/*
* stop myself
*/
static void stop_me(void)
{
pid_t pid;
pid = read_pid_file();
if (pid < 0)
{
pool_error("could not read pid file");
pool_shmem_exit(1);
exit(1);
}
if (kill(pid, stop_sig) == -1)
{
pool_error("could not stop pid: %d. reason: %s", pid, strerror(errno));
pool_shmem_exit(1);
exit(1);
}
fprintf(stderr, "stop request sent to pgpool. waiting for termination...");
while (kill(pid, 0) == 0)
{
fprintf(stderr, ".");
sleep(1);
}
fprintf(stderr, "done.\n");
}
static void myexit(int code)
{
int i;
if (getpid() != mypid)
return;
if (pids != NULL) {
POOL_SETMASK(&AuthBlockSig);
exiting = 1;
for (i = 0; i < pool_config->num_init_children; i++)
{
pid_t pid = pids[i].pid;
if (pid)
{
kill(pid, SIGTERM);
}
}
while (wait(NULL) > 0)
;
if (errno != ECHILD)
pool_error("wait() failed. reason:%s", strerror(errno));
POOL_SETMASK(&UnBlockSig);
}
myunlink(un_addr.sun_path);
myunlink(pcp_un_addr.sun_path);
myunlink(pool_config->pid_file_name);
write_status_file();
pool_shmem_exit(code);
exit(code);
}
/*
* detach control ttys
*/
static void daemonize(void)
{
int i;
pid_t pid;
int fdlimit;
pid = fork();
if (pid == (pid_t) -1)
{
pool_error("fork() failed. reason: %s", strerror(errno));
pool_shmem_exit(1);
exit(1);
return; /* not reached */
}
else if (pid > 0)
{ /* parent */
pool_shmem_exit(0);
exit(0);
}
#ifdef HAVE_SETSID
if (setsid() < 0)
{
pool_error("setsid() failed. reason:%s", strerror(errno));
pool_shmem_exit(1);
exit(1);
}
#endif
mypid = getpid();
chdir("/");
i = open("/dev/null", O_RDWR);
dup2(i, 0);
dup2(i, 1);
dup2(i, 2);
fdlimit = sysconf(_SC_OPEN_MAX);
for (i = 3; i < fdlimit; i++)
close(i);
write_pid_file();
}
static RETSIGTYPE exit_handler(int sig)
{
int i;
POOL_SETMASK(&AuthBlockSig);
/*
* this could happen in a child process if a signal has been sent
* before resetting signal handler
*/
if (getpid() != mypid)
{
pool_debug("exit_handler: I am not parent");
POOL_SETMASK(&UnBlockSig);
pool_shmem_exit(0);
exit(0);
}
if (sig == SIGTERM)
pool_log("received smart shutdown request");
else if (sig == SIGINT)
pool_log("received fast shutdown request");
else if (sig == SIGQUIT)
pool_log("received immediate shutdown request");
else
{
pool_error("exit_handler: unknown signal received %d", sig);
POOL_SETMASK(&UnBlockSig);
return;
}
exiting = 1;
for (i = 0; i < pool_config->num_init_children; i++)
{
pid_t pid = pids[i].pid;
if (pid)
{
kill(pid, sig);
}
}
kill(pcp_pid, sig);
POOL_SETMASK(&UnBlockSig);
while (wait(NULL) > 0)
;
if (errno != ECHILD)
pool_error("wait() failed. reason:%s", strerror(errno));
pids = NULL;
myexit(0);
}
/* if the file has setuid bit and the owner is root, it returns 1, otherwise returns 0 */
static int
has_setuid_bit(char * path)
{
struct stat buf;
if (stat(path,&buf) < 0)
{
pool_error("has_setuid_bit: %s: no such a command", path);
pool_shmem_exit(1);
exit(1);
}
return ((buf.st_uid == 0) && (S_ISREG(buf.st_mode)) && (buf.st_mode & S_ISUID))?1:0;
}
/*
* write the pid file
*/
static void write_pid_file(void)
{
FILE *fd;
char pidbuf[128];
fd = fopen(pool_config->pid_file_name, "w");
if (!fd)
{
pool_error("could not open pid file as %s. reason: %s",
