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repmgrd-physical.c
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repmgrd-physical.c
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/*
* repmgrd-physical.c - physical (streaming) replication functionality for repmgrd
*
* Copyright (c) EnterpriseDB Corporation, 2010-2021
*
* 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 <signal.h>
#include "repmgr.h"
#include "repmgrd.h"
#include "repmgrd-physical.h"
typedef enum
{
FAILOVER_STATE_UNKNOWN = -1,
FAILOVER_STATE_NONE,
FAILOVER_STATE_PROMOTED,
FAILOVER_STATE_PROMOTION_FAILED,
FAILOVER_STATE_PRIMARY_REAPPEARED,
FAILOVER_STATE_LOCAL_NODE_FAILURE,
FAILOVER_STATE_WAITING_NEW_PRIMARY,
FAILOVER_STATE_FOLLOW_NEW_PRIMARY,
FAILOVER_STATE_REQUIRES_MANUAL_FAILOVER,
FAILOVER_STATE_FOLLOWED_NEW_PRIMARY,
FAILOVER_STATE_FOLLOWING_ORIGINAL_PRIMARY,
FAILOVER_STATE_NO_NEW_PRIMARY,
FAILOVER_STATE_FOLLOW_FAIL,
FAILOVER_STATE_NODE_NOTIFICATION_ERROR,
FAILOVER_STATE_ELECTION_RERUN
} FailoverState;
typedef enum
{
ELECTION_NOT_CANDIDATE = -1,
ELECTION_WON,
ELECTION_LOST,
ELECTION_CANCELLED,
ELECTION_RERUN
} ElectionResult;
typedef struct election_stats
{
int visible_nodes;
int shared_upstream_nodes;
int all_nodes;
} election_stats;
typedef struct t_child_node_info
{
int node_id;
char node_name[NAMEDATALEN];
t_server_type type;
NodeAttached attached;
instr_time detached_time;
struct t_child_node_info *next;
} t_child_node_info;
typedef struct t_child_node_info_list
{
t_child_node_info *head;
t_child_node_info *tail;
int node_count;
} t_child_node_info_list;
#define T_CHILD_NODE_INFO_LIST_INITIALIZER { \
NULL, \
NULL, \
0 \
}
static PGconn *upstream_conn = NULL;
static PGconn *primary_conn = NULL;
static FailoverState failover_state = FAILOVER_STATE_UNKNOWN;
static int primary_node_id = UNKNOWN_NODE_ID;
static t_node_info upstream_node_info = T_NODE_INFO_INITIALIZER;
static instr_time last_monitoring_update;
static bool child_nodes_disconnect_command_executed = false;
static ElectionResult do_election(NodeInfoList *sibling_nodes, int *new_primary_id);
static const char *_print_election_result(ElectionResult result);
static FailoverState promote_self(void);
static void notify_followers(NodeInfoList *standby_nodes, int follow_node_id);
static void check_connection(t_node_info *node_info, PGconn **conn);
static bool check_primary_status(int degraded_monitoring_elapsed);
static void check_primary_child_nodes(t_child_node_info_list *local_child_nodes);
static bool wait_primary_notification(int *new_primary_id);
static FailoverState follow_new_primary(int new_primary_id);
static FailoverState witness_follow_new_primary(int new_primary_id);
static void reset_node_voting_status(void);
static bool do_primary_failover(void);
static bool do_upstream_standby_failover(void);
static bool do_witness_failover(void);
static bool update_monitoring_history(void);
static void handle_sighup(PGconn **conn, t_server_type server_type);
static const char *format_failover_state(FailoverState failover_state);
static ElectionResult execute_failover_validation_command(t_node_info *node_info, election_stats *stats);
static void parse_failover_validation_command(const char *template, t_node_info *node_info, election_stats *stats, PQExpBufferData *out);
static bool check_node_can_follow(PGconn *local_conn, XLogRecPtr local_xlogpos, PGconn *follow_target_conn, t_node_info *follow_target_node_info);
static void check_witness_attached(t_node_info *node_info, bool startup);
static t_child_node_info *append_child_node_record(t_child_node_info_list *nodes, int node_id, const char *node_name, t_server_type type, NodeAttached attached);
static void remove_child_node_record(t_child_node_info_list *nodes, int node_id);
static void clear_child_node_info_list(t_child_node_info_list *nodes);
static void parse_child_nodes_disconnect_command(char *parsed_command, char *template, int reporting_node_id);
static void execute_child_nodes_disconnect_command(NodeInfoList *db_child_node_records, t_child_node_info_list *local_child_nodes);
static int try_primary_reconnect(PGconn **conn, PGconn *local_conn, t_node_info *node_info);
void
handle_sigint_physical(SIGNAL_ARGS)
{
