/* -*-pgsql-c-*- */
/*
- *
- * $Header$
*
* pgpool: a language independent connection pool server for PostgreSQL
* written by Tatsuo Ishii
*
- * Copyright (c) 2003-2015 PgPool Global Development Group
+ * Copyright (c) 2003-2018 PgPool Global Development Group
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby
#define MASTER_CONNECTION(p) ((p)->slots[MASTER_NODE_ID])
#define MASTER(p) MASTER_CONNECTION(p)->con
+/*
+ * Backend node status in streaming replication mode.
+ */
+typedef enum {
+ POOL_NODE_STATUS_UNUSED, /* unused */
+ POOL_NODE_STATUS_PRIMARY, /* primary ndoe */
+ POOL_NODE_STATUS_STANDBY, /* standby node */
+ POOL_NODE_STATUS_INVALID /* invalid node (split branin, stand alone) */
+} POOL_NODE_STATUS;
+
#define REPLICATION (pool_config->replication_mode)
#define MASTER_SLAVE (pool_config->master_slave_mode)
#define STREAM (MASTER_SLAVE && pool_config->master_slave_sub_mode == STREAM_MODE)
/* pool_worker_child.c */
extern void do_worker_child(void);
+extern int get_query_result(POOL_CONNECTION_POOL_SLOT **slots, int backend_id, char *query, POOL_SELECT_RESULT **res);
/* md5.c */
extern bool pg_md5_encrypt(const char *passwd, const char *salt, size_t salt_len, char *buf);
extern pid_t pool_waitpid(int *status);
extern int write_status_file(void);
extern void do_health_check_child(int *node_id);
+extern POOL_NODE_STATUS *pool_get_node_status(void);
#endif /* POOL_H */
* pgpool: a language independent connection pool server for PostgreSQL
* written by Tatsuo Ishii
*
- * Copyright (c) 2003-2017 PgPool Global Development Group
+ * Copyright (c) 2003-2018 PgPool Global Development Group
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby
static void initialize_shared_mem_objects(bool clear_memcache_oidmaps);
static int trigger_failover_command(int node, const char *command_line,
int old_master, int new_master, int old_primary);
-static bool verify_backend_node_status(int backend_no, bool* is_standby);
+static POOL_NODE_STATUS *verify_backend_node_status(POOL_CONNECTION_POOL_SLOT **slots);
static int find_primary_node(void);
static int find_primary_node_repeatedly(void);
static void terminate_all_childrens();
* successfull start.
*/
if (first)
+ {
+ int i;
+ int n;
+ POOL_NODE_STATUS *node_status = pool_get_node_status();
+
ereport(LOG,
(errmsg("%s successfully started. version %s (%s)", PACKAGE, VERSION, PGPOOLVERSION)));
+
+ /* Very early stage node checking. It is assumed that find_primary_node got called. */
+ for (i=0;i<NUM_BACKENDS;i++)
+ {
+ ereport(LOG,
+ (errmsg("node status[%d]: %d", i, node_status[i])));
+
+ if (node_status[i] == POOL_NODE_STATUS_INVALID)
+ {
+ ereport(LOG,
+ (errmsg("pgpool_main: invalid node found %d", i)));
+ n = i;
+ degenerate_backend_set(&n, 1, REQ_DETAIL_SWITCHOVER|REQ_DETAIL_CONFIRMED);
+ }
+ }
+ }
first = false;
processState = SLEEPING;
return r;
}
+
/*
- * This function is used by find_primary_node() function and is just a wrapper
- * over make_persistent_db_connection() function and returns boolean value to
- * inform connection status.
- * This function must not throw ereport.
+ * This function is used by find_primary_node(). Find primary node/standby
+ * node and returns static array of status for each backend node. This
+ * function must not throw ereport.
