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/*
* repmgrd.c - Replication manager daemon
* Copyright (C) 2ndQuadrant, 2010-2012
*
* This module connects to the nodes of a replication cluster and monitors
* how far are they from master
*
* 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 <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "repmgr.h"
#include "config.h"
#include "log.h"
#include "strutil.h"
#include "version.h"
/* PostgreSQL's headers needed to export some functionality */
#include "access/xlogdefs.h"
#include "libpq/pqsignal.h"
/*
* we do not export InvalidXLogRecPtr so we need to define it
* but since 9.3 it will be defined in xlogdefs.h which we include
* so better to ask if it's defined to be future proof
*/
#ifndef InvalidXLogRecPtr
const XLogRecPtr InvalidXLogRecPtr = {0, 0};
#endif
/*
* Struct to keep info about the nodes, used in the voting process in
* do_failover()
*/
typedef struct nodeInfo
{
int nodeId;
XLogRecPtr xlog_location;
bool is_ready;
bool is_witness;
} nodeInfo;
char myClusterName[MAXLEN];
/* Local info */
t_configuration_options local_options;
int myLocalMode = STANDBY_MODE;
PGconn *myLocalConn = NULL;
/* Primary info */
t_configuration_options primary_options;
PGconn *primaryConn = NULL;
char sqlquery[QUERY_STR_LEN];
const char *progname;
char *config_file = DEFAULT_CONFIG_FILE;
bool verbose = false;
bool monitoring_history = false;
char repmgr_schema[MAXLEN];
/*
* should initialize with {0} to be ANSI complaint ? but this raises
* error with gcc -Wall
*/
t_configuration_options config = {};
static void help(const char* progname);
static void usage(void);
static void checkClusterConfiguration(PGconn *conn, PGconn *primary);
static void checkNodeConfiguration(char *conninfo);
static void StandbyMonitor(void);
static void WitnessMonitor(void);
static bool CheckPrimaryConnection(void);
static void update_shared_memory(char *last_wal_standby_applied);
static void update_registration(void);
static void do_failover(void);
static unsigned long long int walLocationToBytes(char *wal_location);
/*
* Flag to mark SIGHUP. Whenever the main loop comes around it
* will reread the configuration file.
*/
static volatile sig_atomic_t got_SIGHUP = false;
static void handle_sighup(SIGNAL_ARGS);
static void handle_sigint(SIGNAL_ARGS);
static void setup_event_handlers(void);
#define CloseConnections() \
if (PQisBusy(primaryConn) == 1) \
CancelQuery(primaryConn, local_options.master_response_timeout); \
if (myLocalConn != NULL) \
PQfinish(myLocalConn); \
if (primaryConn != NULL && primaryConn != myLocalConn) \
PQfinish(primaryConn);
int
main(int argc, char **argv)
{
static struct option long_options[] =
{
{"config", required_argument, NULL, 'f'},
{"verbose", no_argument, NULL, 'v'},
{"monitoring-history", no_argument, NULL, 'm'},
{NULL, 0, NULL, 0}
};
int optindex;
int c;
char standby_version[MAXVERSIONSTR];
progname = get_progname(argv[0]);
if (argc > 1)
{
if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
{
help(progname);
exit(SUCCESS);
}
if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
{
printf("%s %s (PostgreSQL %s)\n", progname, REPMGR_VERSION, PG_VERSION);
exit(SUCCESS);
}
}
while ((c = getopt_long(argc, argv, "f:v:m", long_options, &optindex)) != -1)
{
switch (c)
{
case 'f':
config_file = optarg;
break;
case 'v':
verbose = true;
break;
case 'm':
monitoring_history = true;
break;
default:
usage();
exit(ERR_BAD_CONFIG);
}
}
setup_event_handlers();
/*
* Read the configuration file: repmgr.conf
*/
parse_config(config_file, &local_options);
if (local_options.node == -1)
{
log_err(_("Node information is missing. "
"Check the configuration file, or provide one if you have not done so.\n"));
exit(ERR_BAD_CONFIG);
}
logger_init(progname, local_options.loglevel, local_options.logfacility);
if (verbose)
logger_min_verbose(LOG_INFO);
snprintf(repmgr_schema, MAXLEN, "%s%s", DEFAULT_REPMGR_SCHEMA_PREFIX, local_options.cluster_name);
