2 * collectd - src/memcached.c, based on src/hddtemp.c
3 * Copyright (C) 2007 Antony Dovgal
4 * Copyright (C) 2007-2012 Florian Forster
5 * Copyright (C) 2009 Doug MacEachern
6 * Copyright (C) 2009 Franck Lombardi
7 * Copyright (C) 2012 Nicolas Szalay
8 * Copyright (C) 2017 Pavel Rochnyak
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2 of the License, or (at your
13 * option) any later version.
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write to the Free Software Foundation, Inc.,
22 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
25 * Antony Dovgal <tony at daylessday dot org>
26 * Florian octo Forster <octo at collectd.org>
27 * Doug MacEachern <dougm at hyperic.com>
30 * Pavel Rochnyak <pavel2000 ngs.ru>
39 #include <netinet/in.h>
40 #include <netinet/tcp.h>
45 #define MEMCACHED_DEF_HOST "127.0.0.1"
46 #define MEMCACHED_DEF_PORT "11211"
47 #define MEMCACHED_CONNECT_TIMEOUT 10000
48 #define MEMCACHED_IO_TIMEOUT 5000
59 typedef struct prev_s prev_t;
70 typedef struct memcached_s memcached_t;
72 static _Bool memcached_have_instances = 0;
74 static void memcached_free(void *arg) {
75 memcached_t *st = arg;
80 shutdown(st->fd, SHUT_RDWR);
93 static int memcached_connect_unix(memcached_t *st) {
94 struct sockaddr_un serv_addr = {0};
97 serv_addr.sun_family = AF_UNIX;
98 sstrncpy(serv_addr.sun_path, st->socket, sizeof(serv_addr.sun_path));
100 /* create our socket descriptor */
101 fd = socket(AF_UNIX, SOCK_STREAM, 0);
104 ERROR("memcached plugin: memcached_connect_unix: socket(2) failed: %s",
105 sstrerror(errno, errbuf, sizeof(errbuf)));
109 /* connect to the memcached daemon */
110 int status = connect(fd, (struct sockaddr *)&serv_addr, sizeof(serv_addr));
112 shutdown(fd, SHUT_RDWR);
117 /* switch to non-blocking mode */
118 int flags = fcntl(fd, F_GETFL);
119 status = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
126 } /* int memcached_connect_unix */
128 static int memcached_connect_inet(memcached_t *st) {
129 struct addrinfo *ai_list;
133 struct addrinfo ai_hints = {.ai_family = AF_UNSPEC,
134 .ai_flags = AI_ADDRCONFIG,
135 .ai_socktype = SOCK_STREAM};
137 status = getaddrinfo(st->connhost, st->connport, &ai_hints, &ai_list);
140 ERROR("memcached plugin: memcached_connect_inet: "
141 "getaddrinfo(%s,%s) failed: %s",
142 st->connhost, st->connport,
143 (status == EAI_SYSTEM) ? sstrerror(errno, errbuf, sizeof(errbuf))
144 : gai_strerror(status));
148 for (struct addrinfo *ai_ptr = ai_list; ai_ptr != NULL;
149 ai_ptr = ai_ptr->ai_next) {
150 /* create our socket descriptor */
151 fd = socket(ai_ptr->ai_family, ai_ptr->ai_socktype, ai_ptr->ai_protocol);
154 WARNING("memcached plugin: memcached_connect_inet: "
155 "socket(2) failed: %s",
156 sstrerror(errno, errbuf, sizeof(errbuf)));
160 /* switch socket to non-blocking mode */
161 int flags = fcntl(fd, F_GETFL);
162 status = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
169 /* connect to the memcached daemon */
170 status = (int)connect(fd, ai_ptr->ai_addr, ai_ptr->ai_addrlen);
171 if (status != 0 && errno != EINPROGRESS) {
172 shutdown(fd, SHUT_RDWR);
178 /* Wait until connection establishes */
179 struct pollfd pollfd = {
180 .fd = fd, .events = POLLOUT,
183 status = poll(&pollfd, 1, MEMCACHED_CONNECT_TIMEOUT);
184 while (status < 0 && errno == EINTR);
191 /* Check if all is good */
193 status = getsockopt(fd, SOL_SOCKET, SO_ERROR, (void *)&socket_error,
194 &(socklen_t){sizeof(socket_error)});