pool_config->pid_file_name, strerror(errno));
pool_shmem_exit(1);
exit(1);
}
snprintf(pidbuf, sizeof(pidbuf), "%d", (int)getpid());
fwrite(pidbuf, strlen(pidbuf)+1, 1, fd);
if (fclose(fd))
{
pool_error("could not write pid file as %s. reason: %s",
pool_config->pid_file_name, strerror(errno));
pool_shmem_exit(1);
exit(1);
}
}
/*
* pgpool main program
*/
int main(int argc, char **argv)
{
int opt;
int i;
int pid;
int size;
int retrycnt;
int sys_retrycnt;
myargc = argc;
myargv = argv;
snprintf(conf_file, sizeof(conf_file), "%s/%s", DEFAULT_CONFIGDIR, POOL_CONF_FILE_NAME);
snprintf(pcp_conf_file, sizeof(pcp_conf_file), "%s/%s", DEFAULT_CONFIGDIR, PCP_PASSWD_FILE_NAME);
snprintf(hba_file, sizeof(hba_file), "%s/%s", DEFAULT_CONFIGDIR, HBA_CONF_FILE_NAME);
while ((opt = getopt(argc, argv, "a:cdf:F:hm:nv")) != -1)
{
switch (opt)
{
case 'a': /* specify hba configuration file */
if (!optarg)
{
usage();
exit(1);
}
strncpy(hba_file, optarg, sizeof(hba_file));
break;
case 'c': /* clear cache option */
clear_cache = 1;
break;
case 'd': /* debug option */
debug = 1;
break;
case 'f': /* specify configuration file */
if (!optarg)
{
usage();
exit(1);
}
strncpy(conf_file, optarg, sizeof(conf_file));
break;
case 'F': /* specify PCP password file */
if (!optarg)
{
usage();
exit(1);
}
strncpy(pcp_conf_file, optarg, sizeof(pcp_conf_file));
break;
case 'h':
usage();
exit(0);
break;
case 'm': /* stop mode */
if (!optarg)
{
usage();
exit(1);
}
if (*optarg == 's' || !strcmp("smart", optarg))
stop_sig = SIGTERM; /* smart shutdown */
else if (*optarg == 'f' || !strcmp("fast", optarg))
stop_sig = SIGINT; /* fast shutdown */
else if (*optarg == 'i' || !strcmp("immediate", optarg))
stop_sig = SIGQUIT; /* immediate shutdown */
else
{
usage();
exit(1);
}
break;
case 'n': /* no detaching control ttys */
not_detach = 1;
break;
case 'v':
show_version();
exit(0);
default:
usage();
exit(1);
}
}
mypid = getpid();
if (pool_init_config())
exit(1);
if (pool_get_config(conf_file, INIT_CONFIG))
{
pool_error("Unable to get configuration. Exiting...");
exit(1);
}
if (pool_config->enable_pool_hba)
load_hba(hba_file);
/*
* If a non-switch argument remains, then it should be either "reload" or "stop".
*/
if (optind == (argc - 1))
{
if (!strcmp(argv[optind], "reload"))
{
pid_t pid;
pid = read_pid_file();
if (pid < 0)
{
pool_error("could not read pid file");
pool_shmem_exit(1);
exit(1);
}
if (kill(pid, SIGHUP) == -1)
{
pool_error("could not reload configuration file pid: %d. reason: %s", pid, strerror(errno));
pool_shmem_exit(1);
exit(1);
}
pool_shmem_exit(0);
exit(0);
}
if (!strcmp(argv[optind], "stop"))
{
stop_me();
pool_shmem_exit(0);
exit(0);
}
else
{
usage();
pool_shmem_exit(1);
exit(1);
}
}
/*
* else if no non-switch argument remains, then it should be a start request
*/
else if (optind == argc)
{
pid = read_pid_file();
if (pid > 0)
{
if (kill(pid, 0) == 0)
{
fprintf(stderr, "pid file found. is another pgpool(%d) is running?\n", pid);
exit(1);
}
else
fprintf(stderr, "pid file found but it seems bogus. Trying to start pgpool anyway...\n");
}
}
/*
* otherwise an error...