log_info(_("%s Connecting to database '%s'\n"), progname, local_options.conninfo);
myLocalConn = establishDBConnection(local_options.conninfo, true);
/* should be v9 or better */
log_info(_("%s Connected to database, checking its state\n"), progname);
pg_version(myLocalConn, standby_version);
if (strcmp(standby_version, "") == 0)
{
log_err(_("%s needs standby to be PostgreSQL 9.0 or better\n"), progname);
PQfinish(myLocalConn);
exit(ERR_BAD_CONFIG);
}
/*
* Set my server mode, establish a connection to primary
* and start monitor
*/
if (is_witness(myLocalConn, repmgr_schema, local_options.cluster_name, local_options.node))
myLocalMode = WITNESS_MODE;
else if (is_standby(myLocalConn))
myLocalMode = STANDBY_MODE;
else /* is the master */
myLocalMode = PRIMARY_MODE;
switch (myLocalMode)
{
case PRIMARY_MODE:
primary_options.node = local_options.node;
strncpy(primary_options.conninfo, local_options.conninfo, MAXLEN);
primaryConn = myLocalConn;
checkClusterConfiguration(myLocalConn, primaryConn);
checkNodeConfiguration(local_options.conninfo);
if (reload_configuration(config_file, &local_options))
{
PQfinish(myLocalConn);
myLocalConn = establishDBConnection(local_options.conninfo, true);
primaryConn = myLocalConn;
update_registration();
}
log_info(_("%s Starting continuous primary connection check\n"), progname);
/* Check that primary is still alive, and standbies are sending info */
/*
* Every SLEEP_MONITOR seconds, do master checks
* XXX
* Check that standbies are sending info
*/
for (;;)
{
if (CheckPrimaryConnection())
{
/*
CheckActiveStandbiesConnections();
CheckInactiveStandbies();
*/
sleep(SLEEP_MONITOR);
}
else
{
/* XXX
* May we do something more verbose ?
*/
exit (1);
}
if (got_SIGHUP)
{
/* if we can reload, then could need to change myLocalConn */
if (reload_configuration(config_file, &local_options))
{
PQfinish(myLocalConn);
myLocalConn = establishDBConnection(local_options.conninfo, true);
primaryConn = myLocalConn;
update_registration();
}
got_SIGHUP = false;
}
}
break;
case WITNESS_MODE:
case STANDBY_MODE:
/* I need the id of the primary as well as a connection to it */
log_info(_("%s Connecting to primary for cluster '%s'\n"),
progname, local_options.cluster_name);
primaryConn = getMasterConnection(myLocalConn, repmgr_schema,
local_options.cluster_name,
&primary_options.node, NULL);
if (primaryConn == NULL)
{
CloseConnections();
exit(ERR_BAD_CONFIG);
}
checkClusterConfiguration(myLocalConn, primaryConn);
checkNodeConfiguration(local_options.conninfo);
if (reload_configuration(config_file, &local_options))
{
PQfinish(myLocalConn);
myLocalConn = establishDBConnection(local_options.conninfo, true);
update_registration();
}
/*
* Every SLEEP_MONITOR seconds, do checks
*/
if (myLocalMode == WITNESS_MODE)
{
log_info(_("%s Starting continuous witness node monitoring\n"), progname);
}
else if (myLocalMode == STANDBY_MODE)
{
log_info(_("%s Starting continuous standby node monitoring\n"), progname);
}
for (;;)
{
if (myLocalMode == WITNESS_MODE)
WitnessMonitor();
else if (myLocalMode == STANDBY_MODE)
StandbyMonitor();
sleep(SLEEP_MONITOR);
if (got_SIGHUP)
{
/* if we can reload, then could need to change myLocalConn */
if (reload_configuration(config_file, &local_options))
{
PQfinish(myLocalConn);
myLocalConn = establishDBConnection(local_options.conninfo, true);
update_registration();
}
got_SIGHUP = false;
}
}
break;
default:
log_err(_("%s: Unrecognized mode for node %d\n"), progname, local_options.node);
}
/* Prevent a double-free */
if (primaryConn == myLocalConn)
myLocalConn = NULL;
/* close the connection to the database and cleanup */
CloseConnections();
/* Shuts down logging system */
logger_shutdown();
return 0;
}
/*
*
*/
static void
WitnessMonitor(void)
{
char monitor_witness_timestamp[MAXLEN];
PGresult *res;
/*
* Check if the master is still available, if after 5 minutes of retries
* we cannot reconnect, return false.
