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>
36 #include "utils/common/common.h"
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;
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};
96 serv_addr.sun_family = AF_UNIX;
97 sstrncpy(serv_addr.sun_path, st->socket, sizeof(serv_addr.sun_path));
99 /* create our socket descriptor */
100 int fd = socket(AF_UNIX, SOCK_STREAM, 0);
102 ERROR("memcached plugin: memcached_connect_unix: socket(2) failed: %s",
107 /* connect to the memcached daemon */
108 int status = connect(fd, (struct sockaddr *)&serv_addr, sizeof(serv_addr));
110 shutdown(fd, SHUT_RDWR);
115 /* switch to non-blocking mode */
116 int flags = fcntl(fd, F_GETFL);
117 status = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
124 } /* int memcached_connect_unix */
126 static int memcached_connect_inet(memcached_t *st) {
127 struct addrinfo *ai_list;
130 struct addrinfo ai_hints = {.ai_family = AF_UNSPEC,
131 .ai_flags = AI_ADDRCONFIG,
132 .ai_socktype = SOCK_STREAM};
134 int status = getaddrinfo(st->connhost, st->connport, &ai_hints, &ai_list);
136 ERROR("memcached plugin: memcached_connect_inet: "
137 "getaddrinfo(%s,%s) failed: %s",
138 st->connhost, st->connport,
139 (status == EAI_SYSTEM) ? STRERRNO : gai_strerror(status));
143 for (struct addrinfo *ai_ptr = ai_list; ai_ptr != NULL;
144 ai_ptr = ai_ptr->ai_next) {
145 /* create our socket descriptor */
146 fd = socket(ai_ptr->ai_family, ai_ptr->ai_socktype, ai_ptr->ai_protocol);
148 WARNING("memcached plugin: memcached_connect_inet: "
149 "socket(2) failed: %s",
154 /* switch socket to non-blocking mode */
155 int flags = fcntl(fd, F_GETFL);
156 status = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
163 /* connect to the memcached daemon */
164 status = (int)connect(fd, ai_ptr->ai_addr, ai_ptr->ai_addrlen);
165 if (status != 0 && errno != EINPROGRESS) {
166 shutdown(fd, SHUT_RDWR);
172 /* Wait until connection establishes */
173 struct pollfd pollfd = {
178 status = poll(&pollfd, 1, MEMCACHED_CONNECT_TIMEOUT);
179 while (status < 0 && errno == EINTR);
186 /* Check if all is good */
188 status = getsockopt(fd, SOL_SOCKET, SO_ERROR, (void *)&socket_error,
189 &(socklen_t){sizeof(socket_error)});
190 if (status != 0 || socket_error != 0) {
195 /* A socket is opened and connection succeeded. We're done. */
199 freeaddrinfo(ai_list);
201 } /* int memcached_connect_inet */
203 static void memcached_connect(memcached_t *st) {
207 if (st->socket != NULL)
208 st->fd = memcached_connect_unix(st);
210 st->fd = memcached_connect_inet(st);
213 INFO("memcached plugin: Instance \"%s\": connection established.",
217 static int memcached_query_daemon(char *buffer, size_t buffer_size,
222 memcached_connect(st);
224 ERROR("memcached plugin: Instance \"%s\" could not connect to daemon.",
229 struct pollfd pollfd = {
235 status = poll(&pollfd, 1, MEMCACHED_IO_TIMEOUT);
236 while (status < 0 && errno == EINTR);
239 ERROR("memcached plugin: poll() failed for write() call.");
245 status = (int)swrite(st->fd, "stats\r\n", strlen("stats\r\n"));
247 ERROR("memcached plugin: Instance \"%s\": write(2) failed: %s", st->name,
249 shutdown(st->fd, SHUT_RDWR);
255 /* receive data from the memcached daemon */
256 memset(buffer, 0, buffer_size);
259 pollfd.events = POLLIN;
262 status = poll(&pollfd, 1, MEMCACHED_IO_TIMEOUT);
263 while (status < 0 && errno == EINTR);
266 ERROR("memcached plugin: Instance \"%s\": Timeout reading from socket",
274 status = (int)recv(st->fd, buffer + buffer_fill,
275 buffer_size - buffer_fill, /* flags = */ 0);
276 while (status < 0 && errno == EINTR);
278 char const end_token[5] = {'E', 'N', 'D', '\r', '\n'};
281 if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
284 ERROR("memcached plugin: Instance \"%s\": Error reading from socket: %s",
286 shutdown(st->fd, SHUT_RDWR);
290 } else if (status == 0) {
291 ERROR("memcached plugin: Instance \"%s\": Connection closed by peer",
