/*
* send frontend exiting messages to all connections. this is called
* in any case when child process exits, for example failover, child
* life time expires or child max connections expires.
*/
static void send_frontend_exits(void)
{
int i;
POOL_CONNECTION_POOL *p = pool_connection_pool;
#ifdef HAVE_SIGPROCMASK
sigset_t oldmask;
#else
int oldmask;
#endif
POOL_SETMASK2(&BlockSig, &oldmask);
for (i=0;i<pool_config->max_pool;i++, p++)
{
if (!MASTER_CONNECTION(p))
continue;
if (!MASTER_CONNECTION(p)->sp)
continue;
if (MASTER_CONNECTION(p)->sp->user == NULL)
continue;
pool_send_frontend_exits(p);
}
POOL_SETMASK(&oldmask);
}
/*
* set backend connection close timer
*/
void pool_connection_pool_timer(POOL_CONNECTION_POOL *backend)
{
POOL_CONNECTION_POOL *p = pool_connection_pool;
int i;
pool_debug("pool_connection_pool_timer: set close time %ld", time(NULL));
MASTER_CONNECTION(backend)->closetime = time(NULL); /* set connection close time */
if (pool_config->connection_life_time == 0)
return;
/* look for any other timeout */
for (i=0;i<pool_config->max_pool;i++, p++)
{
if (!MASTER_CONNECTION(p))
continue;
if (!MASTER_CONNECTION(p)->sp)
continue;
if (MASTER_CONNECTION(p)->sp->user == NULL)
continue;
if (p != backend && MASTER_CONNECTION(p)->closetime)
return;
}
/* no other timer found. set my timer */
pool_debug("pool_connection_pool_timer: set alarm after %d seconds", pool_config->connection_life_time);
pool_signal(SIGALRM, pool_backend_timer_handler);
alarm(pool_config->connection_life_time);
}
/*
* find connection by user and database
*/
POOL_CONNECTION_POOL *pool_get_cp(char *user, char *database, int protoMajor, int check_socket)
{
#ifdef HAVE_SIGPROCMASK
sigset_t oldmask;
#else
int oldmask;
#endif
int i;
POOL_CONNECTION_POOL *p = pool_connection_pool;
if (p == NULL)
{
pool_error("pool_get_cp: pool_connection_pool is not initialized");
return NULL;
}
POOL_SETMASK2(&BlockSig, &oldmask);
for (i=0;i<pool_config.max_pool;i++)
{
if (MASTER_CONNECTION(p) &&
MASTER_CONNECTION(p)->sp->major == protoMajor &&
MASTER_CONNECTION(p)->sp->user != NULL &&
strcmp(MASTER_CONNECTION(p)->sp->user, user) == 0 &&
strcmp(MASTER_CONNECTION(p)->sp->database, database) == 0)
{
/* mark this connection is under use */
MASTER_CONNECTION(p)->closetime = 0;
POOL_SETMASK(&oldmask);
if (check_socket &&
(check_socket_status(MASTER(p)->fd) < 0 ||
(DUAL_MODE && check_socket_status(MASTER(p)->fd) < 0)))
{
pool_log("connection closed. retry to create new connection pool.");
pool_free_startup_packet(MASTER_CONNECTION(p)->sp);
pool_close(MASTER_CONNECTION(p)->con);
free(MASTER_CONNECTION(p));
if (DUAL_MODE)
{
pool_close(SECONDARY_CONNECTION(p)->con);
free(SECONDARY_CONNECTION(p));
}
memset(p, 0, sizeof(POOL_CONNECTION_POOL));
return NULL;
}
return p;
}
p++;
}
POOL_SETMASK(&oldmask);
return NULL;
}
/*
* Judge if we have to_regclass or not.
*/
bool
pool_has_to_regclass(void)
{
/*
* Query to know if to_regclass exists.
*/
#define HAS_TOREGCLASSQUERY "SELECT count(*) from (SELECT has_function_privilege('%s', 'pg_catalog.to_regclass(cstring)', 'execute') WHERE EXISTS(SELECT * FROM pg_catalog.pg_proc AS p WHERE p.proname = 'to_regclass')) AS s"
bool result;
static POOL_RELCACHE * relcache;
POOL_CONNECTION_POOL *backend;
char *user;
backend = pool_get_session_context(false)->backend;
user = MASTER_CONNECTION(backend)->sp->user;
if (!relcache)
{
relcache = pool_create_relcache(pool_config->relcache_size, HAS_TOREGCLASSQUERY,
int_register_func, int_unregister_func,
false);
if (relcache == NULL)
{
ereport(WARNING,
(errmsg("unable to create relcache, while checking to_regclass presence")));
return false;
}
}
result = pool_search_relcache(relcache, backend, user) == 0 ? 0 : 1;
return result;
}
/*
* Judge if we have pgpool_regclass or not.
*/
bool pool_has_pgpool_regclass(void)
{
/*
* Query to know if pgpool_regclass exists.
*/
#define HASPGPOOL_REGCLASSQUERY "SELECT count(*) from (SELECT has_function_privilege('%s', 'pgpool_regclass(cstring)', 'execute') WHERE EXISTS(SELECT * FROM pg_catalog.pg_proc AS p WHERE p.proname = 'pgpool_regclass')) AS s"
bool result;
static POOL_RELCACHE *relcache;
POOL_CONNECTION_POOL *backend;
char *user;
backend = pool_get_session_context()->backend;
user = MASTER_CONNECTION(backend)->sp->user;
if (!relcache)
{
relcache = pool_create_relcache(pool_config->relcache_size, HASPGPOOL_REGCLASSQUERY,
int_register_func, int_unregister_func,
false);
if (relcache == NULL)
{
pool_error("has_pgpool_regclass: pool_create_relcache error");
return false;
}
}
result = pool_search_relcache(relcache, backend, user)==0?0:1;
return result;
}
/*
* Create "ERROR" etc., timestamp, pid, user name string and return
* it. The returned string is in a static buff and subsequent calls
* will overwrite it.
