return false;
}
+static void
+handle_abort(PoolAgent * agent, StringInfo s)
+{
+ int len;
+ int *pids;
+ const char *database = NULL;
+ const char *user_name = NULL;
+
+ pool_getmessage(&agent->port, s, 0);
+ len = pq_getmsgint(s, 4);
+ if (len > 0)
+ database = pq_getmsgbytes(s, len);
+
+ len = pq_getmsgint(s, 4);
+ if (len > 0)
+ user_name = pq_getmsgbytes(s, len);
+
+ pq_getmsgend(s);
+
+ pids = abort_pids(&len, agent->pid, database, user_name);
+
+ pool_sendpids(&agent->port, pids, len);
+ if (pids)
+ pfree(pids);
+}
+
+static void
+handle_connect(PoolAgent * agent, StringInfo s)
+{
+ int len;
+ const char *database = NULL;
+ const char *user_name = NULL;
+ const char *pgoptions = NULL;
+
+ pool_getmessage(&agent->port, s, 0);
+ agent->pid = pq_getmsgint(s, 4);
+
+ len = pq_getmsgint(s, 4);
+ database = pq_getmsgbytes(s, len);
+
+ len = pq_getmsgint(s, 4);
+ user_name = pq_getmsgbytes(s, len);
+
+ len = pq_getmsgint(s, 4);
+ pgoptions = pq_getmsgbytes(s, len);
+
+ /*
+ * Coordinator pool is not initialized.
+ * With that it would be impossible to create a Database by default.
+ */
+ agent_init(agent, database, user_name, pgoptions);
+ pq_getmsgend(s);
+}
+
+static void
+handle_clean_connection(PoolAgent * agent, StringInfo s)
+{
+ int i, len, res;
+ int datanodecount, coordcount;
+ const char *database = NULL;
+ const char *user_name = NULL;
+ List *nodelist = NIL;
+
+ pool_getmessage(&agent->port, s, 0);
+
+ /* It is possible to clean up only datanode connections */
+ datanodecount = pq_getmsgint(s, 4);
+ for (i = 0; i < datanodecount; i++)
+ {
+ /* Translate index to Oid */
+ int index = pq_getmsgint(s, 4);
+ Oid node = agent->dn_conn_oids[index];
+ nodelist = lappend_oid(nodelist, node);
+ }
+
+ /* It is possible to clean up only coordinator connections */
+ coordcount = pq_getmsgint(s, 4);
+ for (i = 0; i < coordcount; i++)
+ {
+ /* Translate index to Oid */
+ int index = pq_getmsgint(s, 4);
+ Oid node = agent->coord_conn_oids[index];
+ nodelist = lappend_oid(nodelist, node);
+ }
+
+ len = pq_getmsgint(s, 4);
+ if (len > 0)
+ database = pq_getmsgbytes(s, len);
+
+ len = pq_getmsgint(s, 4);
+ if (len > 0)
+ user_name = pq_getmsgbytes(s, len);
+
+ pq_getmsgend(s);
+
+ /* Clean up connections here */
+ res = clean_connection(nodelist, database, user_name);
+
+ list_free(nodelist);
+
+ /* Send success result */
+ pool_sendres(&agent->port, res);
+}
+
+static void
+handle_get_connections(PoolAgent * agent, StringInfo s)
+{
+ int i;
+ int *fds, *pids = NULL;
+ int datanodecount, coordcount;
+ List *datanodelist = NIL;
+ List *coordlist = NIL;
+
+ /*
+ * Length of message is caused by:
+ * - Message header = 4bytes
+ * - List of Datanodes = NumPoolDataNodes * 4bytes (max)
+ * - List of Coordinators = NumPoolCoords * 4bytes (max)
+ * - Number of Datanodes sent = 4bytes
+ * - Number of Coordinators sent = 4bytes
+ * It is better to send in a same message the list of Co and Dn at the same
+ * time, this permits to reduce interactions between postmaster and pooler
+ */
+ pool_getmessage(&agent->port, s, 4 * agent->num_dn_connections + 4 * agent->num_coord_connections + 12);
+
+ datanodecount = pq_getmsgint(s, 4);
+ for (i = 0; i < datanodecount; i++)
+ datanodelist = lappend_int(datanodelist, pq_getmsgint(s, 4));
+
+ /* It is possible that no Coordinators are involved in the transaction */
+ coordcount = pq_getmsgint(s, 4);
+ for (i = 0; i < coordcount; i++)
+ coordlist = lappend_int(coordlist, pq_getmsgint(s, 4));
+
+ pq_getmsgend(s);
+
+ Assert(datanodecount >= 0 && coordcount >= 0);
+
+ /*
+ * In case of error agent_acquire_connections will log the error and
+ * return NULL.