*/
CheckPrimaryConnection(); // this take up to local_options.reconnect_attempts * local_options.reconnect_intvl seconds
if (PQstatus(primaryConn) != CONNECTION_OK)
{
/*
* If we can't reconnect, just exit...
* XXX we need to make witness connect to the new master
*/
PQfinish(myLocalConn);
exit(0);
}
/* Fast path for the case where no history is requested */
if (!monitoring_history)
return;
/*
* Cancel any query that is still being executed,
* so i can insert the current record
*/
CancelQuery(primaryConn, local_options.master_response_timeout);
if (wait_connection_availability(primaryConn, local_options.master_response_timeout) != 1)
return;
/* Get local xlog info */
sqlquery_snprintf(sqlquery, "SELECT CURRENT_TIMESTAMP ");
res = PQexec(myLocalConn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
log_err(_("PQexec failed: %s\n"), PQerrorMessage(myLocalConn));
PQclear(res);
/* if there is any error just let it be and retry in next loop */
return;
}
strcpy(monitor_witness_timestamp, PQgetvalue(res, 0, 0));
PQclear(res);
/*
* Build the SQL to execute on primary
*/
sqlquery_snprintf(sqlquery,
"INSERT INTO %s.repl_monitor "
"VALUES(%d, %d, '%s'::timestamp with time zone, "
" pg_current_xlog_location(), null, "
" 0, 0)",
repmgr_schema, primary_options.node, local_options.node, monitor_witness_timestamp);
/*
* Execute the query asynchronously, but don't check for a result. We
* will check the result next time we pause for a monitor step.
*/
log_debug("WitnessMonitor: %s\n", sqlquery);
if (PQsendQuery(primaryConn, sqlquery) == 0)
log_warning(_("Query could not be sent to primary. %s\n"),
PQerrorMessage(primaryConn));
}
/*
* Insert monitor info, this is basically the time and xlog replayed,
* applied on standby and current xlog location in primary.
* Also do the math to see how far are we in bytes for being uptodate
*/
static void
StandbyMonitor(void)
{
PGresult *res;
char monitor_standby_timestamp[MAXLEN];
char last_wal_primary_location[MAXLEN];
char last_wal_standby_received[MAXLEN];
char last_wal_standby_applied[MAXLEN];
unsigned long long int lsn_primary;
unsigned long long int lsn_standby_received;
unsigned long long int lsn_standby_applied;
int connection_retries;
/*
* Check if the master is still available, if after 5 minutes of retries
* we cannot reconnect, try to get a new master.
*/
CheckPrimaryConnection(); // this take up to local_options.reconnect_attempts * local_options.reconnect_intvl seconds
if (PQstatus(primaryConn) != CONNECTION_OK)
{
if (local_options.failover == MANUAL_FAILOVER)
{
log_err(_("We couldn't reconnect to master. Now checking if another node has been promoted.\n"));
for (connection_retries = 0; connection_retries < 6; connection_retries++)
{
primaryConn = getMasterConnection(myLocalConn, repmgr_schema,
local_options.cluster_name, &primary_options.node, NULL);
if (PQstatus(primaryConn) == CONNECTION_OK)
{
/* Connected, we can continue the process so break the loop */
log_err(_("Connected to node %d, continue monitoring.\n"), primary_options.node);
break;
}
else
{
log_err(_("We haven't found a new master, waiting before retry...\n"));
/* wait 5 minutes before retries, after 6 failures (30 minutes) we stop trying */
sleep(300);
}
}
if (PQstatus(primaryConn) != CONNECTION_OK)
{
log_err(_("We couldn't reconnect for long enough, exiting...\n"));
exit(ERR_DB_CON);
}
}
else if (local_options.failover == AUTOMATIC_FAILOVER)
{
/*
* When we returns from this function we will have a new primary and
* a new primaryConn
*/
do_failover();
}
}
/* Check if we still are a standby, we could have been promoted */
