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diff --git a/src/plugin.c b/src/plugin.c
index b2a8b86511efd1e905fc687301a547f83280eb0b..7ccfc4dd4c2d1803cb049f7bca78a8d9e6d723c6 100644 (file)
--- a/src/plugin.c
+++ b/src/plugin.c
#include "utils_llist.h"
#include "utils_heap.h"
#include "utils_time.h"
+#include "utils_random.h"
#if HAVE_PTHREAD_H
# include <pthread.h>
/*
* Private variables
*/
+static c_avl_tree_t *plugins_loaded = NULL;
+
static llist_t *list_init;
static llist_t *list_write;
static llist_t *list_flush;
static write_queue_t *write_queue_head;
static write_queue_t *write_queue_tail;
+static long write_queue_length = 0;
static _Bool write_loop = 1;
static pthread_mutex_t write_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t write_cond = PTHREAD_COND_INITIALIZER;
static pthread_key_t plugin_ctx_key;
static _Bool plugin_ctx_key_initialized = 0;
+static long write_limit_high = 0;
+static long write_limit_low = 0;
+cdtime_t last_drop_time = 0;
+
/*
* Static functions
*/
{
write_queue_head = q;
write_queue_tail = q;
+ write_queue_length = 1;
}
else
{
write_queue_tail->next = q;
write_queue_tail = q;
+ write_queue_length += 1;
}
pthread_cond_signal (&write_cond);
q = write_queue_head;
write_queue_head = q->next;
- if (write_queue_head == NULL)
+ write_queue_length -= 1;
+ if (write_queue_head == NULL) {
write_queue_tail = NULL;
+ assert(0 == write_queue_length);
+ }
pthread_mutex_unlock (&write_lock);
}
write_queue_head = NULL;
write_queue_tail = NULL;
+ write_queue_length = 0;
pthread_mutex_unlock (&write_lock);
if (i > 0)
}
}
+static _Bool plugin_is_loaded (char const *name)
+{
+ int status;
+
+ if (plugins_loaded == NULL)
+ plugins_loaded = c_avl_create ((void *) strcasecmp);
+ assert (plugins_loaded != NULL);
+
+ status = c_avl_get (plugins_loaded, name, /* ret_value = */ NULL);
+ return (status == 0);
+}
+
+static int plugin_mark_loaded (char const *name)
+{
+ char *name_copy;
+ int status;
+
+ name_copy = strdup (name);
+ if (name_copy == NULL)
+ return (ENOMEM);
+
+ status = c_avl_insert (plugins_loaded,
+ /* key = */ name_copy, /* value = */ NULL);
+ return (status);
+}
+
+static void plugin_free_loaded ()
+{
+ void *key;
+ void *value;
+
+ if (plugins_loaded == NULL)
+ return;
+
+ while (c_avl_pick (plugins_loaded, &key, &value) == 0)
+ {
+ sfree (key);
+ assert (value == NULL);
+ }
+
+ c_avl_destroy (plugins_loaded);
+ plugins_loaded = NULL;
+}
+
#define BUFSIZE 512
-int plugin_load (const char *type, uint32_t flags)
+int plugin_load (char const *plugin_name, uint32_t flags)
{
DIR *dh;
const char *dir;
struct dirent *de;
int status;
+ if (plugin_name == NULL)
+ return (EINVAL);
+
+ /* Check if plugin is already loaded and don't do anything in this
+ * case. */
+ if (plugin_is_loaded (plugin_name))
+ return (0);
+
dir = plugin_get_dir ();
ret = 1;
+ /*
+ * XXX: Magic at work:
+ *
+ * Some of the language bindings, for example the Python and Perl
+ * plugins, need to be able to export symbols to the scripts they run.
+ * For this to happen, the "Globals" flag needs to be set.
+ * Unfortunately, this technical detail is hard to explain to the
+ * average user and she shouldn't have to worry about this, ideally.
