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/*
monitoring links to all other nodes to detect dead nodes
Copyright (C) Ronnie Sahlberg 2007
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 3 of the License, or
(at your option) any later version.
This program 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 program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "lib/events/events.h"
#include "system/filesys.h"
#include "system/wait.h"
#include "../include/ctdb_private.h"
/*
see if any nodes are dead
*/
static void ctdb_check_for_dead_nodes(struct event_context *ev, struct timed_event *te,
struct timeval t, void *private_data)
{
struct ctdb_context *ctdb = talloc_get_type(private_data, struct ctdb_context);
int i;
if (ctdb->monitoring_mode == CTDB_MONITORING_DISABLED) {
event_add_timed(ctdb->ev, ctdb->monitor_context,
timeval_current_ofs(ctdb->tunable.keepalive_interval, 0),
ctdb_check_for_dead_nodes, ctdb);
return;
}
/* send a keepalive to all other nodes, unless */
for (i=0;i<ctdb->num_nodes;i++) {
struct ctdb_node *node = ctdb->nodes[i];
if (node->vnn == ctdb->vnn) {
continue;
}
if (node->flags & NODE_FLAGS_DISCONNECTED) {
/* it might have come alive again */
if (node->rx_cnt != 0) {
ctdb_node_connected(node);
}
continue;
}
if (node->rx_cnt == 0) {
node->dead_count++;
} else {
node->dead_count = 0;
}
node->rx_cnt = 0;
if (node->dead_count >= ctdb->tunable.keepalive_limit) {
DEBUG(0,("dead count reached for node %u\n", node->vnn));
ctdb_node_dead(node);
ctdb_send_keepalive(ctdb, node->vnn);
/* maybe tell the transport layer to kill the
sockets as well?
*/
continue;
}
if (node->tx_cnt == 0) {
DEBUG(5,("sending keepalive to %u\n", node->vnn));
ctdb_send_keepalive(ctdb, node->vnn);
}
node->tx_cnt = 0;
}
event_add_timed(ctdb->ev, ctdb->monitor_context,
timeval_current_ofs(ctdb->tunable.keepalive_interval, 0),
ctdb_check_for_dead_nodes, ctdb);
}
static void ctdb_check_health(struct event_context *ev, struct timed_event *te,
struct timeval t, void *private_data);
/*
called when a health monitoring event script finishes
*/
static void ctdb_health_callback(struct ctdb_context *ctdb, int status, void *p)
{
struct ctdb_node *node = ctdb->nodes[ctdb->vnn];
TDB_DATA data;
struct ctdb_node_flag_change c;
event_add_timed(ctdb->ev, ctdb->monitor_context,
timeval_current_ofs(ctdb->tunable.monitor_interval, 0),
ctdb_check_health, ctdb);
if (status != 0 && !(node->flags & NODE_FLAGS_UNHEALTHY)) {
DEBUG(0,("monitor event failed - disabling node\n"));
node->flags |= NODE_FLAGS_UNHEALTHY;
} else if (status == 0 && (node->flags & NODE_FLAGS_UNHEALTHY)) {
DEBUG(0,("monitor event OK - node re-enabled\n"));
ctdb->nodes[ctdb->vnn]->flags &= ~NODE_FLAGS_UNHEALTHY;
} else {
/* no change */
return;
}
c.vnn = ctdb->vnn;
c.flags = node->flags;
data.dptr = (uint8_t *)&c;
data.dsize = sizeof(c);
/* tell the other nodes that something has changed */
ctdb_daemon_send_message(ctdb, CTDB_BROADCAST_CONNECTED,
CTDB_SRVID_NODE_FLAGS_CHANGED, data);
}
/*
see if the event scripts think we are healthy
*/
static void ctdb_check_health(struct event_context *ev, struct timed_event *te,
struct timeval t, void *private_data)
{
struct ctdb_context *ctdb = talloc_get_type(private_data, struct ctdb_context);
int ret;
if (ctdb->monitoring_mode == CTDB_MONITORING_DISABLED) {
event_add_timed(ctdb->ev, ctdb->monitor_context,
timeval_current_ofs(ctdb->tunable.monitor_interval, 0),
ctdb_check_health, ctdb);
return;
}
ret = ctdb_event_script_callback(ctdb,
timeval_current_ofs(ctdb->tunable.script_timeout, 0),
ctdb->monitor_context, ctdb_health_callback, ctdb, "monitor");
if (ret != 0) {
DEBUG(0,("Unable to launch monitor event script\n"));
event_add_timed(ctdb->ev, ctdb->monitor_context,
timeval_current_ofs(ctdb->tunable.monitor_interval, 0),
ctdb_check_health, ctdb);
}
}
/* stop any monitoring */
void ctdb_stop_monitoring(struct ctdb_context *ctdb)
{
talloc_free(ctdb->monitor_context);
ctdb->monitor_context = talloc_new(ctdb);
CTDB_NO_MEMORY_FATAL(ctdb, ctdb->monitor_context);
}
/*
start watching for nodes that might be dead
*/
void ctdb_start_monitoring(struct ctdb_context *ctdb)
{
struct timed_event *te;
ctdb_stop_monitoring(ctdb);
te = event_add_timed(ctdb->ev, ctdb->monitor_context,
timeval_current_ofs(ctdb->tunable.keepalive_interval, 0),
ctdb_check_for_dead_nodes, ctdb);
CTDB_NO_MEMORY_FATAL(ctdb, te);
te = event_add_timed(ctdb->ev, ctdb->monitor_context,
timeval_current_ofs(ctdb->tunable.monitor_interval, 0),
ctdb_check_health, ctdb);
CTDB_NO_MEMORY_FATAL(ctdb, te);
}
/*
modify flags on a node
*/
int32_t ctdb_control_modflags(struct ctdb_context *ctdb, TDB_DATA indata)
{
struct ctdb_node_modflags *m = (struct ctdb_node_modflags *)indata.dptr;
TDB_DATA data;
struct ctdb_node_flag_change c;
struct ctdb_node *node = ctdb->nodes[ctdb->vnn];
uint32_t old_flags = node->flags;
node->flags |= m->set;
node->flags &= ~m->clear;
if (node->flags == old_flags) {
/* no change */
return 0;
}
DEBUG(0, ("Control modflags on node %u - flags now 0x%x\n", ctdb->vnn, node->flags));
/* if we have been banned, go into recovery mode */
c.vnn = ctdb->vnn;
c.flags = node->flags;
data.dptr = (uint8_t *)&c;
data.dsize = sizeof(c);
/* tell the other nodes that something has changed */
ctdb_daemon_send_message(ctdb, CTDB_BROADCAST_CONNECTED,
CTDB_SRVID_NODE_FLAGS_CHANGED, data);
if ((node->flags & NODE_FLAGS_BANNED) && !(old_flags & NODE_FLAGS_BANNED)) {
/* make sure we are frozen */
DEBUG(0,("This node has been banned - forcing freeze and recovery\n"));
ctdb_start_freeze(ctdb);
ctdb_release_all_ips(ctdb);
ctdb->recovery_mode = CTDB_RECOVERY_ACTIVE;
}
return 0;
}
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