/*
* get a connection to master by reading repl_nodes, creating a connection
* to each node (one at a time) and finding if it is a master or a standby
*
* NB: If master_conninfo_out may be NULL. If it is non-null, it is assumed to
* point to allocated memory of MAXCONNINFO in length, and the master server
* connection string is placed there.
*/
PGconn *
getMasterConnection(PGconn *standby_conn, char *schema, char *cluster,
int *master_id, char *master_conninfo_out)
{
PGconn *master_conn = NULL;
PGresult *res1;
PGresult *res2;
char sqlquery[QUERY_STR_LEN];
char master_conninfo_stack[MAXCONNINFO];
char *master_conninfo = &*master_conninfo_stack;
char schema_quoted[MAXLEN];
int i;
/*
* If the caller wanted to get a copy of the connection info string, sub
* out the local stack pointer for the pointer passed by the caller.
*/
if (master_conninfo_out != NULL)
master_conninfo = master_conninfo_out;
/*
* XXX: This is copied in at least two other procedures
*
* Assemble the unquoted schema name
*/
{
char *identifier = PQescapeIdentifier(standby_conn, schema,
strlen(schema));
maxlen_snprintf(schema_quoted, "%s", identifier);
PQfreemem(identifier);
}
/* find all nodes belonging to this cluster */
log_info(_("finding node list for cluster '%s'\n"),
cluster);
sqlquery_snprintf(sqlquery, "SELECT id, conninfo FROM %s.repl_nodes "
" WHERE cluster = '%s' and not witness",
schema_quoted, cluster);
res1 = PQexec(standby_conn, sqlquery);
if (PQresultStatus(res1) != PGRES_TUPLES_OK)
{
log_err(_("Can't get nodes info: %s\n"),
PQerrorMessage(standby_conn));
PQclear(res1);
PQfinish(standby_conn);
exit(ERR_DB_QUERY);
}
for (i = 0; i < PQntuples(res1); i++)
{
/* initialize with the values of the current node being processed */
*master_id = atoi(PQgetvalue(res1, i, 0));
strncpy(master_conninfo, PQgetvalue(res1, i, 1), MAXCONNINFO);
log_info(_("checking role of cluster node '%s'\n"),
master_conninfo);
master_conn = establishDBConnection(master_conninfo, false);
if (PQstatus(master_conn) != CONNECTION_OK)
continue;
/*
* Can't use the is_standby() function here because on error that
* function closes the connection passed and exits. This still
* needs to close master_conn first.
*/
res2 = PQexec(master_conn, "SELECT pg_is_in_recovery()");
if (PQresultStatus(res2) != PGRES_TUPLES_OK)
{
log_err(_("Can't get recovery state from this node: %s\n"),
PQerrorMessage(master_conn));
PQclear(res2);
PQfinish(master_conn);
continue;
}
/* if false, this is the master */
if (strcmp(PQgetvalue(res2, 0, 0), "f") == 0)
{
PQclear(res2);
PQclear(res1);
return master_conn;
}
else
{
/* if it is a standby clear info */
PQclear(res2);
PQfinish(master_conn);
*master_id = -1;
}
}
/* If we finish this loop without finding a master then
* we doesn't have the info or the master has failed (or we
* reached max_connections or superuser_reserved_connections,
* anything else I'm missing?).
*
* Probably we will need to check the error to know if we need
* to start failover procedure or just fix some situation on the
* standby.