if (!is_standby(myLocalConn))
{
log_err(_("It seems like we have been promoted, so exit from monitoring...\n"));
CloseConnections();
exit(ERR_PROMOTED);
}
/* Fast path for the case where no history is requested */
if (!monitoring_history)
return;
/*
* Cancel any query that is still being executed,
* so i can insert the current record
*/
CancelQuery(primaryConn, local_options.master_response_timeout);
if (wait_connection_availability(primaryConn, local_options.master_response_timeout) != 1)
return;
/* Get local xlog info */
sqlquery_snprintf(
sqlquery,
"SELECT CURRENT_TIMESTAMP, pg_last_xlog_receive_location(), "
"pg_last_xlog_replay_location()");
res = PQexec(myLocalConn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
log_err(_("PQexec failed: %s\n"), PQerrorMessage(myLocalConn));
PQclear(res);
/* if there is any error just let it be and retry in next loop */
return;
}
strncpy(monitor_standby_timestamp, PQgetvalue(res, 0, 0), MAXLEN);
strncpy(last_wal_standby_received , PQgetvalue(res, 0, 1), MAXLEN);
strncpy(last_wal_standby_applied , PQgetvalue(res, 0, 2), MAXLEN);
PQclear(res);
/* Get primary xlog info */
sqlquery_snprintf(sqlquery, "SELECT pg_current_xlog_location() ");
res = PQexec(primaryConn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
log_err(_("PQexec failed: %s\n"), PQerrorMessage(primaryConn));
PQclear(res);
return;
}
strncpy(last_wal_primary_location, PQgetvalue(res, 0, 0), MAXLEN);
PQclear(res);
/* Calculate the lag */
lsn_primary = walLocationToBytes(last_wal_primary_location);
lsn_standby_received = walLocationToBytes(last_wal_standby_received);
lsn_standby_applied = walLocationToBytes(last_wal_standby_applied);
/*
* Build the SQL to execute on primary
*/
sqlquery_snprintf(sqlquery,
"INSERT INTO %s.repl_monitor "
"VALUES(%d, %d, '%s'::timestamp with time zone, "
" '%s', '%s', "
" %lld, %lld)", repmgr_schema,
primary_options.node, local_options.node, monitor_standby_timestamp,
last_wal_primary_location,
last_wal_standby_received,
(lsn_primary - lsn_standby_received),
(lsn_standby_received - lsn_standby_applied));
/*
* Execute the query asynchronously, but don't check for a result. We
* will check the result next time we pause for a monitor step.
*/
log_debug("StandbyMonitor: %s\n", sqlquery);
if (PQsendQuery(primaryConn, sqlquery) == 0)
log_warning(_("Query could not be sent to primary. %s\n"),
PQerrorMessage(primaryConn));
}
static void
do_failover(void)
{
PGresult *res1;
PGresult *res2;
char sqlquery[8192];
int total_nodes = 0;
int visible_nodes = 0;
bool find_best = false;
bool witness = false;
int i;
int r;
int node;
char nodeConninfo[MAXLEN];
unsigned int uxlogid;
unsigned int uxrecoff;
char last_wal_standby_applied[MAXLEN];
PGconn *nodeConn = NULL;
/*
* will get info about until 50 nodes,
* which seems to be large enough for most scenarios
*/
nodeInfo nodes[50];
/* initialize to keep compiler quiet */
nodeInfo best_candidate = {-1, InvalidXLogRecPtr, false, false};
/* first we get info about this node, and update shared memory */
sprintf(sqlquery, "SELECT pg_last_xlog_receive_location()");
res1 = PQexec(myLocalConn, sqlquery);
if (PQresultStatus(res1) != PGRES_TUPLES_OK)
{
log_err(_("PQexec failed: %s.\nReport an invalid value to not be considered as new primary and exit.\n"), PQerrorMessage(myLocalConn));
PQclear(res1);
sprintf(last_wal_standby_applied, "'%X/%X'", 0, 0);
update_shared_memory(last_wal_standby_applied);
exit(ERR_DB_QUERY);
}
/* write last location in shared memory */
update_shared_memory(PQgetvalue(res1, 0, 0));
/*
* we sleep the monitor time + one second
