aio_task_ptr copy_remote_files(
const end_point& remote,
std::string& source_dir,
std::vector<std::string>& files, // empty for all
std::string& dest_dir,
bool overwrite,
task_code callback_code,
servicelet* owner,
aio_handler callback,
int hash /*= 0*/
)
{
aio_task_ptr tsk(callback != nullptr ?
static_cast<aio_task*>(new internal_use_only::service_aio_task(callback_code, owner, callback, hash))
: static_cast<aio_task*>(new aio_task_empty(callback_code, hash))
);
copy_remote_files(remote, source_dir, files, dest_dir, overwrite, tsk);
return tsk;
}
static void
do_standby_clone(void)
{
PGconn *conn;
PGresult *res;
char sqlquery[QUERY_STR_LEN];
int r = 0;
int i;
bool pg_dir = false;
char master_data_directory[MAXLEN];
char master_config_file[MAXLEN];
char master_hba_file[MAXLEN];
char master_ident_file[MAXLEN];
char master_control_file[MAXLEN];
char local_control_file[MAXLEN];
const char *first_wal_segment = NULL;
const char *last_wal_segment = NULL;
char master_version[MAXVERSIONSTR];
/* if dest_dir hasn't been provided, initialize to current directory */
if (dest_dir == NULL)
{
dest_dir = malloc(5);
strcpy(dest_dir, ".");
}
/* Check this directory could be used as a PGDATA dir */
switch (check_dir(dest_dir))
{
case 0:
/* dest_dir not there, must create it */
if (verbose)
printf(_("creating directory %s ... "), dest_dir);
fflush(stdout);
if (!create_directory(dest_dir))
{
fprintf(stderr, _("%s: couldn't create directory %s ... "),
progname, dest_dir);
return;
}
break;
case 1:
/* Present but empty, fix permissions and use it */
if (verbose)
printf(_("fixing permissions on existing directory %s ... "),
dest_dir);
fflush(stdout);
if (!set_directory_permissions(dest_dir))
{
fprintf(stderr, _("%s: could not change permissions of directory \"%s\": %s\n"),
progname, dest_dir, strerror(errno));
return;
}
break;
case 2:
/* Present and not empty */
fprintf(stderr,
_("%s: directory \"%s\" exists but is not empty\n"),
progname, dest_dir);
pg_dir = is_pg_dir(dest_dir);
if (pg_dir && !force)
{
fprintf(stderr, _("\nThis looks like a PostgreSQL directroy.\n"
"If you are sure you want to clone here, "
"please check there is no PostgreSQL server "
"running and use the --force option\n"));
return;
}
else if (pg_dir && force)
{
/* Let it continue */
break;
}
else
return;
default:
/* Trouble accessing directory */
fprintf(stderr, _("%s: could not access directory \"%s\": %s\n"),
progname, dest_dir, strerror(errno));
}
/* Connection parameters for master only */
keywords[0] = "host";
values[0] = host;
keywords[1] = "port";
values[1] = masterport;
/* We need to connect to check configuration and start a backup */
conn = PQconnectdbParams(keywords, values, true);
if (!conn)
{
fprintf(stderr, _("%s: could not connect to master\n"),
progname);
return;
}
/* primary 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 cloning a primary node */
if (is_standby(conn))
{
PQfinish(conn);
fprintf(stderr, "\nThe command should clone a primary node\n");
return;
}
/* And check if it is well configured */
if (!guc_setted(conn, "wal_level", "=", "hot_standby"))
{
PQfinish(conn);
fprintf(stderr, _("%s needs parameter 'wal_level' to be set to 'hot_standby'\n"), progname);
return;
}
if (!guc_setted(conn, "wal_keep_segments", ">=", wal_keep_segments))
{
PQfinish(conn);
fprintf(stderr, _("%s needs parameter 'wal_keep_segments' to be set to %s or greater\n"), wal_keep_segments, progname);
return;
}
if (!guc_setted(conn, "archive_mode", "=", "on"))
{
PQfinish(conn);
fprintf(stderr, _("%s needs parameter 'archive_mode' to be set to 'on'\n"), progname);
return;
}
if (verbose)
printf(_("Succesfully connected to primary. Current installation size is %s\n"), get_cluster_size(conn));
/* Check if the tablespace locations exists and that we can write to them */
sprintf(sqlquery, "select spclocation from pg_tablespace where spcname not in ('pg_default', 'pg_global')");
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;
}
for (i = 0; i < PQntuples(res); i++)
{
char *tblspc_dir = NULL;
strcpy(tblspc_dir, PQgetvalue(res, i, 0));
/* Check this directory could be used as a PGDATA dir */
switch (check_dir(tblspc_dir))
{
case 0:
/* tblspc_dir not there, must create it */
if (verbose)
printf(_("creating directory \"%s\"... "), tblspc_dir);
fflush(stdout);
if (!create_directory(tblspc_dir))
{
fprintf(stderr, _("%s: couldn't create directory \"%s\"... "),
progname, tblspc_dir);
PQclear(res);
PQfinish(conn);
return;
}
break;
case 1:
/* Present but empty, fix permissions and use it */
if (verbose)
printf(_("fixing permissions on existing directory \"%s\"... "),
tblspc_dir);
fflush(stdout);
if (!set_directory_permissions(tblspc_dir))
{
fprintf(stderr, _("%s: could not change permissions of directory \"%s\": %s\n"),
progname, tblspc_dir, strerror(errno));
PQclear(res);
PQfinish(conn);
return;
}
break;
case 2:
/* Present and not empty */
if (!force)
{
fprintf(stderr,