*/
static char *optstring(int kind)
{
static char *kindstr[] = {"ERROR:", "DEBUG:", "LOG: "};
char timebuf[MAXSTRFTIME];
time_t now;
static char optbuf[MAXSTRFTIME+7+8+NAMEDATALEN];
#ifndef POOL_TOOLS
char username[NAMEDATALEN];
#endif
char buf[128];
#ifndef POOL_TOOLS
POOL_SESSION_CONTEXT *c;
#endif
optbuf[0] = '\0';
if (pool_config->print_timestamp)
{
now = time(NULL);
strftime(timebuf, MAXSTRFTIME, "%Y-%m-%d %H:%M:%S ", localtime(&now));
strcat(optbuf, timebuf);
}
snprintf(buf, sizeof(buf), "%s pid: %d", kindstr[kind], (int)getpid());
strcat(optbuf, buf);
#ifndef POOL_TOOLS
if (pool_config->print_user)
{
if ((c = pool_get_session_context()))
if (MASTER_CONNECTION(c->backend) && MASTER_CONNECTION(c->backend)->sp &&
MASTER_CONNECTION(c->backend)->sp->user)
{
strlcpy(username, MASTER_CONNECTION(c->backend)->sp->user, sizeof(username));
strcat(optbuf, " user: ");
strcat(optbuf, username);
}
}
#endif
return optbuf;
}
/*
* signal handler for SIGUSR1
* close all idle connections
*/
static RETSIGTYPE close_idle_connection(int sig)
{
int i, j;
POOL_CONNECTION_POOL *p = pool_connection_pool;
ConnectionInfo *info;
pool_debug("child receives close connection request");
for (j=0;j<pool_config->max_pool;j++, p++)
{
if (!MASTER_CONNECTION(p))
continue;
if (!MASTER_CONNECTION(p)->sp)
continue;
if (MASTER_CONNECTION(p)->sp->user == NULL)
continue;
if (MASTER_CONNECTION(p)->closetime > 0) /* idle connection? */
{
pool_debug("close_idle_connection: close idle connection: user %s database %s", MASTER_CONNECTION(p)->sp->user, MASTER_CONNECTION(p)->sp->database);
pool_send_frontend_exits(p);
for (i=0;i<NUM_BACKENDS;i++)
{
if (!VALID_BACKEND(i))
continue;
if (i == 0)
{
/* only first backend allocated the memory for the start up packet */
pool_free_startup_packet(CONNECTION_SLOT(p, i)->sp);
}
pool_close(CONNECTION(p, i));
}
info = p->info;
memset(p, 0, sizeof(POOL_CONNECTION_POOL));
p->info = info;
memset(p->info, 0, sizeof(ConnectionInfo));
}
}
}
static POOL_CONNECTION_POOL *new_connection(POOL_CONNECTION_POOL *p)
{
/* create master connection */
MASTER_CONNECTION(p) = malloc(sizeof(POOL_CONNECTION_POOL_SLOT));
if (MASTER_CONNECTION(p) == NULL)
{
pool_error("pool_create_cp: malloc() failed");
return NULL;
}
create_cp(MASTER_CONNECTION(p), 0);
/* initialize Paramter Status save structure */
if (pool_init_params(&MASTER(p)->params))
{
return NULL;
}
p->num = 1; /* number of slots */
/* create secondary connection */
if (DUAL_MODE)
{
SECONDARY_CONNECTION(p) = malloc(sizeof(POOL_CONNECTION_POOL_SLOT));
if (SECONDARY_CONNECTION(p) == NULL)
{
pool_error("pool_create_cp: malloc() failed");
return NULL;
}
create_cp(SECONDARY_CONNECTION(p), 1);
/* initialize Paramter Status save structure */
if (pool_init_params(&SECONDARY(p)->params))
{
return NULL;
}
p->num++; /* number of slots */
}
return p;
}
/*
* disconnect and release a connection to the database
*/
void pool_discard_cp(char *user, char *database, int protoMajor)
{
POOL_CONNECTION_POOL *p = pool_get_cp(user, database, protoMajor, 0);
if (p == NULL)
{
pool_error("pool_discard_cp: cannot get connection pool for user %s datbase %s", user, database);
return;
}
pool_free_startup_packet(MASTER_CONNECTION(p)->sp);
pool_close(MASTER_CONNECTION(p)->con);
free(MASTER_CONNECTION(p));
if (DUAL_MODE)
{
/* do not free memory! we did not allocate them */
pool_close(SECONDARY_CONNECTION(p)->con);
free(SECONDARY_CONNECTION(p));
}
memset(p, 0, sizeof(POOL_CONNECTION_POOL));
}
/*
* Show ps idle status
*/
void
pool_ps_idle_display(POOL_CONNECTION_POOL * backend)
{
StartupPacket *sp;
char psbuf[1024];
sp = MASTER_CONNECTION(backend)->sp;
if (MASTER(backend)->tstate == 'T')
snprintf(psbuf, sizeof(psbuf), "%s %s %s idle in transaction",
sp->user, sp->database, remote_ps_data);
else
snprintf(psbuf, sizeof(psbuf), "%s %s %s idle",
sp->user, sp->database, remote_ps_data);
set_ps_display(psbuf, false);
}
/*
* create a connection pool by user and database
*/
POOL_CONNECTION_POOL *pool_create_cp(void)
{
int i, freed = 0;
time_t closetime;
POOL_CONNECTION_POOL *oldestp;
POOL_CONNECTION_POOL *ret;
ConnectionInfo *info;
POOL_CONNECTION_POOL *p = pool_connection_pool;
if (p == NULL)
{
pool_error("pool_create_cp: pool_connection_pool is not initialized");
return NULL;
}
for (i=0;i<pool_config->max_pool;i++)
{
if (MASTER_CONNECTION(p) == NULL)
{
ret = new_connection(p);
if (ret)
pool_index = i;
return ret;
}
p++;
}
pool_debug("no empty connection slot was found");
/*
* no empty connection slot was found. look for the oldest connection and discard it.
