1 /**
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 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2 of the License, or (at your
12 * option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 *
23 * Authors:
24 * Antony Dovgal <tony at daylessday dot org>
25 * Florian octo Forster <octo at collectd.org>
26 * Doug MacEachern <dougm at hyperic.com>
27 * Franck Lombardi
28 * Nicolas Szalay
29 **/
31 #include "collectd.h"
33 #include "common.h"
34 #include "plugin.h"
36 #include <netdb.h>
37 #include <sys/un.h>
38 #include <netinet/in.h>
39 #include <netinet/tcp.h>
41 #define MEMCACHED_DEF_HOST "127.0.0.1"
42 #define MEMCACHED_DEF_PORT "11211"
44 struct memcached_s
45 {
46 char *name;
47 char *socket;
48 char *host;
49 char *port;
50 };
51 typedef struct memcached_s memcached_t;
53 static _Bool memcached_have_instances = 0;
55 static void memcached_free (void *arg)
56 {
57 memcached_t *st = arg;
58 if (st == NULL)
59 return;
61 sfree (st->name);
62 sfree (st->socket);
63 sfree (st->host);
64 sfree (st->port);
65 sfree (st);
66 }
68 static int memcached_connect_unix (memcached_t *st)
69 {
70 struct sockaddr_un serv_addr = { 0 };
71 int fd;
73 serv_addr.sun_family = AF_UNIX;
74 sstrncpy (serv_addr.sun_path, st->socket,
75 sizeof (serv_addr.sun_path));
77 /* create our socket descriptor */
78 fd = socket (AF_UNIX, SOCK_STREAM, 0);
79 if (fd < 0)
80 {
81 char errbuf[1024];
82 ERROR ("memcached plugin: memcached_connect_unix: socket(2) failed: %s",
83 sstrerror (errno, errbuf, sizeof (errbuf)));
84 return (-1);
85 }
87 /* connect to the memcached daemon */
88 int status = connect (fd, (struct sockaddr *)&serv_addr, sizeof(serv_addr));
89 if (status != 0)
90 {
91 shutdown (fd, SHUT_RDWR);
92 close (fd);
93 fd = -1;
94 }
96 return (fd);
97 } /* int memcached_connect_unix */
99 static int memcached_connect_inet (memcached_t *st)
100 {
101 const char *host;
102 const char *port;
104 struct addrinfo *ai_list;
105 int status;
106 int fd = -1;
108 host = (st->host != NULL) ? st->host : MEMCACHED_DEF_HOST;
109 port = (st->port != NULL) ? st->port : MEMCACHED_DEF_PORT;
111 struct addrinfo ai_hints = {
112 .ai_family = AF_UNSPEC,
113 .ai_flags = AI_ADDRCONFIG,
114 .ai_socktype = SOCK_STREAM
115 };
117 status = getaddrinfo (host, port, &ai_hints, &ai_list);
118 if (status != 0)
119 {
120 char errbuf[1024];
121 ERROR ("memcached plugin: memcached_connect_inet: "
122 "getaddrinfo(%s,%s) failed: %s",
123 host, port,
124 (status == EAI_SYSTEM)
125 ? sstrerror (errno, errbuf, sizeof (errbuf))
126 : gai_strerror (status));
127 return (-1);
128 }
130 for (struct addrinfo *ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
131 {
132 /* create our socket descriptor */
133 fd = socket (ai_ptr->ai_family, ai_ptr->ai_socktype, ai_ptr->ai_protocol);
134 if (fd < 0)
135 {
136 char errbuf[1024];
137 WARNING ("memcached plugin: memcached_connect_inet: "
138 "socket(2) failed: %s",
139 sstrerror (errno, errbuf, sizeof (errbuf)));
140 continue;
141 }
143 /* connect to the memcached daemon */
144 status = (int) connect (fd, ai_ptr->ai_addr, ai_ptr->ai_addrlen);
145 if (status != 0)
146 {
147 shutdown (fd, SHUT_RDWR);
148 close (fd);
149 fd = -1;
150 continue;
151 }
153 /* A socket could be opened and connecting succeeded. We're done. */
154 break;
155 }
157 freeaddrinfo (ai_list);
158 return (fd);
159 } /* int memcached_connect_inet */
161 static int memcached_connect (memcached_t *st)
162 {
