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/*
* Copyright (C) 2013 Andrew Beekhof <andrew@beekhof.net>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <crm_internal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <ctype.h>
#include <dirent.h>
#include <crm/crm.h>
#include <crm/msg_xml.h>
#include <crm/cluster.h>
#include <crmd_fsa.h>
#include <throttle.h>
enum throttle_state_e
{
throttle_extreme = 0x1000,
throttle_high = 0x0100,
throttle_med = 0x0010,
throttle_low = 0x0001,
throttle_none = 0x0000,
};
struct throttle_record_s
{
int max;
enum throttle_state_e mode;
char *node;
};
int throttle_job_max = 0;
float throttle_load_target = 0.0;
#define THROTTLE_FACTOR_LOW 1.2
#define THROTTLE_FACTOR_MEDIUM 1.6
#define THROTTLE_FACTOR_HIGH 2.0
GHashTable *throttle_records = NULL;
mainloop_timer_t *throttle_timer = NULL;
int throttle_num_cores(void)
{
static int cores = 0;
char buffer[256];
FILE *stream = NULL;
const char *cpufile = "/proc/cpuinfo";
if(cores) {
return cores;
}
stream = fopen(cpufile, "r");
if(stream == NULL) {
int rc = errno;
crm_warn("Couldn't read %s, assuming a single processor: %s (%d)", cpufile, pcmk_strerror(rc), rc);
return 1;
}
while (fgets(buffer, sizeof(buffer), stream)) {
if(strstr(buffer, "processor") == buffer) {
cores++;
}
}
fclose(stream);
if(cores == 0) {
crm_warn("No processors found in %s, assuming 1", cpufile);
return 1;
}
return cores;
}
/*!
* \internal
* \brief Return name of /proc file containing the CIB deamon's load statistics
*
* \return Newly allocated memory with file name on success, NULL otherwise
*
* \note It is the caller's responsibility to free the return value.
* This will return NULL if the daemon is being run via valgrind.
* This should be called only on Linux systems.
*/
static char *find_cib_loadfile(void)
{
int pid = crm_procfs_pid_of("cib");
return pid? crm_strdup_printf("/proc/%d/stat", pid) : NULL;
}
static bool throttle_cib_load(float *load)
{
/*
/proc/[pid]/stat
Status information about the process. This is used by ps(1). It is defined in /usr/src/linux/fs/proc/array.c.
The fields, in order, with their proper scanf(3) format specifiers, are:
pid %d (1) The process ID.
comm %s (2) The filename of the executable, in parentheses. This is visible whether or not the executable is swapped out.
state %c (3) One character from the string "RSDZTW" where R is running, S is sleeping in an interruptible wait, D is waiting in uninterruptible disk sleep, Z is zombie, T is traced or stopped (on a signal), and W is paging.
ppid %d (4) The PID of the parent.
pgrp %d (5) The process group ID of the process.
session %d (6) The session ID of the process.
tty_nr %d (7) The controlling terminal of the process. (The minor device number is contained in the combination of bits 31 to 20 and 7 to 0; the major device number is in bits 15 to 8.)
tpgid %d (8) The ID of the foreground process group of the controlling terminal of the process.
flags %u (%lu before Linux 2.6.22)
(9) The kernel flags word of the process. For bit meanings, see the PF_* defines in the Linux kernel source file include/linux/sched.h. Details depend on the kernel version.
minflt %lu (10) The number of minor faults the process has made which have not required loading a memory page from disk.
cminflt %lu (11) The number of minor faults that the process's waited-for children have made.
majflt %lu (12) The number of major faults the process has made which have required loading a memory page from disk.
cmajflt %lu (13) The number of major faults that the process's waited-for children have made.
utime %lu (14) Amount of time that this process has been scheduled in user mode, measured in clock ticks (divide by sysconf(_SC_CLK_TCK)). This includes guest time, guest_time (time spent running a virtual CPU, see below), so that applications that are not aware of the guest time field do not lose that time from their calculations.
stime %lu (15) Amount of time that this process has been scheduled in kernel mode, measured in clock ticks (divide by sysconf(_SC_CLK_TCK)).