*/
PQclear(res1);
return NULL;
}
static void
do_standby_promote(void)
{
PGconn *conn;
PGresult *res;
char sqlquery[QUERY_STR_LEN];
char script[QUERY_STR_LEN];
char myClusterName[MAXLEN];
int myLocalId = -1;
char conninfo[MAXLEN];
PGconn *old_master_conn;
int old_master_id;
int r;
char data_dir[MAXLEN];
char recovery_file_path[MAXLEN];
char recovery_done_path[MAXLEN];
char standby_version[MAXVERSIONSTR];
/*
* Read the configuration file: repmgr.conf
*/
parse_config(config_file, myClusterName, &myLocalId, conninfo);
if (myLocalId == -1)
{
fprintf(stderr, "Node information is missing. "
"Check the configuration file.\n");
exit(1);
}
/* We need to connect to check configuration */
conn = establishDBConnection(conninfo, true);
/* we need v9 or better */
pg_version(conn, standby_version);
if (strcmp(standby_version, "") == 0)
{
PQfinish(conn);
fprintf(stderr, _("%s needs standby to be PostgreSQL 9.0 or better\n"), progname);
return;
}
/* Check we are in a standby node */
if (!is_standby(conn))
{
fprintf(stderr, "repmgr: The command should be executed in a standby node\n");
return;
}
/* we also need to check if there isn't any master already */
old_master_conn = getMasterConnection(conn, myLocalId, myClusterName, &old_master_id);
if (old_master_conn != NULL)
{
PQfinish(old_master_conn);
fprintf(stderr, "There is a master already in this cluster");
return;
}
if (verbose)
printf(_("\n%s: Promoting standby...\n"), progname);
/* Get the data directory full path and the last subdirectory */
sprintf(sqlquery, "SELECT setting "
" FROM pg_settings WHERE name = 'data_directory'");
res = PQexec(conn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "Can't get info about data directory: %s\n", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return;
}
strcpy(data_dir, PQgetvalue(res, 0, 0));
PQclear(res);
PQfinish(conn);
sprintf(recovery_file_path, "%s/%s", data_dir, RECOVERY_FILE);
sprintf(recovery_done_path, "%s/%s", data_dir, RECOVERY_DONE_FILE);
rename(recovery_file_path, recovery_done_path);
/* We assume the pg_ctl script is in the PATH */
sprintf(script, "pg_ctl -D %s -m fast restart", data_dir);
r = system(script);
if (r != 0)
{
fprintf(stderr, "Can't restart service\n");
return;
}
/* reconnect to check we got promoted */
/*
* XXX i'm removing this because it gives an annoying message saying couldn't connect
* but is just the server starting up
* conn = establishDBConnection(conninfo, true);
* if (is_standby(conn))
* fprintf(stderr, "\n%s: STANDBY PROMOTE failed, this is still a standby node.\n", progname);
* else
* fprintf(stderr, "\n%s: you should REINDEX any hash indexes you have.\n", progname);
* PQfinish(conn);
*/
return;
}
int
main(int argc, char **argv)
{
static struct option long_options[] =
{
{"config", required_argument, NULL, 'f'},
{"verbose", no_argument, NULL, 'v'},
{"no-history", no_argument, NULL, 'H'},
{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 (PostgreSQL) " PG_VERSION "\n", progname);
exit(SUCCESS);
}
}
while ((c = getopt_long(argc, argv, "f:vH", long_options, &optindex)) != -1)
{
switch (c)
{
case 'f':
config_file = optarg;
break;
case 'v':
verbose = true;
break;
case 'H': /* no-history */
only_one_entry_desired = true;
break;
default:
usage();
exit(ERR_BAD_CONFIG);
}
}
setup_cancel_handler();
/*
* 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)
{
PQfinish(myLocalConn);
log_err(_("%s needs standby to be PostgreSQL 9.0 or better\n"), progname);
exit(ERR_BAD_CONFIG);
}
/*
* Set my server mode, establish a connection to primary
* and start monitor
*/
myLocalMode = is_standby(myLocalConn) ? STANDBY_MODE : PRIMARY_MODE;