*/
oldestp = p = pool_connection_pool;
closetime = MASTER_CONNECTION(p)->closetime;
pool_index = 0;
for (i=0;i<pool_config->max_pool;i++)
{
pool_debug("user: %s database: %s closetime: %ld",
MASTER_CONNECTION(p)->sp->user,
MASTER_CONNECTION(p)->sp->database,
MASTER_CONNECTION(p)->closetime);
if (MASTER_CONNECTION(p)->closetime < closetime)
{
closetime = MASTER_CONNECTION(p)->closetime;
oldestp = p;
pool_index = i;
}
p++;
}
p = oldestp;
pool_send_frontend_exits(p);
pool_debug("discarding old %zd th connection. user: %s database: %s",
oldestp - pool_connection_pool,
MASTER_CONNECTION(p)->sp->user,
MASTER_CONNECTION(p)->sp->database);
for (i=0;i<NUM_BACKENDS;i++)
{
if (!VALID_BACKEND(i))
continue;
if (!freed)
{
pool_free_startup_packet(CONNECTION_SLOT(p, i)->sp);
freed = 1;
}
pool_close(CONNECTION(p, i));
free(CONNECTION_SLOT(p, i));
}
info = p->info;
memset(p, 0, sizeof(POOL_CONNECTION_POOL));
p->info = info;
memset(p->info, 0, sizeof(ConnectionInfo) * MAX_NUM_BACKENDS);
ret = new_connection(p);
return ret;
}
/*
* Send extended query and wait for response
* send_type:
* -1: do not send this node_id
* 0: send to all nodes
* >0: send to this node_id
*/
POOL_STATUS pool_extended_send_and_wait(POOL_QUERY_CONTEXT *query_context,
char *kind, int len, char *contents,
int send_type, int node_id)
{
POOL_SESSION_CONTEXT *session_context;
POOL_CONNECTION *frontend;
POOL_CONNECTION_POOL *backend;
bool is_commit;
bool is_begin_read_write;
int i;
int str_len;
int rewritten_len;
char *str;
char *rewritten_begin;
session_context = pool_get_session_context();
frontend = session_context->frontend;
backend = session_context->backend;
is_commit = is_commit_or_rollback_query(query_context->parse_tree);
is_begin_read_write = false;
str_len = 0;
rewritten_len = 0;
str = NULL;
rewritten_begin = NULL;
/*
* If the query is BEGIN READ WRITE or
* BEGIN ... SERIALIZABLE in master/slave mode,
* we send BEGIN to slaves/standbys instead.
* original_query which is BEGIN READ WRITE is sent to primary.
* rewritten_query which is BEGIN is sent to standbys.
*/
if (pool_need_to_treat_as_if_default_transaction(query_context))
{
is_begin_read_write = true;
if (*kind == 'P')
{
rewritten_begin = remove_read_write(len, contents, &rewritten_len);
if (rewritten_begin == NULL)
return POOL_END;
}
}
if (!rewritten_begin)
{
str_len = len;
str = contents;
}
/* Send query */
for (i=0;i<NUM_BACKENDS;i++)
{
if (!VALID_BACKEND(i))
continue;
else if (send_type < 0 && i == node_id)
continue;
else if (send_type > 0 && i != node_id)
continue;
/*
* If in reset context, we send COMMIT/ABORT to nodes those
* are not in I(idle) state. This will ensure that
* transactions are closed.
*/
if (is_commit && session_context->reset_context && TSTATE(backend, i) == 'I')
{
pool_unset_node_to_be_sent(query_context, i);
continue;
}
if (rewritten_begin)
{
if (REAL_PRIMARY_NODE_ID == i)
{
str = contents;
str_len = len;
}
else
{
str = rewritten_begin;
str_len = rewritten_len;
}
}
if (pool_config->log_per_node_statement)
{
char msgbuf[QUERY_STRING_BUFFER_LEN];
char *stmt;
if (*kind == 'P' || *kind == 'E')
{
if (query_context->rewritten_query)
{
if (is_begin_read_write)
{
if (REAL_PRIMARY_NODE_ID == i)
stmt = query_context->original_query;
else
stmt = query_context->rewritten_query;
}
else
{
stmt = query_context->rewritten_query;
}
}
else
{
stmt = query_context->original_query;
}
if (*kind == 'P')
snprintf(msgbuf, sizeof(msgbuf), "Parse: %s", stmt);
else
snprintf(msgbuf, sizeof(msgbuf), "Execute: %s", stmt);
}
else
{
snprintf(msgbuf, sizeof(msgbuf), "%c message", *kind);
}
per_node_statement_log(backend, i, msgbuf);
}
if (send_extended_protocol_message(backend, i, kind, str_len, str) != POOL_CONTINUE)
{
free(rewritten_begin);
return POOL_END;
}
}
if (!is_begin_read_write)
{
if (query_context->rewritten_query)
str = query_context->rewritten_query;
else
str = query_context->original_query;
}
/* Wait for response */
for (i=0;i<NUM_BACKENDS;i++)
{
if (!VALID_BACKEND(i))
continue;
else if (send_type < 0 && i == node_id)
continue;
else if (send_type > 0 && i != node_id)
continue;
/*
* If in master/slave mode, we do not send COMMIT/ABORT to
* slaves/standbys if it's in I(idle) state.