*/
static char *loadfile = NULL;
static time_t last_call = 0;
static long ticks_per_s = 0;
static unsigned long last_utime, last_stime;
char buffer[64*1024];
FILE *stream = NULL;
time_t now = time(NULL);
if(load == NULL) {
return FALSE;
} else {
*load = 0.0;
}
if(loadfile == NULL) {
last_call = 0;
last_utime = 0;
last_stime = 0;
loadfile = find_cib_loadfile();
if (loadfile == NULL) {
crm_warn("Couldn't find CIB load file");
return FALSE;
}
ticks_per_s = sysconf(_SC_CLK_TCK);
crm_trace("Found %s", loadfile);
}
stream = fopen(loadfile, "r");
if(stream == NULL) {
int rc = errno;
crm_warn("Couldn't read %s: %s (%d)", loadfile, pcmk_strerror(rc), rc);
free(loadfile); loadfile = NULL;
return FALSE;
}
if(fgets(buffer, sizeof(buffer), stream)) {
char *comm = calloc(1, 256);
char state = 0;
int rc = 0, pid = 0, ppid = 0, pgrp = 0, session = 0, tty_nr = 0, tpgid = 0;
unsigned long flags = 0, minflt = 0, cminflt = 0, majflt = 0, cmajflt = 0, utime = 0, stime = 0;
rc = sscanf(buffer, "%d %[^ ] %c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu",
&pid, comm, &state,
&ppid, &pgrp, &session, &tty_nr, &tpgid,
&flags, &minflt, &cminflt, &majflt, &cmajflt, &utime, &stime);
free(comm);
if(rc != 15) {
crm_err("Only %d of 15 fields found in %s", rc, loadfile);
fclose(stream);
return FALSE;
} else if(last_call > 0
&& last_call < now
&& last_utime <= utime
&& last_stime <= stime) {
time_t elapsed = now - last_call;
unsigned long delta_utime = utime - last_utime;
unsigned long delta_stime = stime - last_stime;
*load = (delta_utime + delta_stime); /* Cast to a float before division */
*load /= ticks_per_s;
*load /= elapsed;
crm_debug("cib load: %f (%lu ticks in %lds)", *load, delta_utime + delta_stime, (long)elapsed);
} else {
crm_debug("Init %lu + %lu ticks at %ld (%lu tps)", utime, stime, (long)now, ticks_per_s);
}
last_call = now;
last_utime = utime;
last_stime = stime;
fclose(stream);
return TRUE;
}
fclose(stream);
return FALSE;
}
static bool throttle_load_avg(float *load)
{
char buffer[256];
FILE *stream = NULL;
const char *loadfile = "/proc/loadavg";
if(load == NULL) {
return FALSE;
}
stream = fopen(loadfile, "r");
if(stream == NULL) {
int rc = errno;
crm_warn("Couldn't read %s: %s (%d)", loadfile, pcmk_strerror(rc), rc);
return FALSE;
}
if(fgets(buffer, sizeof(buffer), stream)) {
char *nl = strstr(buffer, "\n");
/* Grab the 1-minute average, ignore the rest */
*load = strtof(buffer, NULL);
if(nl) { nl[0] = 0; }
crm_debug("Current load is %f (full: %s)", *load, buffer);
fclose(stream);
return TRUE;
}
fclose(stream);
return FALSE;
}
static bool throttle_io_load(float *load, unsigned int *blocked)
{
char buffer[64*1024];
FILE *stream = NULL;
const char *loadfile = "/proc/stat";
if(load == NULL) {
return FALSE;
}
stream = fopen(loadfile, "r");
if(stream == NULL) {
int rc = errno;
crm_warn("Couldn't read %s: %s (%d)", loadfile, pcmk_strerror(rc), rc);
return FALSE;
}
if(fgets(buffer, sizeof(buffer), stream)) {
/* Borrowed from procps-ng's sysinfo.c */
char *b = NULL;
unsigned long long cpu_use = 0;
unsigned long long cpu_nic = 0;
unsigned long long cpu_sys = 0;
unsigned long long cpu_idl = 0;
unsigned long long cpu_iow = 0; /* not separated out until the 2.5.41 kernel */
unsigned long long cpu_xxx = 0; /* not separated out until the 2.6.0-test4 kernel */
unsigned long long cpu_yyy = 0; /* not separated out until the 2.6.0-test4 kernel */
unsigned long long cpu_zzz = 0; /* not separated out until the 2.6.11 kernel */
long long divo2 = 0;
long long duse = 0;
long long dsys = 0;
long long didl =0;
long long diow =0;
long long dstl = 0;
long long Div = 0;
b = strstr(buffer, "cpu ");
if(b) sscanf(b, "cpu %Lu %Lu %Lu %Lu %Lu %Lu %Lu %Lu",
&cpu_use, &cpu_nic, &cpu_sys, &cpu_idl, &cpu_iow, &cpu_xxx, &cpu_yyy, &cpu_zzz);
if(blocked) {
b = strstr(buffer, "procs_blocked ");
if(b) sscanf(b, "procs_blocked %u", blocked);
}
duse = cpu_use + cpu_nic;
dsys = cpu_sys + cpu_xxx + cpu_yyy;
didl = cpu_idl;
diow = cpu_iow;
dstl = cpu_zzz;
