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"
31 #include "common.h"
32 #include "plugin.h"
34 /*
35 * Global variables
36 */
38 #if defined(KERNEL_LINUX)
39 #include "utils_llist.h"
40 #define ZOL_ARCSTATS_FILE "/proc/spl/kstat/zfs/arcstats"
42 typedef llist_t kstat_t;
44 static long long get_zfs_value(kstat_t *zfs_stats __attribute__((unused)),
45 char *name)
46 {
47 llentry_t *e;
49 e = llist_search (zfs_stats, name);
50 if (e == NULL)
51 {
52 ERROR ("zfs_arc plugin: `llist_search` failed for key: '%s'.", name);
53 return (-1);
54 }
56 return (*(long long int*)e->value);
57 }
59 #elif !defined(__FreeBSD__) // Solaris
60 extern kstat_ctl_t *kc;
62 static long long get_zfs_value(kstat_t *ksp, char *name)
63 {
65 return (get_kstat_value(ksp, name));
66 }
67 #else // FreeBSD
68 #include <sys/types.h>
69 #include <sys/sysctl.h>
71 const char zfs_arcstat[] = "kstat.zfs.misc.arcstats.";
73 #if !defined(kstat_t)
74 typedef void kstat_t;
75 #endif
77 static long long get_zfs_value(kstat_t *dummy __attribute__((unused)),
78 char const *name)
79 {
80 char buffer[256];
81 long long value;
82 size_t valuelen = sizeof(value);
83 int rv;
85 ssnprintf (buffer, sizeof (buffer), "%s%s", zfs_arcstat, name);
86 rv = sysctlbyname (buffer, (void *) &value, &valuelen,
87 /* new value = */ NULL, /* new length = */ (size_t) 0);
88 if (rv == 0)
89 return (value);
91 return (-1);
92 }
93 #endif
95 static void za_submit (const char* type, const char* type_instance, value_t* values, int values_len)
96 {
97 value_list_t vl = VALUE_LIST_INIT;
99 vl.values = values;
100 vl.values_len = values_len;
102 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
103 sstrncpy (vl.plugin, "zfs_arc", sizeof (vl.plugin));
104 sstrncpy (vl.type, type, sizeof (vl.type));
105 sstrncpy (vl.type_instance, type_instance, sizeof (vl.type_instance));
107 plugin_dispatch_values (&vl);
108 }
110 static void za_submit_gauge (const char* type, const char* type_instance, gauge_t value)
111 {
112 value_t vv;
114 vv.gauge = value;
115 za_submit (type, type_instance, &vv, 1);
116 }
118 static int za_read_derive (kstat_t *ksp, const char *kstat_value,
119 const char *type, const char *type_instance)
120 {
121 long long tmp;
122 value_t v;
124 tmp = get_zfs_value (ksp, (char *)kstat_value);
125 if (tmp == -1LL)
126 {
127 WARNING ("zfs_arc plugin: Reading kstat value \"%s\" failed.", kstat_value);
128 return (-1);
129 }
131 v.derive = (derive_t) tmp;
132 za_submit (type, type_instance, /* values = */ &v, /* values_num = */ 1);
133 return (0);
134 }
136 static int za_read_gauge (kstat_t *ksp, const char *kstat_value,
137 const char *type, const char *type_instance)
138 {
139 long long tmp;
140 value_t v;
142 tmp = get_zfs_value (ksp, (char *)kstat_value);
143 if (tmp == -1LL)
144 {
145 WARNING ("zfs_arc plugin: Reading kstat value \"%s\" failed.", kstat_value);
146 return (-1);
147 }
149 v.gauge = (gauge_t) tmp;
150 za_submit (type, type_instance, /* values = */ &v, /* values_num = */ 1);
151 return (0);
152 }
154 static void za_submit_ratio (const char* type_instance, gauge_t hits, gauge_t misses)
155 {
156 gauge_t ratio = NAN;
158 if (!isfinite (hits) || (hits < 0.0))
159 hits = 0.0;
160 if (!isfinite (misses) || (misses < 0.0))
161 misses = 0.0;
163 if ((hits != 0.0) || (misses != 0.0))
164 ratio = hits / (hits + misses);
166 za_submit_gauge ("cache_ratio", type_instance, ratio);
167 }
169 static int za_read (void)
170 {
171 gauge_t arc_hits, arc_misses, l2_hits, l2_misses;
172 value_t l2_io[2];
173 kstat_t *ksp = NULL;
175 #if KERNEL_LINUX
176 long long int *llvalues = NULL;
177 char file_contents[1024 * 10];
178 char *fields[3];
179 int numfields;
180 ssize_t len;
182 ksp = llist_create ();
183 if (ksp == NULL)
184 {
185 ERROR ("zfs_arc plugin: `llist_create' failed.");
186 return (-1);
187 }
189 len = read_file_contents (ZOL_ARCSTATS_FILE, file_contents, sizeof(file_contents));
190 if (len > 1)
191 {
193 int i=0;
194 char *pnl = file_contents;
195 char *pnnl;
197 file_contents[len] = '\0';
199 while (pnl != NULL)
200 {
201 pnl = strchr(pnl, '\n');
202 i++;
203 if (pnl && (*pnl != '\0'))
204 pnl++;
205 }
