Page MenuHomeClusterLabs Projects
Files F4639351

election.c
No OneTemporary
Actions

election.c
View Options

/*
* Copyright (C) 2004 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/time.h>
#include <sys/resource.h>
#include <crm/msg_xml.h>
#include <crm/common/xml.h>
#include <crm/cluster/internal.h>
#include <crm/crm.h>
#include <crmd_fsa.h>
#include <crmd_messages.h>
#include <crmd_callbacks.h>
#include <tengine.h>
#define STORM_INTERVAL 2 /* in seconds */
#define STORM_MULTIPLIER 5 /* multiplied by the number of nodes */
GHashTable *voted = NULL;
uint highest_born_on = -1;
static int current_election_id = 1;
static int
crm_uptime(struct timeval *output)
{
static time_t expires = 0;
static struct rusage info;
time_t tm_now = time(NULL);
if (expires < tm_now) {
int rc = getrusage(RUSAGE_SELF, &info);
output->tv_sec = 0;
output->tv_usec = 0;
if (rc < 0) {
crm_perror(LOG_ERR, "Could not calculate the current uptime");
expires = 0;
return -1;
}
crm_debug("Current CPU usage is: %lds, %ldus", (long)info.ru_utime.tv_sec,
(long)info.ru_utime.tv_usec);
}
expires = tm_now + STORM_INTERVAL; /* N seconds after the last _access_ */
output->tv_sec = info.ru_utime.tv_sec;
output->tv_usec = info.ru_utime.tv_usec;
return 1;
}
static int
crm_compare_age(struct timeval your_age)
{
struct timeval our_age;
if (crm_uptime(&our_age) < 0) {
return -1;
}
/* We want these times to be "significantly" different */
if (our_age.tv_sec > your_age.tv_sec) {
crm_debug("Win: %ld vs %ld (seconds)", (long)our_age.tv_sec, (long)your_age.tv_sec);
return 1;
} else if (our_age.tv_sec < your_age.tv_sec) {
crm_debug("Loose: %ld vs %ld (seconds)", (long)our_age.tv_sec, (long)your_age.tv_sec);
return -1;
} else if (our_age.tv_usec > your_age.tv_usec) {
crm_debug("Win: %ld.%ld vs %ld.%ld (usec)",
(long)our_age.tv_sec, (long)our_age.tv_usec, (long)your_age.tv_sec, (long)your_age.tv_usec);
return 1;
} else if (our_age.tv_usec < your_age.tv_usec) {
crm_debug("Loose: %ld.%ld vs %ld.%ld (usec)",
(long)our_age.tv_sec, (long)our_age.tv_usec, (long)your_age.tv_sec, (long)your_age.tv_usec);
return -1;
}
return 0;
}
/* A_ELECTION_VOTE */
void
do_election_vote(long long action,
enum crmd_fsa_cause cause,
enum crmd_fsa_state cur_state,
enum crmd_fsa_input current_input, fsa_data_t * msg_data)
{
struct timeval age;
xmlNode *vote = NULL;
gboolean not_voting = FALSE;
/* don't vote if we're in one of these states or wanting to shut down */
switch (cur_state) {
case S_STARTING:
case S_RECOVERY:
case S_STOPPING:
case S_TERMINATE:
crm_warn("Not voting in election, we're in state %s", fsa_state2string(cur_state));
not_voting = TRUE;
break;
default:
break;
}
if (not_voting == FALSE) {
if (is_set(fsa_input_register, R_STARTING)) {
not_voting = TRUE;
}
}
if (not_voting) {
if (AM_I_DC) {
register_fsa_input(C_FSA_INTERNAL, I_RELEASE_DC, NULL);
} else {
register_fsa_input(C_FSA_INTERNAL, I_PENDING, NULL);
}
return;
}
vote = create_request(CRM_OP_VOTE, NULL, NULL, CRM_SYSTEM_CRMD, CRM_SYSTEM_CRMD, NULL);
current_election_id++;
crm_xml_add(vote, F_CRM_ELECTION_OWNER, fsa_our_uuid);
crm_xml_add_int(vote, F_CRM_ELECTION_ID, current_election_id);
crm_uptime(&age);
crm_xml_add_int(vote, F_CRM_ELECTION_AGE_S, age.tv_sec);
crm_xml_add_int(vote, F_CRM_ELECTION_AGE_US, age.tv_usec);
send_cluster_message(NULL, crm_msg_crmd, vote, TRUE);
free_xml(vote);
crm_debug("Started election %d", current_election_id);
if (voted) {
g_hash_table_destroy(voted);
}
voted = NULL;
if (cur_state == S_ELECTION || cur_state == S_RELEASE_DC) {
crm_timer_start(election_timeout);
} else if (cur_state != S_INTEGRATION) {
crm_err("Broken? Voting in state %s", fsa_state2string(cur_state));
}
return;
}
char *dc_hb_msg = NULL;