*/
if (is_commit && MASTER_SLAVE && !IS_MASTER_NODE_ID(i) && TSTATE(backend, i) == 'I')
{
continue;
}
if (is_begin_read_write)
{
if (REAL_PRIMARY_NODE_ID == i)
str = query_context->original_query;
else
str = query_context->rewritten_query;
}
if (wait_for_query_response(frontend, CONNECTION(backend, i), MAJOR(backend)) != POOL_CONTINUE)
{
/* Cancel current transaction */
CancelPacket cancel_packet;
cancel_packet.protoVersion = htonl(PROTO_CANCEL);
cancel_packet.pid = MASTER_CONNECTION(backend)->pid;
cancel_packet.key= MASTER_CONNECTION(backend)->key;
cancel_request(&cancel_packet);
free(rewritten_begin);
return POOL_END;
}
/*
* Check if some error detected. If so, emit
* log. This is usefull when invalid encoding error
* occurs. In this case, PostgreSQL does not report
* what statement caused that error and make users
* confused.
*/
per_node_error_log(backend, i, str, "pool_send_and_wait: Error or notice message from backend: ", true);
}
free(rewritten_begin);
return POOL_CONTINUE;
}
/*
* Send simple query and wait for response
* send_type:
* -1: do not send this node_id
* 0: send to all nodes
* >0: send to this node_id
*/
POOL_STATUS pool_send_and_wait(POOL_QUERY_CONTEXT *query_context,
int send_type, int node_id)
{
POOL_SESSION_CONTEXT *session_context;
POOL_CONNECTION *frontend;
POOL_CONNECTION_POOL *backend;
bool is_commit;
bool is_begin_read_write;
int i;
int len;
char *string;
session_context = pool_get_session_context();
frontend = session_context->frontend;
backend = session_context->backend;
is_commit = is_commit_or_rollback_query(query_context->parse_tree);
is_begin_read_write = false;
len = 0;
string = NULL;
/*
* If the query is BEGIN READ WRITE or
* BEGIN ... SERIALIZABLE in master/slave mode,
* we send BEGIN to slaves/standbys instead.
* original_query which is BEGIN READ WRITE is sent to primary.
* rewritten_query which is BEGIN is sent to standbys.
*/
if (pool_need_to_treat_as_if_default_transaction(query_context))
{
is_begin_read_write = true;
}
else
{
if (query_context->rewritten_query)
{
len = query_context->rewritten_length;
string = query_context->rewritten_query;
}
else
{
len = query_context->original_length;
string = query_context->original_query;
}
}
/* Send query */
for (i=0;i<NUM_BACKENDS;i++)
{
if (!VALID_BACKEND(i))
continue;
else if (send_type < 0 && i == node_id)
continue;
else if (send_type > 0 && i != node_id)
continue;
/*
* If in master/slave mode, we do not send COMMIT/ABORT to
* slaves/standbys if it's in I(idle) state.
*/
if (is_commit && MASTER_SLAVE && !IS_MASTER_NODE_ID(i) && TSTATE(backend, i) == 'I')
{
pool_unset_node_to_be_sent(query_context, i);
continue;
}
/*
* If in reset context, we send COMMIT/ABORT to nodes those
* are not in I(idle) state. This will ensure that
* transactions are closed.
*/
if (is_commit && session_context->reset_context && TSTATE(backend, i) == 'I')
{
pool_unset_node_to_be_sent(query_context, i);
continue;
}
if (is_begin_read_write)
{
if (REAL_PRIMARY_NODE_ID == i)
{
len = query_context->original_length;
string = query_context->original_query;
}
else
{
len = query_context->rewritten_length;
string = query_context->rewritten_query;
}
}
per_node_statement_log(backend, i, string);
if (send_simplequery_message(CONNECTION(backend, i), len, string, MAJOR(backend)) != POOL_CONTINUE)
{
return POOL_END;
}
}
/* Wait for response */
for (i=0;i<NUM_BACKENDS;i++)
{
if (!VALID_BACKEND(i))
continue;
else if (send_type < 0 && i == node_id)
continue;
else if (send_type > 0 && i != node_id)
continue;
#ifdef NOT_USED
/*
* If in master/slave mode, we do not send COMMIT/ABORT to
* slaves/standbys if it's in I(idle) state.
*/
if (is_commit && MASTER_SLAVE && !IS_MASTER_NODE_ID(i) && TSTATE(backend, i) == 'I')
{
continue;
}
#endif
if (is_begin_read_write)
{
if(REAL_PRIMARY_NODE_ID == i)
string = query_context->original_query;
else
string = query_context->rewritten_query;
}
if (wait_for_query_response(frontend, CONNECTION(backend, i), MAJOR(backend)) != POOL_CONTINUE)
{
/* Cancel current transaction */
CancelPacket cancel_packet;
cancel_packet.protoVersion = htonl(PROTO_CANCEL);
cancel_packet.pid = MASTER_CONNECTION(backend)->pid;
cancel_packet.key= MASTER_CONNECTION(backend)->key;
cancel_request(&cancel_packet);
return POOL_END;
}
/*
* Check if some error detected. If so, emit
* log. This is usefull when invalid encoding error
* occurs. In this case, PostgreSQL does not report
* what statement caused that error and make users
* confused.