*/
-static bool
- verify_backend_node_status(int backend_no, bool* is_standby)
+static POOL_NODE_STATUS pool_node_status[MAX_NUM_BACKENDS];
+
+static POOL_NODE_STATUS *
+verify_backend_node_status(POOL_CONNECTION_POOL_SLOT **slots)
{
- POOL_CONNECTION_POOL_SLOT *s = NULL;
- POOL_CONNECTION *con;
POOL_SELECT_RESULT *res;
- BackendInfo *bkinfo = pool_get_node_info(backend_no);
-
- *is_standby = false;
+ bool found_primary = false;
+ int i;
- s = make_persistent_db_connection_noerror(backend_no, bkinfo->backend_hostname,
- bkinfo->backend_port,
- pool_config->sr_check_database,
- pool_config->sr_check_user,
- pool_config->sr_check_password, true);
- if (s)
+ for (i=0;i<NUM_BACKENDS;i++)
{
- MemoryContext oldContext = CurrentMemoryContext;
- con = s->con;
+ pool_node_status[i] = POOL_NODE_STATUS_UNUSED;
- PG_TRY();
+ if (!VALID_BACKEND(i))
+ continue;
+
+ if (!slots[i])
+ continue;
+
+ if (get_query_result(slots, i, "SELECT pg_is_in_recovery()", &res))
{
- do_query(con, "SELECT pg_is_in_recovery()",
- &res, PROTO_MAJOR_V3);
+ continue;
}
- PG_CATCH();
+
+ if (res->data[0] && !strcmp(res->data[0], "t"))
{
- /* ignore the error message */
- res = NULL;
- MemoryContextSwitchTo(oldContext);
- FlushErrorState();
- ereport(LOG,
- (errmsg("verify_backend_node_status: do_query failed")));
+ /* Possibly standby */
+ pool_node_status[i] = POOL_NODE_STATUS_STANDBY;
}
- PG_END_TRY();
- if(res)
+ else if (res->data[0] && !strcmp(res->data[0], "f"))
{
- if (res->numrows <= 0)
- {
- ereport(LOG,
- (errmsg("verify_backend_node_status: do_query returns no rows")));
- }
- if (res->data[0] == NULL)
- {
- ereport(LOG,
- (errmsg("verify_backend_node_status: do_query returns no data")));
- }
- if (res->nullflags[0] == -1)
- {
- ereport(LOG,
- (errmsg("verify_backend_node_status: do_query returns NULL")));
- }
- if (res->data[0] && !strcmp(res->data[0], "t"))
+ /* Possibly primary. Let's see if we already found a primary
+ * (checking split brain)
+ */
+ if (found_primary)
+ pool_node_status[i] = POOL_NODE_STATUS_INVALID;
+ else
{
- *is_standby = true;
+ pool_node_status[i] = POOL_NODE_STATUS_PRIMARY;
+ found_primary = true;
}
- free_select_result(res);
}
- discard_persistent_db_connection(s);
- return true;
+ free_select_result(res);
}
- return false;
+
+ return pool_node_status;
+}
+
+POOL_NODE_STATUS *
+pool_get_node_status(void)
+{
+ return pool_node_status;
}
/*
*/
static int find_primary_node(void)
{
+ BackendInfo *bkinfo;
+ POOL_CONNECTION_POOL_SLOT *slots[MAX_NUM_BACKENDS];
int i;
+ POOL_NODE_STATUS *status;
+ int primary = 0;
/* Streaming replication mode? */
if (!SL_MODE)
}
/*
- *First check for "ALWAYS_MASTER" flags exists. If so, do not perform
+ * First check for "ALWAYS_MASTER" flags exists. If so, do not perform
* actual primary node check and just returns the node id.
*/
for(i=0;i<NUM_BACKENDS;i++)
}
}
- for(i=0;i<NUM_BACKENDS;i++)
+ /*
+ * Establish connections to backend
+ */
+ for (i=0;i<NUM_BACKENDS;i++)
{
- bool node_status;
- bool is_standby;
-
- ereport(LOG,
- (errmsg("find_primary_node: checking backend no %d",i)));
+ slots[i] = NULL;
if (!VALID_BACKEND(i))
continue;
- node_status = verify_backend_node_status(i,&is_standby);
- if (!node_status)
- {
- /*
- * It is possible that a node is down even if
- * VALID_BACKEND tells it's valid. This could happen
- * before health checking detects the failure.
- * Thus we should continue to look for primary node.