+ * So in order to save everyone's sanity use a different default for a
+ * handful of special plugins. --octo
+ */
+ if ((strcasecmp ("perl", plugin_name) == 0)
+ || (strcasecmp ("python", plugin_name) == 0))
+ flags |= PLUGIN_FLAGS_GLOBAL;
+
/* `cpu' should not match `cpufreq'. To solve this we add `.so' to the
* type when matching the filename */
- status = ssnprintf (typename, sizeof (typename), "%s.so", type);
+ status = ssnprintf (typename, sizeof (typename), "%s.so", plugin_name);
if ((status < 0) || ((size_t) status >= sizeof (typename)))
{
- WARNING ("plugin_load: Filename too long: \"%s.so\"", type);
+ WARNING ("plugin_load: Filename too long: \"%s.so\"", plugin_name);
return (-1);
}
typename_len = strlen (typename);
if (status == 0)
{
/* success */
+ plugin_mark_loaded (plugin_name);
ret = 0;
break;
}
else
{
ERROR ("plugin_load: Load plugin \"%s\" failed with "
- "status %i.", type, status);
+ "status %i.", plugin_name, status);
}
}
if (filename[0] == 0)
ERROR ("plugin_load: Could not find plugin \"%s\" in %s",
- type, dir);
+ plugin_name, dir);
return (ret);
}
void plugin_init_all (void)
{
- const char *chain_name;
+ char const *chain_name;
+ long write_threads_num;
llentry_t *le;
int status;
chain_name = global_option_get ("PostCacheChain");
post_cache_chain = fc_chain_get_by_name (chain_name);
+ write_limit_high = global_option_get_long ("WriteQueueLimitHigh",
+ /* default = */ 0);
+ if (write_limit_high < 0)
{
- char const *tmp = global_option_get ("WriteThreads");
- int num = atoi (tmp);
+ ERROR ("WriteQueueLimitHigh must be positive or zero.");
+ write_limit_high = 0;
+ }
- if (num < 1)
- num = 5;
+ write_limit_low = global_option_get_long ("WriteQueueLimitLow",
+ /* default = */ write_limit_high / 2);
+ if (write_limit_low < 0)
+ {
+ ERROR ("WriteQueueLimitLow must be positive or zero.");
+ write_limit_low = write_limit_high / 2;
+ }
+ else if (write_limit_low > write_limit_high)
+ {
+ ERROR ("WriteQueueLimitLow must not be larger than "
+ "WriteQueueLimitHigh.");
+ write_limit_low = write_limit_high;
+ }
- start_write_threads ((size_t) num);
+ write_threads_num = global_option_get_long ("WriteThreads",
+ /* default = */ 5);
+ if (write_threads_num < 1)
+ {
+ ERROR ("WriteThreads must be positive.");
+ write_threads_num = 5;
}
+ start_write_threads ((size_t) write_threads_num);
+
if ((list_init == NULL) && (read_heap == NULL))
return;
destroy_all_callbacks (&list_notification);
destroy_all_callbacks (&list_shutdown);
destroy_all_callbacks (&list_log);
+
+ plugin_free_loaded ();
} /* void plugin_shutdown_all */
int plugin_dispatch_missing (const value_list_t *vl) /* {{{ */
return (0);
} /* int plugin_dispatch_values_internal */
+static _Bool drop_metric(void) {
+ _Bool drop = 0;
+ int wq_len = write_queue_length;
+ /* We store write_queue_length in a local variable because other threads may update write_queue_length.
+ * Having this in a local variable (like a cache) is better : we do not need a lock */
+
+ if(wq_len < write_limit_low) return(0);
+
+ if((write_limit_high > 0) && (wq_len > write_limit_low)) {
+ if(wq_len >= write_limit_high) {
+ /* if high == low, we come here too */
+ drop = 1;
+ } else {
+ /* here, high != low */
+ long probability_to_drop;
+ long n;
+
+ probability_to_drop = (wq_len - write_limit_low);
+
+ n = cdrand_range(write_limit_low, write_limit_high);
+
+ /* Let's have X = high - low.
+ * n is in range [0..X]
+ * probability_to_drop is in range [1..X[
+ * probability_to_drop gets bigger when wq_len gets bigger.
+ */
+ if(n <= probability_to_drop) {
+ drop = 1;
+ }
+ }
+ }
+ if(drop) {
+ cdtime_t now = cdtime();
+ if((now - last_drop_time) > TIME_T_TO_CDTIME_T (60)) {
+ last_drop_time = now;
+ /* If you want to count dropped metrics, don't forget to add a lock here */
+ /* dropped_metrics++; */
+ ERROR ("plugin_dispatch_values : Low water mark reached, dropping a metric");
+ }
+ }
+ return(drop);
+}
+
int plugin_dispatch_values (value_list_t const *vl)
{
int status;
+ if(drop_metric ()) return(0);
+
status = plugin_write_enqueue (vl);
if (status != 0)
{