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_rate(gauge_t part, gauge_t total, gauge_t *prev_part,
396 gauge_t *prev_total) {
397 if (isnan(*prev_part) || isnan(*prev_total) || (part < *prev_part) ||
398 (total < *prev_total)) {
404 gauge_t num = part - *prev_part;
405 gauge_t denom = total - *prev_total;
410 if (num == 0 || denom == 0)
413 return 100.0 * num / denom;
416 static gauge_t calculate_rate2(gauge_t part1, gauge_t part2, gauge_t *prev1,
418 if (isnan(*prev1) || isnan(*prev2) || (part1 < *prev1) || (part2 < *prev2)) {
424 gauge_t num = part1 - *prev1;
425 gauge_t denom = part2 - *prev2 + num;
430 if (num == 0 || denom == 0)
433 return 100.0 * num / denom;
436 static int memcached_read(user_data_t *user_data) {
444 gauge_t bytes_used = NAN;
445 gauge_t bytes_total = NAN;
448 gauge_t incr_hits = NAN;
449 gauge_t incr_misses = NAN;
450 gauge_t decr_hits = NAN;
451 gauge_t decr_misses = NAN;
452 derive_t rusage_user = 0;
453 derive_t rusage_syst = 0;
454 derive_t octets_rx = 0;
455 derive_t octets_tx = 0;
458 st = user_data->data;
459 prev_t *prev = &st->prev;
461 /* get data from daemon */
462 if (memcached_query_daemon(buf, sizeof(buf), st) < 0) {
466 #define FIELD_IS(cnst) \
467 (((sizeof(cnst) - 1) == name_len) && (strcmp(cnst, fields[1]) == 0))
471 while ((line = strtok_r(ptr, "\n\r", &saveptr)) != NULL) {
476 fields_num = strsplit(line, fields, 3);
480 name_len = strlen(fields[1]);
485 * For an explanation on these fields please refer to
486 * <https://github.com/memcached/memcached/blob/master/doc/protocol.txt>
490 * CPU time consumed by the memcached process
492 if (FIELD_IS("rusage_user")) {
493 /* Convert to useconds */
494 rusage_user = atof(fields[2]) * 1000000;
495 } else if (FIELD_IS("rusage_system")) {
496 rusage_syst = atof(fields[2]) * 1000000;
500 * Number of threads of this instance
502 else if (FIELD_IS("threads")) {
503 submit_gauge2("ps_count", NULL, NAN, atof(fields[2]), st);
507 * Number of items stored
509 else if (FIELD_IS("curr_items")) {
510 submit_gauge("memcached_items", "current", atof(fields[2]), st);
514 * Number of bytes used and available (total - used)
516 else if (FIELD_IS("bytes")) {
517 bytes_used = atof(fields[2]);
518 } else if (FIELD_IS("limit_maxbytes")) {
519 bytes_total = atof(fields[2]);
525 else if (FIELD_IS("curr_connections")) {
526 submit_gauge("memcached_connections", "current", atof(fields[2]), st);
527 } else if (FIELD_IS("listen_disabled_num")) {
528 submit_derive("connections", "listen_disabled", atof(fields[2]), st);
531 * Total number of connections opened since the server started running
532 * Report this as connection rate.
534 else if (FIELD_IS("total_connections")) {
535 submit_derive("connections", "opened", atof(fields[2]), st);
541 else if ((name_len > 4) && (strncmp(fields[1], "cmd_", 4) == 0)) {
542 const char *name = fields[1] + 4;
543 submit_derive("memcached_command", name, atoll(fields[2]), st);
544 if (strcmp(name, "get") == 0)
545 gets = atof(fields[2]);
549 * Increment/Decrement
551 else if (FIELD_IS("incr_misses")) {
552 derive_t incr_count = atoll(fields[2]);
553 submit_derive("memcached_ops", "incr_misses", incr_count, st);
554 incr_misses = atof(fields[2]);
555 } else if (FIELD_IS("incr_hits")) {
556 derive_t incr_count = atoll(fields[2]);
557 submit_derive("memcached_ops", "incr_hits", incr_count, st);
558 incr_hits = atof(fields[2]);
559 } else if (FIELD_IS("decr_misses")) {
560 derive_t decr_count = atoll(fields[2]);
561 submit_derive("memcached_ops", "decr_misses", decr_count, st);
562 decr_misses = atof(fields[2]);
563 } else if (FIELD_IS("decr_hits")) {
564 derive_t decr_count = atoll(fields[2]);
565 submit_derive("memcached_ops", "decr_hits", decr_count, st);
566 decr_hits = atof(fields[2]);
570 * Operations on the cache:
572 * - delete hits/misses
575 else if (FIELD_IS("get_hits")) {
576 submit_derive("memcached_ops", "hits", atoll(fields[2]), st);
577 hits = atof(fields[2]);
578 } else if (FIELD_IS("get_misses")) {
579 submit_derive("memcached_ops", "misses", atoll(fields[2]), st);
580 } else if (FIELD_IS("evictions")) {
581 submit_derive("memcached_ops", "evictions", atoll(fields[2]), st);
582 } else if (FIELD_IS("delete_hits")) {
583 submit_derive("memcached_ops", "delete_hits", atoll(fields[2]), st);
584 } else if (FIELD_IS("delete_misses")) {
585 submit_derive("memcached_ops", "delete_misses", atoll(fields[2]), st);
591 else if (FIELD_IS("bytes_read")) {
592 octets_rx = atoll(fields[2]);
593 } else if (FIELD_IS("bytes_written")) {
594 octets_tx = atoll(fields[2]);
596 } /* while ((line = strtok_r (ptr, "\n\r", &saveptr)) != NULL) */
598 if (!isnan(bytes_used) && !isnan(bytes_total) && (bytes_used <= bytes_total))
599 submit_gauge2("df", "cache", bytes_used, bytes_total - bytes_used, st);
601 if ((rusage_user != 0) || (rusage_syst != 0))
602 submit_derive2("ps_cputime", NULL, rusage_user, rusage_syst, st);
604 if ((octets_rx != 0) || (octets_tx != 0))
605 submit_derive2("memcached_octets", NULL, octets_rx, octets_tx, st);
607 if (!isnan(gets) && !isnan(hits)) {
608 gauge_t rate = calculate_rate(hits, gets, &prev->hits, &prev->gets);
609 submit_gauge("percent", "hitratio", rate, st);
612 if (!isnan(incr_hits) && !isnan(incr_misses) &&
613 (incr_hits + incr_misses > 0)) {
614 gauge_t rate = calculate_rate2(incr_hits, incr_misses, &prev->incr_hits,
616 submit_gauge("percent", "incr_hitratio", rate, st);
617 submit_derive("memcached_ops", "incr", incr_hits + incr_misses, st);
620 if (!isnan(decr_hits) && !isnan(decr_misses) &&
621 (decr_hits + decr_misses > 0)) {
622 gauge_t rate = calculate_rate2(decr_hits, decr_misses, &prev->decr_hits,
624 submit_gauge("percent", "decr_hitratio", rate, st);
625 submit_derive("memcached_ops", "decr", decr_hits + decr_misses, st);
629 } /* int memcached_read */
631 static int memcached_set_defaults(memcached_t *st) {
632 /* If no <Address> used then:
633 * - Connect to the destination specified by <Host>, if present.