- */
- continue;
- }
- if (is_standby)
- ereport(DEBUG1,
- (errmsg("find_primary_node: %d node is standby", i)));
- else
- break;
+
+ bkinfo = pool_get_node_info(i);
+
+ slots[i] = make_persistent_db_connection_noerror(i, bkinfo->backend_hostname,
+ bkinfo->backend_port,
+ pool_config->sr_check_database,
+ pool_config->sr_check_user,
+ pool_config->sr_check_password, true);
+ if (!slots[i])
+ {
+ ereport(LOG,
+ (errmsg("find_primary_node: make_persistent_db_connection_noerror failed on node %d", i)));
+ }
}
- if (i == NUM_BACKENDS)
+ /* Verify backend status */
+ status = verify_backend_node_status(slots);
+
+ for(i=0;i<NUM_BACKENDS;i++)
{
- ereport(DEBUG1,
- (errmsg("find_primary_node: no primary node found")));
- return -1;
+ if (status[i] == POOL_NODE_STATUS_PRIMARY)
+ {
+ /* This is the primary */
+ ereport(LOG,
+ (errmsg("find_primary_node: primary node is %d",i)));
+ primary = i;
+ }
+ else if (status[i] == POOL_NODE_STATUS_STANDBY)
+ {
+ ereport(LOG,
+ (errmsg("find_primary_node: standby node is %d", i)));
+ }
+ else if (status[i] == POOL_NODE_STATUS_INVALID)
+ {
+ /* Split brain or invalid node */
+ ereport(LOG,
+ (errmsg("find_primary_node: invalid node %d", i)));
+ }
}
- ereport(LOG,
- (errmsg("find_primary_node: primary node id is %d", i)));
- return i;
+ for (i=0;i<NUM_BACKENDS;i++)
+ {
+ if (slots[i])
+ discard_persistent_db_connection(slots[i]);
+ }
+
+ return primary;
}
static int find_primary_node_repeatedly(void)
/* -*-pgsql-c-*- */
/*
- * $Header$
- *
* pgpool: a language independent connection pool server for PostgreSQL
* written by Tatsuo Ishii
*
- * Copyright (c) 2003-2017 PgPool Global Development Group
+ * Copyright (c) 2003-2018 PgPool Global Development Group
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby
static RETSIGTYPE my_signal_handler(int sig);
static RETSIGTYPE reload_config_handler(int sig);
static void reload_config(void);
-static int get_query_result(int backend_id, char *query, POOL_SELECT_RESULT **res);
#define CHECK_REQUEST \
do { \
{
query = "SELECT current_setting('server_version_num')";
- /* Get backend serversion. If the query fails, keep previous info. */
- if (get_query_result(i, query, &res) == 0)
+ /* Get backend server version. If the query fails, keep previous info. */
+ if (get_query_result(slots, i, query, &res) == 0)
{
server_version[i] = atoi(res->data[0]);
ereport(DEBUG1,
query = "SELECT pg_last_xlog_replay_location()";
}
- if (get_query_result(i, query, &res) == 0)
+ if (get_query_result(slots, i, query, &res) == 0)
{
lsn[i] = text_to_lsn(res->data[0]);
free_select_result(res);
}
/*
- * Execute query against specified backend.
- * Return -1 on failure or 0 otherwise.
- * Caller must prepare memory for POOL_SELECT_RESULT and pass it as "res".
+ * Execute query against specified backend using an established connection to
+ * backend. Return -1 on failure or 0 otherwise. Caller must prepare memory
+ * for POOL_SELECT_RESULT and pass it as "res". It is guaranteed that no
+ * exception occurs within this function.
*/
-
-static int get_query_result(int backend_id, char *query, POOL_SELECT_RESULT **res)
+int get_query_result(POOL_CONNECTION_POOL_SLOT **slots, int backend_id, char *query, POOL_SELECT_RESULT **res)
{
int sts = -1;
+ MemoryContext oldContext = CurrentMemoryContext;
- do_query(slots[backend_id]->con, query, res, PROTO_MAJOR_V3);
+ PG_TRY();
+ {
+ do_query(slots[backend_id]->con, query, res, PROTO_MAJOR_V3);
+ }
+ PG_CATCH();
+ {
+ /* ignore the error message */
+ res = NULL;
+ MemoryContextSwitchTo(oldContext);
+ FlushErrorState();
+ ereport(LOG,
+ (errmsg("get_query_result: do_query failed")));
+ }
+ PG_END_TRY();
if (!res)
{
- ereport(ERROR,
- (errmsg("Failed to check replication time lag"),
- errdetail("Query to node (%d) returned no result for node", backend_id)));
+ ereport(LOG,
+ (errmsg("get_query_result: no result returned"),
+ errdetail("node id (%d)", backend_id)));
return sts;
}
if ((*res)->numrows <= 0)
{
free_select_result(*res);
- ereport(ERROR,
- (errmsg("Failed to check replication time lag"),
- errdetail("Query to node (%d) returned result with no rows", backend_id)));
+ ereport(LOG,
+ (errmsg("get_query_result: no rows returned"),
+ errdetail("node id (%d)", backend_id)));
return sts;
}
if ((*res)->data[0] == NULL)
{
free_select_result(*res);
- ereport(ERROR,
- (errmsg("Failed to check replication time lag"),
- errdetail("Query to node (%d) returned no data", backend_id)));
+ ereport(LOG,
+ (errmsg("get_query_result: no rows returned"),
+ errdetail("node id (%d)", backend_id)));
return sts;
}
if ((*res)->nullflags[0] == -1)
{
free_select_result(*res);
- ereport(ERROR,
- (errmsg("Failed to check replication time lag"),
- errdetail("Query to node (%d) returned NULL data", backend_id)));
+ ereport(LOG,
+ (errmsg("get_query_result: NULL data returned"),
+ errdetail("node id (%d)", backend_id)));
return sts;
}
projects / pgpool2.git / commitdiff