int beat_num = 0;
gboolean
do_dc_heartbeat(gpointer data)
{
return TRUE;
}
struct election_data_s {
const char *winning_uname;
unsigned int winning_bornon;
};
void
do_election_check(long long action,
enum crmd_fsa_cause cause,
enum crmd_fsa_state cur_state,
enum crmd_fsa_input current_input, fsa_data_t * msg_data)
{
int voted_size = 0;
int num_members = crm_active_peers();
if (voted) {
voted_size = g_hash_table_size(voted);
}
/* in the case of #voted > #members, it is better to
* wait for the timeout and give the cluster time to
* stabilize
*/
if (fsa_state != S_ELECTION) {
crm_debug("Ignore election check: we not in an election");
} else if (voted_size >= num_members) {
/* we won and everyone has voted */
crm_timer_stop(election_timeout);
register_fsa_input(C_FSA_INTERNAL, I_ELECTION_DC, NULL);
if (voted_size > num_members) {
GHashTableIter gIter;
const crm_node_t *node;
char *key = NULL;
g_hash_table_iter_init(&gIter, crm_peer_cache);
while (g_hash_table_iter_next(&gIter, NULL, (gpointer *) & node)) {
if (crm_is_peer_active(node)) {
crm_err("member: %s proc=%.32x", node->uname, node->processes);
}
}
g_hash_table_iter_init(&gIter, voted);
while (g_hash_table_iter_next(&gIter, (gpointer *) & key, NULL)) {
crm_err("voted: %s", key);
}
}
crm_debug("Destroying voted hash");
g_hash_table_destroy(voted);
voted = NULL;
} else {
crm_debug("Still waiting on %d non-votes (%d total)",
num_members - voted_size, num_members);
}
return;
}
#define loss_dampen 2 /* in seconds */
/* A_ELECTION_COUNT */
void
do_election_count_vote(long long action,
enum crmd_fsa_cause cause,
enum crmd_fsa_state cur_state,
enum crmd_fsa_input current_input, fsa_data_t * msg_data)
{
int age = 0;
int election_id = -1;
int log_level = LOG_INFO;
gboolean use_born_on = FALSE;
gboolean done = FALSE;
gboolean we_loose = FALSE;
const char *op = NULL;
const char *vote_from = NULL;
const char *election_owner = NULL;
const char *reason = "unknown";
crm_node_t *our_node = NULL, *your_node = NULL;
ha_msg_input_t *vote = fsa_typed_data(fsa_dt_ha_msg);
static int election_wins = 0;
time_t tm_now = time(NULL);
static time_t expires = 0;
static time_t last_election_loss = 0;
/* if the membership copy is NULL we REALLY shouldnt be voting
* the question is how we managed to get here.
*/
CRM_CHECK(msg_data != NULL, return);
CRM_CHECK(vote != NULL, crm_err("Bogus data from %s", msg_data->origin); return);
CRM_CHECK(vote->msg != NULL, crm_err("Bogus data from %s", msg_data->origin); return);
if(crm_peer_cache == NULL) {
if(is_not_set(fsa_input_register, R_SHUTDOWN)) {
crm_err("Internal error, no peer cache");
}
return;
}
op = crm_element_value(vote->msg, F_CRM_TASK);
vote_from = crm_element_value(vote->msg, F_CRM_HOST_FROM);
election_owner = crm_element_value(vote->msg, F_CRM_ELECTION_OWNER);
crm_element_value_int(vote->msg, F_CRM_ELECTION_ID, &election_id);
CRM_CHECK(vote_from != NULL, vote_from = fsa_our_uname);
your_node = crm_get_peer(0, vote_from);
our_node = crm_get_peer(0, fsa_our_uname);
if (voted == NULL) {
crm_debug("Created voted hash");
voted = g_hash_table_new_full(crm_str_hash, g_str_equal,
g_hash_destroy_str, g_hash_destroy_str);
}
if (is_heartbeat_cluster()) {
use_born_on = TRUE;
} else if (is_classic_ais_cluster()) {
use_born_on = TRUE;
}
if (cur_state == S_STARTING) {
reason = "Still starting";
we_loose = TRUE;
} else if (our_node == NULL || crm_is_peer_active(our_node) == FALSE) {
reason = "We are not part of the cluster";
log_level = LOG_ERR;
we_loose = TRUE;
} else if (election_id != current_election_id && crm_str_eq(fsa_our_uuid, election_owner, TRUE)) {
log_level = LOG_DEBUG_2;
reason = "Superceeded";
done = TRUE;
} else if (your_node == NULL || crm_is_peer_active(your_node) == FALSE) {