163 if (st->socket != NULL)
164 return (memcached_connect_unix (st));
165 else
166 return (memcached_connect_inet (st));
167 }
169 static int memcached_query_daemon (char *buffer, size_t buffer_size, memcached_t *st)
170 {
171 int fd, status;
172 size_t buffer_fill;
174 fd = memcached_connect (st);
175 if (fd < 0) {
176 ERROR ("memcached plugin: Instance \"%s\" could not connect to daemon.",
177 st->name);
178 return -1;
179 }
181 status = (int) swrite (fd, "stats\r\n", strlen ("stats\r\n"));
182 if (status != 0)
183 {
184 char errbuf[1024];
185 ERROR ("memcached plugin: write(2) failed: %s",
186 sstrerror (errno, errbuf, sizeof (errbuf)));
187 shutdown(fd, SHUT_RDWR);
188 close (fd);
189 return (-1);
190 }
192 /* receive data from the memcached daemon */
193 memset (buffer, 0, buffer_size);
195 buffer_fill = 0;
196 while ((status = (int) recv (fd, buffer + buffer_fill,
197 buffer_size - buffer_fill, /* flags = */ 0)) != 0)
198 {
199 char const end_token[5] = {'E', 'N', 'D', '\r', '\n'};
200 if (status < 0)
201 {
202 char errbuf[1024];
204 if ((errno == EAGAIN) || (errno == EINTR))
205 continue;
207 ERROR ("memcached: Error reading from socket: %s",
208 sstrerror (errno, errbuf, sizeof (errbuf)));
209 shutdown(fd, SHUT_RDWR);
210 close (fd);
211 return (-1);
212 }
214 buffer_fill += (size_t) status;
215 if (buffer_fill > buffer_size)
216 {
217 buffer_fill = buffer_size;
218 WARNING ("memcached plugin: Message was truncated.");
219 break;
220 }
222 /* If buffer ends in end_token, we have all the data. */
223 if (memcmp (buffer + buffer_fill - sizeof (end_token),
224 end_token, sizeof (end_token)) == 0)
225 break;
226 } /* while (recv) */
228 status = 0;
229 if (buffer_fill == 0)
230 {
231 WARNING ("memcached plugin: No data returned by memcached.");
232 status = -1;
233 }
235 shutdown(fd, SHUT_RDWR);
236 close(fd);
237 return (status);
238 } /* int memcached_query_daemon */
240 static void memcached_init_vl (value_list_t *vl, memcached_t const *st)
241 {
242 char const *host = st->host;
244 /* Set vl->host to hostname_g, if:
245 * - Legacy mode is used.
246 * - "Socket" option is given (doc: "Host option is ignored").
247 * - "Host" option is not provided.
248 * - "Host" option is set to "localhost" or "127.0.0.1". */
249 if ((strcmp (st->name, "__legacy__") == 0)
250 || (st->socket != NULL)
251 || (st->host == NULL)
252 || (strcmp ("127.0.0.1", st->host) == 0)
253 || (strcmp ("localhost", st->host) == 0))
254 host = hostname_g;
256 sstrncpy (vl->plugin, "memcached", sizeof (vl->plugin));
257 sstrncpy (vl->host, host, sizeof (vl->host));
258 if (strcmp (st->name, "__legacy__") != 0)
259 sstrncpy (vl->plugin_instance, st->name, sizeof (vl->plugin_instance));
260 }
262 static void submit_derive (const char *type, const char *type_inst,
263 derive_t value, memcached_t *st)
264 {
265 value_t values[1];
266 value_list_t vl = VALUE_LIST_INIT;
267 memcached_init_vl (&vl, st);
269 values[0].derive = value;
271 vl.values = values;
272 vl.values_len = 1;
273 sstrncpy (vl.type, type, sizeof (vl.type));
274 if (type_inst != NULL)
275 sstrncpy (vl.type_instance, type_inst, sizeof (vl.type_instance));
277 plugin_dispatch_values (&vl);
278 }
280 static void submit_derive2 (const char *type, const char *type_inst,
281 derive_t value0, derive_t value1, memcached_t *st)
282 {
283 value_t values[2];
284 value_list_t vl = VALUE_LIST_INIT;
285 memcached_init_vl (&vl, st);
287 values[0].derive = value0;