+ */
+ fds = agent_acquire_connections(agent, datanodelist, coordlist, &pids);
+
+ list_free(datanodelist);
+ list_free(coordlist);
+
+ pool_sendfds(&agent->port, fds, fds ? datanodecount + coordcount : 0);
+ if (fds)
+ pfree(fds);
+
+ /*
+ * Also send the PIDs of the remote backend processes serving
+ * these connections
+ */
+ pool_sendpids(&agent->port, pids, pids ? datanodecount + coordcount : 0);
+ if (pids)
+ pfree(pids);
+}
+
+static void
+handle_query_cancel(PoolAgent * agent, StringInfo s)
+{
+ int i;
+ int datanodecount, coordcount;
+ List *datanodelist = NIL;
+ List *coordlist = NIL;
+
+ /*
+ * Length of message is caused by:
+ * - Message header = 4bytes
+ * - List of Datanodes = NumPoolDataNodes * 4bytes (max)
+ * - List of Coordinators = NumPoolCoords * 4bytes (max)
+ * - Number of Datanodes sent = 4bytes
+ * - Number of Coordinators sent = 4bytes
+ */
+ pool_getmessage(&agent->port, s, 4 * agent->num_dn_connections + 4 * agent->num_coord_connections + 12);
+
+ datanodecount = pq_getmsgint(s, 4);
+ for (i = 0; i < datanodecount; i++)
+ datanodelist = lappend_int(datanodelist, pq_getmsgint(s, 4));
+
+ coordcount = pq_getmsgint(s, 4);
+ /* It is possible that no Coordinators are involved in the transaction */
+ for (i = 0; i < coordcount; i++)
+ coordlist = lappend_int(coordlist, pq_getmsgint(s, 4));
+
+ pq_getmsgend(s);
+
+ cancel_query_on_connections(agent, datanodelist, coordlist);
+ list_free(datanodelist);
+ list_free(coordlist);
+
+ /* Send success result */
+ pool_sendres(&agent->port, QUERY_CANCEL_COMPLETED);
+}
+
/*
* Handle messages to agent
*/
static void
agent_handle_input(PoolAgent * agent, StringInfo s)
{
- int qtype;
+ /* read byte from the buffer (and recv if empty) */
+ int qtype = pool_getbyte(&agent->port);
- qtype = pool_getbyte(&agent->port);
/*
* We can have multiple messages, so handle them all
*/
for (;;)
{
- const char *database = NULL;
- const char *user_name = NULL;
- const char *pgoptions = NULL;
- int datanodecount;
- int coordcount;
- List *nodelist = NIL;
- List *datanodelist = NIL;
- List *coordlist = NIL;
- int *fds;
- int *pids;
- int i, len, res;
-
/*
* During a pool cleaning, Abort, Connect and Get Connections messages
* are not allowed on pooler side.
switch (qtype)
{
case 'a': /* ABORT */
- pool_getmessage(&agent->port, s, 0);
- len = pq_getmsgint(s, 4);
- if (len > 0)
- database = pq_getmsgbytes(s, len);
-
- len = pq_getmsgint(s, 4);
- if (len > 0)
- user_name = pq_getmsgbytes(s, len);
-
- pq_getmsgend(s);
-
- pids = abort_pids(&len, agent->pid, database, user_name);
-
- pool_sendpids(&agent->port, pids, len);
- if (pids)
- pfree(pids);
+ handle_abort(agent, s);
break;
case 'c': /* CONNECT */
- pool_getmessage(&agent->port, s, 0);
- agent->pid = pq_getmsgint(s, 4);
- len = pq_getmsgint(s, 4);
- database = pq_getmsgbytes(s, len);
- len = pq_getmsgint(s, 4);
- user_name = pq_getmsgbytes(s, len);
- len = pq_getmsgint(s, 4);
- pgoptions = pq_getmsgbytes(s, len);
- /*
- * Coordinator pool is not initialized.
- * With that it would be impossible to create a Database by default.