PGconn *writeable_conn;
PQExpBufferData event_details;
initPQExpBuffer(&event_details);
appendPQExpBuffer(&event_details,
_("%s signal received"),
postgres_signal_arg == SIGTERM
? "TERM" : "INT");
log_notice("%s", event_details.data);
if (local_node_info.type == PRIMARY)
writeable_conn = local_conn;
else
writeable_conn = primary_conn;
if (PQstatus(writeable_conn) == CONNECTION_OK)
create_event_notification(writeable_conn,
&config_file_options,
config_file_options.node_id,
"repmgrd_shutdown",
true,
event_details.data);
termPQExpBuffer(&event_details);
terminate(SUCCESS);
}
/* perform some sanity checks on the node's configuration */
void
do_physical_node_check(PGconn *conn)
{
/*
* If node record is "inactive"; if not, attempt to set it to "active".
*
* Usually it will have become inactive due to e.g. a standby being shut down
* while repmgrd was running in an unpaused state. In this case it's
* perfectly reasonable to automatically mark the node as "active".
*/
if (local_node_info.active == false)
{
char *hint = "Check that \"repmgr (primary|standby) register\" was executed for this node";
RecoveryType recovery_type = get_recovery_type(conn);
/*
* If the local node's recovery status is incompatible with its registered
* status, e.g. registered as primary but running as a standby, refuse to start.
*
* This typically happens when a failed primary is recloned but the node was not
* re-registered, leaving the cluster in a potentially ambiguous state. In
* this case it would not be possible or desirable to attempt to set the
* node to active; the user should ensure the cluster is in the correct state.
*/
if (recovery_type != RECTYPE_UNKNOWN && local_node_info.type != UNKNOWN)
{
bool require_reregister = false;
PQExpBufferData event_details;
initPQExpBuffer(&event_details);
if (recovery_type == RECTYPE_STANDBY && local_node_info.type != STANDBY)
{
appendPQExpBuffer(&event_details,
_("node is registered as a %s but running as a standby"),
get_node_type_string(local_node_info.type));
require_reregister = true;
}
else if (recovery_type == RECTYPE_PRIMARY && local_node_info.type == STANDBY)
{
log_error(_("node is registered as a standby but running as a %s"), get_node_type_string(local_node_info.type));
require_reregister = true;
}
if (require_reregister == true)
{
log_error("%s", event_details.data);
log_hint(_("%s"), hint);
create_event_notification(NULL,
&config_file_options,
config_file_options.node_id,
"repmgrd_start",
false,
event_details.data);
termPQExpBuffer(&event_details);
terminate(ERR_BAD_CONFIG);
}
termPQExpBuffer(&event_details);
}
/*
* Attempt to set node record active (unless explicitly configured not to)
*/
log_notice(_("setting node record for node \"%s\" (ID: %i) to \"active\""),
local_node_info.node_name,
local_node_info.node_id);
if (config_file_options.repmgrd_exit_on_inactive_node == false)
{
PGconn *primary_conn = get_primary_connection(conn, NULL, NULL);
bool success = true;
if (PQstatus(primary_conn) != CONNECTION_OK)
{
log_error(_("unable to connect to the primary node to activate the node record"));
success = false;
}
else
{
success = update_node_record_set_active(primary_conn, local_node_info.node_id, true);
PQfinish(primary_conn);
}
if (success == true)
{
local_node_info.active = true;
}
}
/*
* Corner-case where it was not possible to set the node to "active"
*/
if (local_node_info.active == false)
{
switch (config_file_options.failover)
{
/* "failover" is an enum, all values should be covered here */
case FAILOVER_AUTOMATIC:
log_error(_("this node is marked as inactive and cannot be used as a failover target"));
log_hint(_("%s"), hint);
create_event_notification(NULL,
&config_file_options,
config_file_options.node_id,
"repmgrd_start",
false,
"node is inactive and cannot be used as a failover target");
terminate(ERR_BAD_CONFIG);
break;
case FAILOVER_MANUAL:
log_warning(_("this node is marked as inactive and will be passively monitored only"));
log_hint(_("%s"), hint);
break;
}
}
}
if (config_file_options.failover == FAILOVER_AUTOMATIC)
{
/*
* Check that "promote_command" and "follow_command" are defined, otherwise repmgrd
* won't be able to perform any useful action in a failover situation.
