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-rw-r--r--daemons/controld/controld_throttle.c574
1 files changed, 574 insertions, 0 deletions
diff --git a/daemons/controld/controld_throttle.c b/daemons/controld/controld_throttle.c
new file mode 100644
index 0000000..5b7f9c0
--- /dev/null
+++ b/daemons/controld/controld_throttle.c
@@ -0,0 +1,574 @@
+/*
+ * Copyright 2013-2021 the Pacemaker project contributors
+ *
+ * The version control history for this file may have further details.
+ *
+ * This source code is licensed under the GNU General Public License version 2
+ * or later (GPLv2+) WITHOUT ANY WARRANTY.
+ */
+
+#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 <pacemaker-controld.h>
+
+/* These values don't need to be bits, but these particular values must be kept
+ * for backward compatibility during rolling upgrades.
+ */
+enum throttle_state_e {
+ throttle_none = 0x0000,
+ throttle_low = 0x0001,
+ throttle_med = 0x0010,
+ throttle_high = 0x0100,
+ throttle_extreme = 0x1000,
+};
+
+struct throttle_record_s {
+ int max;
+ enum throttle_state_e mode;
+ char *node;
+};
+
+static int throttle_job_max = 0;
+static float throttle_load_target = 0.0;
+
+#define THROTTLE_FACTOR_LOW 1.2
+#define THROTTLE_FACTOR_MEDIUM 1.6
+#define THROTTLE_FACTOR_HIGH 2.0
+
+static GHashTable *throttle_records = NULL;
+static mainloop_timer_t *throttle_timer = NULL;
+
+static const char *
+load2str(enum throttle_state_e mode)
+{
+ switch (mode) {
+ case throttle_extreme: return "extreme";
+ case throttle_high: return "high";
+ case throttle_med: return "medium";
+ case throttle_low: return "low";
+ case throttle_none: return "negligible";
+ default: return "undetermined";
+ }
+}
+
+#if HAVE_LINUX_PROCFS
+/*!
+ * \internal
+ * \brief Return name of /proc file containing the CIB daemon'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)
+{
+ pid_t pid = pcmk__procfs_pid_of("pacemaker-based");
+
+ return pid? crm_strdup_printf("/proc/%lld/stat", (long long) 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; }
+
+ fclose(stream);
+ return TRUE;
+ }
+
+ fclose(stream);
+ return FALSE;
+}
+
+/*!
+ * \internal
+ * \brief Check a load value against throttling thresholds
+ *
+ * \param[in] load Load value to check
+ * \param[in] desc Description of metric (for logging)
+ * \param[in] thresholds Low/medium/high/extreme thresholds
+ *
+ * \return Throttle mode corresponding to load value
+ */
+static enum throttle_state_e
+throttle_check_thresholds(float load, const char *desc,
+ const float thresholds[4])
+{
+ if (load > thresholds[3]) {
+ crm_notice("Extreme %s detected: %f", desc, load);
+ return throttle_extreme;
+
+ } else if (load > thresholds[2]) {
+ crm_notice("High %s detected: %f", desc, load);
+ return throttle_high;
+
+ } else if (load > thresholds[1]) {
+ crm_info("Moderate %s detected: %f", desc, load);
+ return throttle_med;
+
+ } else if (load > thresholds[0]) {
+ crm_debug("Noticeable %s detected: %f", desc, load);
+ return throttle_low;
+ }
+
+ crm_trace("Negligible %s detected: %f", desc, load);
+ return throttle_none;
+}
+
+static enum throttle_state_e
+throttle_handle_load(float load, const char *desc, int cores)
+{
+ float normalize;
+ float thresholds[4];
+
+ if (cores == 1) {
+ /* On a single core machine, a load of 1.0 is already too high */
+ normalize = 0.6;
+
+ } else {
+ /* Normalize the load to be per-core */
+ normalize = cores;
+ }
+ thresholds[0] = throttle_load_target * normalize * THROTTLE_FACTOR_LOW;
+ thresholds[1] = throttle_load_target * normalize * THROTTLE_FACTOR_MEDIUM;
+ thresholds[2] = throttle_load_target * normalize * THROTTLE_FACTOR_HIGH;
+ thresholds[3] = load + 1.0; /* never extreme */
+
+ return throttle_check_thresholds(load, desc, thresholds);
+}
+#endif // HAVE_LINUX_PROCFS
+
+static enum throttle_state_e
+throttle_mode(void)
+{
+ enum throttle_state_e mode = throttle_none;
+
+#if HAVE_LINUX_PROCFS
+ unsigned int cores;
+ float load;
+ float thresholds[4];
+
+ cores = pcmk__procfs_num_cores();
+ if(throttle_cib_load(&load)) {
+ float cib_max_cpu = 0.95;
+
+ /* 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 therefore be maxed out
+ * (causing operations to fail or appear to fail) even though
+ * the overall system load is still reasonable.