195 if (status != 0 || socket_error != 0) {
200 /* A socket is opened and connection succeeded. We're done. */
204 freeaddrinfo(ai_list);
206 } /* int memcached_connect_inet */
208 static void memcached_connect(memcached_t *st) {
212 if (st->socket != NULL)
213 st->fd = memcached_connect_unix(st);
215 st->fd = memcached_connect_inet(st);
218 INFO("memcached plugin: Instance \"%s\": connection established.",
222 static int memcached_query_daemon(char *buffer, size_t buffer_size,
227 memcached_connect(st);
229 ERROR("memcached plugin: Instance \"%s\" could not connect to daemon.",
234 struct pollfd pollfd = {
235 .fd = st->fd, .events = POLLOUT,
239 status = poll(&pollfd, 1, MEMCACHED_IO_TIMEOUT);
240 while (status < 0 && errno == EINTR);
243 ERROR("memcached plugin: poll() failed for write() call.");
249 status = (int)swrite(st->fd, "stats\r\n", strlen("stats\r\n"));
252 ERROR("memcached plugin: Instance \"%s\": write(2) failed: %s", st->name,
253 sstrerror(errno, errbuf, sizeof(errbuf)));
254 shutdown(st->fd, SHUT_RDWR);
260 /* receive data from the memcached daemon */
261 memset(buffer, 0, buffer_size);
264 pollfd.events = POLLIN;
267 status = poll(&pollfd, 1, MEMCACHED_IO_TIMEOUT);
268 while (status < 0 && errno == EINTR);
271 ERROR("memcached plugin: Instance \"%s\": Timeout reading from socket",
279 status = (int)recv(st->fd, buffer + buffer_fill,
280 buffer_size - buffer_fill, /* flags = */ 0);
281 while (status < 0 && errno == EINTR);
283 char const end_token[5] = {'E', 'N', 'D', '\r', '\n'};
287 if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
290 ERROR("memcached plugin: Instance \"%s\": Error reading from socket: %s",
291 st->name, sstrerror(errno, errbuf, sizeof(errbuf)));
292 shutdown(st->fd, SHUT_RDWR);
298 buffer_fill += (size_t)status;
299 if (buffer_fill > buffer_size) {
300 buffer_fill = buffer_size;
301 WARNING("memcached plugin: Instance \"%s\": Message was truncated.",
303 shutdown(st->fd, SHUT_RDWR);
309 /* If buffer ends in end_token, we have all the data. */
310 if (memcmp(buffer + buffer_fill - sizeof(end_token), end_token,
311 sizeof(end_token)) == 0)
316 if (buffer_fill == 0) {
317 WARNING("memcached plugin: Instance \"%s\": No data returned by memcached.",
323 } /* int memcached_query_daemon */
325 static void memcached_init_vl(value_list_t *vl, memcached_t const *st) {
326 sstrncpy(vl->plugin, "memcached", sizeof(vl->plugin));
327 if (st->host != NULL)
328 sstrncpy(vl->host, st->host, sizeof(vl->host));
329 if (st->name != NULL)
330 sstrncpy(vl->plugin_instance, st->name, sizeof(vl->plugin_instance));
333 static void submit_derive(const char *type, const char *type_inst,
334 derive_t value, memcached_t *st) {
335 value_list_t vl = VALUE_LIST_INIT;
337 memcached_init_vl(&vl, st);
338 vl.values = &(value_t){.derive = value};
340 sstrncpy(vl.type, type, sizeof(vl.type));
341 if (type_inst != NULL)
342 sstrncpy(vl.type_instance, type_inst, sizeof(vl.type_instance));
344 plugin_dispatch_values(&vl);
347 static void submit_derive2(const char *type, const char *type_inst,
348 derive_t value0, derive_t value1, memcached_t *st) {
349 value_list_t vl = VALUE_LIST_INIT;
351 {.derive = value0}, {.derive = value1},
354 memcached_init_vl(&vl, st);
356 vl.values_len = STATIC_ARRAY_SIZE(values);
357 sstrncpy(vl.type, type, sizeof(vl.type));
358 if (type_inst != NULL)
359 sstrncpy(vl.type_instance, type_inst, sizeof(vl.type_instance));
361 plugin_dispatch_values(&vl);
