1 /**
2 * collectd - src/zfs_arc.c
3 * Copyright (C) 2009 Anthony Dewhurst
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 *
18 * Authors:
19 * Anthony Dewhurst <dewhurst at gmail>
20 **/
22 #include "collectd.h"
23 #include "common.h"
24 #include "plugin.h"
26 /*
27 * Global variables
28 */
29 static kstat_t *ksp;
30 extern kstat_ctl_t *kc;
32 static void za_submit (const char* type, const char* type_instance, value_t* values, int values_len)
33 {
34 value_list_t vl = VALUE_LIST_INIT;
36 vl.values = values;
37 vl.values_len = values_len;
39 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
40 sstrncpy (vl.plugin, "zfs_arc", sizeof (vl.plugin));
41 sstrncpy (vl.type, type, sizeof (vl.type));
42 sstrncpy (vl.type_instance, type_instance, sizeof (vl.type_instance));
44 plugin_dispatch_values (&vl);
45 }
47 static void za_submit_gauge (const char* type, const char* type_instance, gauge_t value)
48 {
49 value_t vv;
51 vv.gauge = value;
52 za_submit (type, type_instance, &vv, 1);
53 }
55 static void za_submit_derive (const char* type, const char* type_instance, derive_t dv)
56 {
57 value_t vv;
59 vv.derive = dv;
60 za_submit (type, type_instance, &vv, 1);
61 }
63 static void za_submit_ratio (const char* type_instance, gauge_t hits, gauge_t misses)
64 {
65 gauge_t ratio = NAN;
67 if (!isfinite (hits) || (hits < 0.0))
68 hits = 0.0;
69 if (!isfinite (misses) || (misses < 0.0))
70 misses = 0.0;
72 if ((hits != 0.0) || (misses != 0.0))
73 ratio = hits / (hits + misses);
75 za_submit_gauge ("cache_ratio", type_instance, ratio);
76 }
78 static int za_read (void)
79 {
80 gauge_t arc_size, l2_size;
81 derive_t demand_data_hits,
82 demand_metadata_hits,
83 prefetch_data_hits,
84 prefetch_metadata_hits,
85 demand_data_misses,
86 demand_metadata_misses,
87 prefetch_data_misses,
88 prefetch_metadata_misses;
89 gauge_t arc_hits, arc_misses, l2_hits, l2_misses;
90 value_t l2_io[2];
91 derive_t mutex_miss;
92 derive_t allocated, deleted, stolen;
93 derive_t evict_l2_cached, evict_l2_eligible, evict_l2_ineligible;
94 derive_t hash_collisions;
96 get_kstat (&ksp, "zfs", 0, "arcstats");
97 if (ksp == NULL)
98 {
99 ERROR ("zfs_arc plugin: Cannot find zfs:0:arcstats kstat.");
100 return (-1);
101 }
103 /* Sizes */
104 arc_size = get_kstat_value(ksp, "size");
105 l2_size = get_kstat_value(ksp, "l2_size");
107 za_submit_gauge ("cache_size", "arc", arc_size);
108 za_submit_gauge ("cache_size", "L2", l2_size);
110 mutex_miss = get_kstat_value (ksp, "mutex_miss");
111 za_submit_derive ("mutex_operation", "miss", mutex_miss);
113 allocated = get_kstat_value(ksp, "allocated");
114 deleted = get_kstat_value(ksp, "deleted");
115 stolen = get_kstat_value(ksp, "stolen");
116 za_submit_derive ("cache_operation", "allocated", allocated);
117 za_submit_derive ("cache_operation", "deleted", deleted);
118 za_submit_derive ("cache_operation", "stolen", stolen);
120 hash_collisions = get_kstat_value(ksp, "hash_collisions");
121 za_submit_derive ("hash_collisions", "", hash_collisions);
123 evict_l2_cached = get_kstat_value(ksp, "evict_l2_cached");
124 evict_l2_eligible = get_kstat_value(ksp, "evict_l2_eligible");
125 evict_l2_ineligible = get_kstat_value(ksp, "evict_l2_ineligible");
127 za_submit_derive ("cache_eviction", "cached", evict_l2_cached);
128 za_submit_derive ("cache_eviction", "eligible", evict_l2_eligible);
129 za_submit_derive ("cache_eviction", "ineligible", evict_l2_ineligible);
131 /* Hits / misses */
132 demand_data_hits = get_kstat_value(ksp, "demand_data_hits");
133 demand_metadata_hits = get_kstat_value(ksp, "demand_metadata_hits");
134 prefetch_data_hits = get_kstat_value(ksp, "prefetch_data_hits");
135 prefetch_metadata_hits = get_kstat_value(ksp, "prefetch_metadata_hits");
137 demand_data_misses = get_kstat_value(ksp, "demand_data_misses");
138 demand_metadata_misses = get_kstat_value(ksp, "demand_metadata_misses");
139 prefetch_data_misses = get_kstat_value(ksp, "prefetch_data_misses");
140 prefetch_metadata_misses = get_kstat_value(ksp, "prefetch_metadata_misses");
142 za_submit_derive ("cache_result", "demand_data-hit", demand_data_hits);
143 za_submit_derive ("cache_result", "demand_metadata-hit", demand_metadata_hits);
144 za_submit_derive ("cache_result", "prefetch_data-hit", prefetch_data_hits);
145 za_submit_derive ("cache_result", "prefetch_metadata-hit", prefetch_metadata_hits);
147 za_submit_derive ("cache_result", "demand_data-miss", demand_data_misses);
148 za_submit_derive ("cache_result", "demand_metadata-miss", demand_metadata_misses);
149 za_submit_derive ("cache_result", "prefetch_data-miss", prefetch_data_misses);
150 za_submit_derive ("cache_result", "prefetch_metadata-miss", prefetch_metadata_misses);
152 /* Ratios */
153 arc_hits = (gauge_t) get_kstat_value(ksp, "hits");
154 arc_misses = (gauge_t) get_kstat_value(ksp, "misses");
155 l2_hits = (gauge_t) get_kstat_value(ksp, "l2_hits");
156 l2_misses = (gauge_t) get_kstat_value(ksp, "l2_misses");
158 za_submit_ratio ("arc", arc_hits, arc_misses);
159 za_submit_ratio ("L2", l2_hits, l2_misses);
161 /* I/O */
162 l2_io[0].derive = get_kstat_value(ksp, "l2_read_bytes");
163 l2_io[1].derive = get_kstat_value(ksp, "l2_write_bytes");
165 za_submit ("io_octets", "L2", l2_io, /* num values = */ 2);
167 return (0);
168 } /* int za_read */
170 static int za_init (void) /* {{{ */
171 {
172 ksp = NULL;
174 /* kstats chain already opened by update_kstat (using *kc), verify everything went fine. */
175 if (kc == NULL)
176 {
177 ERROR ("zfs_arc plugin: kstat chain control structure not available.");
178 return (-1);
179 }
181 return (0);
182 } /* }}} int za_init */
184 void module_register (void)
185 {
186 plugin_register_init ("zfs_arc", za_init);
187 plugin_register_read ("zfs_arc", za_read);
188 } /* void module_register */
190 /* vmi: set sw=8 noexpandtab fdm=marker : */