+ *
+ * Therefore, 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;
+ }
+
+ thresholds[0] = cib_max_cpu * 0.8;
+ thresholds[1] = cib_max_cpu * 0.9;
+ thresholds[2] = cib_max_cpu;
+ /* Can only happen on machines with a low number of cores */
+ thresholds[3] = cib_max_cpu * 1.5;
+
+ mode = throttle_check_thresholds(load, "CIB load", thresholds);
+ }
+
+ 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)) {
+ enum throttle_state_e cpu_load;
+
+ cpu_load = throttle_handle_load(load, "CPU load", cores);
+ if (cpu_load > mode) {
+ mode = cpu_load;
+ }
+ crm_debug("Current load is %f across %u core(s)", load, cores);
+ }
+#endif // HAVE_LINUX_PROCFS
+ return mode;
+}
+
+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: %s load (was %s)",
+ load2str(mode), load2str(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)
+{
+ throttle_send_command(throttle_mode());
+ return TRUE;
+}
+
+static void
+throttle_record_free(gpointer p)
+{
+ struct throttle_record_s *r = p;
+ free(r->node);
+ free(r);
+}
+
+static void
+throttle_set_load_target(float target)
+{
+ throttle_load_target = target;
+}
+
+/*!
+ * \internal
+ * \brief Update the maximum number of simultaneous jobs
+ *
+ * \param[in] preference Cluster-wide node-action-limit from the CIB
+ */
+static void
+throttle_update_job_max(const char *preference)
+{
+ long long max = 0LL;
+ const char *env_limit = getenv("PCMK_node_action_limit");
+
+ if (env_limit != NULL) {
+ preference = env_limit; // Per-node override
+ }
+ if (preference != NULL) {
+ pcmk__scan_ll(preference, &max, 0LL);
+ }
+ if (max > 0) {
+ throttle_job_max = (int) max;
+ } else {
+ // Default is based on the number of cores detected
+ throttle_job_max = 2 * pcmk__procfs_num_cores();
+ }
+}
+
+void
+throttle_init(void)
+{
+ if(throttle_records == NULL) {
+ throttle_records = pcmk__strkey_table(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);
+}
+
+/*!
+ * \internal
+ * \brief Configure throttle options based on the CIB
+ *
+ * \param[in,out] options Name/value pairs for configured options
+ */
+void
+controld_configure_throttle(GHashTable *options)
+{
+ const char *value = g_hash_table_lookup(options, "load-threshold");
+
+ if (value != NULL) {
+ throttle_set_load_target(strtof(value, NULL) / 100.0);
+ }
+
+ value = g_hash_table_lookup(options, "node-action-limit");
+ throttle_update_job_max(value);
+}
+
+void
+throttle_fini(void)
+{
+ if (throttle_timer != NULL) {
+ mainloop_timer_del(throttle_timer);
+ throttle_timer = NULL;
+ }
+ if (throttle_records != 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;
+ int 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, &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 = (enum throttle_state_e) mode;
+
+ crm_debug("Node %s has %s load and supports at most %d jobs; new job limit %d",
+ from, load2str((enum throttle_state_e) mode), max,
+ throttle_get_job_limit(from));
+}
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