634 * If not, use the default address.
635 * - Use the default hostname (set st->host to NULL), if
636 * - Legacy mode is used (no configuration options at all), or
637 * - "Host" option is not provided, or
638 * - "Host" option is set to "localhost" or "127.0.0.1".
640 * If <Address> used then host may be set to "localhost" or "127.0.0.1"
643 if (st->connhost == NULL) {
645 st->connhost = strdup(st->host);
646 if (st->connhost == NULL)
649 if ((strcmp("127.0.0.1", st->host) == 0) ||
650 (strcmp("localhost", st->host) == 0))
653 st->connhost = strdup(MEMCACHED_DEF_HOST);
654 if (st->connhost == NULL)
659 if (st->connport == NULL) {
660 st->connport = strdup(MEMCACHED_DEF_PORT);
661 if (st->connport == NULL)
665 assert(st->connhost != NULL);
666 assert(st->connport != NULL);
670 st->prev.incr_hits = NAN;
671 st->prev.incr_misses = NAN;
672 st->prev.decr_hits = NAN;
673 st->prev.decr_misses = NAN;
676 } /* int memcached_set_defaults */
678 static int memcached_add_read_callback(memcached_t *st) {
679 char callback_name[3 * DATA_MAX_NAME_LEN];
681 if (memcached_set_defaults(st) != 0) {
686 snprintf(callback_name, sizeof(callback_name), "memcached/%s",
687 (st->name != NULL) ? st->name : "__legacy__");
689 return plugin_register_complex_read(
690 /* group = */ "memcached",
691 /* name = */ callback_name,
692 /* callback = */ memcached_read,
695 .data = st, .free_func = memcached_free,
697 } /* int memcached_add_read_callback */
699 /* Configuration handling functiions
701 * <Instance "instance_name">
708 static int config_add_instance(oconfig_item_t *ci) {
712 /* Disable automatic generation of default instance in the init callback. */
713 memcached_have_instances = 1;
715 st = calloc(1, sizeof(*st));
717 ERROR("memcached plugin: calloc failed.");
729 if (strcasecmp(ci->key, "Instance") == 0)
730 status = cf_util_get_string(ci, &st->name);
737 for (int i = 0; i < ci->children_num; i++) {
738 oconfig_item_t *child = ci->children + i;
740 if (strcasecmp("Socket", child->key) == 0)
741 status = cf_util_get_string(child, &st->socket);
742 else if (strcasecmp("Host", child->key) == 0)
743 status = cf_util_get_string(child, &st->host);
744 else if (strcasecmp("Address", child->key) == 0)
745 status = cf_util_get_string(child, &st->connhost);
746 else if (strcasecmp("Port", child->key) == 0)
747 status = cf_util_get_service(child, &st->connport);
749 WARNING("memcached plugin: Option `%s' not allowed here.", child->key);
762 return memcached_add_read_callback(st);
763 } /* int config_add_instance */
765 static int memcached_config(oconfig_item_t *ci) {
766 _Bool have_instance_block = 0;
768 for (int i = 0; i < ci->children_num; i++) {
769 oconfig_item_t *child = ci->children + i;
771 if (strcasecmp("Instance", child->key) == 0) {
772 config_add_instance(child);
773 have_instance_block = 1;
774 } else if (!have_instance_block) {
775 /* Non-instance option: Assume legacy configuration (without <Instance />
776 * blocks) and call config_add_instance() with the <Plugin /> block. */
777 return config_add_instance(ci);
779 WARNING("memcached plugin: The configuration option "
780 "\"%s\" is not allowed here. Did you "
781 "forget to add an <Instance /> block "
782 "around the configuration?",
784 } /* for (ci->children) */
787 } /* int memcached_config */
789 static int memcached_init(void) {
793 if (memcached_have_instances)
796 /* No instances were configured, lets start a default instance. */
797 st = calloc(1, sizeof(*st));
808 status = memcached_add_read_callback(st);
810 memcached_have_instances = 1;
813 } /* int memcached_init */
815 void module_register(void) {
816 plugin_register_complex_config("memcached", memcached_config);
817 plugin_register_init("memcached", memcached_init);