*/
bool required_param_missing = false;
if (config_file_options.promote_command[0] == '\0')
{
log_error(_("\"promote_command\" must be defined in the configuration file"));
if (config_file_options.service_promote_command[0] != '\0')
{
/*
* "service_promote_command" is *not* a substitute for "promote_command";
* it is intended for use in those systems (e.g. Debian) where there's a service
* level promote command (e.g. pg_ctlcluster).
*
* "promote_command" should either execute "repmgr standby promote" directly, or
* a script which executes "repmgr standby promote". This is essential, as the
* repmgr metadata is updated by "repmgr standby promote".
*
* "service_promote_command", if set, will be executed by "repmgr standby promote",
* but never by repmgrd.
*
*/
log_hint(_("\"service_promote_command\" is set, but can only be executed by \"repmgr standby promote\""));
}
required_param_missing = true;
}
if (config_file_options.follow_command[0] == '\0')
{
log_error(_("\"follow_command\" must be defined in the configuration file"));
required_param_missing = true;
}
if (required_param_missing == true)
{
log_hint(_("add the missing configuration parameter(s) and start repmgrd again"));
terminate(ERR_BAD_CONFIG);
}
}
}
/*
* repmgrd running on the primary server
*/
void
monitor_streaming_primary(void)
{
instr_time log_status_interval_start;
instr_time child_nodes_check_interval_start;
t_child_node_info_list local_child_nodes = T_CHILD_NODE_INFO_LIST_INITIALIZER;
reset_node_voting_status();
repmgrd_set_upstream_node_id(local_conn, NO_UPSTREAM_NODE);
{
PQExpBufferData event_details;
initPQExpBuffer(&event_details);
appendPQExpBuffer(&event_details,
_("monitoring cluster primary \"%s\" (ID: %i)"),
local_node_info.node_name,
local_node_info.node_id);
/* Log startup event */
if (startup_event_logged == false)
{
create_event_notification(local_conn,
&config_file_options,
config_file_options.node_id,
"repmgrd_start",
true,
event_details.data);
startup_event_logged = true;
}
else
{
create_event_notification(local_conn,
&config_file_options,
config_file_options.node_id,
"repmgrd_reload",
true,
event_details.data);
}
log_notice("%s", event_details.data);
termPQExpBuffer(&event_details);
}
INSTR_TIME_SET_CURRENT(log_status_interval_start);
INSTR_TIME_SET_CURRENT(child_nodes_check_interval_start);
local_node_info.node_status = NODE_STATUS_UP;
/*
* get list of expected and attached nodes
*/
{
NodeInfoList db_child_node_records = T_NODE_INFO_LIST_INITIALIZER;
bool success = get_child_nodes(local_conn, config_file_options.node_id, &db_child_node_records);
if (!success)
{
log_error(_("unable to retrieve list of child nodes"));
}
else
{
NodeInfoListCell *cell;
for (cell = db_child_node_records.head; cell; cell = cell->next)
{
/*
* At startup, if a node for which a repmgr record exists, is not found
* in pg_stat_replication, we can't know whether it has become detached, or
* (e.g. during a provisioning operation) is a new node which has not yet
* attached. We set the status to "NODE_ATTACHED_UNKNOWN" to stop repmgrd
* emitting bogus "node has become detached" alerts.