* we bet it should be enough for other repmgrd to update their own data
*/
sleep(SLEEP_MONITOR + 1);
/* get a list of standby nodes, including myself */
sprintf(sqlquery, "SELECT id, conninfo, witness "
" FROM %s.repl_nodes "
" WHERE id <> %d "
" AND cluster = '%s' "
" ORDER BY priority ",
repmgr_schema, primary_options.node, local_options.cluster_name);
res1 = PQexec(myLocalConn, sqlquery);
if (PQresultStatus(res1) != PGRES_TUPLES_OK)
{
log_err(_("Can't get nodes info: %s\n"), PQerrorMessage(myLocalConn));
PQclear(res1);
PQfinish(myLocalConn);
exit(ERR_DB_QUERY);
}
log_debug(_("%s: there are %d nodes registered"), progname, PQntuples(res1));
/* ask for the locations */
for (i = 0; i < PQntuples(res1); i++)
{
node = atoi(PQgetvalue(res1, i, 0));
/* Initialize on false so if we can't reach this node we know that later */
nodes[i].is_ready = false;
strncpy(nodeConninfo, PQgetvalue(res1, i, 1), MAXLEN);
witness = (strcmp(PQgetvalue(res1, i, 2), "t") == 0) ? true : false;
log_debug(_("%s: node=%d conninfo=\"%s\" witness=%s"), progname, node, nodeConninfo, (witness) ? "true" : "false");
nodeConn = establishDBConnection(nodeConninfo, false);
/* if we can't see the node just skip it */
if (PQstatus(nodeConn) != CONNECTION_OK)
continue;
/* the witness will always show 0/0 so avoid a useless query */
if (!witness)
{
sqlquery_snprintf(sqlquery, "SELECT %s.repmgr_get_last_standby_location()", repmgr_schema);
res2 = PQexec(nodeConn, sqlquery);
if (PQresultStatus(res2) != PGRES_TUPLES_OK)
{
log_info(_("Can't get node's last standby location: %s\n"), PQerrorMessage(nodeConn));
log_info(_("Connection details: %s\n"), nodeConninfo);
PQclear(res2);
PQfinish(nodeConn);
continue;
}
if (sscanf(PQgetvalue(res2, 0, 0), "%X/%X", &uxlogid, &uxrecoff) != 2)
log_info(_("could not parse transaction log location \"%s\"\n"), PQgetvalue(res2, 0, 0));
PQclear(res2);
}
else
{
uxlogid = 0;
uxrecoff = 0;
}
visible_nodes++;
nodes[i].nodeId = node;
nodes[i].xlog_location.xlogid = uxlogid;
nodes[i].xlog_location.xrecoff = uxrecoff;
nodes[i].is_ready = true;
nodes[i].is_witness = witness;
PQfinish(nodeConn);
}
PQclear(res1);
/* Close the connection to this server */
PQfinish(myLocalConn);
/*
* total nodes that are registered, include master which is a node but was
* not counted because it's not a standby
*/
total_nodes = i + 1;
/*
* am i on the group that should keep alive?
* if i see less than half of total_nodes then i should do nothing
*/
if (visible_nodes < (total_nodes / 2.0))
{
log_err(_("Can't reach most of the nodes.\n"
"Let the other standby servers decide which one will be the primary.\n"
"Manual action will be needed to readd this node to the cluster.\n"));
exit(ERR_FAILOVER_FAIL);
}
/*
* determine which one is the best candidate to promote to primary
*/
for (i = 0; i < total_nodes - 1; i++)
{
/* witness is never a good candidate */
if (nodes[i].is_witness)
continue;
if (!nodes[i].is_ready)
continue;
if (!find_best)
{
/* start with the first ready node, and then move on to the next one */
best_candidate.nodeId = nodes[i].nodeId;
best_candidate.xlog_location.xlogid = nodes[i].xlog_location.xlogid;
best_candidate.xlog_location.xrecoff = nodes[i].xlog_location.xrecoff;
best_candidate.is_ready = nodes[i].is_ready;
best_candidate.is_witness = nodes[i].is_witness;
find_best = true;
}
/* we use the macros provided by xlogdefs.h to compare XLogRecPtr */
/*
* Nodes are retrieved ordered by priority, so if the current
* best candidate is lower than the next node's wal location
* then assign next node as the new best candidate.