288 values[1].derive = value1;
290 vl.values = values;
291 vl.values_len = 2;
292 sstrncpy (vl.type, type, sizeof (vl.type));
293 if (type_inst != NULL)
294 sstrncpy (vl.type_instance, type_inst, sizeof (vl.type_instance));
296 plugin_dispatch_values (&vl);
297 }
299 static void submit_gauge (const char *type, const char *type_inst,
300 gauge_t value, memcached_t *st)
301 {
302 value_t values[1];
303 value_list_t vl = VALUE_LIST_INIT;
304 memcached_init_vl (&vl, st);
306 values[0].gauge = value;
308 vl.values = values;
309 vl.values_len = 1;
310 sstrncpy (vl.type, type, sizeof (vl.type));
311 if (type_inst != NULL)
312 sstrncpy (vl.type_instance, type_inst, sizeof (vl.type_instance));
314 plugin_dispatch_values (&vl);
315 }
317 static void submit_gauge2 (const char *type, const char *type_inst,
318 gauge_t value0, gauge_t value1, memcached_t *st)
319 {
320 value_t values[2];
321 value_list_t vl = VALUE_LIST_INIT;
322 memcached_init_vl (&vl, st);
324 values[0].gauge = value0;
325 values[1].gauge = value1;
327 vl.values = values;
328 vl.values_len = 2;
329 sstrncpy (vl.type, type, sizeof (vl.type));
330 if (type_inst != NULL)
331 sstrncpy (vl.type_instance, type_inst, sizeof (vl.type_instance));
333 plugin_dispatch_values (&vl);
334 }
336 static int memcached_read (user_data_t *user_data)
337 {
338 char buf[4096];
339 char *fields[3];
340 char *ptr;
341 char *line;
342 char *saveptr;
343 int fields_num;
345 gauge_t bytes_used = NAN;
346 gauge_t bytes_total = NAN;
347 gauge_t hits = NAN;
348 gauge_t gets = NAN;
349 gauge_t incr_hits = NAN;
350 derive_t incr = 0;
351 gauge_t decr_hits = NAN;
352 derive_t decr = 0;
353 derive_t rusage_user = 0;
354 derive_t rusage_syst = 0;
355 derive_t octets_rx = 0;
356 derive_t octets_tx = 0;
358 memcached_t *st;
359 st = user_data->data;
361 /* get data from daemon */
362 if (memcached_query_daemon (buf, sizeof (buf), st) < 0) {
363 return -1;
364 }
366 #define FIELD_IS(cnst) \
367 (((sizeof(cnst) - 1) == name_len) && (strcmp (cnst, fields[1]) == 0))
369 ptr = buf;
370 saveptr = NULL;
371 while ((line = strtok_r (ptr, "\n\r", &saveptr)) != NULL)
372 {
373 int name_len;
375 ptr = NULL;
377 fields_num = strsplit(line, fields, 3);
378 if (fields_num != 3)
379 continue;
381 name_len = strlen(fields[1]);
382 if (name_len == 0)
383 continue;
385 /*
386 * For an explanation on these fields please refer to
387 * <https://github.com/memcached/memcached/blob/master/doc/protocol.txt>
388 */
390 /*
391 * CPU time consumed by the memcached process
392 */
393 if (FIELD_IS ("rusage_user"))
394 {
395 rusage_user = atoll (fields[2]);
396 }
397 else if (FIELD_IS ("rusage_system"))
398 {
399 rusage_syst = atoll(fields[2]);
400 }
402 /*
403 * Number of threads of this instance
404 */
405 else if (FIELD_IS ("threads"))
406 {
407 submit_gauge2 ("ps_count", NULL, NAN, atof (fields[2]), st);
408 }
410 /*
411 * Number of items stored
412 */
413 else if (FIELD_IS ("curr_items"))
414 {
415 submit_gauge ("memcached_items", "current", atof (fields[2]), st);
416 }
418 /*
419 * Number of bytes used and available (total - used)
420 */
421 else if (FIELD_IS ("bytes"))
422 {
423 bytes_used = atof (fields[2]);
424 }
425 else if (FIELD_IS ("limit_maxbytes"))
426 {
427 bytes_total = atof(fields[2]);
428 }
430 /*
431 * Connections
432 */
433 else if (FIELD_IS ("curr_connections"))
434 {
435 submit_gauge ("memcached_connections", "current", atof (fields[2]), st);
436 }
