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_list_t vl = VALUE_LIST_INIT;
267 memcached_init_vl (&vl, st);
268 vl.values = &(value_t) { .derive = value };
269 vl.values_len = 1;
270 sstrncpy (vl.type, type, sizeof (vl.type));
271 if (type_inst != NULL)
272 sstrncpy (vl.type_instance, type_inst, sizeof (vl.type_instance));
274 plugin_dispatch_values (&vl);
275 }
277 static void submit_derive2 (const char *type, const char *type_inst,
278 derive_t value0, derive_t value1, memcached_t *st)
279 {
280 value_t values[2];
281 value_list_t vl = VALUE_LIST_INIT;
282 memcached_init_vl (&vl, st);
284 values[0].derive = value0;
285 values[1].derive = value1;
287 vl.values = values;
288 vl.values_len = 2;
289 sstrncpy (vl.type, type, sizeof (vl.type));
290 if (type_inst != NULL)
291 sstrncpy (vl.type_instance, type_inst, sizeof (vl.type_instance));
293 plugin_dispatch_values (&vl);
294 }
296 static void submit_gauge (const char *type, const char *type_inst,
297 gauge_t value, memcached_t *st)
298 {
299 value_list_t vl = VALUE_LIST_INIT;
301 memcached_init_vl (&vl, st);
302 vl.values = &(value_t) { .gauge = value };
303 vl.values_len = 1;
304 sstrncpy (vl.type, type, sizeof (vl.type));
305 if (type_inst != NULL)
306 sstrncpy (vl.type_instance, type_inst, sizeof (vl.type_instance));
308 plugin_dispatch_values (&vl);
309 }
311 static void submit_gauge2 (const char *type, const char *type_inst,
312 gauge_t value0, gauge_t value1, memcached_t *st)
313 {
314 value_t values[2];
315 value_list_t vl = VALUE_LIST_INIT;
316 memcached_init_vl (&vl, st);
318 values[0].gauge = value0;
319 values[1].gauge = value1;
321 vl.values = values;
322 vl.values_len = 2;
323 sstrncpy (vl.type, type, sizeof (vl.type));
324 if (type_inst != NULL)
325 sstrncpy (vl.type_instance, type_inst, sizeof (vl.type_instance));
327 plugin_dispatch_values (&vl);
328 }
330 static int memcached_read (user_data_t *user_data)
331 {
332 char buf[4096];
333 char *fields[3];
334 char *ptr;
335 char *line;
336 char *saveptr;
337 int fields_num;
339 gauge_t bytes_used = NAN;
340 gauge_t bytes_total = NAN;
341 gauge_t hits = NAN;
342 gauge_t gets = NAN;
343 gauge_t incr_hits = NAN;
344 derive_t incr = 0;
345 gauge_t decr_hits = NAN;
346 derive_t decr = 0;
347 derive_t rusage_user = 0;
348 derive_t rusage_syst = 0;
349 derive_t octets_rx = 0;
350 derive_t octets_tx = 0;
352 memcached_t *st;
353 st = user_data->data;
355 /* get data from daemon */
356 if (memcached_query_daemon (buf, sizeof (buf), st) < 0) {
357 return -1;
358 }
360 #define FIELD_IS(cnst) \
361 (((sizeof(cnst) - 1) == name_len) && (strcmp (cnst, fields[1]) == 0))
363 ptr = buf;
364 saveptr = NULL;
365 while ((line = strtok_r (ptr, "\n\r", &saveptr)) != NULL)
366 {
367 int name_len;
369 ptr = NULL;
371 fields_num = strsplit(line, fields, 3);
372 if (fields_num != 3)
373 continue;
375 name_len = strlen(fields[1]);
376 if (name_len == 0)
377 continue;
379 /*
380 * For an explanation on these fields please refer to
381 * <https://github.com/memcached/memcached/blob/master/doc/protocol.txt>
382 */
384 /*
385 * CPU time consumed by the memcached process
386 */
387 if (FIELD_IS ("rusage_user"))
388 {
389 rusage_user = atoll (fields[2]);
390 }
391 else if (FIELD_IS ("rusage_system"))
392 {
393 rusage_syst = atoll(fields[2]);
394 }
396 /*
397 * Number of threads of this instance
398 */
399 else if (FIELD_IS ("threads"))
400 {
401 submit_gauge2 ("ps_count", NULL, NAN, atof (fields[2]), st);
402 }
404 /*
405 * Number of items stored
406 */
407 else if (FIELD_IS ("curr_items"))
408 {
409 submit_gauge ("memcached_items", "current", atof (fields[2]), st);
410 }
