buffer_len,
                const data_set_t *ds, const value_list_t *vl)
 {
@@ -560,7 +223,7 @@ static int value_list_to_string (char *buffer, int buffer_len,
 } /* int value_list_to_string */
 
 static int value_list_to_filename (char *buffer, int buffer_len,
-               const data_set_t *ds, const value_list_t *vl)
+               const data_set_t __attribute__((unused)) *ds, const value_list_t *vl)
 {
        int offset = 0;
        int status;
@@ -603,37 +266,93 @@ static int value_list_to_filename (char *buffer, int buffer_len,
        return (0);
 } /* int value_list_to_filename */
 
-static void *rrd_queue_thread (void *data)
+static void *rrd_queue_thread (void __attribute__((unused)) *data)
 {
+        struct timeval tv_next_update;
+        struct timeval tv_now;
+
+        gettimeofday (&tv_next_update, /* timezone = */ NULL);
+
        while (42)
        {
                rrd_queue_t *queue_entry;
                rrd_cache_t *cache_entry;
                char **values;
                int    values_num;
+               int    status;
                int    i;
 
-               /* XXX: If you need to lock both, cache_lock and queue_lock, at
-                * the same time, ALWAYS lock `cache_lock' first! */
-
-               /* wait until an entry is available */
-               pthread_mutex_lock (&queue_lock);
-               while ((queue_head == NULL) && (do_shutdown == 0))
-                       pthread_cond_wait (&queue_cond, &queue_lock);
-
-               /* We're in the shutdown phase */
-               if (queue_head == NULL)
-               {
-                       pthread_mutex_unlock (&queue_lock);
-                       break;
-               }
-
-               /* Dequeue the first entry */
-               queue_entry = queue_head;
-               if (queue_head == queue_tail)
-                       queue_head = queue_tail = NULL;
-               else
-                       queue_head = queue_head->next;
+                pthread_mutex_lock (&queue_lock);
+                /* Wait for values to arrive */
+                while (true)
+                {
+                  struct timespec ts_wait;
+
+                  while ((flushq_head == NULL) && (queue_head == NULL)
+                      && (do_shutdown == 0))
+                    pthread_cond_wait (&queue_cond, &queue_lock);
+
+                  if ((flushq_head == NULL) && (queue_head == NULL))
+                    break;
+
+                  /* Don't delay if there's something to flush */
+                  if (flushq_head != NULL)
+                    break;
+
+                  /* Don't delay if we're shutting down */
+                  if (do_shutdown != 0)
+                    break;
+
+                  /* Don't delay if no delay was configured. */
+                  if (write_rate <= 0.0)
+                    break;
+
+                  gettimeofday (&tv_now, /* timezone = */ NULL);
+                  status = timeval_cmp (tv_next_update, tv_now, NULL);
+                  /* We're good to go */
+                  if (status <= 0)
+                    break;
+
+                  /* We're supposed to wait a bit with this update, so we'll
+                   * wait for the next addition to the queue or to the end of
+                   * the wait period - whichever comes first. */
+                  ts_wait.tv_sec = tv_next_update.tv_sec;
+                  ts_wait.tv_nsec = 1000 * tv_next_update.tv_usec;
+
+                  status = pthread_cond_timedwait (&queue_cond, &queue_lock,
+                      &ts_wait);
+                  if (status == ETIMEDOUT)
+                    break;
+                } /* while (true) */
+
+                /* XXX: If you need to lock both, cache_lock and queue_lock, at
+                 * the same time, ALWAYS lock `cache_lock' first! */
+
+                /* We're in the shutdown phase */
+                if ((flushq_head == NULL) && (queue_head == NULL))
+                {
+                  pthread_mutex_unlock (&queue_lock);
+                  break;
+                }
+
+                if (flushq_head != NULL)
+                {
+                  /* Dequeue the first flush entry */
+                  queue_entry = flushq_head;
+                  if (flushq_head == flushq_tail)
+                    flushq_head = flushq_tail = NULL;
+                  else
+                    flushq_head = flushq_head->next;
+                }
+                else /* if (queue_head != NULL) */
+                {
+                  /* Dequeue the first regular entry */
+                  queue_entry = queue_head;
+                  if (queue_head == queue_tail)
+                    queue_head = queue_tail = NULL;
+                  else
+                    queue_head = queue_head->next;
+                }
 