437 else if (FIELD_IS ("listen_disabled_num"))
438 {
439 submit_derive ("connections", "listen_disabled", atof (fields[2]), st);
440 }
442 /*
443 * Commands
444 */
445 else if ((name_len > 4) && (strncmp (fields[1], "cmd_", 4) == 0))
446 {
447 const char *name = fields[1] + 4;
448 submit_derive ("memcached_command", name, atoll (fields[2]), st);
449 if (strcmp (name, "get") == 0)
450 gets = atof (fields[2]);
451 }
453 /*
454 * Increment/Decrement
455 */
456 else if (FIELD_IS("incr_misses"))
457 {
458 derive_t incr_count = atoll (fields[2]);
459 submit_derive ("memcached_ops", "incr_misses", incr_count, st);
460 incr += incr_count;
461 }
462 else if (FIELD_IS ("incr_hits"))
463 {
464 derive_t incr_count = atoll (fields[2]);
465 submit_derive ("memcached_ops", "incr_hits", incr_count, st);
466 incr_hits = atof (fields[2]);
467 incr += incr_count;
468 }
469 else if (FIELD_IS ("decr_misses"))
470 {
471 derive_t decr_count = atoll (fields[2]);
472 submit_derive ("memcached_ops", "decr_misses", decr_count, st);
473 decr += decr_count;
474 }
475 else if (FIELD_IS ("decr_hits"))
476 {
477 derive_t decr_count = atoll (fields[2]);
478 submit_derive ("memcached_ops", "decr_hits", decr_count, st);
479 decr_hits = atof (fields[2]);
480 decr += decr_count;
481 }
483 /*
484 * Operations on the cache, i. e. cache hits, cache misses and evictions of items
485 */
486 else if (FIELD_IS ("get_hits"))
487 {
488 submit_derive ("memcached_ops", "hits", atoll (fields[2]), st);
489 hits = atof (fields[2]);
490 }
491 else if (FIELD_IS ("get_misses"))
492 {
493 submit_derive ("memcached_ops", "misses", atoll (fields[2]), st);
494 }
495 else if (FIELD_IS ("evictions"))
496 {
497 submit_derive ("memcached_ops", "evictions", atoll (fields[2]), st);
498 }
500 /*
501 * Network traffic
502 */
503 else if (FIELD_IS ("bytes_read"))
504 {
505 octets_rx = atoll (fields[2]);
506 }
507 else if (FIELD_IS ("bytes_written"))
508 {
509 octets_tx = atoll (fields[2]);
510 }
511 } /* while ((line = strtok_r (ptr, "\n\r", &saveptr)) != NULL) */
513 if (!isnan (bytes_used) && !isnan (bytes_total) && (bytes_used <= bytes_total))
514 submit_gauge2 ("df", "cache", bytes_used, bytes_total - bytes_used, st);
516 if ((rusage_user != 0) || (rusage_syst != 0))
517 submit_derive2 ("ps_cputime", NULL, rusage_user, rusage_syst, st);
519 if ((octets_rx != 0) || (octets_tx != 0))
520 submit_derive2 ("memcached_octets", NULL, octets_rx, octets_tx, st);
522 if (!isnan (gets) && !isnan (hits))
523 {
524 gauge_t rate = NAN;
526 if (gets != 0.0)
527 rate = 100.0 * hits / gets;
529 submit_gauge ("percent", "hitratio", rate, st);
530 }
532 if (!isnan (incr_hits) && incr != 0)
533 {
534 gauge_t incr_rate = 100.0 * incr_hits / incr;
535 submit_gauge ("percent", "incr_hitratio", incr_rate, st);
536 submit_derive ("memcached_ops", "incr", incr, st);
537 }
539 if (!isnan (decr_hits) && decr != 0)
540 {
541 gauge_t decr_rate = 100.0 * decr_hits / decr;
542 submit_gauge ("percent", "decr_hitratio", decr_rate, st);
543 submit_derive ("memcached_ops", "decr", decr, st);
544 }
546 return 0;
547 } /* int memcached_read */
549 static int memcached_add_read_callback (memcached_t *st)
550 {
551 char callback_name[3*DATA_MAX_NAME_LEN];
552 int status;
554 assert (st->name != NULL);
555 ssnprintf (callback_name, sizeof (callback_name), "memcached/%s", st->name);
557 user_data_t ud = {
558 .data = st,
559 .free_func = memcached_free
560 };
