Addition of system function pgxc_pool_check

This new system function is used to check connection information
consistency cached in pooler with pgxc_node.
The information checked for consistency is node Oid, connection
port and connection host.
This function returns a boolean depending on connection data
being consistent or not.

11 files changed, 221 insertions, 24 deletions

diff --git a/doc-xc/src/sgml/func.sgmlin b/doc-xc/src/sgml/func.sgmlin
index c8cf40fa2f..07dab181eb 100644
--- a/doc-xc/src/sgml/func.sgmlin
+++ b/doc-xc/src/sgml/func.sgmlin
@@ -15325,9 +15325,48 @@ SELECT (pg_stat_file('filename')).modification;
     locks held by the current session.  (This function is implicitly invoked
     at session end, even if the client disconnects ungracefully.)
    </para>
+
 <!## XC>
 &xconly;
    <para>
+    The functions shown in <xref linkend="functions-pgxc-pooler"> manage
+    Postgres-XC pooler.  For details about Postgres-XC pooler, see
+    <xref linkend="xc-overview-pooler">.
+   </para>
+   <table id="functions-pgxc-pooler">
+    <title>Postgres-XC pooler functions</title>
+    <tgroup cols="3">
+     <thead>
+      <row><entry>Name</entry> <entry>Return Type</entry> <entry>Description</entry>
+      </row>
+     </thead>
+     <tbody>
+      <row>
+       <entry>
+        <literal><function>pgxc_pool_check()</function></literal>
+       </entry>
+       <entry><type>boolean</type></entry>
+       <entry>Check if connection data cached in pooler is consistent with
+              <link linkend="catalog-pgxc-node"><structname>pgxc_node</structname></link>.
+       </entry>
+      </row>
+     </tbody>
+    </tgroup>
+   </table>
+
+   <indexterm>
+    <primary>pgxc_pool_check</primary>
+   </indexterm>
+   <para>
+    <function>pgxc_pool_check</> verifies if connection data cached in Postgres-XC pooler
+    is consistent with <link linkend="catalog-pgxc-node"><structname>pgxc_node</structname></link>
+    catalog. Data checked for consistency is Node Oid (<literal><link linkend="catalog-pgxc-node"><structname>pgxc_node</structname></link>.oid</literal>),
+    node port (<literal><link linkend="catalog-pgxc-node"><structname>pgxc_node</structname></link>.node_port</literal>)
+    and node host (<literal><link linkend="catalog-pgxc-node"><structname>pgxc_node</structname></link>.node_host</literal>).
+   </para>
+
+&xconly;
+   <para>
     Please note that these functions works just locally.  
     The lock obtained in a coordinator is effective only in the coordinator.
     Transaction started at different coordinator can obtain the lock with the same
diff --git a/src/backend/pgxc/nodemgr/nodemgr.c b/src/backend/pgxc/nodemgr/nodemgr.c
index 12e40a63fb..74f83ac959 100644
--- a/src/backend/pgxc/nodemgr/nodemgr.c
+++ b/src/backend/pgxc/nodemgr/nodemgr.c
@@ -132,17 +132,17 @@ cmp_nodes(const void *p1, const void *p2)
  * an ordered list of node Oids for each PGXC node type.
  */
 void
-PgxcNodeListAndCount(Oid **coOids, Oid **dnOids, Oid **coslaveOids, Oid **dnslaveOids)
+PgxcNodeListAndCount(Oid **coOids, Oid **dnOids, Oid **coslaveOids, Oid **dnslaveOids,
+					 int *num_coords, int *num_dns, int *num_co_slaves, int *num_dn_slaves)
 {
 	Relation rel;
 	HeapScanDesc scan;
 	HeapTuple   tuple;
 
-	/* Reinitialize counts */
-	NumCoords = 0;
-	NumDataNodes = 0;
-	NumCoordSlaves = 0;
-	NumDataNodeSlaves = 0;
+	*num_coords = 0;
+	*num_dns = 0;
+	*num_co_slaves = 0;
+	*num_dn_slaves = 0;
 