364 static void submit_gauge(const char *type, const char *type_inst, gauge_t value,
366 value_list_t vl = VALUE_LIST_INIT;
368 memcached_init_vl(&vl, st);
369 vl.values = &(value_t){.gauge = value};
371 sstrncpy(vl.type, type, sizeof(vl.type));
372 if (type_inst != NULL)
373 sstrncpy(vl.type_instance, type_inst, sizeof(vl.type_instance));
375 plugin_dispatch_values(&vl);
378 static void submit_gauge2(const char *type, const char *type_inst,
379 gauge_t value0, gauge_t value1, memcached_t *st) {
380 value_list_t vl = VALUE_LIST_INIT;
382 {.gauge = value0}, {.gauge = value1},
385 memcached_init_vl(&vl, st);
387 vl.values_len = STATIC_ARRAY_SIZE(values);
388 sstrncpy(vl.type, type, sizeof(vl.type));
389 if (type_inst != NULL)
390 sstrncpy(vl.type_instance, type_inst, sizeof(vl.type_instance));
392 plugin_dispatch_values(&vl);
395 static gauge_t calculate_ratio_percent(gauge_t part, gauge_t total,
397 gauge_t *prev_total) {
398 if (isnan(*prev_part) || isnan(*prev_total) || (part < *prev_part) ||
399 (total < *prev_total)) {
405 gauge_t num = part - *prev_part;
406 gauge_t denom = total - *prev_total;
411 if (num == 0 || denom == 0)
414 return 100.0 * num / denom;
417 static gauge_t calculate_ratio_percent2(gauge_t part1, gauge_t part2,
418 gauge_t *prev1, gauge_t *prev2) {
419 if (isnan(*prev1) || isnan(*prev2) || (part1 < *prev1) || (part2 < *prev2)) {
425 gauge_t num = part1 - *prev1;
426 gauge_t denom = part2 - *prev2 + num;
431 if (num == 0 || denom == 0)
434 return 100.0 * num / denom;
437 static int memcached_read(user_data_t *user_data) {
445 gauge_t bytes_used = NAN;
446 gauge_t bytes_total = NAN;
449 gauge_t incr_hits = NAN;
450 gauge_t incr_misses = NAN;
451 gauge_t decr_hits = NAN;
452 gauge_t decr_misses = NAN;
453 derive_t rusage_user = 0;
454 derive_t rusage_syst = 0;
455 derive_t octets_rx = 0;
456 derive_t octets_tx = 0;
459 st = user_data->data;
460 prev_t *prev = &st->prev;
462 /* get data from daemon */
463 if (memcached_query_daemon(buf, sizeof(buf), st) < 0) {
467 #define FIELD_IS(cnst) \
468 (((sizeof(cnst) - 1) == name_len) && (strcmp(cnst, fields[1]) == 0))
472 while ((line = strtok_r(ptr, "\n\r", &saveptr)) != NULL) {
477 fields_num = strsplit(line, fields, 3);
481 name_len = strlen(fields[1]);
486 * For an explanation on these fields please refer to
487 * <https://github.com/memcached/memcached/blob/master/doc/protocol.txt>
491 * CPU time consumed by the memcached process
493 if (FIELD_IS("rusage_user")) {
494 /* Convert to useconds */
495 rusage_user = atof(fields[2]) * 1000000;
496 } else if (FIELD_IS("rusage_system")) {
497 rusage_syst = atof(fields[2]) * 1000000;
501 * Number of threads of this instance
503 else if (FIELD_IS("threads")) {
504 submit_gauge2("ps_count", NULL, NAN, atof(fields[2]), st);
508 * Number of items stored
510 else if (FIELD_IS("curr_items")) {
511 submit_gauge("memcached_items", "current", atof(fields[2]), st);
515 * Number of bytes used and available (total - used)
517 else if (FIELD_IS("bytes")) {
518 bytes_used = atof(fields[2]);
519 } else if (FIELD_IS("limit_maxbytes")) {
520 bytes_total = atof(fields[2]);
526 else if (FIELD_IS("curr_connections")) {
527 submit_gauge("memcached_connections", "current", atof(fields[2]), st);
528 } else if (FIELD_IS("listen_disabled_num")) {
529 submit_derive("connections", "listen_disabled", atof(fields[2]), st);
532 * Total number of connections opened since the server started running
533 * Report this as connection rate.