if (myLocalMode == PRIMARY_MODE)
{
primary_options.node = local_options.node;
strncpy(primary_options.conninfo, local_options.conninfo, MAXLEN);
primaryConn = myLocalConn;
}
else
{
/* 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, local_options.node,
local_options.cluster_name,
&primary_options.node,NULL);
if (primaryConn == NULL)
{
CloseConnections();
exit(ERR_BAD_CONFIG);
}
}
checkClusterConfiguration(myLocalConn,primaryConn);
checkNodeConfiguration(local_options.conninfo);
if (myLocalMode == STANDBY_MODE)
{
log_info(_("%s Starting continuous standby node monitoring\n"), progname);
MonitorCheck();
}
else
{
log_info(_("%s This is a primary node, program not needed here; exiting'\n"), progname);
}
/* 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
do_master_register(void)
{
PGconn *conn;
PGresult *res;
char sqlquery[QUERY_STR_LEN];
char myClusterName[MAXLEN];
int myLocalId = -1;
char conninfo[MAXLEN];
bool schema_exists = false;
char master_version[MAXVERSIONSTR];
/*
* Read the configuration file: repmgr.conf
*/
parse_config(config_file, myClusterName, &myLocalId, conninfo);
if (myLocalId == -1)
{
fprintf(stderr, "Node information is missing. "
"Check the configuration file.\n");
exit(1);
}
conn = establishDBConnection(conninfo, true);
/* master should be v9 or better */
pg_version(conn, master_version);
if (strcmp(master_version, "") == 0)
{
PQfinish(conn);
fprintf(stderr, _("%s needs master to be PostgreSQL 9.0 or better\n"), progname);
return;
}
/* Check we are a master */
if (is_standby(conn))
{
fprintf(stderr, "repmgr: This node should be a master\n");
PQfinish(conn);
return;
}
/* Check if there is a schema for this cluster */
sprintf(sqlquery, "SELECT 1 FROM pg_namespace WHERE nspname = 'repmgr_%s'", myClusterName);
res = PQexec(conn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "Can't get info about schemas: %s\n", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return;
}
if (PQntuples(res) > 0) /* schema exists */
{
if (!force) /* and we are not forcing so error */
{
fprintf(stderr, "Schema repmgr_%s already exists.", myClusterName);
PQclear(res);
PQfinish(conn);
return;
}
schema_exists = true;
}
PQclear(res);
if (!schema_exists)
{
/* ok, create the schema */
sprintf(sqlquery, "CREATE SCHEMA repmgr_%s", myClusterName);
if (!PQexec(conn, sqlquery))
{
fprintf(stderr, "Cannot create the schema repmgr_%s: %s\n",
myClusterName, PQerrorMessage(conn));
PQfinish(conn);
return;
}
/* ... the tables */
sprintf(sqlquery, "CREATE TABLE repmgr_%s.repl_nodes ( "
" id integer primary key, "
" cluster text not null, "
" conninfo text not null)", myClusterName);
if (!PQexec(conn, sqlquery))
{
fprintf(stderr, "Cannot create the table repmgr_%s.repl_nodes: %s\n",
myClusterName, PQerrorMessage(conn));
PQfinish(conn);
return;
}
sprintf(sqlquery, "CREATE TABLE repmgr_%s.repl_monitor ( "
" primary_node INTEGER NOT NULL, "
" standby_node INTEGER NOT NULL, "
" last_monitor_time TIMESTAMP WITH TIME ZONE NOT NULL, "
" last_wal_primary_location TEXT NOT NULL, "
" last_wal_standby_location TEXT NOT NULL, "
" replication_lag BIGINT NOT NULL, "
" apply_lag BIGINT NOT NULL) ", myClusterName);
if (!PQexec(conn, sqlquery))
{
fprintf(stderr, "Cannot create the table repmgr_%s.repl_monitor: %s\n",
myClusterName, PQerrorMessage(conn));
PQfinish(conn);
return;
}
/* and the view */
sprintf(sqlquery, "CREATE VIEW repmgr_%s.repl_status AS "
" WITH monitor_info AS (SELECT *, ROW_NUMBER() OVER (PARTITION BY primary_node, standby_node "
" ORDER BY last_monitor_time desc) "
" FROM repmgr_%s.repl_monitor) "
" SELECT primary_node, standby_node, last_monitor_time, last_wal_primary_location, "