412 /*
413 * Number of bytes used and available (total - used)
414 */
415 else if (FIELD_IS ("bytes"))
416 {
417 bytes_used = atof (fields[2]);
418 }
419 else if (FIELD_IS ("limit_maxbytes"))
420 {
421 bytes_total = atof(fields[2]);
422 }
424 /*
425 * Connections
426 */
427 else if (FIELD_IS ("curr_connections"))
428 {
429 submit_gauge ("memcached_connections", "current", atof (fields[2]), st);
430 }
431 else if (FIELD_IS ("listen_disabled_num"))
432 {
433 submit_derive ("connections", "listen_disabled", atof (fields[2]), st);
434 }
436 /*
437 * Commands
438 */
439 else if ((name_len > 4) && (strncmp (fields[1], "cmd_", 4) == 0))
440 {
441 const char *name = fields[1] + 4;
442 submit_derive ("memcached_command", name, atoll (fields[2]), st);
443 if (strcmp (name, "get") == 0)
444 gets = atof (fields[2]);
445 }
447 /*
448 * Increment/Decrement
449 */
450 else if (FIELD_IS("incr_misses"))
451 {
452 derive_t incr_count = atoll (fields[2]);
453 submit_derive ("memcached_ops", "incr_misses", incr_count, st);
454 incr += incr_count;
455 }
456 else if (FIELD_IS ("incr_hits"))
457 {
458 derive_t incr_count = atoll (fields[2]);
459 submit_derive ("memcached_ops", "incr_hits", incr_count, st);
460 incr_hits = atof (fields[2]);
461 incr += incr_count;
462 }
463 else if (FIELD_IS ("decr_misses"))
464 {
465 derive_t decr_count = atoll (fields[2]);
466 submit_derive ("memcached_ops", "decr_misses", decr_count, st);
467 decr += decr_count;
468 }
469 else if (FIELD_IS ("decr_hits"))
470 {
471 derive_t decr_count = atoll (fields[2]);
472 submit_derive ("memcached_ops", "decr_hits", decr_count, st);
473 decr_hits = atof (fields[2]);
474 decr += decr_count;
475 }
477 /*
478 * Operations on the cache, i. e. cache hits, cache misses and evictions of items
479 */
480 else if (FIELD_IS ("get_hits"))
481 {
482 submit_derive ("memcached_ops", "hits", atoll (fields[2]), st);
483 hits = atof (fields[2]);
484 }
485 else if (FIELD_IS ("get_misses"))
486 {
487 submit_derive ("memcached_ops", "misses", atoll (fields[2]), st);
488 }
489 else if (FIELD_IS ("evictions"))
490 {
491 submit_derive ("memcached_ops", "evictions", atoll (fields[2]), st);
492 }
494 /*
495 * Network traffic
496 */
497 else if (FIELD_IS ("bytes_read"))
498 {
499 octets_rx = atoll (fields[2]);
500 }
501 else if (FIELD_IS ("bytes_written"))
502 {
503 octets_tx = atoll (fields[2]);
504 }
505 } /* while ((line = strtok_r (ptr, "\n\r", &saveptr)) != NULL) */
507 if (!isnan (bytes_used) && !isnan (bytes_total) && (bytes_used <= bytes_total))
508 submit_gauge2 ("df", "cache", bytes_used, bytes_total - bytes_used, st);
510 if ((rusage_user != 0) || (rusage_syst != 0))
511 submit_derive2 ("ps_cputime", NULL, rusage_user, rusage_syst, st);
513 if ((octets_rx != 0) || (octets_tx != 0))
514 submit_derive2 ("memcached_octets", NULL, octets_rx, octets_tx, st);
516 if (!isnan (gets) && !isnan (hits))
517 {
518 gauge_t rate = NAN;
520 if (gets != 0.0)
521 rate = 100.0 * hits / gets;
523 submit_gauge ("percent", "hitratio", rate, st);
524 }
526 if (!isnan (incr_hits) && incr != 0)
527 {
528 gauge_t incr_rate = 100.0 * incr_hits / incr;
529 submit_gauge ("percent", "incr_hitratio", incr_rate, st);
530 submit_derive ("memcached_ops", "incr", incr, st);
531 }
533 if (!isnan (decr_hits) && decr != 0)
534 {
535 gauge_t decr_rate = 100.0 * decr_hits / decr;
536 submit_gauge ("percent", "decr_hitratio", decr_rate, st);
537 submit_derive ("memcached_ops", "decr", decr, st);
538 }
540 return 0;
541 } /* int memcached_read */
543 static int memcached_add_read_callback (memcached_t *st)
544 {
545 char callback_name[3*DATA_MAX_NAME_LEN];
546 int status;