535 else if (FIELD_IS("total_connections")) {
536 submit_derive("connections", "opened", atof(fields[2]), st);
542 else if ((name_len > 4) && (strncmp(fields[1], "cmd_", 4) == 0)) {
543 const char *name = fields[1] + 4;
544 submit_derive("memcached_command", name, atoll(fields[2]), st);
545 if (strcmp(name, "get") == 0)
546 gets = atof(fields[2]);
550 * Increment/Decrement
552 else if (FIELD_IS("incr_misses")) {
553 derive_t incr_count = atoll(fields[2]);
554 submit_derive("memcached_ops", "incr_misses", incr_count, st);
555 incr_misses = atof(fields[2]);
556 } else if (FIELD_IS("incr_hits")) {
557 derive_t incr_count = atoll(fields[2]);
558 submit_derive("memcached_ops", "incr_hits", incr_count, st);
559 incr_hits = atof(fields[2]);
560 } else if (FIELD_IS("decr_misses")) {
561 derive_t decr_count = atoll(fields[2]);
562 submit_derive("memcached_ops", "decr_misses", decr_count, st);
563 decr_misses = atof(fields[2]);
564 } else if (FIELD_IS("decr_hits")) {
565 derive_t decr_count = atoll(fields[2]);
566 submit_derive("memcached_ops", "decr_hits", decr_count, st);
567 decr_hits = atof(fields[2]);
571 * Operations on the cache:
573 * - delete hits/misses
576 else if (FIELD_IS("get_hits")) {
577 submit_derive("memcached_ops", "hits", atoll(fields[2]), st);
578 hits = atof(fields[2]);
579 } else if (FIELD_IS("get_misses")) {
580 submit_derive("memcached_ops", "misses", atoll(fields[2]), st);
581 } else if (FIELD_IS("evictions")) {
582 submit_derive("memcached_ops", "evictions", atoll(fields[2]), st);
583 } else if (FIELD_IS("delete_hits")) {
584 submit_derive("memcached_ops", "delete_hits", atoll(fields[2]), st);
585 } else if (FIELD_IS("delete_misses")) {
586 submit_derive("memcached_ops", "delete_misses", atoll(fields[2]), st);
592 else if (FIELD_IS("bytes_read")) {
593 octets_rx = atoll(fields[2]);
594 } else if (FIELD_IS("bytes_written")) {
595 octets_tx = atoll(fields[2]);
597 } /* while ((line = strtok_r (ptr, "\n\r", &saveptr)) != NULL) */
599 if (!isnan(bytes_used) && !isnan(bytes_total) && (bytes_used <= bytes_total))
600 submit_gauge2("df", "cache", bytes_used, bytes_total - bytes_used, st);
602 if ((rusage_user != 0) || (rusage_syst != 0))
603 submit_derive2("ps_cputime", NULL, rusage_user, rusage_syst, st);
605 if ((octets_rx != 0) || (octets_tx != 0))
606 submit_derive2("memcached_octets", NULL, octets_rx, octets_tx, st);
608 if (!isnan(gets) && !isnan(hits)) {
610 calculate_ratio_percent(hits, gets, &prev->hits, &prev->gets);
611 submit_gauge("percent", "hitratio", ratio, st);
614 if (!isnan(incr_hits) && !isnan(incr_misses) &&
615 (incr_hits + incr_misses > 0)) {
616 gauge_t ratio = calculate_ratio_percent2(
617 incr_hits, incr_misses, &prev->incr_hits, &prev->incr_misses);
618 submit_gauge("percent", "incr_hitratio", ratio, st);
619 submit_derive("memcached_ops", "incr", incr_hits + incr_misses, st);
622 if (!isnan(decr_hits) && !isnan(decr_misses) &&
623 (decr_hits + decr_misses > 0)) {
624 gauge_t ratio = calculate_ratio_percent2(
625 decr_hits, decr_misses, &prev->decr_hits, &prev->decr_misses);
626 submit_gauge("percent", "decr_hitratio", ratio, st);
627 submit_derive("memcached_ops", "decr", decr_hits + decr_misses, st);
631 } /* int memcached_read */
633 static int memcached_set_defaults(memcached_t *st) {
634 /* If no <Address> used then:
635 * - Connect to the destination specified by <Host>, if present.
