1 /**
2 * collectd - src/zfs_arc.c
3 * Copyright (C) 2009 Anthony Dewhurst
4 * Copyright (C) 2012 Aurelien Rougemont
5 * Copyright (C) 2013 Xin Li
6 * Copyright (C) 2014 Marc Fournier
7 * Copyright (C) 2014 Wilfried Goesgens
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; only version 2 of the License is applicable.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 * Authors:
23 * Anthony Dewhurst <dewhurst at gmail>
24 * Aurelien Rougemont <beorn at gandi.net>
25 * Xin Li <delphij at FreeBSD.org>
26 * Marc Fournier <marc.fournier at camptocamp.com>
27 * Wilfried Goesgens <dothebart at citadel.org>
28 **/
30 #include "collectd.h"
32 #include "common.h"
33 #include "plugin.h"
35 /*
36 * Global variables
37 */
39 #if defined(KERNEL_LINUX)
40 #include "utils_llist.h"
41 #define ZOL_ARCSTATS_FILE "/proc/spl/kstat/zfs/arcstats"
43 typedef llist_t kstat_t;
45 static int put_zfs_value (kstat_t *ksp, char const *k, value_t v)
46 {
47 llentry_t *e;
48 char *k_copy;
49 value_t *v_copy;
51 k_copy = strdup (k);
52 if (k_copy == NULL)
53 return ENOMEM;
55 v_copy = malloc (sizeof (*v_copy));
56 if (v_copy == NULL)
57 {
58 sfree (k_copy);
59 return ENOMEM;
60 }
61 *v_copy = v;
63 e = llentry_create (k_copy, v_copy);
64 if (e == NULL)
65 {
66 sfree (v_copy);
67 sfree (k_copy);
68 return ENOMEM;
69 }
71 llist_append (ksp, e);
72 return 0;
73 }
75 static long long get_zfs_value(kstat_t *ksp, const char *key)
76 {
77 llentry_t *e;
78 value_t *v;
80 e = llist_search (ksp, key);
81 if (e == NULL)
82 {
83 ERROR ("zfs_arc plugin: `llist_search` failed for key: '%s'.", key);
84 return (-1);
85 }
87 v = e->value;
88 return ((long long) v->derive);
89 }
91 static void free_zfs_values (kstat_t *ksp)
92 {
93 if (ksp == NULL)
94 return;
96 for (llentry_t *e = llist_head (ksp); e != NULL; e = e->next)
97 {
98 sfree (e->key);
99 sfree (e->value);
100 }
102 llist_destroy (ksp);
103 }
105 #elif defined(KERNEL_SOLARIS)
106 extern kstat_ctl_t *kc;
108 static long long get_zfs_value(kstat_t *ksp, char *name)
109 {
111 return (get_kstat_value(ksp, name));
112 }
113 #elif defined(KERNEL_FREEBSD)
114 #include <sys/types.h>
115 #include <sys/sysctl.h>
117 const char zfs_arcstat[] = "kstat.zfs.misc.arcstats.";
119 #if !defined(kstat_t)
120 typedef void kstat_t;
121 #endif
123 static long long get_zfs_value(kstat_t *dummy __attribute__((unused)),
124 char const *name)
125 {
126 char buffer[256];
127 long long value;
128 size_t valuelen = sizeof(value);
129 int rv;
131 ssnprintf (buffer, sizeof (buffer), "%s%s", zfs_arcstat, name);
132 rv = sysctlbyname (buffer, (void *) &value, &valuelen,
133 /* new value = */ NULL, /* new length = */ (size_t) 0);
134 if (rv == 0)
135 return (value);
137 return (-1);
138 }
139 #endif
141 static void za_submit (const char* type, const char* type_instance, value_t* values, size_t values_len)
142 {
143 value_list_t vl = VALUE_LIST_INIT;
145 vl.values = values;
146 vl.values_len = values_len;
148 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
149 sstrncpy (vl.plugin, "zfs_arc", sizeof (vl.plugin));
150 sstrncpy (vl.type, type, sizeof (vl.type));
151 sstrncpy (vl.type_instance, type_instance, sizeof (vl.type_instance));
153 plugin_dispatch_values (&vl);
154 }
156 static void za_submit_gauge (const char* type, const char* type_instance, gauge_t value)
157 {
158 za_submit (type, type_instance, &(value_t) { .gauge = value }, 1);
