diff --git a/crmd/throttle.c b/crmd/throttle.c index b9add7da2c..8ab6f01852 100644 --- a/crmd/throttle.c +++ b/crmd/throttle.c @@ -1,682 +1,692 @@ /* * Copyright (C) 2013 Andrew Beekhof * * 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 #include #include #include #include #include #include #include #include #include #include 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; }; 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 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; } +/*! + * \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_handle_load(float load, const char *desc, int cores) +throttle_check_thresholds(float load, const char *desc, float thresholds[4]) { - 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 (load > thresholds[3]) { + crm_notice("Extreme %s detected: %f", desc, load); + return throttle_extreme; - if(adjusted_load > THROTTLE_FACTOR_HIGH * throttle_load_target) { + } else if (load > thresholds[2]) { crm_notice("High %s detected: %f", desc, load); return throttle_high; - } else if(adjusted_load > THROTTLE_FACTOR_MEDIUM * throttle_load_target) { + } else if (load > thresholds[1]) { crm_info("Moderate %s detected: %f", desc, load); return throttle_med; - } else if(adjusted_load > THROTTLE_FACTOR_LOW * throttle_load_target) { + } else if (load > thresholds[0]) { crm_debug("Noticeable %s detected: %f", desc, load); return throttle_low; } - crm_trace("Negligible %s detected: %f", desc, adjusted_load); + 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); +} + static enum throttle_state_e throttle_mode(void) { int cores; float load; + float thresholds[4]; 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 + + /* 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 + * 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. * - * Therefor the 'normal' thresholds can not apply here and we + * 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; } - 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; + 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; - } 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("Negligible %s detected: %f", desc, load); - } + 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)) { 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_set_load_target(float target) { throttle_load_target = target; } 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)); }