                /* Unlock the queue again */
                pthread_mutex_unlock (&queue_lock);
@@ -642,17 +361,42 @@ static void *rrd_queue_thread (void *data)
                 * we make a copy of it's values */
                pthread_mutex_lock (&cache_lock);
 
-               c_avl_get (cache, queue_entry->filename, (void *) &cache_entry);
+               status = c_avl_get (cache, queue_entry->filename,
+                               (void *) &cache_entry);
 
-               values = cache_entry->values;
-               values_num = cache_entry->values_num;
+               if (status == 0)
+               {
+                       values = cache_entry->values;
+                       values_num = cache_entry->values_num;
 
-               cache_entry->values = NULL;
-               cache_entry->values_num = 0;
-               cache_entry->flags = FLAG_NONE;
+                       cache_entry->values = NULL;
+                       cache_entry->values_num = 0;
+                       cache_entry->flags = FLAG_NONE;
+               }
 
                pthread_mutex_unlock (&cache_lock);
 
+               if (status != 0)
+               {
+                       sfree (queue_entry->filename);
+                       sfree (queue_entry);
+                       continue;
+               }
+
+               /* Update `tv_next_update' */
+               if (write_rate > 0.0) 
+                {
+                  gettimeofday (&tv_now, /* timezone = */ NULL);
+                  tv_next_update.tv_sec = tv_now.tv_sec;
+                  tv_next_update.tv_usec = tv_now.tv_usec
+                    + ((suseconds_t) (1000000 * write_rate));
+                  while (tv_next_update.tv_usec > 1000000)
+                  {
+                    tv_next_update.tv_sec++;
+                    tv_next_update.tv_usec -= 1000000;
+                  }
+                }
+
                /* Write the values to the RRD-file */
                srrd_update (queue_entry->filename, NULL,
                                values_num, (const char **)values);
@@ -677,7 +421,8 @@ static void *rrd_queue_thread (void *data)
        return ((void *) 0);
 } /* void *rrd_queue_thread */
 
-static int rrd_queue_cache_entry (const char *filename, rrd_queue_dir_t dir)
+static int rrd_queue_enqueue (const char *filename,
+    rrd_queue_t **head, rrd_queue_t **tail)
 {
   rrd_queue_t *queue_entry;
 
@@ -695,55 +440,60 @@ static int rrd_queue_cache_entry (const char *filename, rrd_queue_dir_t dir)
   queue_entry->next = NULL;
 
   pthread_mutex_lock (&queue_lock);
-  if (dir == QUEUE_INSERT_FRONT)
-  {
-    queue_entry->next = queue_head;
-    queue_head = queue_entry;
-    if (queue_tail == NULL)
-      queue_tail = queue_head;
-  }
-  else /* (dir == QUEUE_INSERT_BACK) */
-  {
-    if (queue_tail == NULL)
-      queue_head = queue_entry;
-    else
-      queue_tail->next = queue_entry;
-    queue_tail = queue_entry;
-  }
+
+  if (*tail == NULL)
+    *head = queue_entry;
+  else
+    (*tail)->next = queue_entry;
+  *tail = queue_entry;
+
   pthread_cond_signal (&queue_cond);
   pthread_mutex_unlock (&queue_lock);
 
-  DEBUG ("rrdtool plugin: Put `%s' into the update queue", filename);
-
   return (0);
-} /* int rrd_queue_cache_entry */
+} /* int rrd_queue_enqueue */
 
-static int rrd_queue_move_to_front (const char *filename)
+static int rrd_queue_dequeue (const char *filename,
+    rrd_queue_t **head, rrd_queue_t **tail)
 {
   rrd_queue_t *this;
   rrd_queue_t *prev;
 