*/
else
{
usage();
exit(1);
}
/* set signal masks */
poolinitmask();
if (not_detach)
write_pid_file();
else
daemonize();
if (pool_semaphore_create(MAX_NUM_SEMAPHORES))
{
pool_error("Unable to create semaphores. Exiting...");
pool_shmem_exit(1);
exit(1);
}
/*
* Restore previous backend status if possible
*/
read_status_file();
/* clear cache */
if (clear_cache && pool_config->enable_query_cache && SYSDB_STATUS == CON_UP)
{
Interval interval[1];
interval[0].quantity = 0;
interval[0].unit = second;
pool_clear_cache_by_time(interval, 1);
}
/* set unix domain socket path */
snprintf(un_addr.sun_path, sizeof(un_addr.sun_path), "%s/.s.PGSQL.%d",
pool_config->socket_dir,
pool_config->port);
/* set up signal handlers */
pool_signal(SIGPIPE, SIG_IGN);
/* create unix domain socket */
unix_fd = create_unix_domain_socket(un_addr);
/* create inet domain socket if any */
if (pool_config->listen_addresses[0])
{
inet_fd = create_inet_domain_socket(pool_config->listen_addresses, pool_config->port);
}
size = pool_config->num_init_children * pool_config->max_pool * sizeof(ConnectionInfo);
con_info = pool_shared_memory_create(size);
if (con_info == NULL)
{
pool_error("failed to allocate connection informations");
myexit(1);
}
memset(con_info, 0, size);
size = pool_config->num_init_children * (sizeof(ProcessInfo));
pids = pool_shared_memory_create(size);
if (pids == NULL)
{
pool_error("failed to allocate pids");
myexit(1);
}
memset(pids, 0, size);
for (i = 0; i < pool_config->num_init_children; i++)
{
pids[i].connection_info = &con_info[i * pool_config->max_pool];
}
/* create fail over/switch over event area */
Req_info = pool_shared_memory_create(sizeof(POOL_REQUEST_INFO));
if (Req_info == NULL)
{
pool_error("failed to allocate Req_info");
myexit(1);
}
/* initialize Req_info */
Req_info->kind = NODE_UP_REQUEST;
memset(Req_info->node_id, -1, sizeof(int) * MAX_NUM_BACKENDS);
Req_info->master_node_id = get_next_master_node();
Req_info->conn_counter = 0;
InRecovery = pool_shared_memory_create(sizeof(int));
if (InRecovery == NULL)
{
pool_error("failed to allocate InRecovery");
myexit(1);
}
*InRecovery = 0;
/*
* We need to block signal here. Otherwise child might send some
* signals, for example SIGUSR1(fail over). Children will inherit
* signal blocking but they do unblock signals at the very beginning
* of process. So this is harmless.
*/
POOL_SETMASK(&BlockSig);
/* fork the children */
for (i=0;i<pool_config->num_init_children;i++)
{
pids[i].pid = fork_a_child(unix_fd, inet_fd, i);
pids[i].start_time = time(NULL);
}
/* set up signal handlers */
pool_signal(SIGTERM, exit_handler);
pool_signal(SIGINT, exit_handler);
pool_signal(SIGQUIT, exit_handler);
pool_signal(SIGCHLD, reap_handler);
pool_signal(SIGUSR1, failover_handler);
pool_signal(SIGUSR2, wakeup_handler);
pool_signal(SIGHUP, reload_config_handler);
/* create pipe for delivering event */
if (pipe(pipe_fds) < 0)
{
pool_error("failed to create pipe");
myexit(1);
}
pool_log("pgpool successfully started");
/* fork a child for PCP handling */
snprintf(pcp_un_addr.sun_path, sizeof(pcp_un_addr.sun_path), "%s/.s.PGSQL.%d",
pool_config->pcp_socket_dir,
pool_config->pcp_port);
pcp_unix_fd = create_unix_domain_socket(pcp_un_addr);
/* maybe change "*" to pool_config->pcp_listen_addresses */
pcp_inet_fd = create_inet_domain_socket("*", pool_config->pcp_port);
pcp_pid = pcp_fork_a_child(pcp_unix_fd, pcp_inet_fd, pcp_conf_file);
retrycnt = 0; /* reset health check retry counter */
sys_retrycnt = 0; /* reset SystemDB health check retry counter */
/*
* This is the main loop
*/
for (;;)
{
CHECK_REQUEST;
/* do we need health checking for PostgreSQL? */
if (pool_config->health_check_period > 0)
{
int sts;
int sys_sts = 0;
unsigned int sleep_time;
if (retrycnt == 0)
{
pool_debug("starting health checking");
}
else
{
pool_debug("retrying %d th health checking", retrycnt);
}
if (pool_config->health_check_timeout > 0)
{
/*
* set health checker timeout. we want to detect
* communication path failure much earlier before
* TCP/IP stack detects it.