*/
per_node_error_log(backend, i, string, "pool_send_and_wait: Error or notice message from backend: ", true);
}
return POOL_CONTINUE;
}
/*
* child main loop
*/
void do_child(int unix_fd, int inet_fd)
{
POOL_CONNECTION *frontend;
POOL_CONNECTION_POOL *backend;
struct timeval now;
struct timezone tz;
struct timeval timeout;
static int connected; /* non 0 if has been accepted connections from frontend */
int connections_count = 0; /* used if child_max_connections > 0 */
int found;
char psbuf[NI_MAXHOST + 128];
pool_debug("I am %d", getpid());
/* Identify myself via ps */
init_ps_display("", "", "", "");
/* set up signal handlers */
signal(SIGALRM, SIG_DFL);
signal(SIGTERM, die);
signal(SIGINT, die);
signal(SIGHUP, reload_config_handler);
signal(SIGQUIT, die);
signal(SIGCHLD, SIG_DFL);
signal(SIGUSR1, close_idle_connection);
signal(SIGUSR2, wakeup_handler);
signal(SIGPIPE, SIG_IGN);
#ifdef NONE_BLOCK
/* set listen fds to none-blocking */
pool_set_nonblock(unix_fd);
if (inet_fd)
{
pool_set_nonblock(inet_fd);
}
#endif
/* Initialize my backend status */
pool_initialize_private_backend_status();
/* Initialize per process context */
pool_init_process_context();
/* initialize random seed */
gettimeofday(&now, &tz);
#if defined(sun) || defined(__sun)
srand((unsigned int) now.tv_usec);
#else
srandom((unsigned int) now.tv_usec);
#endif
/* initialize system db connection */
init_system_db_connection();
/* initialize connection pool */
if (pool_init_cp())
{
child_exit(1);
}
/*
* Open pool_passwd in child process. This is necessary to avoid the
* file descriptor race condition reported in [pgpool-general: 1141].
*/
if (strcmp("", pool_config->pool_passwd))
{
pool_reopen_passwd_file();
}
timeout.tv_sec = pool_config->child_life_time;
timeout.tv_usec = 0;
for (;;)
{
StartupPacket *sp;
idle = 1;
/* pgpool stop request already sent? */
check_stop_request();
/* Check if restart request is set because of failback event
* happend. If so, exit myself with exit code 1 to be
* restarted by pgpool parent.
*/
if (pool_get_my_process_info()->need_to_restart)
{
pool_log("do_child: failback event found. restart myself.");
pool_get_my_process_info()->need_to_restart = 0;
child_exit(1);
}
accepted = 0;
/* perform accept() */
frontend = do_accept(unix_fd, inet_fd, &timeout);
if (frontend == NULL) /* connection request from frontend timed out */
{
/* check select() timeout */
if (connected && pool_config->child_life_time > 0 &&
timeout.tv_sec == 0 && timeout.tv_usec == 0)
{
pool_debug("child life %d seconds expired", pool_config->child_life_time);
/*
* Doesn't need to call this. child_exit() calls it.
* send_frontend_exits();
*/
child_exit(2);
}
continue;
}
/* set frontend fd to blocking */
pool_unset_nonblock(frontend->fd);
/* reset busy flag */
idle = 0;
/* check backend timer is expired */
if (backend_timer_expired)
{
pool_backend_timer();
backend_timer_expired = 0;
}
/* read the startup packet */
retry_startup:
sp = read_startup_packet(frontend);
if (sp == NULL)
{
/* failed to read the startup packet. return to the accept() loop */
pool_close(frontend);
connection_count_down();
continue;
}
/* cancel request? */
if (sp->major == 1234 && sp->minor == 5678)
{
cancel_request((CancelPacket *)sp->startup_packet);
pool_close(frontend);
pool_free_startup_packet(sp);
connection_count_down();
continue;
}
/* SSL? */
if (sp->major == 1234 && sp->minor == 5679 && !frontend->ssl_active)
{
pool_debug("SSLRequest from client");
pool_ssl_negotiate_serverclient(frontend);
goto retry_startup;
}
if (pool_config->enable_pool_hba)
{
/*
* do client authentication.
* Note that ClientAuthentication does not return if frontend
* was rejected; it simply terminates this process.
*/
frontend->protoVersion = sp->major;
frontend->database = strdup(sp->database);
if (frontend->database == NULL)
{
pool_error("do_child: strdup failed: %s\n", strerror(errno));
child_exit(1);
}
frontend->username = strdup(sp->user);
if (frontend->username == NULL)
{
pool_error("do_child: strdup failed: %s\n", strerror(errno));
child_exit(1);
}
ClientAuthentication(frontend);
}
/*
* Ok, negotiation with frontend has been done. Let's go to the
* next step. Connect to backend if there's no existing
* connection which can be reused by this frontend.
* Authentication is also done in this step.
*/
/* Check if restart request is set because of failback event
* happend. If so, close idle connections to backend and make
* a new copy of backend status.
*/
if (pool_get_my_process_info()->need_to_restart)
{
pool_log("do_child: failback event found. discard existing connections");
pool_get_my_process_info()->need_to_restart = 0;
close_idle_connection(0);
pool_initialize_private_backend_status();
}
/*
* if there's no connection associated with user and database,
* we need to connect to the backend and send the startup packet.
*/
/* look for existing connection */
found = 0;
backend = pool_get_cp(sp->user, sp->database, sp->major, 1);
if (backend != NULL)
{
found = 1;
/* existing connection associated with same user/database/major found.
* however we should make sure that the startup packet contents are identical.
* OPTION data and others might be different.