 	/* 
 	 * Node information initialization is made in one scan:
@@ -163,23 +163,23 @@ PgxcNodeListAndCount(Oid **coOids, Oid **dnOids, Oid **coslaveOids, Oid **dnslav
 		switch (nodeForm->node_type)
 		{
 			case PGXC_NODE_COORD_MASTER:
-				NumCoords++;
-				numnodes = NumCoords;
+				(*num_coords)++;
+				numnodes = *num_coords;
 				nodes = coOids;
 				break;
 			case PGXC_NODE_DATANODE_MASTER:
-				NumDataNodes++;
-				numnodes = NumDataNodes;
+				(*num_dns)++;
+				numnodes = *num_dns;
 				nodes = dnOids;
 				break;
 			case PGXC_NODE_COORD_SLAVE:
-				NumCoordSlaves++;
-				numnodes = NumCoordSlaves;
+				(*num_co_slaves)++;
+				numnodes = *num_co_slaves;
 				nodes = coslaveOids;
 				break;
 			case PGXC_NODE_DATANODE_SLAVE:
-				NumDataNodeSlaves++;
-				numnodes = NumDataNodeSlaves;
+				(*num_dn_slaves)++;
+				numnodes = *num_dn_slaves;
 				nodes = dnslaveOids;
 				break;
 			default:
@@ -211,13 +211,13 @@ PgxcNodeListAndCount(Oid **coOids, Oid **dnOids, Oid **coslaveOids, Oid **dnslav
 
 	/* Finally sort the lists to be sent back */
 	if (NumCoords != 0)
-		qsort(*coOids, NumCoords, sizeof(Oid), cmp_nodes);
+		qsort(*coOids, *num_coords, sizeof(Oid), cmp_nodes);
 	if (NumDataNodes != 0)
-		qsort(*dnOids, NumDataNodes, sizeof(Oid), cmp_nodes);
+		qsort(*dnOids, *num_dns, sizeof(Oid), cmp_nodes);
 	if (NumDataNodeSlaves != 0)
-		qsort(*coslaveOids, NumCoordSlaves, sizeof(Oid), cmp_nodes);
+		qsort(*coslaveOids, *num_co_slaves, sizeof(Oid), cmp_nodes);
 	if (NumDataNodeSlaves != 0)
-		qsort(*dnslaveOids, NumDataNodeSlaves, sizeof(Oid), cmp_nodes);
+		qsort(*dnslaveOids, *num_dn_slaves, sizeof(Oid), cmp_nodes);
 }
 
 /*
diff --git a/src/backend/pgxc/pool/pgxcnode.c b/src/backend/pgxc/pool/pgxcnode.c
index b90c0ba98a..2e82b686d1 100644
--- a/src/backend/pgxc/pool/pgxcnode.c
+++ b/src/backend/pgxc/pool/pgxcnode.c
@@ -127,7 +127,8 @@ InitMultinodeExecutor(void)
 		return;
 
 	/* Get classified list of node Oids */
-	PgxcNodeListAndCount(&coOids, &dnOids, &coslaveOids, &dnslaveOids);
+	PgxcNodeListAndCount(&coOids, &dnOids, &coslaveOids, &dnslaveOids,
+						 &NumCoords, &NumDataNodes, &NumCoordSlaves, &NumDataNodeSlaves);
 
 	/* Do proper initialization of handles */
 	if (NumDataNodes > 0)
diff --git a/src/backend/pgxc/pool/poolmgr.c b/src/backend/pgxc/pool/poolmgr.c
index bd29ece2fc..43fa441025 100644
--- a/src/backend/pgxc/pool/poolmgr.c
+++ b/src/backend/pgxc/pool/poolmgr.c
@@ -99,6 +99,7 @@ static int	is_pool_cleaning = false;
 static int	server_fd = -1;
 
 static void node_info_load(void);
+static int	node_info_check(void);
 static void agent_init(PoolAgent *agent, const char *database, const char *user_name);
 static void agent_destroy(PoolAgent *agent);
 static void agent_create(void);
@@ -245,7 +246,8 @@ node_info_load(void)
 	Oid *dnslaveOids = NULL;
 
 	/* Update number of PGXC nodes saved in cache */
-	PgxcNodeListAndCount(&coOids, &dnOids, &coslaveOids, &dnslaveOids);
+	PgxcNodeListAndCount(&coOids, &dnOids, &coslaveOids, &dnslaveOids,
+						 &NumCoords, &NumDataNodes, &NumCoordSlaves, &NumDataNodeSlaves);
 
 	/* Then initialize the node informations */
 	if (NumDataNodes != 0)
@@ -299,6 +301,94 @@ node_info_load(void)
 }
 