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;
355 memcached_init_vl(&vl, st);
357 vl.values_len = STATIC_ARRAY_SIZE(values);
358 sstrncpy(vl.type, type, sizeof(vl.type));
359 if (type_inst != NULL)
360 sstrncpy(vl.type_instance, type_inst, sizeof(vl.type_instance));
362 plugin_dispatch_values(&vl);
365 static void submit_gauge(const char *type, const char *type_inst, gauge_t value,
367 value_list_t vl = VALUE_LIST_INIT;
369 memcached_init_vl(&vl, st);
370 vl.values = &(value_t){.gauge = value};
372 sstrncpy(vl.type, type, sizeof(vl.type));
373 if (type_inst != NULL)
374 sstrncpy(vl.type_instance, type_inst, sizeof(vl.type_instance));
376 plugin_dispatch_values(&vl);
379 static void submit_gauge2(const char *type, const char *type_inst,
380 gauge_t value0, gauge_t value1, memcached_t *st) {
381 value_list_t vl = VALUE_LIST_INIT;
387 memcached_init_vl(&vl, st);
389 vl.values_len = STATIC_ARRAY_SIZE(values);
390 sstrncpy(vl.type, type, sizeof(vl.type));
391 if (type_inst != NULL)
392 sstrncpy(vl.type_instance, type_inst, sizeof(vl.type_instance));
394 plugin_dispatch_values(&vl);
397 static gauge_t calculate_ratio_percent(derive_t part, derive_t total,
399 derive_t *prev_total) {
400 if ((*prev_part == 0) || (*prev_total == 0) || (part < *prev_part) ||
401 (total < *prev_total)) {
407 derive_t num = part - *prev_part;
408 derive_t denom = total - *prev_total;
419 return 100.0 * (gauge_t)num / (gauge_t)denom;
422 static gauge_t calculate_ratio_percent2(derive_t part1, derive_t part2,
423 derive_t *prev1, derive_t *prev2) {
424 if ((*prev1 == 0) || (*prev2 == 0) || (part1 < *prev1) || (part2 < *prev2)) {
430 derive_t num = part1 - *prev1;
431 derive_t denom = part2 - *prev2 + num;
442 return 100.0 * (gauge_t)num / (gauge_t)denom;
445 static int memcached_read(user_data_t *user_data) {
450 derive_t bytes_used = 0;
451 derive_t bytes_total = 0;
452 derive_t get_hits = 0;
453 derive_t cmd_get = 0;
454 derive_t incr_hits = 0;
455 derive_t incr_misses = 0;
456 derive_t decr_hits = 0;
457 derive_t decr_misses = 0;
458 derive_t rusage_user = 0;
459 derive_t rusage_syst = 0;
460 derive_t octets_rx = 0;
461 derive_t octets_tx = 0;
463 memcached_t *st = user_data->data;
464 prev_t *prev = &st->prev;
466 /* get data from daemon */
467 if (memcached_query_daemon(buf, sizeof(buf), st) < 0) {
471 #define FIELD_IS(cnst) \
472 (((sizeof(cnst) - 1) == name_len) && (strcmp(cnst, fields[1]) == 0))
475 char *saveptr = NULL;
476 while ((line = strtok_r(ptr, "\n\r", &saveptr)) != NULL) {
479 if (strsplit(line, fields, 3) != 3)
482 size_t name_len = strlen(fields[1]);
487 * For an explanation on these fields please refer to
488 * <https://github.com/memcached/memcached/blob/master/doc/protocol.txt>
492 * CPU time consumed by the memcached process
494 if (FIELD_IS("rusage_user")) {
495 /* Convert to useconds */
496 rusage_user = atof(fields[2]) * 1000000;
497 } else if (FIELD_IS("rusage_system")) {
498 rusage_syst = atof(fields[2]) * 1000000;
502 * Number of threads of this instance
504 else if (FIELD_IS("threads")) {
505 submit_gauge2("ps_count", NULL, NAN, atof(fields[2]), st);
509 * Number of items stored
511 else if (FIELD_IS("curr_items")) {
512 submit_gauge("memcached_items", "current", atof(fields[2]), st);
516 * Number of secs since the server started
518 else if (FIELD_IS("uptime")) {
519 submit_gauge("uptime", NULL, atof(fields[2]), st);
523 * Number of bytes used and available (total - used)
525 else if (FIELD_IS("bytes")) {
526 bytes_used = atoll(fields[2]);
527 } else if (FIELD_IS("limit_maxbytes")) {
528 bytes_total = atoll(fields[2]);
534 else if (FIELD_IS("curr_connections")) {
535 submit_gauge("memcached_connections", "current", atof(fields[2]), st);
536 } else if (FIELD_IS("listen_disabled_num")) {
537 submit_derive("total_events", "listen_disabled", atoll(fields[2]), st);
540 * Total number of connections opened since the server started running
541 * Report this as connection rate.