*/
if (sp->len != MASTER_CONNECTION(backend)->sp->len)
{
pool_debug("do_child: connection exists but startup packet length is not identical");
found = 0;
}
else if(memcmp(sp->startup_packet, MASTER_CONNECTION(backend)->sp->startup_packet, sp->len) != 0)
{
pool_debug("do_child: connection exists but startup packet contents is not identical");
found = 0;
}
if (found == 0)
{
/* we need to discard existing connection since startup packet is different */
pool_discard_cp(sp->user, sp->database, sp->major);
backend = NULL;
}
}
if (backend == NULL)
{
/* create a new connection to backend */
if ((backend = connect_backend(sp, frontend)) == NULL)
{
connection_count_down();
continue;
}
}
else
{
/* reuse existing connection */
if (!connect_using_existing_connection(frontend, backend, sp))
continue;
}
connected = 1;
/* show ps status */
sp = MASTER_CONNECTION(backend)->sp;
snprintf(psbuf, sizeof(psbuf), "%s %s %s idle",
sp->user, sp->database, remote_ps_data);
set_ps_display(psbuf, false);
/*
* Initialize per session context
*/
pool_init_session_context(frontend, backend);
/* Mark this connection pool is connected from frontend */
pool_coninfo_set_frontend_connected(pool_get_process_context()->proc_id, pool_pool_index());
/* query process loop */
for (;;)
{
POOL_STATUS status;
status = pool_process_query(frontend, backend, 0);
sp = MASTER_CONNECTION(backend)->sp;
switch (status)
{
/* client exits */
case POOL_END:
/*
* do not cache connection if:
* pool_config->connection_cahe == 0 or
* database name is template0, template1, postgres or regression
*/
if (pool_config->connection_cache == 0 ||
!strcmp(sp->database, "template0") ||
!strcmp(sp->database, "template1") ||
!strcmp(sp->database, "postgres") ||
!strcmp(sp->database, "regression"))
{
reset_connection();
pool_close(frontend);
pool_send_frontend_exits(backend);
pool_discard_cp(sp->user, sp->database, sp->major);
}
else
{
POOL_STATUS status1;
/* send reset request to backend */
status1 = pool_process_query(frontend, backend, 1);
pool_close(frontend);
/* if we detect errors on resetting connection, we need to discard
* this connection since it might be in unknown status
*/
if (status1 != POOL_CONTINUE)
{
pool_debug("error in resetting connections. discarding connection pools...");
pool_send_frontend_exits(backend);
pool_discard_cp(sp->user, sp->database, sp->major);
}
else
pool_connection_pool_timer(backend);
}
break;
/* error occurred. discard backend connection pool
and disconnect connection to the frontend */
case POOL_ERROR:
pool_log("do_child: exits with status 1 due to error");
child_exit(1);
break;
/* fatal error occurred. just exit myself... */
case POOL_FATAL:
notice_backend_error(1);
child_exit(1);
break;
/* not implemented yet */
case POOL_IDLE:
do_accept(unix_fd, inet_fd, &timeout);
pool_debug("accept while idle");
break;
default:
break;
}
if (status != POOL_CONTINUE)
break;
}
/* Destroy session context */
pool_session_context_destroy();
/* Mark this connection pool is not connected from frontend */
pool_coninfo_unset_frontend_connected(pool_get_process_context()->proc_id, pool_pool_index());
accepted = 0;
connection_count_down();
timeout.tv_sec = pool_config->child_life_time;
timeout.tv_usec = 0;
/* increment queries counter if necessary */
if ( pool_config->child_max_connections > 0 )
connections_count++;
/* check if maximum connections count for this child reached */
if ( ( pool_config->child_max_connections > 0 ) &&
( connections_count >= pool_config->child_max_connections ) )
{
pool_log("child exiting, %d connections reached", pool_config->child_max_connections);
send_frontend_exits();
child_exit(2);
}
}
child_exit(0);
}
/*
* Search relcache. If found, return user data. Otherwise return 0.
* If not found in cache, do the query and store the result into cache and return it.
*/
void *pool_search_relcache(POOL_RELCACHE *relcache, POOL_CONNECTION_POOL *backend, char *table)
{
char *rel;
char *dbname;
int i;
int maxrefcnt = INT_MAX;
char query[1024];
POOL_SELECT_RESULT *res = NULL;
int index = 0;
/* Eliminate double quotes */
rel = malloc(strlen(table)+1);
if (!rel)
{
pool_error("pool_search_relcache: malloc failed");
return NULL;
}
for(i=0;*table;table++)
{
if (*table != '"')
rel[i++] = *table;
}
rel[i] = '\0';
/* Obtain database name */
dbname = MASTER_CONNECTION(backend)->sp->database;
/* Look for cache first */
for (i=0;i<relcache->num;i++)
{
/*
* If cache is session local, we need to check session id
*/
if (relcache->cache_is_session_local)
{
if (relcache->cache[i].session_id != LocalSessionId)
continue;
}
if (strcasecmp(relcache->cache[i].dbname, dbname) == 0 &&
strcasecmp(relcache->cache[i].relname, rel) == 0)
{
/* Found */
if (relcache->cache[i].refcnt < INT_MAX)
relcache->cache[i].refcnt++;
free(rel);
return relcache->cache[i].data;
}
}
/* Not in cache. Check the system catalog */
snprintf(query, sizeof(query), relcache->sql, rel);
per_node_statement_log(backend, MASTER_NODE_ID, query);
if (do_query(MASTER(backend), query, &res) != POOL_CONTINUE)
{
pool_error("pool_search_relcache: do_query failed");
if (res)
free_select_result(res);
free(rel);
return NULL;
}
/*
* Look for replacement in cache
*/
for (i=0;i<relcache->num;i++)
{
/*
* If cache is session local, we can discard old cache immediately
*/
if (relcache->cache_is_session_local)
{
if (relcache->cache[i].session_id != LocalSessionId)
{
index = i;
break;
}
}
if (relcache->cache[i].refcnt == 0)
{
/* Found empty slot */
index = i;
break;
}
else if (relcache->cache[i].refcnt < maxrefcnt)
{
maxrefcnt = relcache->cache[i].refcnt;
index = i;
}
}
/* Register cache */
strncpy(relcache->cache[index].dbname, dbname, MAX_ITEM_LENGTH);
strncpy(relcache->cache[index].relname, rel, MAX_ITEM_LENGTH);
relcache->cache[index].refcnt = 1;
relcache->cache[index].session_id = LocalSessionId;
free(rel);
/*
* Call user defined unregister/register fuction.