 /*
+ * Check connection info consistency with system catalogs
+ */
+static int
+node_info_check(void)
+{
+	int res = POOL_CHECK_SUCCESS;
+	int	num_coord, num_dn,
+		num_coord_slave, num_dn_slave, i, j;
+	Oid *coOids = NULL;
+	Oid *dnOids = NULL;
+	Oid *coslaveOids = NULL;
+	Oid *dnslaveOids = NULL;
+
+	/* Update number of PGXC nodes saved in cache */
+	PgxcNodeListAndCount(&coOids, &dnOids, &coslaveOids, &dnslaveOids,
+						 &num_coord, &num_dn, &num_coord_slave, &num_dn_slave);
+
+	/* Check first if node numbers are consistent */
+	if (NumCoords != num_coord ||
+		NumDataNodes != num_dn ||
+		NumCoordSlaves != num_coord_slave ||
+		NumDataNodeSlaves != num_dn_slave)
+	{
+		res = POOL_CHECK_FAILED;
+		goto finish;
+	}
+
+	/* Now do a check element by element */
+	for (i = 0; i < 4; i++)
+	{
+		int numnodes;
+		PGXCNodeConnectionInfo *conninfo;
+		Oid *oid_vector;
+
+		/* Take all the elements necessary for check */
+		switch(i)
+		{
+			case 0:
+				numnodes = NumCoords;
+				oid_vector = coOids;
+				conninfo = coord_connInfos;
+				break;
+			case 1:
+				numnodes = NumDataNodes;
+				oid_vector = dnOids;
+				conninfo = datanode_connInfos;
+				break;
+			case 2:
+				numnodes = NumCoordSlaves;
+				oid_vector = coslaveOids;
+				conninfo = coord_slave_connInfos;
+				break;
+			case 3:
+				numnodes = NumDataNodeSlaves;
+				oid_vector = dnslaveOids;
+				conninfo = datanode_slave_connInfos;
+				break;
+			default:
+				Assert(0);
+		}
+
+		/* Then check data consistency for port, host and node Oid */
+		for (j = 0; j < numnodes; j++)
+		{
+			if (conninfo[j].nodeoid != oid_vector[j] ||
+				conninfo[j].port != get_pgxc_nodeport(oid_vector[j]) ||
+				strcmp(conninfo[j].host, get_pgxc_nodehost(oid_vector[j])))
+			{
+				res = POOL_CHECK_FAILED;
+				goto finish;
+			}
+		}
+	}
+
+finish:
+	/* Clean everything */
+	if (coOids)
+		pfree(coOids);
+	if (dnOids)
+		pfree(dnOids);
+	if (coslaveOids)
+		pfree(coslaveOids);
+	if (dnslaveOids)
+		pfree(dnslaveOids);
+	return res;
+}
+
+/*
  * Destroy internal structures
  */
 int
@@ -802,6 +892,27 @@ PoolManagerCleanConnection(List *datanodelist, List *coordlist, char *dbname, ch
 
 
 /*
+ * Check connection information consistency cached in pooler with catalog information
+ */
+bool
+PoolManagerCheckConnectionInfo(void)
+{
+	int res;
+
+	Assert(poolHandle);
+	pool_putmessage(&poolHandle->port, 'q', NULL, 0);
+	pool_flush(&poolHandle->port);
+
+	res = pool_recvres(&poolHandle->port);
+
+	if (res == POOL_CHECK_SUCCESS)
+		return true;
+
+	return false;
+}
+
+
+/*
  * Handle messages to agent
  */
 static void
@@ -960,9 +1071,17 @@ agent_handle_input(PoolAgent * agent, StringInfo s)
 				cancel_query_on_connections(agent, datanodelist, coordlist);
 				list_free(datanodelist);
 				list_free(coordlist);
-
 				break;
+			case 'q':			/* Check connection info consistency */
+				pool_getmessage(&agent->port, s, 4);
+				pq_getmsgend(s);
 
+				/* Check cached info consistency */
+				res = node_info_check();
+
+				/* Send result */
+				pool_sendres(&agent->port, res);
+				break;
 			case 'r':			/* RELEASE CONNECTIONS */
 				pool_getmessage(&agent->port, s, 4);
 				pq_getmsgend(s);
diff --git a/src/backend/pgxc/pool/poolutils.c b/src/backend/pgxc/pool/poolutils.c
index 9ac7131803..92954993db 100644
--- a/src/backend/pgxc/pool/poolutils.c
+++ b/src/backend/pgxc/pool/poolutils.c
@@ -26,9 +26,27 @@
 #include "pgxc/pgxcnode.h"
 #include "access/gtm.h"
 #include "commands/dbcommands.h"
-#include "utils/lsyscache.h"
 #include "utils/acl.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
 