548 assert (st->name != NULL);
549 ssnprintf (callback_name, sizeof (callback_name), "memcached/%s", st->name);
551 status = plugin_register_complex_read (/* group = */ "memcached",
552 /* name = */ callback_name,
553 /* callback = */ memcached_read,
554 /* interval = */ 0,
555 &(user_data_t) {
556 .data = st,
557 .free_func = memcached_free,
558 });
560 return (status);
561 } /* int memcached_add_read_callback */
563 /* Configuration handling functiions
564 * <Plugin memcached>
565 * <Instance "instance_name">
566 * Host foo.zomg.com
567 * Port "1234"
568 * </Instance>
569 * </Plugin>
570 */
571 static int config_add_instance(oconfig_item_t *ci)
572 {
573 memcached_t *st;
574 int status = 0;
576 /* Disable automatic generation of default instance in the init callback. */
577 memcached_have_instances = 1;
579 st = calloc (1, sizeof (*st));
580 if (st == NULL)
581 {
582 ERROR ("memcached plugin: calloc failed.");
583 return (-1);
584 }
586 st->name = NULL;
587 st->socket = NULL;
588 st->host = NULL;
589 st->port = NULL;
591 if (strcasecmp (ci->key, "Plugin") == 0) /* default instance */
592 st->name = sstrdup ("__legacy__");
593 else /* <Instance /> block */
594 status = cf_util_get_string (ci, &st->name);
595 if (status != 0)
596 {
597 sfree (st);
598 return (status);
599 }
600 assert (st->name != NULL);
602 for (int i = 0; i < ci->children_num; i++)
603 {
604 oconfig_item_t *child = ci->children + i;
606 if (strcasecmp ("Socket", child->key) == 0)
607 status = cf_util_get_string (child, &st->socket);
608 else if (strcasecmp ("Host", child->key) == 0)
609 status = cf_util_get_string (child, &st->host);
610 else if (strcasecmp ("Port", child->key) == 0)
611 status = cf_util_get_service (child, &st->port);
612 else
613 {
614 WARNING ("memcached plugin: Option `%s' not allowed here.",
615 child->key);
616 status = -1;
617 }
619 if (status != 0)
620 break;
621 }
623 if (status == 0)
624 status = memcached_add_read_callback (st);
626 if (status != 0)
627 {
628 memcached_free(st);
629 return (-1);
630 }
632 return (0);
633 }
635 static int memcached_config (oconfig_item_t *ci)
636 {
637 int status = 0;
638 _Bool have_instance_block = 0;
640 for (int i = 0; i < ci->children_num; i++)
641 {
642 oconfig_item_t *child = ci->children + i;
644 if (strcasecmp ("Instance", child->key) == 0)
645 {
646 config_add_instance (child);
647 have_instance_block = 1;
648 }
649 else if (!have_instance_block)
650 {
651 /* Non-instance option: Assume legacy configuration (without <Instance />
652 * blocks) and call config_add_instance() with the <Plugin /> block. */
653 return (config_add_instance (ci));
654 }
655 else
656 WARNING ("memcached plugin: The configuration option "
657 "\"%s\" is not allowed here. Did you "
658 "forget to add an <Instance /> block "
659 "around the configuration?",
660 child->key);
661 } /* for (ci->children) */
663 return (status);
664 }
666 static int memcached_init (void)
667 {
668 memcached_t *st;
669 int status;
671 if (memcached_have_instances)
672 return (0);
674 /* No instances were configured, lets start a default instance. */
675 st = calloc (1, sizeof (*st));
676 if (st == NULL)
677 return (ENOMEM);
678 st->name = sstrdup ("__legacy__");
679 st->socket = NULL;
680 st->host = NULL;
681 st->port = NULL;
683 status = memcached_add_read_callback (st);
684 if (status == 0)
685 memcached_have_instances = 1;
686 else
687 memcached_free (st);
689 return (status);
690 } /* int memcached_init */
692 void module_register (void)
693 {
694 plugin_register_complex_config ("memcached", memcached_config);
695 plugin_register_init ("memcached", memcached_init);
696 }