-  this = NULL;
-  prev = NULL;
   pthread_mutex_lock (&queue_lock);
-  for (this = queue_head; this != NULL; this = this->next)
+
+  prev = NULL;
+  this = *head;
+
+  while (this != NULL)
   {
     if (strcmp (this->filename, filename) == 0)
       break;
+    
     prev = this;
+    this = this->next;
   }
 
-  /* Check if we found the entry and if it is NOT the first entry. */
-  if ((this != NULL) && (prev != NULL))
+  if (this == NULL)
   {
-    prev->next = this->next;
-    this->next = queue_head;
-    queue_head = this;
+    pthread_mutex_unlock (&queue_lock);
+    return (-1);
   }
+
+  if (prev == NULL)
+    *head = this->next;
+  else
+    prev->next = this->next;
+
+  if (this->next == NULL)
+    *tail = prev;
+
   pthread_mutex_unlock (&queue_lock);
 
+  sfree (this->filename);
+  sfree (this);
+
   return (0);
-} /* int rrd_queue_move_to_front */
+} /* int rrd_queue_dequeue */
 
 static void rrd_cache_flush (int timeout)
 {
@@ -765,13 +515,16 @@ static void rrd_cache_flush (int timeout)
        iter = c_avl_get_iterator (cache);
        while (c_avl_iterator_next (iter, (void *) &key, (void *) &rc) == 0)
        {
-               if (rc->flags == FLAG_QUEUED)
+               if (rc->flags != FLAG_NONE)
                        continue;
                else if ((now - rc->first_value) < timeout)
                        continue;
                else if (rc->values_num > 0)
                {
-                       if (rrd_queue_cache_entry (key, QUEUE_INSERT_BACK) == 0)
+                       int status;
+
+                       status = rrd_queue_enqueue (key, &queue_head,  &queue_tail);
+                       if (status == 0)
                                rc->flags = FLAG_QUEUED;
                }
                else /* ancient and no values -> waste of memory */
@@ -833,31 +586,42 @@ static int rrd_cache_flush_identifier (int timeout, const char *identifier)
   now = time (NULL);
 
   if (datadir == NULL)
-         snprintf (key, sizeof (key), "%s.rrd",
-                         identifier);
+    snprintf (key, sizeof (key), "%s.rrd",
+        identifier);
   else
-         snprintf (key, sizeof (key), "%s/%s.rrd",
-                         datadir, identifier);
+    snprintf (key, sizeof (key), "%s/%s.rrd",
+        datadir, identifier);
   key[sizeof (key) - 1] = 0;
 
   status = c_avl_get (cache, key, (void *) &rc);
   if (status != 0)
   {
     WARNING ("rrdtool plugin: rrd_cache_flush_identifier: "
-       "c_avl_get (%s) failed. Does that file really exist?",
-       key);
+        "c_avl_get (%s) failed. Does that file really exist?",
+        key);
     return (status);
   }
 
-  if (rc->flags == FLAG_QUEUED)
-    status = rrd_queue_move_to_front (key);
+  if (rc->flags == FLAG_FLUSHQ)
+  {
+    status = 0;
+  }
+  else if (rc->flags == FLAG_QUEUED)
+  {
+    rrd_queue_dequeue (key, &queue_head, &queue_tail);
+    status = rrd_queue_enqueue (key, &flushq_head, &flushq_tail);
+    if (status == 0)
+      rc->flags = FLAG_FLUSHQ;
+  }
   else if ((now - rc->first_value) < timeout)
+  {
     status = 0;
+  }
   else if (rc->values_num > 0)
   {
-    status = rrd_queue_cache_entry (key, QUEUE_INSERT_FRONT);
+    status = rrd_queue_enqueue (key, &flushq_head, &flushq_tail);
     if (status == 0)
-      rc->flags = FLAG_QUEUED;
+      rc->flags = FLAG_FLUSHQ;
   }
 
   return (status);
@@ -872,6 +636,15 @@ static int rrd_cache_insert (const char *filename,
 
        pthread_mutex_lock (&cache_lock);
 