159 }
161 static int za_read_derive (kstat_t *ksp, const char *kstat_value,
162 const char *type, const char *type_instance)
163 {
164 long long tmp = get_zfs_value (ksp, (char *)kstat_value);
165 if (tmp == -1LL)
166 {
167 WARNING ("zfs_arc plugin: Reading kstat value \"%s\" failed.", kstat_value);
168 return (-1);
169 }
171 za_submit (type, type_instance, &(value_t) { .derive = (derive_t) tmp }, /* values_num = */ 1);
172 return (0);
173 }
175 static int za_read_gauge (kstat_t *ksp, const char *kstat_value,
176 const char *type, const char *type_instance)
177 {
178 long long tmp = get_zfs_value (ksp, (char *)kstat_value);
179 if (tmp == -1LL)
180 {
181 WARNING ("zfs_arc plugin: Reading kstat value \"%s\" failed.", kstat_value);
182 return (-1);
183 }
185 za_submit (type, type_instance, &(value_t) { .gauge = (gauge_t) tmp }, /* values_num = */ 1);
186 return (0);
187 }
189 static void za_submit_ratio (const char* type_instance, gauge_t hits, gauge_t misses)
190 {
191 gauge_t ratio = NAN;
193 if (!isfinite (hits) || (hits < 0.0))
194 hits = 0.0;
195 if (!isfinite (misses) || (misses < 0.0))
196 misses = 0.0;
198 if ((hits != 0.0) || (misses != 0.0))
199 ratio = hits / (hits + misses);
201 za_submit_gauge ("cache_ratio", type_instance, ratio);
202 }
204 static int za_read (void)
205 {
206 gauge_t arc_hits, arc_misses, l2_hits, l2_misses;
207 kstat_t *ksp = NULL;
209 #if defined(KERNEL_LINUX)
210 FILE *fh;
211 char buffer[1024];
213 fh = fopen (ZOL_ARCSTATS_FILE, "r");
214 if (fh == NULL)
215 {
216 char errbuf[1024];
217 ERROR ("zfs_arc plugin: Opening \"%s\" failed: %s", ZOL_ARCSTATS_FILE,
218 sstrerror (errno, errbuf, sizeof (errbuf)));
219 return (-1);
220 }
222 ksp = llist_create ();
223 if (ksp == NULL)
224 {
225 ERROR ("zfs_arc plugin: `llist_create' failed.");
226 fclose (fh);
227 return (-1);
228 }
230 while (fgets (buffer, sizeof (buffer), fh) != NULL)
231 {
232 char *fields[3];
233 value_t v;
234 int status;
236 status = strsplit (buffer, fields, STATIC_ARRAY_SIZE (fields));
237 if (status != 3)
238 continue;
240 status = parse_value (fields[2], &v, DS_TYPE_DERIVE);
241 if (status != 0)
242 continue;
244 put_zfs_value (ksp, fields[0], v);
245 }
247 fclose (fh);
249 #elif defined(KERNEL_SOLARIS)
250 get_kstat (&ksp, "zfs", 0, "arcstats");
251 if (ksp == NULL)
252 {
253 ERROR ("zfs_arc plugin: Cannot find zfs:0:arcstats kstat.");
254 return (-1);
255 }
256 #endif
258 /* Sizes */
259 za_read_gauge (ksp, "anon_size", "cache_size", "anon_size");
260 za_read_gauge (ksp, "c", "cache_size", "c");
261 za_read_gauge (ksp, "c_max", "cache_size", "c_max");
262 za_read_gauge (ksp, "c_min", "cache_size", "c_min");
263 za_read_gauge (ksp, "hdr_size", "cache_size", "hdr_size");
264 za_read_gauge (ksp, "metadata_size", "cache_size", "metadata_size");
265 za_read_gauge (ksp, "mfu_ghost_size", "cache_size", "mfu_ghost_size");
266 za_read_gauge (ksp, "mfu_size", "cache_size", "mfu_size");
267 za_read_gauge (ksp, "mru_ghost_size", "cache_size", "mru_ghost_size");
268 za_read_gauge (ksp, "mru_size", "cache_size", "mru_size");
269 za_read_gauge (ksp, "other_size", "cache_size", "other_size");
270 za_read_gauge (ksp, "p", "cache_size", "p");
271 za_read_gauge (ksp, "size", "cache_size", "arc");
273 /* The "l2_size" value has disappeared from Solaris some time in
274 * early 2013, and has only reappeared recently in Solaris 11.2.