207 if (i > 0)
208 {
209 llentry_t *e;
210 llvalues = malloc(sizeof(long long int) * i);
211 int j = 0;
213 pnl = file_contents;
214 while (pnl != NULL)
215 {
216 pnnl = strchr(pnl, '\n');
217 if (pnnl != NULL)
218 *pnnl = '\0';
220 numfields = strsplit (pnl, fields, 4);
221 if (numfields == 3)
222 {
223 llvalues[j] = atoll (fields[2]);
225 e = llentry_create (fields[0], &llvalues[j]);
226 if (e == NULL)
227 {
228 ERROR ("zfs_arc plugin: `llentry_create' failed.");
229 }
230 else
231 {
232 llist_append (ksp, e);
233 }
234 j++;
235 }
236 pnl = pnnl;
237 if (pnl != NULL)
238 pnl ++;
239 }
240 }
241 }
243 #elif !defined(__FreeBSD__) // Solaris
244 get_kstat (&ksp, "zfs", 0, "arcstats");
245 if (ksp == NULL)
246 {
247 ERROR ("zfs_arc plugin: Cannot find zfs:0:arcstats kstat.");
248 return (-1);
249 }
250 #endif
252 /* Sizes */
253 za_read_gauge (ksp, "size", "cache_size", "arc");
254 za_read_gauge (ksp, "c", "cache_size", "c");
255 za_read_gauge (ksp, "c_min", "cache_size", "c_min");
256 za_read_gauge (ksp, "c_max", "cache_size", "c_max");
258 /* The "l2_size" value has disappeared from Solaris some time in
259 * early 2013, and has only reappeared recently in Solaris 11.2.
260 * Stop trying if we ever fail to read it, so we don't spam the log.
261 */
262 static int l2_size_avail = 1;
263 if (l2_size_avail && za_read_gauge (ksp, "l2_size", "cache_size", "L2") != 0)
264 l2_size_avail = 0;
266 /* Operations */
267 za_read_derive (ksp, "deleted", "cache_operation", "deleted");
268 #if __FreeBSD__
269 za_read_derive (ksp, "allocated","cache_operation", "allocated");
270 za_read_derive (ksp, "stolen", "cache_operation", "stolen");
271 #endif
273 /* Issue indicators */
274 za_read_derive (ksp, "mutex_miss", "mutex_operations", "miss");
275 za_read_derive (ksp, "hash_collisions", "hash_collisions", "");
277 /* Evictions */
278 za_read_derive (ksp, "evict_l2_cached", "cache_eviction", "cached");
279 za_read_derive (ksp, "evict_l2_eligible", "cache_eviction", "eligible");
280 za_read_derive (ksp, "evict_l2_ineligible", "cache_eviction", "ineligible");
282 /* Hits / misses */
283 za_read_derive (ksp, "demand_data_hits", "cache_result", "demand_data-hit");
284 za_read_derive (ksp, "demand_metadata_hits", "cache_result", "demand_metadata-hit");
285 za_read_derive (ksp, "prefetch_data_hits", "cache_result", "prefetch_data-hit");
286 za_read_derive (ksp, "prefetch_metadata_hits", "cache_result", "prefetch_metadata-hit");
287 za_read_derive (ksp, "demand_data_misses", "cache_result", "demand_data-miss");
288 za_read_derive (ksp, "demand_metadata_misses", "cache_result", "demand_metadata-miss");
289 za_read_derive (ksp, "prefetch_data_misses", "cache_result", "prefetch_data-miss");
290 za_read_derive (ksp, "prefetch_metadata_misses", "cache_result", "prefetch_metadata-miss");
292 /* Ratios */
293 arc_hits = (gauge_t) get_zfs_value(ksp, "hits");
294 arc_misses = (gauge_t) get_zfs_value(ksp, "misses");
295 l2_hits = (gauge_t) get_zfs_value(ksp, "l2_hits");
296 l2_misses = (gauge_t) get_zfs_value(ksp, "l2_misses");
298 za_submit_ratio ("arc", arc_hits, arc_misses);
299 za_submit_ratio ("L2", l2_hits, l2_misses);
301 /* I/O */
302 l2_io[0].derive = get_zfs_value(ksp, "l2_read_bytes");
303 l2_io[1].derive = get_zfs_value(ksp, "l2_write_bytes");
305 za_submit ("io_octets", "L2", l2_io, /* num values = */ 2);
307 #if defined(KERNEL_LINUX)
308 if (llvalues != NULL)
309 {
310 free(llvalues);
311 }
312 if (ksp != NULL)
313 {
314 llist_destroy (ksp);
315 }
316 #endif
318 return (0);
319 } /* int za_read */
321 static int za_init (void) /* {{{ */
322 {
323 #if !defined(__FreeBSD__) && !defined(KERNEL_LINUX) // Solaris
324 /* kstats chain already opened by update_kstat (using *kc), verify everything went fine. */
325 if (kc == NULL)
326 {
327 ERROR ("zfs_arc plugin: kstat chain control structure not available.");
328 return (-1);
329 }
330 #endif
332 return (0);
333 } /* }}} int za_init */
335 void module_register (void)
336 {
337 plugin_register_init ("zfs_arc", za_init);
338 plugin_register_read ("zfs_arc", za_read);
339 } /* void module_register */
341 /* vmi: set sw=8 noexpandtab fdm=marker : */