*/
(void) append_child_node_record(&local_child_nodes,
cell->node_info->node_id,
cell->node_info->node_name,
cell->node_info->type,
cell->node_info->attached == NODE_ATTACHED ? NODE_ATTACHED : NODE_ATTACHED_UNKNOWN);
/*
* witness will not be "attached" in the normal way
*/
if (cell->node_info->type == WITNESS)
{
check_witness_attached(cell->node_info, true);
}
if (cell->node_info->attached == NODE_ATTACHED)
{
log_info(_("child node \"%s\" (ID: %i) is attached"),
cell->node_info->node_name,
cell->node_info->node_id);
}
else
{
log_info(_("child node \"%s\" (ID: %i) is not yet attached"),
cell->node_info->node_name,
cell->node_info->node_id);
}
}
}
}
while (true)
{
/*
* TODO: cache node list here, refresh at `node_list_refresh_interval`
* also return reason for inavailability so we can log it
*/
(void) connection_ping(local_conn);
check_connection(&local_node_info, &local_conn);
if (PQstatus(local_conn) != CONNECTION_OK)
{
/* local node is down, we were expecting it to be up */
if (local_node_info.node_status == NODE_STATUS_UP)
{
instr_time local_node_unreachable_start;
INSTR_TIME_SET_CURRENT(local_node_unreachable_start);
{
PQExpBufferData event_details;
initPQExpBuffer(&event_details);
appendPQExpBufferStr(&event_details,
_("unable to connect to local node"));
log_warning("%s", event_details.data);
/*
* as we're monitoring the primary, no point in trying to
* write the event to the database
*
* TODO: possibly add pre-action event here
*/
create_event_notification(NULL,
&config_file_options,
config_file_options.node_id,
"repmgrd_local_disconnect",
true,
event_details.data);
termPQExpBuffer(&event_details);
}
local_node_info.node_status = NODE_STATUS_UNKNOWN;
try_reconnect(&local_conn, &local_node_info);
if (local_node_info.node_status == NODE_STATUS_UP)
{
int local_node_unreachable_elapsed = calculate_elapsed(local_node_unreachable_start);
int stored_local_node_id = UNKNOWN_NODE_ID;
PQExpBufferData event_details;
initPQExpBuffer(&event_details);
appendPQExpBuffer(&event_details,
_("reconnected to local node after %i seconds"),
local_node_unreachable_elapsed);
log_notice("%s", event_details.data);
create_event_notification(local_conn,
&config_file_options,
config_file_options.node_id,
"repmgrd_local_reconnect",
true,
event_details.data);
termPQExpBuffer(&event_details);
/*
* If the local node was restarted, we'll need to reinitialise values
* stored in shared memory.
*/
stored_local_node_id = repmgrd_get_local_node_id(local_conn);
if (stored_local_node_id == UNKNOWN_NODE_ID)
{
repmgrd_set_local_node_id(local_conn, config_file_options.node_id);
repmgrd_set_pid(local_conn, getpid(), pid_file);
}
/*
* check that the local node is still primary, otherwise switch
* to standby monitoring
*/
if (check_primary_status(NO_DEGRADED_MONITORING_ELAPSED) == false)
return;
goto loop;
}
monitoring_state = MS_DEGRADED;
INSTR_TIME_SET_CURRENT(degraded_monitoring_start);
log_notice(_("unable to connect to local node, falling back to degraded monitoring"));
}
}
if (monitoring_state == MS_DEGRADED)
{
int degraded_monitoring_elapsed = calculate_elapsed(degraded_monitoring_start);
if (config_file_options.degraded_monitoring_timeout > 0
&& degraded_monitoring_elapsed > config_file_options.degraded_monitoring_timeout)
{
PQExpBufferData event_details;
initPQExpBuffer(&event_details);
appendPQExpBuffer(&event_details,
_("degraded monitoring timeout (%i seconds) exceeded, terminating"),
degraded_monitoring_elapsed);
log_notice("%s", event_details.data);
create_event_notification(NULL,
&config_file_options,
config_file_options.node_id,
"repmgrd_shutdown",
true,
event_details.data);
termPQExpBuffer(&event_details);