Div = duse + dsys + didl + diow + dstl;
if (!Div) Div = 1, didl = 1;
divo2 = Div / 2UL;
/* vmstat output:
*
* procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
* r b swpd free buff cache si so bi bo in cs us sy id wa
* 1 0 5537800 958592 204180 1737740 1 1 12 15 0 0 2 1 97 0
*
* The last four columns are calculated as:
*
* (unsigned)( (100*duse + divo2) / Div ),
* (unsigned)( (100*dsys + divo2) / Div ),
* (unsigned)( (100*didl + divo2) / Div ),
* (unsigned)( (100*diow + divo2) / Div )
*
*/
*load = (diow + divo2) / Div;
crm_debug("Current IO load is %f", *load);
fclose(stream);
return TRUE;
}
fclose(stream);
return FALSE;
}
static enum throttle_state_e
throttle_handle_load(float load, const char *desc, int cores)
{
float adjusted_load = load;
if(cores <= 0) {
/* No fudging of the supplied load value */
} else if(cores == 1) {
/* On a single core machine, a load of 1.0 is already too high */
adjusted_load = load * THROTTLE_FACTOR_MEDIUM;
} else {
/* Normalize the load to be per-core */
adjusted_load = load / cores;
}
if(adjusted_load > THROTTLE_FACTOR_HIGH * throttle_load_target) {
crm_notice("High %s detected: %f", desc, load);
return throttle_high;
} else if(adjusted_load > THROTTLE_FACTOR_MEDIUM * throttle_load_target) {
crm_info("Moderate %s detected: %f", desc, load);
return throttle_med;
} else if(adjusted_load > THROTTLE_FACTOR_LOW * throttle_load_target) {
crm_debug("Noticeable %s detected: %f", desc, load);
return throttle_low;
}
crm_trace("Negligable %s detected: %f", desc, adjusted_load);
return throttle_none;
}
static enum throttle_state_e
throttle_mode(void)
{
int cores;
float load;
unsigned int blocked = 0;
enum throttle_state_e mode = throttle_none;
#if defined(ON_BSD) || defined(ON_SOLARIS)
return throttle_none;
#endif
cores = throttle_num_cores();
if(throttle_cib_load(&load)) {
float cib_max_cpu = 0.95;
const char *desc = "CIB load";
/* The CIB is a single threaded task and thus cannot consume
* more than 100% of a CPU (and 1/cores of the overall system
* load).
*
* On a many cored system, the CIB might therefor be maxed out
* (causing operations to fail or appear to fail) even though
* the overall system load is still reasonable.
*
* Therefor the 'normal' thresholds can not apply here and we
* need a special case.
*/
if(cores == 1) {
cib_max_cpu = 0.4;
}
if(throttle_load_target > 0.0 && throttle_load_target < cib_max_cpu) {
cib_max_cpu = throttle_load_target;
}
if(load > 1.5 * cib_max_cpu) {
/* Can only happen on machines with a low number of cores */
crm_notice("Extreme %s detected: %f", desc, load);
mode |= throttle_extreme;
} else if(load > cib_max_cpu) {
crm_notice("High %s detected: %f", desc, load);
mode |= throttle_high;
} else if(load > cib_max_cpu * 0.9) {
crm_info("Moderate %s detected: %f", desc, load);
mode |= throttle_med;
} else if(load > cib_max_cpu * 0.8) {
crm_debug("Noticeable %s detected: %f", desc, load);
mode |= throttle_low;
} else {
crm_trace("Negligable %s detected: %f", desc, load);
}
}
if(throttle_load_target <= 0) {
/* If we ever make this a valid value, the cluster will at least behave as expected */
return mode;
}
if(throttle_load_avg(&load)) {
mode |= throttle_handle_load(load, "CPU load", cores);
}
if(throttle_io_load(&load, &blocked)) {
mode |= throttle_handle_load(load, "IO load", 0);
mode |= throttle_handle_load(blocked, "blocked IO ratio", cores);
}
if(mode & throttle_extreme) {
return throttle_extreme;
} else if(mode & throttle_high) {
return throttle_high;
} else if(mode & throttle_med) {
return throttle_med;
} else if(mode & throttle_low) {
return throttle_low;
}
return throttle_none;
}
static void
throttle_send_command(enum throttle_state_e mode)
{
xmlNode *xml = NULL;
static enum throttle_state_e last = -1;
if(mode != last) {
crm_info("New throttle mode: %.4x (was %.4x)", mode, last);
last = mode;
xml = create_request(CRM_OP_THROTTLE, NULL, NULL, CRM_SYSTEM_CRMD, CRM_SYSTEM_CRMD, NULL);
crm_xml_add_int(xml, F_CRM_THROTTLE_MODE, mode);