+       /* This shouldn't happen, but it did happen at least once, so we'll be
+        * careful. */
+       if (cache == NULL)
+       {
+               pthread_mutex_unlock (&cache_lock);
+               WARNING ("rrdtool plugin: cache == NULL.");
+               return (-1);
+       }
+
        c_avl_get (cache, filename, (void *) &rc);
 
        if (rc == NULL)
@@ -957,9 +730,12 @@ static int rrd_cache_insert (const char *filename,
        {
                /* XXX: If you need to lock both, cache_lock and queue_lock, at
                 * the same time, ALWAYS lock `cache_lock' first! */
-               if (rc->flags != FLAG_QUEUED)
+               if (rc->flags == FLAG_NONE)
                {
-                       if (rrd_queue_cache_entry (filename, QUEUE_INSERT_BACK) == 0)
+                       int status;
+
+                       status = rrd_queue_enqueue (filename, &queue_head, &queue_tail);
+                       if (status == 0)
                                rc->flags = FLAG_QUEUED;
                }
                else
@@ -972,7 +748,6 @@ static int rrd_cache_insert (const char *filename,
                        ((time (NULL) - cache_flush_last) > cache_flush_timeout))
                rrd_cache_flush (cache_flush_timeout);
 
-
        pthread_mutex_unlock (&cache_lock);
 
        return (0);
@@ -1013,7 +788,9 @@ static int rrd_write (const data_set_t *ds, const value_list_t *vl)
        {
                if (errno == ENOENT)
                {
-                       if (rrd_create_file (filename, ds, vl))
+                       status = cu_rrd_create_file (filename,
+                                       ds, vl, &rrdcreate_config);
+                       if (status != 0)
                                return (-1);
                }
                else
@@ -1061,6 +838,8 @@ static int rrd_config (const char *key, const char *value)
                {
                        fprintf (stderr, "rrdtool: `CacheTimeout' must "
                                        "be greater than 0.\n");
+                       ERROR ("rrdtool: `CacheTimeout' must "
+                                       "be greater than 0.\n");
                        return (1);
                }
                cache_timeout = tmp;
@@ -1072,6 +851,8 @@ static int rrd_config (const char *key, const char *value)
                {
                        fprintf (stderr, "rrdtool: `CacheFlush' must "
                                        "be greater than 0.\n");
+                       ERROR ("rrdtool: `CacheFlush' must "
+                                       "be greater than 0.\n");
                        return (1);
                }
                cache_flush_timeout = tmp;
@@ -1098,15 +879,15 @@ static int rrd_config (const char *key, const char *value)
        }
        else if (strcasecmp ("StepSize", key) == 0)
        {
-               stepsize = atoi (value);
-               if (stepsize < 0)
-                       stepsize = 0;
+               int temp = atoi (value);
+               if (temp > 0)
+                       rrdcreate_config.stepsize = temp;
        }
        else if (strcasecmp ("HeartBeat", key) == 0)
        {
-               heartbeat = atoi (value);
-               if (heartbeat < 0)
-                       heartbeat = 0;
+               int temp = atoi (value);
+               if (temp > 0)
+                       rrdcreate_config.heartbeat = temp;
        }
        else if (strcasecmp ("RRARows", key) == 0)
        {
@@ -1115,9 +896,11 @@ static int rrd_config (const char *key, const char *value)
                {
                        fprintf (stderr, "rrdtool: `RRARows' must "
                                        "be greater than 0.\n");
+                       ERROR ("rrdtool: `RRARows' must "
+                                       "be greater than 0.\n");
                        return (1);
                }
-               rrarows = tmp;
+               rrdcreate_config.rrarows = tmp;
        }
        else if (strcasecmp ("RRATimespan", key) == 0)
        {
@@ -1136,23 +919,24 @@ static int rrd_config (const char *key, const char *value)
                {
                        dummy = NULL;
                        