_("%s: directory \"%s\" exists but is not empty\n"),
progname, tblspc_dir);
PQclear(res);
PQfinish(conn);
return;
}
default:
/* Trouble accessing directory */
fprintf(stderr, _("%s: could not access directory \"%s\": %s\n"),
progname, tblspc_dir, strerror(errno));
PQclear(res);
PQfinish(conn);
return;
}
}
fprintf(stderr, "Starting backup...\n");
/* Get the data directory full path and the configuration files location */
sprintf(sqlquery, "SELECT name, setting "
" FROM pg_settings "
" WHERE name IN ('data_directory', 'config_file', 'hba_file', 'ident_file')");
res = PQexec(conn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "Can't get info about data directory and configuration files: %s\n", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return;
}
for (i = 0; i < PQntuples(res); i++)
{
if (strcmp(PQgetvalue(res, i, 0), "data_directory") == 0)
strcpy(master_data_directory, PQgetvalue(res, i, 1));
else if (strcmp(PQgetvalue(res, i, 0), "config_file") == 0)
strcpy(master_config_file, PQgetvalue(res, i, 1));
else if (strcmp(PQgetvalue(res, i, 0), "hba_file") == 0)
strcpy(master_hba_file, PQgetvalue(res, i, 1));
else if (strcmp(PQgetvalue(res, i, 0), "ident_file") == 0)
strcpy(master_ident_file, PQgetvalue(res, i, 1));
else
fprintf(stderr, _("uknown parameter: %s"), PQgetvalue(res, i, 0));
}
PQclear(res);
/*
* inform the master we will start a backup and get the first XLog filename
* so we can say to the user we need those files
*/
sprintf(sqlquery, "SELECT pg_xlogfile_name(pg_start_backup('repmgr_standby_clone_%ld'))", time(NULL));
res = PQexec(conn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "Can't start backup: %s\n", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return;
}
first_wal_segment = PQgetvalue(res, 0, 0);
PQclear(res);
/*
* 1) first move global/pg_control
*
* 2) then move data_directory ommiting the files we have already moved and pg_xlog
* content
*
* 3) finally We need to backup configuration files (that could be on other directories, debian
* like systems likes to do that), so look at config_file, hba_file and ident_file but we
* can omit external_pid_file ;)
*
* On error we need to return but before that execute pg_stop_backup()
*/
/* need to create the global sub directory */
sprintf(master_control_file, "%s/global/pg_control", master_data_directory);
sprintf(local_control_file, "%s/global", dest_dir);
if (!create_directory(local_control_file))
{
fprintf(stderr, _("%s: couldn't create directory %s ... "),
progname, dest_dir);
goto stop_backup;
}
r = copy_remote_files(host, remote_user, master_control_file, local_control_file, false);
if (r != 0)
goto stop_backup;
r = copy_remote_files(host, remote_user, master_data_directory, dest_dir, true);
if (r != 0)
goto stop_backup;
/*
* Copy tablespace locations, i'm doing this separately because i couldn't find and appropiate
* rsync option but besides we could someday make all these rsync happen concurrently
*/
sprintf(sqlquery, "select spclocation from pg_tablespace where spcname not in ('pg_default', 'pg_global')");
res = PQexec(conn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "Can't get info about tablespaces: %s\n", PQerrorMessage(conn));
PQclear(res);
goto stop_backup;
}
for (i = 0; i < PQntuples(res); i++)
{
r = copy_remote_files(host, remote_user, PQgetvalue(res, i, 0), PQgetvalue(res, i, 0), true);
if (r != 0)
goto stop_backup;
}
r = copy_remote_files(host, remote_user, master_config_file, dest_dir, false);
if (r != 0)
goto stop_backup;
r = copy_remote_files(host, remote_user, master_hba_file, dest_dir, false);
if (r != 0)
goto stop_backup;
r = copy_remote_files(host, remote_user, master_ident_file, dest_dir, false);
if (r != 0)
goto stop_backup;
stop_backup:
/* inform the master that we have finished the backup */
conn = PQconnectdbParams(keywords, values, true);
if (!conn)
{
fprintf(stderr, _("%s: could not connect to master\n"),
progname);
return;
}
fprintf(stderr, "Finishing backup...\n");
sprintf(sqlquery, "SELECT pg_xlogfile_name(pg_stop_backup())");
res = PQexec(conn, sqlquery);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "Can't stop backup: %s\n", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return;
}
last_wal_segment = PQgetvalue(res, 0, 0);
PQclear(res);
PQfinish(conn);
/* Now, if the rsync failed then exit */
if (r != 0)
return;
if (verbose)
printf(_("%s requires primary to keep WAL files %s until at least %s\n"),
progname, first_wal_segment, last_wal_segment);
/* we need to create the pg_xlog sub directory too, i'm reusing a variable here */
sprintf(local_control_file, "%s/pg_xlog", dest_dir);
if (!create_directory(local_control_file))
{
fprintf(stderr, _("%s: couldn't create directory %s, you will need to do it manually...\n"),
progname, dest_dir);
}
/* Finally, write the recovery.conf file */
create_recovery_file(dest_dir);
/* We don't start the service because we still may want to move the directory */
return;
}
