2 * collectd - src/zfs_arc.c
3 * Copyright (C) 2009 Anthony Dewhurst
4 * Copyright (C) 2012 Aurelien Rougemont
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; only version 2 of the License is applicable.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * Anthony Dewhurst <dewhurst at gmail>
21 * Aurelien Rougemont <beorn at gandi.net>
32 #if !defined(__FreeBSD__)
33 extern kstat_ctl_t *kc;
35 static long long get_zfs_value(kstat_t *ksp, char *name)
38 return (get_kstat_value(ksp, name));
41 #include <sys/types.h>
42 #include <sys/sysctl.h>
44 const char zfs_arcstat[] = "kstat.zfs.misc.arcstats.";
50 static long long get_zfs_value(void * dummy __unused, const char *kstat_value)
53 size_t valuelen = sizeof(value);
57 key = ssnprintf_alloc("%s%s", zfs_arcstat, kstat_value);
59 if (strlen(key) > 0) {
60 rv = sysctlbyname(key, (void *)&value, &valuelen, NULL, (size_t)0);
72 static void za_submit (const char* type, const char* type_instance, value_t* values, int values_len)
74 value_list_t vl = VALUE_LIST_INIT;
77 vl.values_len = values_len;
79 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
80 sstrncpy (vl.plugin, "zfs_arc", sizeof (vl.plugin));
81 sstrncpy (vl.type, type, sizeof (vl.type));
82 sstrncpy (vl.type_instance, type_instance, sizeof (vl.type_instance));
84 plugin_dispatch_values (&vl);
87 static void za_submit_gauge (const char* type, const char* type_instance, gauge_t value)
92 za_submit (type, type_instance, &vv, 1);
95 static int za_read_derive (kstat_t *ksp, const char *kstat_value,
96 const char *type, const char *type_instance)
101 tmp = get_zfs_value (ksp, (char *)kstat_value);
104 ERROR ("zfs_arc plugin: Reading kstat value \"%s\" failed.", kstat_value);
108 v.derive = (derive_t) tmp;
109 za_submit (type, type_instance, /* values = */ &v, /* values_num = */ 1);
113 static int za_read_gauge (kstat_t *ksp, const char *kstat_value,
114 const char *type, const char *type_instance)
119 tmp = get_zfs_value (ksp, (char *)kstat_value);
122 ERROR ("zfs_arc plugin: Reading kstat value \"%s\" failed.", kstat_value);
126 v.gauge = (gauge_t) tmp;
127 za_submit (type, type_instance, /* values = */ &v, /* values_num = */ 1);
131 static void za_submit_ratio (const char* type_instance, gauge_t hits, gauge_t misses)
135 if (!isfinite (hits) || (hits < 0.0))
137 if (!isfinite (misses) || (misses < 0.0))
140 if ((hits != 0.0) || (misses != 0.0))
141 ratio = hits / (hits + misses);
143 za_submit_gauge ("cache_ratio", type_instance, ratio);
146 static int za_read (void)
148 gauge_t arc_hits, arc_misses, l2_hits, l2_misses;
152 #if !defined(__FreeBSD__)
153 get_kstat (&ksp, "zfs", 0, "arcstats");
156 ERROR ("zfs_arc plugin: Cannot find zfs:0:arcstats kstat.");
162 za_read_gauge (ksp, "size", "cache_size", "arc");
163 za_read_gauge (ksp, "l2_size", "cache_size", "L2");
166 za_read_derive (ksp, "allocated","cache_operation", "allocated");
167 za_read_derive (ksp, "deleted", "cache_operation", "deleted");
168 za_read_derive (ksp, "stolen", "cache_operation", "stolen");
170 /* Issue indicators */
171 za_read_derive (ksp, "mutex_miss", "mutex_operations", "miss");
172 za_read_derive (ksp, "hash_collisions", "hash_collisions", "");
175 za_read_derive (ksp, "evict_l2_cached", "cache_eviction", "cached");
176 za_read_derive (ksp, "evict_l2_eligible", "cache_eviction", "eligible");
177 za_read_derive (ksp, "evict_l2_ineligible", "cache_eviction", "ineligible");
180 za_read_derive (ksp, "demand_data_hits", "cache_result", "demand_data-hit");
181 za_read_derive (ksp, "demand_metadata_hits", "cache_result", "demand_metadata-hit");
182 za_read_derive (ksp, "prefetch_data_hits", "cache_result", "prefetch_data-hit");
183 za_read_derive (ksp, "prefetch_metadata_hits", "cache_result", "prefetch_metadata-hit");
184 za_read_derive (ksp, "demand_data_misses", "cache_result", "demand_data-miss");
185 za_read_derive (ksp, "demand_metadata_misses", "cache_result", "demand_metadata-miss");
186 za_read_derive (ksp, "prefetch_data_misses", "cache_result", "prefetch_data-miss");
187 za_read_derive (ksp, "prefetch_metadata_misses", "cache_result", "prefetch_metadata-miss");
190 arc_hits = (gauge_t) get_zfs_value(ksp, "hits");
191 arc_misses = (gauge_t) get_zfs_value(ksp, "misses");
192 l2_hits = (gauge_t) get_zfs_value(ksp, "l2_hits");
193 l2_misses = (gauge_t) get_zfs_value(ksp, "l2_misses");
195 za_submit_ratio ("arc", arc_hits, arc_misses);
196 za_submit_ratio ("L2", l2_hits, l2_misses);
199 l2_io[0].derive = get_zfs_value(ksp, "l2_read_bytes");
200 l2_io[1].derive = get_zfs_value(ksp, "l2_write_bytes");
202 za_submit ("io_octets", "L2", l2_io, /* num values = */ 2);
207 static int za_init (void) /* {{{ */
209 #if !defined(__FreeBSD__)
210 /* kstats chain already opened by update_kstat (using *kc), verify everything went fine. */
213 ERROR ("zfs_arc plugin: kstat chain control structure not available.");
219 } /* }}} int za_init */
221 void module_register (void)
223 plugin_register_init ("zfs_arc", za_init);
224 plugin_register_read ("zfs_arc", za_read);
225 } /* void module_register */
227 /* vmi: set sw=8 noexpandtab fdm=marker : */