/* Possibly we cached the message in the FSA queue at a point that it wasn't */
reason = "Peer is not part of our cluster";
log_level = LOG_WARNING;
done = TRUE;
} else if (crm_str_eq(op, CRM_OP_NOVOTE, TRUE)) {
char *op_copy = strdup(op);
char *uname_copy = strdup(vote_from);
CRM_ASSERT(crm_str_eq(fsa_our_uuid, election_owner, TRUE));
/* update the list of nodes that have voted */
g_hash_table_replace(voted, uname_copy, op_copy);
reason = "Recorded";
done = TRUE;
} else {
struct timeval your_age;
const char *your_version = crm_element_value(vote->msg, F_CRM_VERSION);
your_age.tv_sec = 0;
your_age.tv_usec = 0;
crm_element_value_int(vote->msg, F_CRM_ELECTION_AGE_S, (int *)&(your_age.tv_sec));
crm_element_value_int(vote->msg, F_CRM_ELECTION_AGE_US, (int *)&(your_age.tv_usec));
age = crm_compare_age(your_age);
if(your_age.tv_sec == 0 && your_age.tv_usec == 0) {
crm_log_xml_trace(vote->msg, "bad vote");
crm_write_blackbox(0, NULL);
}
if (crm_str_eq(vote_from, fsa_our_uname, TRUE)) {
char *op_copy = strdup(op);
char *uname_copy = strdup(vote_from);
CRM_ASSERT(crm_str_eq(fsa_our_uuid, election_owner, TRUE));
/* update ourselves in the list of nodes that have voted */
g_hash_table_replace(voted, uname_copy, op_copy);
reason = "Recorded";
done = TRUE;
} else if (compare_version(your_version, CRM_FEATURE_SET) < 0) {
reason = "Version";
we_loose = TRUE;
} else if (compare_version(your_version, CRM_FEATURE_SET) > 0) {
reason = "Version";
} else if (age < 0) {
reason = "Uptime";
we_loose = TRUE;
} else if (age > 0) {
reason = "Uptime";
/* TODO: Check for y(our) born < 0 */
} else if (use_born_on && your_node->born < our_node->born) {
reason = "Born";
we_loose = TRUE;
} else if (use_born_on && your_node->born > our_node->born) {
reason = "Born";
} else if (fsa_our_uname == NULL) {
reason = "Unknown host name";
we_loose = TRUE;
} else if (strcasecmp(fsa_our_uname, vote_from) > 0) {
reason = "Host name";
we_loose = TRUE;
} else {
reason = "Host name";
CRM_ASSERT(strcasecmp(fsa_our_uname, vote_from) < 0);
/* cant happen...
* } else if(strcasecmp(fsa_our_uname, vote_from) == 0) {
*
*/
}
}
if (expires < tm_now) {
election_wins = 0;
expires = tm_now + STORM_INTERVAL;
} else if (done == FALSE && we_loose == FALSE) {
int peers = 1 + g_hash_table_size(crm_peer_cache);
/* If every node has to vote down every other node, thats N*(N-1) total elections
* Allow some leway before _really_ complaining
*/
election_wins++;
if (election_wins > (peers * peers)) {
crm_warn("Election storm detected: %d elections in %d seconds", election_wins,
STORM_INTERVAL);
election_wins = 0;
expires = tm_now + STORM_INTERVAL;
crm_write_blackbox(0, NULL);
}
}
if (done) {
do_crm_log(log_level + 1, "Election %d (current: %d, owner: %s): Processed %s from %s (%s)",
election_id, current_election_id, election_owner, op, vote_from, reason);
} else if (we_loose) {
xmlNode *novote = create_request(CRM_OP_NOVOTE, NULL, vote_from,
CRM_SYSTEM_CRMD, CRM_SYSTEM_CRMD, NULL);
do_crm_log(log_level, "Election %d (owner: %s) lost: %s from %s (%s)",
election_id, election_owner, op, vote_from, reason);
update_dc(NULL);
crm_timer_stop(election_timeout);
if (fsa_input_register & R_THE_DC) {
crm_trace("Give up the DC to %s", vote_from);
register_fsa_input(C_FSA_INTERNAL, I_RELEASE_DC, NULL);
fsa_cib_conn->cmds->set_slave(fsa_cib_conn, cib_scope_local);
} else if (cur_state != S_STARTING) {
crm_trace("We werent the DC anyway");
register_fsa_input(C_FSA_INTERNAL, I_PENDING, NULL);
}
crm_xml_add(novote, F_CRM_ELECTION_OWNER, election_owner);
crm_xml_add_int(novote, F_CRM_ELECTION_ID, election_id);
send_cluster_message(crm_get_peer(0, vote_from), crm_msg_crmd, novote, TRUE);