562 status = plugin_register_complex_read (/* group = */ "memcached",
563 /* name = */ callback_name,
564 /* callback = */ memcached_read,
565 /* interval = */ 0,
566 /* user_data = */ &ud);
567 return (status);
568 } /* int memcached_add_read_callback */
570 /* Configuration handling functiions
571 * <Plugin memcached>
572 * <Instance "instance_name">
573 * Host foo.zomg.com
574 * Port "1234"
575 * </Instance>
576 * </Plugin>
577 */
578 static int config_add_instance(oconfig_item_t *ci)
579 {
580 memcached_t *st;
581 int status = 0;
583 /* Disable automatic generation of default instance in the init callback. */
584 memcached_have_instances = 1;
586 st = calloc (1, sizeof (*st));
587 if (st == NULL)
588 {
589 ERROR ("memcached plugin: calloc failed.");
590 return (-1);
591 }
593 st->name = NULL;
594 st->socket = NULL;
595 st->host = NULL;
596 st->port = NULL;
598 if (strcasecmp (ci->key, "Plugin") == 0) /* default instance */
599 st->name = sstrdup ("__legacy__");
600 else /* <Instance /> block */
601 status = cf_util_get_string (ci, &st->name);
602 if (status != 0)
603 {
604 sfree (st);
605 return (status);
606 }
607 assert (st->name != NULL);
609 for (int i = 0; i < ci->children_num; i++)
610 {
611 oconfig_item_t *child = ci->children + i;
613 if (strcasecmp ("Socket", child->key) == 0)
614 status = cf_util_get_string (child, &st->socket);
615 else if (strcasecmp ("Host", child->key) == 0)
616 status = cf_util_get_string (child, &st->host);
617 else if (strcasecmp ("Port", child->key) == 0)
618 status = cf_util_get_service (child, &st->port);
619 else
620 {
621 WARNING ("memcached plugin: Option `%s' not allowed here.",
622 child->key);
623 status = -1;
624 }
626 if (status != 0)
627 break;
628 }
630 if (status == 0)
631 status = memcached_add_read_callback (st);
633 if (status != 0)
634 {
635 memcached_free(st);
636 return (-1);
637 }
639 return (0);
640 }
642 static int memcached_config (oconfig_item_t *ci)
643 {
644 int status = 0;
645 _Bool have_instance_block = 0;
647 for (int i = 0; i < ci->children_num; i++)
648 {
649 oconfig_item_t *child = ci->children + i;
651 if (strcasecmp ("Instance", child->key) == 0)
652 {
653 config_add_instance (child);
654 have_instance_block = 1;
655 }
656 else if (!have_instance_block)
657 {
658 /* Non-instance option: Assume legacy configuration (without <Instance />
659 * blocks) and call config_add_instance() with the <Plugin /> block. */
660 return (config_add_instance (ci));
661 }
662 else
663 WARNING ("memcached plugin: The configuration option "
664 "\"%s\" is not allowed here. Did you "
665 "forget to add an <Instance /> block "
666 "around the configuration?",
667 child->key);
668 } /* for (ci->children) */
670 return (status);
671 }
673 static int memcached_init (void)
674 {
675 memcached_t *st;
676 int status;
678 if (memcached_have_instances)
679 return (0);
681 /* No instances were configured, lets start a default instance. */
682 st = calloc (1, sizeof (*st));
683 if (st == NULL)
684 return (ENOMEM);
685 st->name = sstrdup ("__legacy__");
686 st->socket = NULL;
687 st->host = NULL;
688 st->port = NULL;
690 status = memcached_add_read_callback (st);
691 if (status == 0)
692 memcached_have_instances = 1;
693 else
694 memcached_free (st);
696 return (status);
697 } /* int memcached_init */
699 void module_register (void)
700 {
701 plugin_register_complex_config ("memcached", memcached_config);
702 plugin_register_init ("memcached", memcached_init);
703 }