*/
(*relcache->unregister_func)(relcache->cache[index].data);
relcache->cache[index].data = (*relcache->register_func)(res);
free_select_result(res);
return relcache->cache[index].data;
}
void pool_backend_timer(void)
{
#define TMINTMAX 0x7fffffff
POOL_CONNECTION_POOL *p = pool_connection_pool;
int i, j;
time_t now;
time_t nearest = TMINTMAX;
ConnectionInfo *info;
POOL_SETMASK(&BlockSig);
now = time(NULL);
pool_debug("pool_backend_timer_handler called at %ld", now);
for (i=0;i<pool_config->max_pool;i++, p++)
{
if (!MASTER_CONNECTION(p))
continue;
if (!MASTER_CONNECTION(p)->sp)
continue;
if (MASTER_CONNECTION(p)->sp->user == NULL)
continue;
/* timer expire? */
if (MASTER_CONNECTION(p)->closetime)
{
int freed = 0;
pool_debug("pool_backend_timer_handler: expire time: %ld",
MASTER_CONNECTION(p)->closetime+pool_config->connection_life_time);
if (now >= (MASTER_CONNECTION(p)->closetime+pool_config->connection_life_time))
{
/* discard expired connection */
pool_debug("pool_backend_timer_handler: expires user %s database %s",
MASTER_CONNECTION(p)->sp->user, MASTER_CONNECTION(p)->sp->database);
pool_send_frontend_exits(p);
for (j=0;j<NUM_BACKENDS;j++)
{
if (!VALID_BACKEND(j))
continue;
if (!freed)
{
pool_free_startup_packet(CONNECTION_SLOT(p, j)->sp);
freed = 1;
}
pool_close(CONNECTION(p, j));
free(CONNECTION_SLOT(p, j));
}
info = p->info;
memset(p, 0, sizeof(POOL_CONNECTION_POOL));
p->info = info;
memset(p->info, 0, sizeof(ConnectionInfo) * MAX_NUM_BACKENDS);
/* prepare to shutdown connections to system db */
if(pool_config->system_db_dynamic_connection && (pool_config->parallel_mode || pool_config->enable_query_cache))
{
if (system_db_info->pgconn)
pool_close_libpq_connection();
if (pool_system_db_connection() && pool_system_db_connection()->con)
{
pool_send_frontend_exit(pool_system_db_connection()->con);
pool_close(pool_system_db_connection()->con);
}
if( system_db_info->connection )
{
free( system_db_info->connection );
memset(system_db_info->connection, 0, sizeof(POOL_CONNECTION_POOL_SLOT));
system_db_info->connection = NULL;
}
}
}
else
{
/* look for nearest timer */
if (MASTER_CONNECTION(p)->closetime < nearest)
nearest = MASTER_CONNECTION(p)->closetime;
}
}
}
/* any remaining timer */
if (nearest != TMINTMAX)
{
nearest = pool_config->connection_life_time - (now - nearest);
if (nearest <= 0)
nearest = 1;
pool_signal(SIGALRM, pool_backend_timer_handler);
alarm(nearest);
}
POOL_SETMASK(&UnBlockSig);
}
/*
* create a connection pool by user and database
*/
POOL_CONNECTION_POOL *pool_create_cp(void)
{
int i;
time_t closetime;
POOL_CONNECTION_POOL *oldestp;
POOL_CONNECTION_POOL *p = pool_connection_pool;
if (p == NULL)
{
pool_error("pool_create_cp: pool_connection_pool is not initialized");
return NULL;
}
for (i=0;i<pool_config.max_pool;i++)
{
if (MASTER_CONNECTION(p) == NULL)
return new_connection(p);
p++;
}
pool_debug("no empty connection slot was found");
/*
* no empty connection slot was found. look for the oldest connection and discard it.
*/
oldestp = p = pool_connection_pool;
closetime = MASTER_CONNECTION(p)->closetime;
for (i=0;i<pool_config.max_pool;i++)
{
pool_debug("user: %s database: %s closetime: %d",
MASTER_CONNECTION(p)->sp->user,
MASTER_CONNECTION(p)->sp->database,
MASTER_CONNECTION(p)->closetime);
if (MASTER_CONNECTION(p)->closetime < closetime)
{
closetime = MASTER_CONNECTION(p)->closetime;
oldestp = p;
}
p++;
}
p = oldestp;
pool_send_frontend_exits(p);
pool_debug("discarding old %d th connection. user: %s database: %s",
oldestp - pool_connection_pool,
MASTER_CONNECTION(p)->sp->user,
MASTER_CONNECTION(p)->sp->database);
pool_free_startup_packet(MASTER_CONNECTION(p)->sp);
pool_close(MASTER_CONNECTION(p)->con);
free(MASTER_CONNECTION(p));
if (DUAL_MODE)
{
/* do not free memory! we did not allocate them */
pool_close(SECONDARY_CONNECTION(p)->con);
free(SECONDARY_CONNECTION(p));
}
memset(p, 0, sizeof(POOL_CONNECTION_POOL));
return new_connection(p);
}
void pool_backend_timer(void)
{
#define TMINTMAX 0x7fffffff
POOL_CONNECTION_POOL *p = pool_connection_pool;
int i;
time_t now;
time_t nearest = TMINTMAX;
POOL_SETMASK(&BlockSig);
now = time(NULL);
pool_debug("pool_backend_timer_handler called at %d", now);
for (i=0;i<pool_config.max_pool;i++, p++)
{
if (!MASTER_CONNECTION(p))
continue;
if (MASTER_CONNECTION(p)->sp->user == NULL)
continue;
/* timer expire? */
if (MASTER_CONNECTION(p)->closetime)
{
pool_debug("pool_backend_timer_handler: expire time: %d",