terminate(ERR_MONITORING_TIMEOUT);
}
log_debug("monitoring node in degraded state for %i seconds", degraded_monitoring_elapsed);
if (is_server_available(local_node_info.conninfo) == true)
{
close_connection(&local_conn);
local_conn = establish_db_connection(local_node_info.conninfo, false);
if (PQstatus(local_conn) != CONNECTION_OK)
{
log_warning(_("node appears to be up but no connection could be made"));
close_connection(&local_conn);
}
else
{
local_node_info.node_status = NODE_STATUS_UP;
if (check_primary_status(degraded_monitoring_elapsed) == false)
return;
goto loop;
}
}
/*
* possibly attempt to find another node from cached list check if
* there's a new primary - if so add hook for fencing? loop, if
* starts up check status, switch monitoring mode
*/
}
else
{
if (config_file_options.child_nodes_check_interval > 0)
{
int child_nodes_check_interval_elapsed = calculate_elapsed(child_nodes_check_interval_start);
if (child_nodes_check_interval_elapsed >= config_file_options.child_nodes_check_interval)
{
INSTR_TIME_SET_CURRENT(child_nodes_check_interval_start);
check_primary_child_nodes(&local_child_nodes);
}
}
}
loop:
/* check node is still primary, if not restart monitoring */
if (check_primary_status(NO_DEGRADED_MONITORING_ELAPSED) == false)
return;
/* emit "still alive" log message at regular intervals, if requested */
if (config_file_options.log_status_interval > 0)
{
int log_status_interval_elapsed = calculate_elapsed(log_status_interval_start);
if (log_status_interval_elapsed >= config_file_options.log_status_interval)
{
log_info(_("monitoring primary node \"%s\" (ID: %i) in %s state"),
local_node_info.node_name,
local_node_info.node_id,
print_monitoring_state(monitoring_state));
if (monitoring_state == MS_DEGRADED)
{
log_detail(_("waiting for the node to become available"));
}
INSTR_TIME_SET_CURRENT(log_status_interval_start);
}
}
if (got_SIGHUP)
{
handle_sighup(&local_conn, PRIMARY);
}
log_verbose(LOG_DEBUG, "sleeping %i seconds (parameter \"monitor_interval_secs\")",
config_file_options.monitor_interval_secs);
sleep(config_file_options.monitor_interval_secs);
}
}
/*
* If monitoring a primary, it's possible that after an outage of the local node
* (due to e.g. a switchover), the node has come back as a standby. We therefore
* need to verify its status and if everything looks OK, restart monitoring in
* standby mode.
*
* Returns "true" to indicate repmgrd should continue monitoring the node as
* a primary; "false" indicates repmgrd should start monitoring the node as
* a standby.
*/
bool
check_primary_status(int degraded_monitoring_elapsed)
{
PGconn *new_primary_conn;
RecordStatus record_status;
bool resume_monitoring = true;
RecoveryType recovery_type = get_recovery_type(local_conn);
if (recovery_type == RECTYPE_UNKNOWN)
{
log_warning(_("unable to determine node recovery status"));
/* "true" to indicate repmgrd should continue monitoring in degraded state */
return true;
}
/* node is still primary - resume monitoring */
if (recovery_type == RECTYPE_PRIMARY)
{
if (degraded_monitoring_elapsed != NO_DEGRADED_MONITORING_ELAPSED)
{
PQExpBufferData event_details;
monitoring_state = MS_NORMAL;
initPQExpBuffer(&event_details);
appendPQExpBuffer(&event_details,
_("reconnected to primary node after %i seconds, resuming monitoring"),
degraded_monitoring_elapsed);
create_event_notification(local_conn,
&config_file_options,
config_file_options.node_id,
"repmgrd_local_reconnect",
true,
event_details.data);
log_notice("%s", event_details.data);
termPQExpBuffer(&event_details);
}
return true;
}
/* the node is now a standby */
{
PQExpBufferData event_details;
initPQExpBuffer(&event_details);