*/
if (XLByteLT(best_candidate.xlog_location, nodes[i].xlog_location))
{
best_candidate.nodeId = nodes[i].nodeId;
best_candidate.xlog_location.xlogid = nodes[i].xlog_location.xlogid;
best_candidate.xlog_location.xrecoff = nodes[i].xlog_location.xrecoff;
best_candidate.is_ready = nodes[i].is_ready;
best_candidate.is_witness = nodes[i].is_witness;
}
}
/* once we know who is the best candidate, promote it */
if (find_best && (best_candidate.nodeId == local_options.node))
{
if (best_candidate.is_witness)
{
log_err(_("%s: Node selected as new master is a witness. Can't be promoted.\n"), progname);
exit(ERR_FAILOVER_FAIL);
}
if (verbose)
log_info(_("%s: This node is the best candidate to be the new primary, promoting...\n"),
progname);
log_debug(_("promote command is: \"%s\"\n"), local_options.promote_command);
r = system(local_options.promote_command);
if (r != 0)
{
log_err(_("%s: promote command failed. You could check and try it manually.\n"), progname);
exit(ERR_BAD_CONFIG);
}
}
else if (find_best)
{
if (verbose)
log_info(_("%s: Node %d is the best candidate to be the new primary, we should follow it...\n"),
progname, best_candidate.nodeId);
log_debug(_("follow command is: \"%s\"\n"), local_options.follow_command);
/*
* New Primary need some time to be promoted.
* The follow command should take care of that.
*/
r = system(local_options.follow_command);
if (r != 0)
{
log_err(_("%s: follow command failed. You could check and try it manually.\n"), progname);
exit(ERR_BAD_CONFIG);
}
}
else
{
log_err(_("%s: Did not find candidates. You should check and try manually.\n"), progname);
exit(ERR_FAILOVER_FAIL);
}
/* and reconnect to the local database */
myLocalConn = establishDBConnection(local_options.conninfo, true);
}
static bool
CheckPrimaryConnection(void)
{
int connection_retries;
/*
* Check if the master is still available
* if after local_options.reconnect_attempts * local_options.reconnect_intvl seconds of retries
* we cannot reconnect
* return false
*/
for (connection_retries = 0; connection_retries < local_options.reconnect_attempts; connection_retries++)
{
if (!is_pgup(primaryConn, local_options.master_response_timeout))
{
log_warning(_("%s: Connection to master has been lost, trying to recover... %i seconds before failover decision\n"),
progname,
(local_options.reconnect_intvl * (local_options.reconnect_attempts - connection_retries)));
/* wait local_options.reconnect_intvl seconds between retries */
sleep(local_options.reconnect_intvl);
}
else
{
if ( connection_retries > 0)
{
log_info(_("%s: Connection to master has been restored.\n"), progname);
}
return true;
}
}
if (!is_pgup(primaryConn, local_options.master_response_timeout))
{
log_err(_("%s: We couldn't reconnect for long enough, exiting...\n"), progname);
/* XXX Anything else to do here? */
return false;
}
return true;
}
static void
checkClusterConfiguration(PGconn *conn, PGconn *primary)
{
PGresult *res;
log_info(_("%s Checking cluster configuration with schema '%s'\n"),
progname, repmgr_schema);
sqlquery_snprintf(sqlquery, "SELECT oid FROM pg_class "
" WHERE oid = '%s.repl_nodes'::regclass",
repmgr_schema);
res = PQexec(conn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
log_err(_("PQexec failed: %s\n"), PQerrorMessage(conn));
PQclear(res);
CloseConnections();
exit(ERR_DB_QUERY);
}
/*
* If there isn't any results then we have not configured a primary node
* yet in repmgr or the connection string is pointing to the wrong
* database.
*
* XXX if we are the primary, should we try to create the tables needed?