MASTER_CONNECTION(p)->closetime+pool_config.connection_life_time);
if (now >= (MASTER_CONNECTION(p)->closetime+pool_config.connection_life_time))
{
/* discard expired connection */
pool_debug("pool_backend_timer_handler: expires user %s database %s", MASTER_CONNECTION(p)->sp->user, MASTER_CONNECTION(p)->sp->database);
pool_send_frontend_exits(p);
pool_free_startup_packet(MASTER_CONNECTION(p)->sp);
pool_close(MASTER_CONNECTION(p)->con);
free(MASTER_CONNECTION(p));
if (DUAL_MODE)
{
pool_close(SECONDARY_CONNECTION(p)->con);
free(SECONDARY_CONNECTION(p));
}
memset(p, 0, sizeof(POOL_CONNECTION_POOL));
}
else
{
/* look for nearest timer */
if (MASTER_CONNECTION(p)->closetime < nearest)
nearest = MASTER_CONNECTION(p)->closetime;
}
}
}
/* any remaining timer */
if (nearest != TMINTMAX)
{
nearest = pool_config.connection_life_time - (now - nearest);
if (nearest <= 0)
nearest = 1;
pool_signal(SIGALRM, pool_backend_timer_handler);
alarm(nearest);
}
POOL_SETMASK(&UnBlockSig);
}
/*
* find connection by user and database
*/
POOL_CONNECTION_POOL *pool_get_cp(char *user, char *database, int protoMajor, int check_socket)
{
#ifdef HAVE_SIGPROCMASK
sigset_t oldmask;
#else
int oldmask;
#endif
int i, freed = 0;
ConnectionInfo *info;
POOL_CONNECTION_POOL *p = pool_connection_pool;
if (p == NULL)
{
pool_error("pool_get_cp: pool_connection_pool is not initialized");
return NULL;
}
POOL_SETMASK2(&BlockSig, &oldmask);
for (i=0;i<pool_config->max_pool;i++)
{
if (MASTER_CONNECTION(p) &&
MASTER_CONNECTION(p)->sp &&
MASTER_CONNECTION(p)->sp->major == protoMajor &&
MASTER_CONNECTION(p)->sp->user != NULL &&
strcmp(MASTER_CONNECTION(p)->sp->user, user) == 0 &&
strcmp(MASTER_CONNECTION(p)->sp->database, database) == 0)
{
int sock_broken = 0;
int j;
/* mark this connection is under use */
MASTER_CONNECTION(p)->closetime = 0;
for (j=0;j<NUM_BACKENDS;j++)
{
p->info[j].counter++;
}
POOL_SETMASK(&oldmask);
if (check_socket)
{
for (j=0;j<NUM_BACKENDS;j++)
{
if (!VALID_BACKEND(j))
continue;
if (CONNECTION_SLOT(p, j))
{
sock_broken = check_socket_status(CONNECTION(p, j)->fd);
if (sock_broken < 0)
break;
}
else
{
sock_broken = -1;
break;
}
}
if (sock_broken < 0)
{
pool_log("connection closed. retry to create new connection pool.");
for (j=0;j<NUM_BACKENDS;j++)
{
if (!VALID_BACKEND(j) || (CONNECTION_SLOT(p, j) == NULL))
continue;
if (!freed)
{
pool_free_startup_packet(CONNECTION_SLOT(p, j)->sp);
freed = 1;
}
pool_close(CONNECTION(p, j));
free(CONNECTION_SLOT(p, j));
}
info = p->info;
memset(p, 0, sizeof(POOL_CONNECTION_POOL_SLOT));
p->info = info;
memset(p->info, 0, sizeof(ConnectionInfo) * MAX_NUM_BACKENDS);
POOL_SETMASK(&oldmask);
return NULL;
}
}
POOL_SETMASK(&oldmask);
pool_index = i;
return p;
}
p++;
}
POOL_SETMASK(&oldmask);
return NULL;
}
/*
* Reuse existing connection
*/
static bool connect_using_existing_connection(POOL_CONNECTION *frontend,
POOL_CONNECTION_POOL *backend,
StartupPacket *sp)
{
int i, freed = 0;
/*
* Save startup packet info
*/
for (i = 0; i < NUM_BACKENDS; i++)
{
if (VALID_BACKEND(i))
{
if (!freed)
{
pool_free_startup_packet(backend->slots[i]->sp);
freed = 1;
}
backend->slots[i]->sp = sp;
}
}
/* Reuse existing connection to backend */
if (pool_do_reauth(frontend, backend))
{
pool_close(frontend);
connection_count_down();
return false;
}
if (MAJOR(backend) == 3)
{
char command_buf[1024];
/* If we have received application_name in the start up
* packet, we send SET command to backend. Also we add or
* replace existing application_name data.
*/
if (sp->application_name)
{
snprintf(command_buf, sizeof(command_buf), "SET application_name TO '%s'", sp->application_name);
for (i=0;i<NUM_BACKENDS;i++)
{
if (VALID_BACKEND(i))
if (do_command(frontend, CONNECTION(backend, i),
command_buf, MAJOR(backend),
MASTER_CONNECTION(backend)->pid,
MASTER_CONNECTION(backend)->key, 0) != POOL_CONTINUE)
{
pool_error("connect_using_existing_connection: do_command failed. command: %s", command_buf);
return false;
}
}
pool_add_param(&MASTER(backend)->params, "application_name", sp->application_name);
}
if (send_params(frontend, backend))
{
pool_close(frontend);
connection_count_down();
return false;
}
}
/* Send ReadyForQuery to frontend */
pool_write(frontend, "Z", 1);
if (MAJOR(backend) == 3)
{
int len;
char tstate;
len = htonl(5);
pool_write(frontend, &len, sizeof(len));
tstate = TSTATE(backend, MASTER_NODE_ID);
pool_write(frontend, &tstate, 1);
}
if (pool_flush(frontend) < 0)
{
pool_close(frontend);
connection_count_down();
return false;
}
return true;
}