" last_wal_standby_location, pg_size_pretty(replication_lag) replication_lag, "
" pg_size_pretty(apply_lag) apply_lag, age(now(), last_monitor_time) AS time_lag "
" FROM monitor_info a "
" WHERE row_number = 1", myClusterName, myClusterName);
if (!PQexec(conn, sqlquery))
{
fprintf(stderr, "Cannot create the view repmgr_%s.repl_status: %s\n",
myClusterName, PQerrorMessage(conn));
PQfinish(conn);
return;
}
}
else
{
PGconn *master_conn;
int id;
/* Ensure there isn't any other master already registered */
master_conn = getMasterConnection(conn, myLocalId, myClusterName, &id);
if (master_conn != NULL)
{
PQfinish(master_conn);
fprintf(stderr, "There is a master already in this cluster");
return;
}
}
/* Now register the master */
if (force)
{
sprintf(sqlquery, "DELETE FROM repmgr_%s.repl_nodes "
" WHERE id = %d",
myClusterName, myLocalId);
if (!PQexec(conn, sqlquery))
{
fprintf(stderr, "Cannot delete node details, %s\n",
PQerrorMessage(conn));
PQfinish(conn);
return;
}
}
sprintf(sqlquery, "INSERT INTO repmgr_%s.repl_nodes "
"VALUES (%d, '%s', '%s')",
myClusterName, myLocalId, myClusterName, conninfo);
if (!PQexec(conn, sqlquery))
{
fprintf(stderr, "Cannot insert node details, %s\n",
PQerrorMessage(conn));
PQfinish(conn);
return;
}
PQfinish(conn);
return;
}
static void
do_standby_register(void)
{
PGconn *conn;
PGconn *master_conn;
int master_id;
PGresult *res;
char sqlquery[QUERY_STR_LEN];
char myClusterName[MAXLEN];
int myLocalId = -1;
char conninfo[MAXLEN];
char master_version[MAXVERSIONSTR];
char standby_version[MAXVERSIONSTR];
/*
* Read the configuration file: repmgr.conf
*/
parse_config(config_file, myClusterName, &myLocalId, conninfo);
if (myLocalId == -1)
{
fprintf(stderr, "Node information is missing. "
"Check the configuration file.\n");
exit(1);
}
conn = establishDBConnection(conninfo, true);
/* should be v9 or better */
pg_version(conn, standby_version);
if (strcmp(standby_version, "") == 0)
{
PQfinish(conn);
fprintf(stderr, _("%s needs standby to be PostgreSQL 9.0 or better\n"), progname);
return;
}
/* Check we are a standby */
if (!is_standby(conn))
{
fprintf(stderr, "repmgr: This node should be a standby\n");
PQfinish(conn);
return;
}
/* Check if there is a schema for this cluster */
sprintf(sqlquery, "SELECT 1 FROM pg_namespace WHERE nspname = 'repmgr_%s'", myClusterName);
res = PQexec(conn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "Can't get info about tablespaces: %s\n", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return;
}
if (PQntuples(res) == 0) /* schema doesn't exists */
{
fprintf(stderr, "Schema repmgr_%s doesn't exists.", myClusterName);
PQclear(res);
PQfinish(conn);
return;
}
PQclear(res);
/* check if there is a master in this cluster */
master_conn = getMasterConnection(conn, myLocalId, myClusterName, &master_id);
if (!master_conn)
return;
/* master should be v9 or better */
pg_version(master_conn, master_version);
if (strcmp(master_version, "") == 0)
{
PQfinish(conn);
PQfinish(master_conn);
fprintf(stderr, _("%s needs master to be PostgreSQL 9.0 or better\n"), progname);
return;
}
/* master and standby version should match */
if (strcmp(master_version, standby_version) != 0)
{
PQfinish(conn);
PQfinish(master_conn);
fprintf(stderr, _("%s needs versions of both master (%s) and standby (%s) to match.\n"),
progname, master_version, standby_version);
return;
}
/* Now register the standby */
if (force)
{
sprintf(sqlquery, "DELETE FROM repmgr_%s.repl_nodes "
" WHERE id = %d",
myClusterName, myLocalId);
if (!PQexec(master_conn, sqlquery))
{
fprintf(stderr, "Cannot delete node details, %s\n",