if (degraded_monitoring_elapsed != NO_DEGRADED_MONITORING_ELAPSED)
{
appendPQExpBuffer(&event_details,
_("reconnected to node after %i seconds, node is now a standby, switching to standby monitoring"),
degraded_monitoring_elapsed);
}
else
{
appendPQExpBufferStr(&event_details,
_("node is now a standby, switching to standby monitoring"));
}
log_notice("%s", event_details.data);
termPQExpBuffer(&event_details);
}
primary_node_id = UNKNOWN_NODE_ID;
new_primary_conn = get_primary_connection_quiet(local_conn, &primary_node_id, NULL);
if (PQstatus(new_primary_conn) != CONNECTION_OK)
{
if (primary_node_id == UNKNOWN_NODE_ID)
{
log_warning(_("unable to determine a new primary node"));
}
else
{
log_warning(_("unable to connect to new primary node %i"), primary_node_id);
log_detail("\n%s", PQerrorMessage(new_primary_conn));
}
close_connection(&new_primary_conn);
/* "true" to indicate repmgrd should continue monitoring in degraded state */
return true;
}
log_debug("primary node ID is now %i", primary_node_id);
record_status = get_node_record(new_primary_conn, config_file_options.node_id, &local_node_info);
/*
* If, for whatever reason, the new primary has no record of this node,
* we won't be able to perform proper monitoring. In that case
* terminate and let the user sort out the situation.
*/
if (record_status == RECORD_NOT_FOUND)
{
PQExpBufferData event_details;
initPQExpBuffer(&event_details);
appendPQExpBuffer(&event_details,
_("no metadata record found for this node on current primary %i"),
primary_node_id);
log_error("%s", event_details.data);
log_hint(_("check that 'repmgr (primary|standby) register' was executed for this node"));
close_connection(&new_primary_conn);
create_event_notification(NULL,
&config_file_options,
config_file_options.node_id,
"repmgrd_shutdown",
false,
event_details.data);
termPQExpBuffer(&event_details);
terminate(ERR_BAD_CONFIG);
}
log_debug("node %i is registered with type = %s",
config_file_options.node_id,
get_node_type_string(local_node_info.type));
/*
* node has recovered but metadata not updated - we can do that ourselves,
*/
if (local_node_info.type == PRIMARY)
{
log_notice(_("node \"%s\" (ID: %i) still registered as primary, setting to standby"),
config_file_options.node_name,
config_file_options.node_id);
if (update_node_record_set_active_standby(new_primary_conn, config_file_options.node_id) == false)
{
resume_monitoring = false;
}
else
{
/* refresh our copy of the node record from the primary */
record_status = get_node_record(new_primary_conn, config_file_options.node_id, &local_node_info);
/* this is unlikely to happen */
if (record_status != RECORD_FOUND)
{
log_warning(_("unable to retrieve local node record from primary node %i"), primary_node_id);
resume_monitoring = false;
}
}
}
if (resume_monitoring == true)
{
PQExpBufferData event_details;
initPQExpBuffer(&event_details);
if (degraded_monitoring_elapsed != NO_DEGRADED_MONITORING_ELAPSED)
{
monitoring_state = MS_NORMAL;
log_notice(_("former primary has been restored as standby after %i seconds, updating node record and resuming monitoring"),
degraded_monitoring_elapsed);
appendPQExpBuffer(&event_details,
_("node restored as standby after %i seconds, monitoring connection to upstream node %i"),
degraded_monitoring_elapsed,
local_node_info.upstream_node_id);
}
else
{
if (local_node_info.upstream_node_id == UNKNOWN_NODE_ID)
{
/*
* If upstream_node_id is not set, it's possible that following a switchover
* of some kind (possibly forced in some way), the updated node record has
* not yet propagated to the local node. In this case however we can safely
* assume we're monitoring the primary.