*/
pool_signal(SIGALRM, health_check_timer_handler);
alarm(pool_config->health_check_timeout);
}
/*
* do actual health check. trying to connect to the backend
*/
errno = 0;
health_check_timer_expired = 0;
POOL_SETMASK(&UnBlockSig);
sts = health_check();
POOL_SETMASK(&BlockSig);
if (pool_config->parallel_mode || pool_config->enable_query_cache)
sys_sts = system_db_health_check();
if ((sts > 0 || sys_sts < 0) && (errno != EINTR || (errno == EINTR && health_check_timer_expired)))
{
if (sts > 0)
{
sts--;
if (!pool_config->parallel_mode)
{
pool_log("set %d th backend down status", sts);
Req_info->kind = NODE_DOWN_REQUEST;
Req_info->node_id[0] = sts;
failover();
/* need to distribute this info to children */
}
else
{
retrycnt++;
pool_signal(SIGALRM, SIG_IGN); /* Cancel timer */
if (retrycnt > NUM_BACKENDS)
{
/* retry count over */
pool_log("set %d th backend down status", sts);
Req_info->kind = NODE_DOWN_REQUEST;
Req_info->node_id[0] = sts;
failover();
retrycnt = 0;
}
else
{
/* continue to retry */
sleep_time = pool_config->health_check_period/NUM_BACKENDS;
pool_debug("retry sleep time: %d seconds", sleep_time);
pool_sleep(sleep_time);
continue;
}
}
}
if (sys_sts < 0)
{
sys_retrycnt++;
pool_signal(SIGALRM, SIG_IGN);
if (sys_retrycnt > NUM_BACKENDS)
{
pool_log("set SystemDB down status");
SYSDB_STATUS = CON_DOWN;
sys_retrycnt = 0;
}
else if (sts == 0) /* goes to sleep only when SystemDB alone was down */
{
sleep_time = pool_config->health_check_period/NUM_BACKENDS;
pool_debug("retry sleep time: %d seconds", sleep_time);
pool_sleep(sleep_time);
continue;
}
}
}
if (pool_config->health_check_timeout > 0)
{
/* seems ok. cancel health check timer */
pool_signal(SIGALRM, SIG_IGN);
}
sleep_time = pool_config->health_check_period;
pool_sleep(sleep_time);
}
else
{
for (;;)
{
int r;
struct timeval t = {3, 0};
POOL_SETMASK(&UnBlockSig);
r = pool_pause(&t);
POOL_SETMASK(&BlockSig);
if (r > 0)
break;
}
}
}
pool_shmem_exit(0);
}
static RETSIGTYPE exit_handler(int sig)
{
int i;
int status;
pid_t pid;
POOL_SETMASK(&AuthBlockSig);
/*
* this could happen in a child process if a signal has been sent
* before resetting signal handler
*/
if (getpid() != mypid)
{
pool_debug("exit_handler: I am not parent");
POOL_SETMASK(&UnBlockSig);
pool_shmem_exit(0);
exit(0);
}
if (sig == SIGTERM)
pool_log("received smart shutdown request");
else if (sig == SIGINT)
pool_log("received fast shutdown request");
else if (sig == SIGQUIT)
pool_log("received immediate shutdown request");
else
{
pool_error("exit_handler: unknown signal received %d", sig);
POOL_SETMASK(&UnBlockSig);
return;
}
exiting = 1;
for (i = 0; i < pool_config->num_init_children; i++)
{
pid = pids[i].pid;
if (pid)
{
pool_log("send signal(%d) to pid=%d (pgrp=%d), i=%d", sig, pid, getpgid(pid), i);
kill(pid, sig);
}
}
kill(pcp_pid, sig);
pool_log("send signal(%d) to pcp_pid=%d", sig, pcp_pid);
POOL_SETMASK(&UnBlockSig);
i = 0;
while (pid = wait(&status) > 0) {
pool_log("got wait(): i=%d, pid=%d, status=0x%04x", i++, pid, status);
if (!WIFEXITED(status)) {
pool_error("wait(): pid=%d, status=0x%04x", pid, status);
}
}
if (errno != ECHILD)
pool_error("wait() failed. reason:%s", strerror(errno));
pids = NULL;
myexit(0);
}