PQerrorMessage(master_conn));
PQfinish(master_conn);
PQfinish(conn);
return;
}
}
sprintf(sqlquery, "INSERT INTO repmgr_%s.repl_nodes "
"VALUES (%d, '%s', '%s')",
myClusterName, myLocalId, myClusterName, conninfo);
if (!PQexec(master_conn, sqlquery))
{
fprintf(stderr, "Cannot insert node details, %s\n",
PQerrorMessage(master_conn));
PQfinish(master_conn);
PQfinish(conn);
return;
}
PQfinish(master_conn);
PQfinish(conn);
return;
}
static void
do_standby_follow(void)
{
PGconn *conn;
PGresult *res;
char sqlquery[QUERY_STR_LEN];
char script[QUERY_STR_LEN];
char myClusterName[MAXLEN];
int myLocalId = -1;
char conninfo[MAXLEN];
PGconn *master_conn;
int master_id;
int r;
char data_dir[MAXLEN];
char master_version[MAXVERSIONSTR];
char standby_version[MAXVERSIONSTR];
/*
* Read the configuration file: repmgr.conf
*/
parse_config(config_file, myClusterName, &myLocalId, conninfo);
if (myLocalId == -1)
{
fprintf(stderr, "Node information is missing. "
"Check the configuration file.\n");
exit(1);
}
/* We need to connect to check configuration */
conn = establishDBConnection(conninfo, true);
/* Check we are in a standby node */
if (!is_standby(conn))
{
fprintf(stderr, "\n%s: The command should be executed in a standby node\n", progname);
return;
}
/* should be v9 or better */
pg_version(conn, standby_version);
if (strcmp(standby_version, "") == 0)
{
PQfinish(conn);
fprintf(stderr, _("\n%s needs standby to be PostgreSQL 9.0 or better\n"), progname);
return;
}
/* we also need to check if there is any master in the cluster */
master_conn = getMasterConnection(conn, myLocalId, myClusterName, &master_id);
if (master_conn == NULL)
{
PQfinish(conn);
fprintf(stderr, "There isn't a master to follow in this cluster");
return;
}
/* Check we are going to point to a master */
if (is_standby(master_conn))
{
PQfinish(conn);
fprintf(stderr, "%s: The node to follow should be a master\n", progname);
return;
}
/* should be v9 or better */
pg_version(master_conn, master_version);
if (strcmp(master_version, "") == 0)
{
PQfinish(conn);
PQfinish(master_conn);
fprintf(stderr, _("%s needs master to be PostgreSQL 9.0 or better\n"), progname);
return;
}
/* master and standby version should match */
if (strcmp(master_version, standby_version) != 0)
{
PQfinish(conn);
PQfinish(master_conn);
fprintf(stderr, _("%s needs versions of both master (%s) and standby (%s) to match.\n"),
progname, master_version, standby_version);
return;
}
/*
* set the host and masterport variables with the master ones
* before closing the connection because we will need them to
* recreate the recovery.conf file
*/
host = malloc(20);
masterport = malloc(10);
strcpy(host, PQhost(master_conn));
strcpy(masterport, PQport(master_conn));
PQfinish(master_conn);
if (verbose)
printf(_("\n%s: Changing standby's master...\n"), progname);
/* Get the data directory full path */
sprintf(sqlquery, "SELECT setting "
" FROM pg_settings WHERE name = 'data_directory'");
res = PQexec(conn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "Can't get info about data directory: %s\n", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return;
}
strcpy(data_dir, PQgetvalue(res, 0, 0));
PQclear(res);
PQfinish(conn);
/* write the recovery.conf file */
if (!create_recovery_file(data_dir))
return;
/* Finally, restart the service */
/* We assume the pg_ctl script is in the PATH */
sprintf(script, "pg_ctl -D %s -m fast restart", data_dir);
r = system(script);
if (r != 0)
{
fprintf(stderr, "Can't restart service\n");
return;
}
return;
}
static void
do_failover(void)
{
PGresult *res1;
PGresult *res2;
char sqlquery[8192];
int total_nodes = 0;