free_xml(novote);
last_election_loss = tm_now;
} else {
do_crm_log(log_level, "Election %d (owner: %s) pass: %s from %s (%s)",
election_id, election_owner, op, vote_from, reason);
if (last_election_loss) {
if (tm_now - last_election_loss < (time_t) loss_dampen) {
crm_info("Election %d ignore: We already lost an election less than %ds ago (%s)",
election_id, loss_dampen, ctime(&last_election_loss));
update_dc(NULL);
return;
}
last_election_loss = 0;
}
register_fsa_input(C_FSA_INTERNAL, I_ELECTION, NULL);
g_hash_table_destroy(voted);
voted = NULL;
}
}
/* A_ELECT_TIMER_START, A_ELECTION_TIMEOUT */
/* we won */
void
do_election_timer_ctrl(long long action,
enum crmd_fsa_cause cause,
enum crmd_fsa_state cur_state,
enum crmd_fsa_input current_input, fsa_data_t * msg_data)
{
}
static void
feature_update_callback(xmlNode * msg, int call_id, int rc, xmlNode * output, void *user_data)
{
if (rc != pcmk_ok) {
fsa_data_t *msg_data = NULL;
crm_notice("Update failed: %s (%d)", pcmk_strerror(rc), rc);
register_fsa_error(C_FSA_INTERNAL, I_ERROR, NULL);
}
}
/* A_DC_TAKEOVER */
void
do_dc_takeover(long long action,
enum crmd_fsa_cause cause,
enum crmd_fsa_state cur_state,
enum crmd_fsa_input current_input, fsa_data_t * msg_data)
{
int rc = pcmk_ok;
xmlNode *cib = NULL;
GListPtr gIter = NULL;
const char *cluster_type = name_for_cluster_type(get_cluster_type());
crm_info("Taking over DC status for this partition");
set_bit(fsa_input_register, R_THE_DC);
for (gIter = stonith_cleanup_list; gIter != NULL; gIter = gIter->next) {
char *target = gIter->data;
crm_node_t *target_node = crm_get_peer(0, target);
const char *uuid = crm_peer_uuid(target_node);
crm_notice("Marking %s, target of a previous stonith action, as clean", target);
send_stonith_update(NULL, target, uuid);
free(target);
}
g_list_free(stonith_cleanup_list);
stonith_cleanup_list = NULL;
#if SUPPORT_COROSYNC
if (is_classic_ais_cluster()) {
send_cluster_text(crm_class_quorum, NULL, TRUE, NULL, crm_msg_ais);
}
#endif
if (voted != NULL) {
crm_trace("Destroying voted hash");
g_hash_table_destroy(voted);
voted = NULL;
}
set_bit(fsa_input_register, R_JOIN_OK);
set_bit(fsa_input_register, R_INVOKE_PE);
fsa_cib_conn->cmds->set_master(fsa_cib_conn, cib_scope_local);
cib = create_xml_node(NULL, XML_TAG_CIB);
crm_xml_add(cib, XML_ATTR_CRM_VERSION, CRM_FEATURE_SET);
fsa_cib_update(XML_TAG_CIB, cib, cib_quorum_override, rc, NULL);
fsa_register_cib_callback(rc, FALSE, NULL, feature_update_callback);
update_attr_delegate(fsa_cib_conn, cib_none, XML_CIB_TAG_CRMCONFIG, NULL, NULL, NULL, NULL,
"dc-version", VERSION "-" BUILD_VERSION, FALSE, NULL);
update_attr_delegate(fsa_cib_conn, cib_none, XML_CIB_TAG_CRMCONFIG, NULL, NULL, NULL, NULL,
"cluster-infrastructure", cluster_type, FALSE, NULL);
mainloop_set_trigger(config_read);
free_xml(cib);
}
/* A_DC_RELEASE */
void
do_dc_release(long long action,
enum crmd_fsa_cause cause,
enum crmd_fsa_state cur_state,
enum crmd_fsa_input current_input, fsa_data_t * msg_data)
{
if (action & A_DC_RELEASE) {
crm_debug("Releasing the role of DC");
clear_bit(fsa_input_register, R_THE_DC);
} else if (action & A_DC_RELEASED) {
crm_info("DC role released");
#if 0
if (are there errors) {
/* we cant stay up if not healthy */
/* or perhaps I_ERROR and go to S_RECOVER? */
result = I_SHUTDOWN;
}
#endif
register_fsa_input(C_FSA_INTERNAL, I_RELEASE_SUCCESS, NULL);
} else {
crm_err("Unknown action %s", fsa_action2string(action));
}
crm_trace("Am I still the DC? %s", AM_I_DC ? XML_BOOLEAN_YES : XML_BOOLEAN_NO);
}

File Metadata

Mime Type
text/x-c
Expires
Thu, Jul 10, 2:50 AM (1 d, 10 h)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
2009789
Default Alt Text
election.c (18 KB)

Event Timeline