543 else if (FIELD_IS("total_connections")) {
544 submit_derive("connections", "opened", atoll(fields[2]), st);
550 else if ((name_len > 4) && (strncmp(fields[1], "cmd_", 4) == 0)) {
551 const char *name = fields[1] + 4;
552 submit_derive("memcached_command", name, atoll(fields[2]), st);
553 if (strcmp(name, "get") == 0)
554 cmd_get = atoll(fields[2]);
558 * Increment/Decrement
560 else if (FIELD_IS("incr_misses")) {
561 incr_misses = atoll(fields[2]);
562 submit_derive("memcached_ops", "incr_misses", incr_misses, st);
563 } else if (FIELD_IS("incr_hits")) {
564 incr_hits = atoll(fields[2]);
565 submit_derive("memcached_ops", "incr_hits", incr_hits, st);
566 } else if (FIELD_IS("decr_misses")) {
567 decr_misses = atoll(fields[2]);
568 submit_derive("memcached_ops", "decr_misses", decr_misses, st);
569 } else if (FIELD_IS("decr_hits")) {
570 decr_hits = atoll(fields[2]);
571 submit_derive("memcached_ops", "decr_hits", decr_hits, st);
575 * Operations on the cache:
577 * - delete hits/misses
580 else if (FIELD_IS("get_hits")) {
581 get_hits = atoll(fields[2]);
582 submit_derive("memcached_ops", "hits", get_hits, st);
583 } else if (FIELD_IS("get_misses")) {
584 submit_derive("memcached_ops", "misses", atoll(fields[2]), st);
585 } else if (FIELD_IS("evictions")) {
586 submit_derive("memcached_ops", "evictions", atoll(fields[2]), st);
587 } else if (FIELD_IS("delete_hits")) {
588 submit_derive("memcached_ops", "delete_hits", atoll(fields[2]), st);
589 } else if (FIELD_IS("delete_misses")) {
590 submit_derive("memcached_ops", "delete_misses", atoll(fields[2]), st);
596 else if (FIELD_IS("bytes_read")) {
597 octets_rx = atoll(fields[2]);
598 } else if (FIELD_IS("bytes_written")) {
599 octets_tx = atoll(fields[2]);
601 } /* while ((line = strtok_r (ptr, "\n\r", &saveptr)) != NULL) */
603 if ((bytes_total > 0) && (bytes_used <= bytes_total))
604 submit_gauge2("df", "cache", bytes_used, bytes_total - bytes_used, st);
606 if ((rusage_user != 0) || (rusage_syst != 0))
607 submit_derive2("ps_cputime", NULL, rusage_user, rusage_syst, st);
609 if ((octets_rx != 0) || (octets_tx != 0))
610 submit_derive2("memcached_octets", NULL, octets_rx, octets_tx, st);
612 if ((cmd_get != 0) && (get_hits != 0)) {
614 calculate_ratio_percent(get_hits, cmd_get, &prev->hits, &prev->gets);
615 submit_gauge("percent", "hitratio", ratio, st);
618 if ((incr_hits != 0) && (incr_misses != 0)) {
619 gauge_t ratio = calculate_ratio_percent2(
620 incr_hits, incr_misses, &prev->incr_hits, &prev->incr_misses);
621 submit_gauge("percent", "incr_hitratio", ratio, st);
622 submit_derive("memcached_ops", "incr", incr_hits + incr_misses, st);
625 if ((decr_hits != 0) && (decr_misses != 0)) {
626 gauge_t ratio = calculate_ratio_percent2(
627 decr_hits, decr_misses, &prev->decr_hits, &prev->decr_misses);
628 submit_gauge("percent", "decr_hitratio", ratio, st);
629 submit_derive("memcached_ops", "decr", decr_hits + decr_misses, st);
633 } /* int memcached_read */
635 static int memcached_set_defaults(memcached_t *st) {
636 /* If no <Address> used then:
637 * - Connect to the destination specified by <Host>, if present.