int visible_nodes = 0;
bool find_best = 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];
nodeInfo best_candidate;
/* first we get info about this node, and update shared memory */
sprintf(sqlquery, "SELECT pg_last_xlog_replay_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 "
" FROM %s.repl_nodes "
" WHERE id IN (SELECT standby_node FROM %s.repl_status) "
" AND cluster = '%s' "
" ORDER BY priority ",
repmgr_schema, repmgr_schema, 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);
}
/* 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);
nodeConn = establishDBConnection(nodeConninfo, false);
/* if we can't see the node just skip it */
if (PQstatus(nodeConn) != CONNECTION_OK)
continue;
sqlquery_snprintf(sqlquery, "SELECT repmgr_get_last_standby_location()");
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;
}
visible_nodes++;
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));
nodes[i].nodeId = node;
nodes[i].xlog_location.xlogid = uxlogid;
nodes[i].xlog_location.xrecoff = uxrecoff;
nodes[i].is_ready = true;
PQclear(res2);
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++)
{
if (!nodes[i].is_ready)
continue;
else 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;
find_best = true;
}
/* we use the macros provided by xlogdefs.h to compare XLogPtr */
/*
* Nodes are retrieved ordered by priority, so if the current
* best candidate is lower or equal to the next node's wal location
* then assign next node as the new best candidate.
*/
if (XLByteLE(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;
}
}
/* once we know who is the best candidate, promote it */
if (find_best && (best_candidate.nodeId == local_options.node))
{
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);
}
int
main(int argc, char **argv)
{
static struct option long_options[] =
{
{"config", required_argument, NULL, 'f'},
{"verbose", no_argument, NULL, 'v'},
{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 (PostgreSQL) " PG_VERSION "\n", progname);
exit(SUCCESS);
}
}
while ((c = getopt_long(argc, argv, "f:v", long_options, &optindex)) != -1)
{
switch (c)
{
case 'f':
config_file = optarg;
break;
case 'v':
verbose = 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.node,
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;
}
bool
reload_configuration(char *config_file, t_configuration_options *orig_options)
{
PGconn *conn;
t_configuration_options new_options;
/*
* Re-read the configuration file: repmgr.conf
*/
log_info(_("Reloading configuration file and updating repmgr tables\n"));
parse_config(config_file, &new_options);
if (new_options.node == -1)
{
log_warning(_("\nCannot load new configuration, will keep current one.\n"));
return false;
}
if (strcmp(new_options.cluster_name, orig_options->cluster_name) != 0)
{
log_warning(_("\nCannot change cluster name, will keep current configuration.\n"));
return false;
}
if (new_options.node != orig_options->node)
{
log_warning(_("\nCannot change node number, will keep current configuration.\n"));
return false;
}
if (new_options.node_name != orig_options->node_name)
{
log_warning(_("\nCannot change standby name, will keep current configuration.\n"));
return false;
}
if (new_options.failover != MANUAL_FAILOVER && new_options.failover != AUTOMATIC_FAILOVER)
{
log_warning(_("\nNew value for failover is not valid. Should be MANUAL or AUTOMATIC.\n"));
return false;
}
if (new_options.master_response_timeout <= 0)
{
log_warning(_("\nNew value for master_response_timeout is not valid. Should be greater than zero.\n"));
return false;
}
if (new_options.reconnect_attempts < 0)
{