crm_xml_add_int(xml, F_CRM_THROTTLE_MAX, throttle_job_max);
send_cluster_message(NULL, crm_msg_crmd, xml, TRUE);
free_xml(xml);
}
}
static gboolean
throttle_timer_cb(gpointer data)
{
static bool send_updates = FALSE;
enum throttle_state_e now = throttle_none;
if(send_updates) {
now = throttle_mode();
throttle_send_command(now);
} else if(compare_version(fsa_our_dc_version, "3.0.8") < 0) {
/* Optimize for the true case */
crm_trace("DC version %s doesn't support throttling", fsa_our_dc_version);
} else {
send_updates = TRUE;
now = throttle_mode();
throttle_send_command(now);
}
return TRUE;
}
static void
throttle_record_free(gpointer p)
{
struct throttle_record_s *r = p;
free(r->node);
free(r);
}
void
throttle_update_job_max(const char *preference)
{
int max = 0;
throttle_job_max = 2 * throttle_num_cores();
if(preference) {
/* Global preference from the CIB */
max = crm_int_helper(preference, NULL);
if(max > 0) {
throttle_job_max = max;
}
}
preference = getenv("LRMD_MAX_CHILDREN");
if(preference) {
/* Legacy env variable */
max = crm_int_helper(preference, NULL);
if(max > 0) {
throttle_job_max = max;
}
}
preference = getenv("PCMK_node_action_limit");
if(preference) {
/* Per-node override */
max = crm_int_helper(preference, NULL);
if(max > 0) {
throttle_job_max = max;
}
}
}
void
throttle_init(void)
{
if(throttle_records == NULL) {
throttle_records = g_hash_table_new_full(
crm_str_hash, g_str_equal, NULL, throttle_record_free);
throttle_timer = mainloop_timer_add("throttle", 30 * 1000, TRUE, throttle_timer_cb, NULL);
}
throttle_update_job_max(NULL);
mainloop_timer_start(throttle_timer);
}
void
throttle_fini(void)
{
mainloop_timer_del(throttle_timer); throttle_timer = NULL;
g_hash_table_destroy(throttle_records); throttle_records = NULL;
}
int
throttle_get_total_job_limit(int l)
{
/* Cluster-wide limit */
GHashTableIter iter;
int limit = l;
int peers = crm_active_peers();
struct throttle_record_s *r = NULL;
g_hash_table_iter_init(&iter, throttle_records);
while (g_hash_table_iter_next(&iter, NULL, (gpointer *) &r)) {
switch(r->mode) {
case throttle_extreme:
if(limit == 0 || limit > peers/4) {
limit = QB_MAX(1, peers/4);
}
break;
case throttle_high:
if(limit == 0 || limit > peers/2) {
limit = QB_MAX(1, peers/2);
}
break;
default:
break;
}
}
if(limit == l) {
/* crm_trace("No change to batch-limit=%d", limit); */
} else if(l == 0) {
crm_trace("Using batch-limit=%d", limit);
} else {
crm_trace("Using batch-limit=%d instead of %d", limit, l);
}
return limit;
}
int
throttle_get_job_limit(const char *node)
{
int jobs = 1;
struct throttle_record_s *r = NULL;
r = g_hash_table_lookup(throttle_records, node);
if(r == NULL) {
r = calloc(1, sizeof(struct throttle_record_s));
r->node = strdup(node);
r->mode = throttle_low;
r->max = throttle_job_max;
crm_trace("Defaulting to local values for unknown node %s", node);
g_hash_table_insert(throttle_records, r->node, r);
}
switch(r->mode) {
case throttle_extreme:
case throttle_high:
jobs = 1; /* At least one job must always be allowed */
break;
case throttle_med:
jobs = QB_MAX(1, r->max / 4);
break;
case throttle_low:
jobs = QB_MAX(1, r->max / 2);
break;
case throttle_none:
jobs = QB_MAX(1, r->max);
break;
default:
crm_err("Unknown throttle mode %.4x on %s", r->mode, node);
break;
}
return jobs;
}
void
throttle_update(xmlNode *xml)
{
int max = 0;
enum throttle_state_e mode = 0;
struct throttle_record_s *r = NULL;
const char *from = crm_element_value(xml, F_CRM_HOST_FROM);
crm_element_value_int(xml, F_CRM_THROTTLE_MODE, (int*)&mode);
crm_element_value_int(xml, F_CRM_THROTTLE_MAX, &max);
r = g_hash_table_lookup(throttle_records, from);
if(r == NULL) {
r = calloc(1, sizeof(struct throttle_record_s));
r->node = strdup(from);
g_hash_table_insert(throttle_records, r->node, r);
}
r->max = max;
r->mode = mode;
crm_debug("Host %s supports a maximum of %d jobs and throttle mode %.4x. New job limit is %d",
from, max, mode, throttle_get_job_limit(from));
}

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