*/
if (PQntuples(res) == 0)
{
log_err(_("The replication cluster is not configured\n"));
PQclear(res);
CloseConnections();
exit(ERR_BAD_CONFIG);
}
PQclear(res);
}
static void
checkNodeConfiguration(char *conninfo)
{
PGresult *res;
/*
* Check if we have my node information in repl_nodes
*/
log_info(_("%s Checking node %d in cluster '%s'\n"),
progname, local_options.node, local_options.cluster_name);
sqlquery_snprintf(sqlquery, "SELECT * FROM %s.repl_nodes "
" WHERE id = %d AND cluster = '%s' ",
repmgr_schema, local_options.node,
local_options.cluster_name);
res = PQexec(myLocalConn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
log_err(_("PQexec failed: %s\n"), PQerrorMessage(myLocalConn));
PQclear(res);
CloseConnections();
exit(ERR_BAD_CONFIG);
}
/*
* If there isn't any results then we have not configured this node yet
* in repmgr, if that is the case we will insert the node to the cluster,
* except if it is a witness
*/
if (PQntuples(res) == 0)
{
PQclear(res);
if (myLocalMode == WITNESS_MODE)
{
log_err(_("The witness is not configured\n"));
CloseConnections();
exit(ERR_BAD_CONFIG);
}
/* Adding the node */
log_info(_("%s Adding node %d to cluster '%s'\n"),
progname, local_options.node, local_options.cluster_name);
sqlquery_snprintf(sqlquery, "INSERT INTO %s.repl_nodes "
"VALUES (%d, '%s', '%s', '%s', 0, 'f')",
repmgr_schema, local_options.node,
local_options.cluster_name,
local_options.node_name,
local_options.conninfo);
if (!PQexec(primaryConn, sqlquery))
{
log_err(_("Cannot insert node details, %s\n"),
PQerrorMessage(primaryConn));
CloseConnections();
exit(ERR_BAD_CONFIG);
}
}
else
{
PQclear(res);
}
}
static unsigned long long int
walLocationToBytes(char *wal_location)
{
unsigned int xlogid;
unsigned int xrecoff;
if (sscanf(wal_location, "%X/%X", &xlogid, &xrecoff) != 2)
{
log_err(_("wrong log location format: %s\n"), wal_location);
return 0;
}
return (( (long long) xlogid * 16 * 1024 * 1024 * 255) + xrecoff);
}
void usage(void)
{
log_err(_("%s: Replicator manager daemon \n"), progname);
log_err(_("Try \"%s --help\" for more information.\n"), progname);
}
void help(const char *progname)
{
printf(_("Usage: %s [OPTIONS]\n"), progname);
printf(_("Replicator manager daemon for PostgreSQL.\n"));
printf(_("\nOptions:\n"));
printf(_(" --help show this help, then exit\n"));
printf(_(" --version output version information, then exit\n"));
printf(_(" --verbose output verbose activity information\n"));
printf(_(" --monitoring-history track advance or lag of the replication in every standby in repl_monitor\n"));
printf(_(" -f, --config_file=PATH configuration file\n"));
printf(_("\n%s monitors a cluster of servers.\n"), progname);
}
#ifndef WIN32
static void
handle_sigint(SIGNAL_ARGS)
{
CloseConnections();
exit(1);
}
/* SIGHUP: set flag to re-read config file at next convenient time */
static void
handle_sighup(SIGNAL_ARGS)
{
got_SIGHUP = true;
}
static void
setup_event_handlers(void)
{
pqsignal(SIGHUP, handle_sighup);
pqsignal(SIGINT, handle_sigint);
}
#endif
static void
update_shared_memory(char *last_wal_standby_applied)
{
PGresult *res;
sprintf(sqlquery, "SELECT %s.repmgr_update_standby_location('%s')",
repmgr_schema, last_wal_standby_applied);
/* If an error happens, just inform about that and continue */
res = PQexec(myLocalConn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
log_warning(_("Cannot update this standby's shared memory: %s\n"), PQerrorMessage(myLocalConn));
/* XXX is this enough reason to terminate this repmgrd? */
}
PQclear(res);
}
static void
update_registration(void)
{
PGresult *res;
sqlquery_snprintf(sqlquery, "UPDATE %s.repl_nodes "
" SET conninfo = '%s', "
" priority = %d "
" WHERE id = %d",
repmgr_schema, local_options.conninfo, local_options.priority, local_options.node);
res = PQexec(primaryConn, sqlquery);
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
log_err(_("Cannot update registration: %s\n"), PQerrorMessage(primaryConn));
CloseConnections();
exit(ERR_DB_CON);
}
PQclear(res);
}