275 * Stop trying if we ever fail to read it, so we don't spam the log.
276 */
277 static int l2_size_avail = 1;
278 if (l2_size_avail && za_read_gauge (ksp, "l2_size", "cache_size", "L2") != 0)
279 l2_size_avail = 0;
281 /* Operations */
282 za_read_derive (ksp, "deleted", "cache_operation", "deleted");
283 #if defined(KERNEL_FREEBSD)
284 za_read_derive (ksp, "allocated","cache_operation", "allocated");
285 #endif
287 /* Issue indicators */
288 za_read_derive (ksp, "mutex_miss", "mutex_operations", "miss");
289 za_read_derive (ksp, "hash_collisions", "hash_collisions", "");
290 za_read_derive (ksp, "memory_throttle_count", "memory_throttle_count", "");
292 /* Evictions */
293 za_read_derive (ksp, "evict_l2_cached", "cache_eviction", "cached");
294 za_read_derive (ksp, "evict_l2_eligible", "cache_eviction", "eligible");
295 za_read_derive (ksp, "evict_l2_ineligible", "cache_eviction", "ineligible");
297 /* Hits / misses */
298 za_read_derive (ksp, "demand_data_hits", "cache_result", "demand_data-hit");
299 za_read_derive (ksp, "demand_metadata_hits", "cache_result", "demand_metadata-hit");
300 za_read_derive (ksp, "prefetch_data_hits", "cache_result", "prefetch_data-hit");
301 za_read_derive (ksp, "prefetch_metadata_hits", "cache_result", "prefetch_metadata-hit");
302 za_read_derive (ksp, "demand_data_misses", "cache_result", "demand_data-miss");
303 za_read_derive (ksp, "demand_metadata_misses", "cache_result", "demand_metadata-miss");
304 za_read_derive (ksp, "prefetch_data_misses", "cache_result", "prefetch_data-miss");
305 za_read_derive (ksp, "prefetch_metadata_misses", "cache_result", "prefetch_metadata-miss");
306 za_read_derive (ksp, "mfu_hits", "cache_result", "mfu-hit");
307 za_read_derive (ksp, "mfu_ghost_hits", "cache_result", "mfu_ghost-hit");
308 za_read_derive (ksp, "mru_hits", "cache_result", "mru-hit");
309 za_read_derive (ksp, "mru_ghost_hits", "cache_result", "mru_ghost-hit");
310 za_read_derive (ksp, "prefetch_metadata_misses", "cache_result", "prefetch_metadata-miss");
312 /* Ratios */
313 arc_hits = (gauge_t) get_zfs_value(ksp, "hits");
314 arc_misses = (gauge_t) get_zfs_value(ksp, "misses");
315 l2_hits = (gauge_t) get_zfs_value(ksp, "l2_hits");
316 l2_misses = (gauge_t) get_zfs_value(ksp, "l2_misses");
318 za_submit_ratio ("arc", arc_hits, arc_misses);
319 za_submit_ratio ("L2", l2_hits, l2_misses);
321 /* I/O */
322 value_t l2_io[] = {
323 { .derive = (derive_t) get_zfs_value(ksp, "l2_read_bytes") },
324 { .derive = (derive_t) get_zfs_value(ksp, "l2_write_bytes") },
325 };
326 za_submit ("io_octets", "L2", l2_io, STATIC_ARRAY_SIZE (l2_io));
328 #if defined(KERNEL_LINUX)
329 free_zfs_values (ksp);
330 #endif
332 return (0);
333 } /* int za_read */
335 static int za_init (void) /* {{{ */
336 {
337 #if defined(KERNEL_SOLARIS)
338 /* kstats chain already opened by update_kstat (using *kc), verify everything went fine. */
339 if (kc == NULL)
340 {
341 ERROR ("zfs_arc plugin: kstat chain control structure not available.");
342 return (-1);
343 }
344 #endif
346 return (0);
347 } /* }}} int za_init */
349 void module_register (void)
350 {
351 plugin_register_init ("zfs_arc", za_init);
352 plugin_register_read ("zfs_arc", za_read);
353 } /* void module_register */
355 /* vmi: set sw=8 noexpandtab fdm=marker : */