log_warning(_("\nNew value for reconnect_attempts is not valid. Should be greater or equal than zero.\n"));
return false;
}
if (new_options.reconnect_intvl < 0)
{
log_warning(_("\nNew value for reconnect_interval is not valid. Should be greater or equal than zero.\n"));
return false;
}
/* Test conninfo string */
conn = establishDBConnection(new_options.conninfo, false);
if (!conn || (PQstatus(conn) != CONNECTION_OK))
{
log_warning(_("\nconninfo string is not valid, will keep current configuration.\n"));
return false;
}
PQfinish(conn);
/* Configuration seems ok, will load new values */
strcpy(orig_options->cluster_name, new_options.cluster_name);
orig_options->node = new_options.node;
strcpy(orig_options->conninfo, new_options.conninfo);
orig_options->failover = new_options.failover;
orig_options->priority = new_options.priority;
strcpy(orig_options->node_name, new_options.node_name);
strcpy(orig_options->promote_command, new_options.promote_command);
strcpy(orig_options->follow_command, new_options.follow_command);
strcpy(orig_options->rsync_options, new_options.rsync_options);
strcpy(orig_options->ssh_options, new_options.ssh_options);
orig_options->master_response_timeout = new_options.master_response_timeout;
orig_options->reconnect_attempts = new_options.reconnect_attempts;
orig_options->reconnect_intvl = new_options.reconnect_intvl;
/*
* XXX These ones can change with a simple SIGHUP?
strcpy (orig_options->loglevel, new_options.loglevel);
strcpy (orig_options->logfacility, new_options.logfacility);
logger_shutdown();
XXX do we have progname here ?
logger_init(progname, orig_options.loglevel, orig_options.logfacility);
*/
return true;
}
int
main(int argc, char **argv)
{
static struct option long_options[] =
{
{"config", required_argument, NULL, 'f'},
{"verbose", no_argument, NULL, 'v'},
{NULL, 0, NULL, 0}
};
int optindex;
int c;
char conninfo[MAXLEN];
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(0);
}
if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
{
printf("%s (PostgreSQL) " PG_VERSION "\n", progname);
exit(0);
}
}
while ((c = getopt_long(argc, argv, "f:v", long_options, &optindex)) != -1)
{
switch (c)
{
case 'f':
config_file = optarg;
break;
case 'v':
verbose = true;
break;
default:
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
}
setup_cancel_handler();
if (config_file == NULL)
{
config_file = malloc(5 + sizeof(CONFIG_FILE));
sprintf(config_file, "./%s", CONFIG_FILE);
}
/*
* Read the configuration file: repmgr.conf
*/
parse_config(config_file, myClusterName, &myLocalId, conninfo);
if (myLocalId == -1)
{
fprintf(stderr, "Node information is missing. "
"Check the configuration file.\n");
exit(1);
}
myLocalConn = establishDBConnection(conninfo, true);
/* should be v9 or better */
pg_version(myLocalConn, standby_version);
if (strcmp(standby_version, "") == 0)
{
PQfinish(myLocalConn);
fprintf(stderr, _("%s needs standby to be PostgreSQL 9.0 or better\n"), progname);
exit(1);
}
/*
* Set my server mode, establish a connection to primary
* and start monitor
*/
myLocalMode = is_standby(myLocalConn) ? STANDBY_MODE : PRIMARY_MODE;
if (myLocalMode == PRIMARY_MODE)
{
primaryId = myLocalId;
strcpy(primaryConninfo, conninfo);
primaryConn = myLocalConn;
}
else
{
/* I need the id of the primary as well as a connection to it */
primaryConn = getMasterConnection(myLocalConn, myLocalId, myClusterName, &primaryId);
if (primaryConn == NULL)
exit(1);
}
checkClusterConfiguration();
checkNodeConfiguration(conninfo);
if (myLocalMode == STANDBY_MODE)
{
MonitorCheck();
}
/* close the connection to the database and cleanup */
CloseConnections();
return 0;
}