+/*
+ * pgxc_pool_check
+ *
+ * Check if Pooler information in catalog is consistent
+ * with information cached.
+ */
+Datum
+pgxc_pool_check(PG_FUNCTION_ARGS)
+{
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to manage pooler"))));
+
+	/* Simply check with pooler */
+	PG_RETURN_BOOL(PoolManagerCheckConnectionInfo());
+}
 
 /*
  * CleanConnection()
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index fe61ee6645..7f8245ce30 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -56,7 +56,9 @@
 #include "utils/snapmgr.h"
 #include "utils/syscache.h"
 #include "utils/tqual.h"
-
+#ifdef PGXC
+#include "pgxc/poolmgr.h"
+#endif
 
 static HeapTuple GetDatabaseTuple(const char *dbname);
 static HeapTuple GetDatabaseTupleByOid(Oid dboid);
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index d6ce6d92d7..cfe923eda9 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -4341,6 +4341,10 @@ DESCR("fetch the last row value");
 DATA(insert OID = 3114 (  nth_value		PGNSP PGUID 12 1 0 0 f t f t f i 2 0 2283 "2283 23" _null_ _null_ _null_ _null_ window_nth_value _null_ _null_ _null_ ));
 DESCR("fetch the Nth row value");
 
+#ifdef PGXC
+DATA(insert OID = 3200 ( pgxc_pool_check	PGNSP PGUID 12 1 0 0 f f f t f v 0 0 16 "" _null_ _null_ _null_ _null_ pgxc_pool_check _null_ _null_ _null_ ));
+DESCR("check connection information consistency in pooler");
+#endif
 
 /*
  * Symbolic values for provolatile column: these indicate whether the result
diff --git a/src/include/pgxc/nodemgr.h b/src/include/pgxc/nodemgr.h
index ff00b56d1d..18e3054456 100644
--- a/src/include/pgxc/nodemgr.h
+++ b/src/include/pgxc/nodemgr.h
@@ -26,7 +26,9 @@ extern int  NumCoordSlaves;
 extern int  NumDataNodeSlaves;
 
 extern void PgxcNodeListAndCount(Oid **coOids, Oid **dnOids,
-								 Oid **coslaveOids, Oid **dnslaveOids);
+								 Oid **coslaveOids, Oid **dnslaveOids,
+								 int *num_coords, int *num_dns,
+								 int *num_co_slaves, int *num_dn_slaves);
 extern void PgxcNodeAlter(AlterNodeStmt *stmt);
 extern void PgxcNodeCreate(CreateNodeStmt *stmt);
 extern void PgxcNodeRemove(DropNodeStmt *stmt);
diff --git a/src/include/pgxc/poolmgr.h b/src/include/pgxc/poolmgr.h
index cda434d97e..a120c38695 100644
--- a/src/include/pgxc/poolmgr.h
+++ b/src/include/pgxc/poolmgr.h
@@ -157,6 +157,9 @@ extern int *PoolManagerGetConnections(List *datanodelist, List *coordlist);
 /* Clean pool connections */
 extern void PoolManagerCleanConnection(List *datanodelist, List *coordlist, char *dbname, char *username);
 
+/* Check consistency of connection information cached in pooler with catalogs */
+extern bool PoolManagerCheckConnectionInfo(void);
+
 /* Send Abort signal to transactions being run */
 extern int	PoolManagerAbortTransactions(char *dbname, char *username, int **proc_pids);
 
diff --git a/src/include/pgxc/poolutils.h b/src/include/pgxc/poolutils.h
index fff8b9ed1f..a8c216d4e3 100644
--- a/src/include/pgxc/poolutils.h
+++ b/src/include/pgxc/poolutils.h
@@ -26,6 +26,10 @@
 #define CLEAN_CONNECTION_TX_REMAIN			2
 #define	CLEAN_CONNECTION_EOF				-1
 
+/* Results for pooler connection info check */
+#define POOL_CHECK_SUCCESS					0
+#define POOL_CHECK_FAILED					1
+
 void CleanConnection(CleanConnStmt *stmt);
 void DropDBCleanConnection(char *dbname);
 #endif
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index b11db63ace..47fb36b9f2 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -1120,4 +1120,9 @@ extern Datum pg_prepared_statement(PG_FUNCTION_ARGS);
 /* utils/mmgr/portalmem.c */
 extern Datum pg_cursor(PG_FUNCTION_ARGS);
 
+#ifdef PGXC
+/* backend/pgxc/pool/poolutils.c */
+extern Datum pgxc_pool_check(PG_FUNCTION_ARGS);
+#endif
+
 #endif   /* BUILTINS_H */