-                       tmp_alloc = realloc (rra_timespans_custom,
-                                       sizeof (int) * (rra_timespans_custom_num + 1));
+                       tmp_alloc = realloc (rrdcreate_config.timespans,
+                                       sizeof (int) * (rrdcreate_config.timespans_num + 1));
                        if (tmp_alloc == NULL)
                        {
                                fprintf (stderr, "rrdtool: realloc failed.\n");
+                               ERROR ("rrdtool: realloc failed.\n");
                                free (value_copy);
                                return (1);
                        }
-                       rra_timespans_custom = tmp_alloc;
-                       rra_timespans_custom[rra_timespans_custom_num] = atoi (ptr);
-                       if (rra_timespans_custom[rra_timespans_custom_num] != 0)
-                               rra_timespans_custom_num++;
+                       rrdcreate_config.timespans = tmp_alloc;
+                       rrdcreate_config.timespans[rrdcreate_config.timespans_num] = atoi (ptr);
+                       if (rrdcreate_config.timespans[rrdcreate_config.timespans_num] != 0)
+                               rrdcreate_config.timespans_num++;
                } /* while (strtok_r) */
 
-               qsort (/* base = */ rra_timespans_custom,
-                               /* nmemb  = */ rra_timespans_custom_num,
-                               /* size   = */ sizeof (rra_timespans_custom[0]),
+               qsort (/* base = */ rrdcreate_config.timespans,
+                               /* nmemb  = */ rrdcreate_config.timespans_num,
+                               /* size   = */ sizeof (rrdcreate_config.timespans[0]),
                                /* compar = */ rrd_compare_numeric);
 
                free (value_copy);
@@ -1164,9 +948,30 @@ static int rrd_config (const char *key, const char *value)
                {
                        fprintf (stderr, "rrdtool: `XFF' must "
                                        "be in the range 0 to 1 (exclusive).");
+                       ERROR ("rrdtool: `XFF' must "
+                                       "be in the range 0 to 1 (exclusive).");
                        return (1);
                }
-               xff = tmp;
+               rrdcreate_config.xff = tmp;
+       }
+       else if (strcasecmp ("WritesPerSecond", key) == 0)
+       {
+               double wps = atof (value);
+
+               if (wps < 0.0)
+               {
+                       fprintf (stderr, "rrdtool: `WritesPerSecond' must be "
+                                       "greater than or equal to zero.");
+                       return (1);
+               }
+               else if (wps == 0.0)
+               {
+                       write_rate = 0.0;
+               }
+               else
+               {
+                       write_rate = 1.0 / wps;
+               }
        }
        else
        {
@@ -1201,16 +1006,18 @@ static int rrd_init (void)
 {
        int status;
 
-       if (stepsize < 0)
-               stepsize = 0;
-       if (heartbeat <= 0)
-               heartbeat = 2 * stepsize;
+       if (rrdcreate_config.stepsize < 0)
+               rrdcreate_config.stepsize = 0;
+       if (rrdcreate_config.heartbeat <= 0)
+               rrdcreate_config.heartbeat = 2 * rrdcreate_config.stepsize;
 
-       if ((heartbeat > 0) && (heartbeat < interval_g))
+       if ((rrdcreate_config.heartbeat > 0)
+                       && (rrdcreate_config.heartbeat < interval_g))
                WARNING ("rrdtool plugin: Your `heartbeat' is "
                                "smaller than your `interval'. This will "
                                "likely cause problems.");
-       else if ((stepsize > 0) && (stepsize < interval_g))
+       else if ((rrdcreate_config.stepsize > 0)
+                       && (rrdcreate_config.stepsize < interval_g))
                WARNING ("rrdtool plugin: Your `stepsize' is "
                                "smaller than your `interval'. This will "
                                "create needlessly big RRD-files.");
@@ -1246,7 +1053,10 @@ static int rrd_init (void)
        DEBUG ("rrdtool plugin: rrd_init: datadir = %s; stepsize = %i;"
                        " heartbeat = %i; rrarows = %i; xff = %lf;",
                        (datadir == NULL) ? "(null)" : datadir,
-                       stepsize, heartbeat, rrarows, xff);
+                       rrdcreate_config.stepsize,
+                       rrdcreate_config.heartbeat,
+                       rrdcreate_config.rrarows,
+                       rrdcreate_config.xff);
 
        return (0);
 } /* int rrd_init */