*/
appendPQExpBuffer(&event_details,
_("node has become a standby, monitoring connection to primary node %i"),
primary_node_id);
}
else
{
appendPQExpBuffer(&event_details,
_("node has become a standby, monitoring connection to upstream node %i"),
local_node_info.upstream_node_id);
}
}
create_event_notification(new_primary_conn,
&config_file_options,
config_file_options.node_id,
"repmgrd_standby_reconnect",
true,
event_details.data);
termPQExpBuffer(&event_details);
close_connection(&new_primary_conn);
/* restart monitoring as standby */
return false;
}
/* continue monitoring as before */
return true;
}
static void
check_primary_child_nodes(t_child_node_info_list *local_child_nodes)
{
NodeInfoList db_child_node_records = T_NODE_INFO_LIST_INITIALIZER;
NodeInfoListCell *cell;
/* lists for newly attached and missing nodes */
t_child_node_info_list disconnected_child_nodes = T_CHILD_NODE_INFO_LIST_INITIALIZER;
t_child_node_info_list reconnected_child_nodes = T_CHILD_NODE_INFO_LIST_INITIALIZER;
t_child_node_info_list new_child_nodes = T_CHILD_NODE_INFO_LIST_INITIALIZER;
bool success = get_child_nodes(local_conn, config_file_options.node_id, &db_child_node_records);
if (!success)
{
/* unlikely this will happen, but if it does, we'll try again next time round */
log_error(_("unable to retrieve list of child nodes"));
return;
}
if (db_child_node_records.node_count == 0)
{
/* no registered child nodes - nothing to do */
return;
}
/*
* compare DB records with our internal list;
* this will tell us about:
* - previously known nodes and their current status
* - newly registered nodes we didn't know about
*
* We'll need to compare the opposite way to check for nodes
* which are in the internal list, but which have now vanished
*/
for (cell = db_child_node_records.head; cell; cell = cell->next)
{
t_child_node_info *local_child_node_rec;
bool local_child_node_rec_found = false;
/*
* witness will not be "attached" in the normal way
*/
if (cell->node_info->type == WITNESS)
{
check_witness_attached(cell->node_info, false);
}
log_debug("child node: %i; attached: %s",
cell->node_info->node_id,
cell->node_info->attached == NODE_ATTACHED ? "yes" : "no");
for (local_child_node_rec = local_child_nodes->head; local_child_node_rec; local_child_node_rec = local_child_node_rec->next)
{
if (local_child_node_rec->node_id == cell->node_info->node_id)
{
local_child_node_rec_found = true;
break;
}
}
if (local_child_node_rec_found == true)
{
/* our node record shows node attached, DB record indicates detached */
if (local_child_node_rec->attached == NODE_ATTACHED && cell->node_info->attached == NODE_DETACHED)
{
t_child_node_info *detached_child_node;
local_child_node_rec->attached = NODE_DETACHED;
INSTR_TIME_SET_CURRENT(local_child_node_rec->detached_time);
detached_child_node = append_child_node_record(&disconnected_child_nodes,
local_child_node_rec->node_id,
local_child_node_rec->node_name,
local_child_node_rec->type,
NODE_DETACHED);
detached_child_node->detached_time = local_child_node_rec->detached_time;
}
/* our node record shows node detached, DB record indicates attached */
else if (local_child_node_rec->attached == NODE_DETACHED && cell->node_info->attached == NODE_ATTACHED)
{
t_child_node_info *attached_child_node;
local_child_node_rec->attached = NODE_ATTACHED;
attached_child_node = append_child_node_record(&reconnected_child_nodes,
local_child_node_rec->node_id,
local_child_node_rec->node_name,
local_child_node_rec->type,
NODE_ATTACHED);
attached_child_node->detached_time = local_child_node_rec->detached_time;
INSTR_TIME_SET_ZERO(local_child_node_rec->detached_time);
}
else if (local_child_node_rec->attached == NODE_ATTACHED_UNKNOWN && cell->node_info->attached == NODE_ATTACHED)
{
local_child_node_rec->attached = NODE_ATTACHED;
append_child_node_record(&new_child_nodes,
local_child_node_rec->node_id,
local_child_node_rec->node_name,
local_child_node_rec->type,
NODE_ATTACHED);
}
}
else
{
/* node we didn't know about before */
NodeAttached attached = cell->node_info->attached;