X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Fplugin.c;h=6c7aa057cf2d272b126eadf6308a76188d3f3b1a;hb=13cd1495b95cb1cbebcbf6abebc171ebcddc192c;hp=4e106a5b1eb5193c3188ff87934feff0f4d4fa49;hpb=1115921a0d8f73c08fd505344af4266105e1155d;p=collectd.git diff --git a/src/plugin.c b/src/plugin.c index 4e106a5b..6c7aa057 100644 --- a/src/plugin.c +++ b/src/plugin.c @@ -31,6 +31,7 @@ #include "utils_llist.h" #include "utils_heap.h" #include "utils_time.h" +#include "utils_random.h" #if HAVE_PTHREAD_H # include @@ -108,7 +109,7 @@ static int read_threads_num = 0; static write_queue_t *write_queue_head; static write_queue_t *write_queue_tail; -static long write_queue_size = 0; +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; @@ -118,10 +119,8 @@ static size_t write_threads_num = 0; static pthread_key_t plugin_ctx_key; static _Bool plugin_ctx_key_initialized = 0; -static long writequeuelengthlimit_high = 0; -static long writequeuelengthlimit_low = 0; - -static unsigned int random_seed; +static long write_limit_high = 0; +static long write_limit_low = 0; /* * Static functions @@ -676,13 +675,13 @@ static int plugin_write_enqueue (value_list_t const *vl) /* {{{ */ { write_queue_head = q; write_queue_tail = q; - write_queue_size = 1; + write_queue_length = 1; } else { write_queue_tail->next = q; write_queue_tail = q; - write_queue_size += 1; + write_queue_length += 1; } pthread_cond_signal (&write_cond); @@ -709,10 +708,10 @@ static value_list_t *plugin_write_dequeue (void) /* {{{ */ q = write_queue_head; write_queue_head = q->next; - write_queue_size -= 1; + write_queue_length -= 1; if (write_queue_head == NULL) { write_queue_tail = NULL; - write_queue_size = 0; /* Maybe instead of setting write_queue_size to 0, we should assert(write_queue_size == 0) ? */ + assert(0 == write_queue_length); } pthread_mutex_unlock (&write_lock); @@ -816,7 +815,7 @@ static void stop_write_threads (void) /* {{{ */ } write_queue_head = NULL; write_queue_tail = NULL; - write_queue_size = 0; + write_queue_length = 0; pthread_mutex_unlock (&write_lock); if (i > 0) @@ -1218,6 +1217,27 @@ int plugin_register_shutdown (const char *name, (void *) callback, /* user_data = */ NULL)); } /* int plugin_register_shutdown */ +static void plugin_free_data_sets (void) +{ + void *key; + void *value; + + if (data_sets == NULL) + return; + + while (c_avl_pick (data_sets, &key, &value) == 0) + { + data_set_t *ds = value; + /* key is a pointer to ds->type */ + + sfree (ds->ds); + sfree (ds); + } + + c_avl_destroy (data_sets); + data_sets = NULL; +} /* void plugin_free_data_sets */ + int plugin_register_data_set (const data_set_t *ds) { data_set_t *ds_copy; @@ -1435,7 +1455,8 @@ int plugin_unregister_notification (const char *name) void plugin_init_all (void) { - const char *chain_name; + char const *chain_name; + long write_threads_num; llentry_t *le; int status; @@ -1448,71 +1469,38 @@ void plugin_init_all (void) 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) { - const char *str_writequeuelengthlimithigh = global_option_get ("WriteQueueLengthLimitHigh"); - const char *str_writequeuelengthlimitlow = global_option_get ("WriteQueueLengthLimitLow"); - - writequeuelengthlimit_high = 0; - writequeuelengthlimit_low = 0; - - if(NULL != str_writequeuelengthlimithigh) { - errno = 0; - /* get high limit */ - writequeuelengthlimit_high = strtol(str_writequeuelengthlimithigh, NULL, 10); - if ((errno == ERANGE && (writequeuelengthlimit_high == LONG_MAX || writequeuelengthlimit_high == LONG_MIN)) - || (errno != 0 && writequeuelengthlimit_high == 0) - ) { - writequeuelengthlimit_high = 0; - ERROR("Config 'WriteQueueLengthLimitHigh' accepts one integer value only. Running with no limit !"); - } - if(writequeuelengthlimit_high < 0) { - ERROR("Config 'WriteQueueLengthLimitHigh' accepts positive values only. Running with no limit !"); - writequeuelengthlimit_high = 0; - } - } - - if((writequeuelengthlimit_high > 0) && (NULL != str_writequeuelengthlimitlow)) { - errno = 0; - /* get low limit */ - writequeuelengthlimit_low = strtol(str_writequeuelengthlimitlow, NULL, 10); - if ((errno == ERANGE && (writequeuelengthlimit_low == LONG_MAX || writequeuelengthlimit_low == LONG_MIN)) - || (errno != 0 && writequeuelengthlimit_low == 0) - ) { - writequeuelengthlimit_low = 0; - ERROR("Config 'WriteQueueLengthLimitLow' accepts one integer value only. Using default low limit instead"); - } - - if(writequeuelengthlimit_low < 0) { - ERROR("Config 'WriteQueueLengthLimitLow' accepts positive values only. Using default low limit instead"); - writequeuelengthlimit_low = 0; - } else if(writequeuelengthlimit_low > writequeuelengthlimit_high) { - ERROR("Config 'WriteQueueLengthLimitLow' (%ld) cannot be bigger than high limit (%ld). Using default low limit