638 * If not, use the default address.
639 * - Use the default hostname (set st->host to NULL), if
640 * - Legacy mode is used (no configuration options at all), or
641 * - "Host" option is not provided, or
642 * - "Host" option is set to "localhost" or "127.0.0.1".
644 * If <Address> used then host may be set to "localhost" or "127.0.0.1"
647 if (st->connhost == NULL) {
649 st->connhost = strdup(st->host);
650 if (st->connhost == NULL)
653 if ((strcmp("127.0.0.1", st->host) == 0) ||
654 (strcmp("localhost", st->host) == 0))
657 st->connhost = strdup(MEMCACHED_DEF_HOST);
658 if (st->connhost == NULL)
663 if (st->connport == NULL) {
664 st->connport = strdup(MEMCACHED_DEF_PORT);
665 if (st->connport == NULL)
669 assert(st->connhost != NULL);
670 assert(st->connport != NULL);
674 st->prev.incr_hits = 0;
675 st->prev.incr_misses = 0;
676 st->prev.decr_hits = 0;
677 st->prev.decr_misses = 0;
680 } /* int memcached_set_defaults */
682 static int memcached_add_read_callback(memcached_t *st) {
683 char callback_name[3 * DATA_MAX_NAME_LEN];
685 if (memcached_set_defaults(st) != 0) {
690 snprintf(callback_name, sizeof(callback_name), "memcached/%s",
691 (st->name != NULL) ? st->name : "__legacy__");
693 return plugin_register_complex_read(
694 /* group = */ "memcached",
695 /* name = */ callback_name,
696 /* callback = */ memcached_read,
700 .free_func = memcached_free,
702 } /* int memcached_add_read_callback */
704 /* Configuration handling functiions
706 * <Instance "instance_name">
713 static int config_add_instance(oconfig_item_t *ci) {
716 /* Disable automatic generation of default instance in the init callback. */
717 memcached_have_instances = true;
719 memcached_t *st = calloc(1, sizeof(*st));
721 ERROR("memcached plugin: calloc failed.");
733 if (strcasecmp(ci->key, "Instance") == 0)
734 status = cf_util_get_string(ci, &st->name);
741 for (int i = 0; i < ci->children_num; i++) {
742 oconfig_item_t *child = ci->children + i;
744 if (strcasecmp("Socket", child->key) == 0)
745 status = cf_util_get_string(child, &st->socket);
746 else if (strcasecmp("Host", child->key) == 0)
747 status = cf_util_get_string(child, &st->host);
748 else if (strcasecmp("Address", child->key) == 0)
749 status = cf_util_get_string(child, &st->connhost);
750 else if (strcasecmp("Port", child->key) == 0)
751 status = cf_util_get_service(child, &st->connport);
753 WARNING("memcached plugin: Option `%s' not allowed here.", child->key);
766 return memcached_add_read_callback(st);
767 } /* int config_add_instance */
769 static int memcached_config(oconfig_item_t *ci) {
770 bool have_instance_block = 0;
772 for (int i = 0; i < ci->children_num; i++) {
773 oconfig_item_t *child = ci->children + i;
775 if (strcasecmp("Instance", child->key) == 0) {
776 config_add_instance(child);
777 have_instance_block = 1;
778 } else if (!have_instance_block) {
779 /* Non-instance option: Assume legacy configuration (without <Instance />
780 * blocks) and call config_add_instance() with the <Plugin /> block. */
781 return config_add_instance(ci);
783 WARNING("memcached plugin: The configuration option "
784 "\"%s\" is not allowed here. Did you "
785 "forget to add an <Instance /> block "
786 "around the configuration?",
788 } /* for (ci->children) */
791 } /* int memcached_config */
793 static int memcached_init(void) {
795 if (memcached_have_instances)
798 /* No instances were configured, lets start a default instance. */
799 memcached_t *st = calloc(1, sizeof(*st));
810 int status = memcached_add_read_callback(st);
812 memcached_have_instances = true;
815 } /* int memcached_init */
817 void module_register(void) {
818 plugin_register_complex_config("memcached", memcached_config);
819 plugin_register_init("memcached", memcached_init);