636 * If not, use the default address.
637 * - Use the default hostname (set st->host to NULL), if
638 * - Legacy mode is used (no configuration options at all), or
639 * - "Host" option is not provided, or
640 * - "Host" option is set to "localhost" or "127.0.0.1".
642 * If <Address> used then host may be set to "localhost" or "127.0.0.1"
645 if (st->connhost == NULL) {
647 st->connhost = strdup(st->host);
648 if (st->connhost == NULL)
651 if ((strcmp("127.0.0.1", st->host) == 0) ||
652 (strcmp("localhost", st->host) == 0))
655 st->connhost = strdup(MEMCACHED_DEF_HOST);
656 if (st->connhost == NULL)
661 if (st->connport == NULL) {
662 st->connport = strdup(MEMCACHED_DEF_PORT);
663 if (st->connport == NULL)
667 assert(st->connhost != NULL);
668 assert(st->connport != NULL);
672 st->prev.incr_hits = NAN;
673 st->prev.incr_misses = NAN;
674 st->prev.decr_hits = NAN;
675 st->prev.decr_misses = NAN;
678 } /* int memcached_set_defaults */
680 static int memcached_add_read_callback(memcached_t *st) {
681 char callback_name[3 * DATA_MAX_NAME_LEN];
683 if (memcached_set_defaults(st) != 0) {
688 snprintf(callback_name, sizeof(callback_name), "memcached/%s",
689 (st->name != NULL) ? st->name : "__legacy__");
691 return plugin_register_complex_read(
692 /* group = */ "memcached",
693 /* name = */ callback_name,
694 /* callback = */ memcached_read,
697 .data = st, .free_func = memcached_free,
699 } /* int memcached_add_read_callback */
701 /* Configuration handling functiions
703 * <Instance "instance_name">
710 static int config_add_instance(oconfig_item_t *ci) {
714 /* Disable automatic generation of default instance in the init callback. */
715 memcached_have_instances = 1;
717 st = calloc(1, sizeof(*st));
719 ERROR("memcached plugin: calloc failed.");
731 if (strcasecmp(ci->key, "Instance") == 0)
732 status = cf_util_get_string(ci, &st->name);
739 for (int i = 0; i < ci->children_num; i++) {
740 oconfig_item_t *child = ci->children + i;
742 if (strcasecmp("Socket", child->key) == 0)
743 status = cf_util_get_string(child, &st->socket);
744 else if (strcasecmp("Host", child->key) == 0)
745 status = cf_util_get_string(child, &st->host);
746 else if (strcasecmp("Address", child->key) == 0)
747 status = cf_util_get_string(child, &st->connhost);
748 else if (strcasecmp("Port", child->key) == 0)
749 status = cf_util_get_service(child, &st->connport);
751 WARNING("memcached plugin: Option `%s' not allowed here.", child->key);
764 return memcached_add_read_callback(st);
765 } /* int config_add_instance */
767 static int memcached_config(oconfig_item_t *ci) {
768 _Bool have_instance_block = 0;
770 for (int i = 0; i < ci->children_num; i++) {
771 oconfig_item_t *child = ci->children + i;
773 if (strcasecmp("Instance", child->key) == 0) {
774 config_add_instance(child);
775 have_instance_block = 1;
776 } else if (!have_instance_block) {
777 /* Non-instance option: Assume legacy configuration (without <Instance />
778 * blocks) and call config_add_instance() with the <Plugin /> block. */
779 return config_add_instance(ci);
781 WARNING("memcached plugin: The configuration option "
782 "\"%s\" is not allowed here. Did you "
783 "forget to add an <Instance /> block "
784 "around the configuration?",
786 } /* for (ci->children) */
789 } /* int memcached_config */
791 static int memcached_init(void) {
795 if (memcached_have_instances)
798 /* No instances were configured, lets start a default instance. */
799 st = calloc(1, sizeof(*st));
810 status = memcached_add_read_callback(st);
812 memcached_have_instances = 1;
815 } /* int memcached_init */
817 void module_register(void) {
818 plugin_register_complex_config("memcached", memcached_config);
819 plugin_register_init("memcached", memcached_init);