instead", - writequeuelengthlimit_low, writequeuelengthlimit_high); - writequeuelengthlimit_low = 0; - } - } - /* Check/compute low limit if not/badly defined */ - if(writequeuelengthlimit_high > 0) { - if(0 == writequeuelengthlimit_low) { - writequeuelengthlimit_low = .5 * writequeuelengthlimit_high; - } - INFO("Config 'WriteQueueLengthLimit*' : Running with limits high=%ld low=%ld", writequeuelengthlimit_high, writequeuelengthlimit_low); - random_seed = time(0); - } else { - writequeuelengthlimit_low = 0; /* This should be useless, but in case... */ - } + ERROR ("WriteQueueLimitHigh must be positive or zero."); + write_limit_high = 0; } + write_limit_low = global_option_get_long ("WriteQueueLimitLow", + /* default = */ write_limit_high / 2); + if (write_limit_low < 0) { - char const *tmp = global_option_get ("WriteThreads"); - int num = atoi (tmp); - - if (num < 1) - num = 5; + 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; @@ -1797,6 +1785,7 @@ void plugin_shutdown_all (void) destroy_all_callbacks (&list_log); plugin_free_loaded (); + plugin_free_data_sets (); } /* void plugin_shutdown_all */ int plugin_dispatch_missing (const value_list_t *vl) /* {{{ */ @@ -2017,63 +2006,84 @@ static int plugin_dispatch_values_internal (value_list_t *vl) return (0); } /* int plugin_dispatch_values_internal */ -int plugin_dispatch_values (value_list_t const *vl) +static double get_drop_probability (void) /* {{{ */ { + long pos; + long size; + long wql; + + pthread_mutex_lock (&write_lock); + wql = write_queue_length; + pthread_mutex_unlock (&write_lock); + + if (wql < write_limit_low) + return (0.0); + if (wql >= write_limit_high) + return (1.0); + + pos = 1 + wql - write_limit_low; + size = 1 + write_limit_high - write_limit_low; + + return (((double) pos) / ((double) size)); +} /* }}} double get_drop_probability */ + +static _Bool check_drop_value (void) /* {{{ */ +{ + static cdtime_t last_message_time = 0; + static pthread_mutex_t last_message_lock = PTHREAD_MUTEX_INITIALIZER; + + double p; + double q; int status; - int wq_size = write_queue_size; - /* We store write_queue_size in a local variable because other threads may update write_queue_size. - * Having this in a local variable (like a cache) is better : we do not need a lock */ - short metric_will_be_dropped = 0; - - if((writequeuelengthlimit_high > 0) && (wq_size > writequeuelengthlimit_low)) { - if(wq_size >= writequeuelengthlimit_high) { - /* if high == low, we come here too */ - metric_will_be_dropped = 1; - } else { - /* here, high != low */ - long probability_to_drop; - long n; - - probability_to_drop = (wq_size - writequeuelengthlimit_low); - - /* We use rand_r with its bad RNG because it's enough for playing dices. - * There is no security consideration here so rand_r() should be enough here. - */ - n = rand_r(&random_seed) % (writequeuelengthlimit_high - writequeuelengthlimit_low) ; - - /* 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_size gets bigger. - */ - if(n <= probability_to_drop) { - metric_will_be_dropped = 1; - } - } - } - if( ! metric_will_be_dropped) { - status = plugin_write_enqueue (vl); - if (status != 0) + if (write_limit_high == 0) + return (0); + + p = get_drop_probability (); + if (p == 0.0) + return (0); + + status = pthread_mutex_trylock (&last_message_lock); + if (status == 0) + { + cdtime_t now; + + now = cdtime (); + if ((now - last_message_time) > TIME_T_TO_CDTIME_T (1)) { - char errbuf[1024]; - ERROR ("plugin_dispatch_values: plugin_write_enqueue failed " - "with status %i (%s).", status, - sstrerror (status, errbuf, sizeof (errbuf))); - return (status); + last_message_time = now; + ERROR ("plugin_dispatch_values: Low water mark " + "reached. Dropping %.0f%% of metrics.", + 100.0 * p); } + pthread_mutex_unlock (&last_message_lock); } + + if (p == 1.0) + return (1); + + q = cdrand_d (); + if (q > p) + return (1); else + return (0); +} /* }}} _Bool check_drop_value */ + +int plugin_dispatch_values (value_list_t const *vl) +{ + int status; + + if (check_drop_value ()) + return (0); + + status = plugin_write_enqueue (vl); + if (status != 0) { - /* If you want to count dropped metrics, don't forget to add a lock here */ - /* dropped_metrics++; */ - ERROR ("plugin_dispatch_values: value dropped (write queue %ld > %ld) : time = %.3f; interval = %.3f ; %s/%s%s%s/%s%s%s", - write_queue_size, writequeuelengthlimit_low, - CDTIME_T_TO_DOUBLE (vl->time), - CDTIME_T_TO_DOUBLE (vl->interval), - vl->host, - vl->plugin, vl->plugin_instance[0]?"-":"", vl->plugin_instance, - vl->type, vl->type_instance[0]?"-":"", vl->type_instance); + char errbuf[1024]; + ERROR ("plugin_dispatch_values: plugin_write_enqueue failed " + "with status %i (%s).", status, + sstrerror (status, errbuf, sizeof (errbuf))); + return (status); } return (0);