- */
- agent_init(agent, database, user_name, pgoptions);
- pq_getmsgend(s);
+ handle_connect(agent, s);
break;
case 'd': /* DISCONNECT */
pool_getmessage(&agent->port, s, 4);
pq_getmsgend(s);
break;
case 'f': /* CLEAN CONNECTION */
- pool_getmessage(&agent->port, s, 0);
- datanodecount = pq_getmsgint(s, 4);
- /* It is possible to clean up only datanode connections */
- for (i = 0; i < datanodecount; i++)
- {
- /* Translate index to Oid */
- int index = pq_getmsgint(s, 4);
- Oid node = agent->dn_conn_oids[index];
- nodelist = lappend_oid(nodelist, node);
- }
- coordcount = pq_getmsgint(s, 4);
- /* It is possible to clean up only coordinator connections */
- for (i = 0; i < coordcount; i++)
- {
- /* Translate index to Oid */
- int index = pq_getmsgint(s, 4);
- Oid node = agent->coord_conn_oids[index];
- nodelist = lappend_oid(nodelist, node);
- }
- len = pq_getmsgint(s, 4);
- if (len > 0)
- database = pq_getmsgbytes(s, len);
- len = pq_getmsgint(s, 4);
- if (len > 0)
- user_name = pq_getmsgbytes(s, len);
-
- pq_getmsgend(s);
-
- /* Clean up connections here */
- res = clean_connection(nodelist, database, user_name);
-
- list_free(nodelist);
-
- /* Send success result */
- pool_sendres(&agent->port, res);
+ handle_clean_connection(agent, s);
break;
case 'g': /* GET CONNECTIONS */
- /*
- * Length of message is caused by:
- * - Message header = 4bytes
- * - List of Datanodes = NumPoolDataNodes * 4bytes (max)
- * - List of Coordinators = NumPoolCoords * 4bytes (max)
- * - Number of Datanodes sent = 4bytes
- * - Number of Coordinators sent = 4bytes
- * It is better to send in a same message the list of Co and Dn at the same
- * time, this permits to reduce interactions between postmaster and pooler
- */
- pool_getmessage(&agent->port, s, 4 * agent->num_dn_connections + 4 * agent->num_coord_connections + 12);
- datanodecount = pq_getmsgint(s, 4);
- for (i = 0; i < datanodecount; i++)
- datanodelist = lappend_int(datanodelist, pq_getmsgint(s, 4));
- coordcount = pq_getmsgint(s, 4);
- /* It is possible that no Coordinators are involved in the transaction */
- for (i = 0; i < coordcount; i++)
- coordlist = lappend_int(coordlist, pq_getmsgint(s, 4));
- pq_getmsgend(s);
-
- /*
- * In case of error agent_acquire_connections will log
- * the error and return NULL
- */
- pids = NULL;
- fds = agent_acquire_connections(agent, datanodelist, coordlist,
- &pids);
- list_free(datanodelist);
- list_free(coordlist);
-
- pool_sendfds(&agent->port, fds, fds ? datanodecount + coordcount : 0);
- if (fds)
- pfree(fds);
-
- /*
- * Also send the PIDs of the remote backend processes serving
- * these connections
- */
- pool_sendpids(&agent->port, pids, pids ? datanodecount + coordcount : 0);
- if (pids)
- pfree(pids);
+ handle_get_connections(agent, s);
break;
case 'h': /* Cancel SQL Command in progress on specified connections */
- /*
- * Length of message is caused by:
- * - Message header = 4bytes
- * - List of Datanodes = NumPoolDataNodes * 4bytes (max)
- * - List of Coordinators = NumPoolCoords * 4bytes (max)
- * - Number of Datanodes sent = 4bytes
- * - Number of Coordinators sent = 4bytes
- */
- pool_getmessage(&agent->port, s, 4 * agent->num_dn_connections + 4 * agent->num_coord_connections + 12);
- datanodecount = pq_getmsgint(s, 4);
- for (i = 0; i < datanodecount; i++)
- datanodelist = lappend_int(datanodelist, pq_getmsgint(s, 4));
- coordcount = pq_getmsgint(s, 4);
- /* It is possible that no Coordinators are involved in the transaction */
- for (i = 0; i < coordcount; i++)
- coordlist = lappend_int(coordlist, pq_getmsgint(s, 4));
- pq_getmsgend(s);
-
- cancel_query_on_connections(agent, datanodelist, coordlist);
- list_free(datanodelist);
- list_free(coordlist);
-
- /* Send success result */
- pool_sendres(&agent->port, QUERY_CANCEL_COMPLETED);
+ handle_query_cancel(agent, s);
break;
case 'o': /* Lock/unlock pooler */
pool_getmessage(&agent->port, s, 8);
pq_getmsgend(s);
break;
case 'p': /* Reload connection info */
- /*
- * Connection information reloaded concerns all the database pools.
- * A database pool is reloaded as follows for each remote node:
- * - node pool is deleted if the node has been deleted from catalog.
- * Subsequently all its connections are dropped.
- * - node pool is deleted if its port or host information is changed.
- * Subsequently all its connections are dropped.
- * - node pool is kept unchanged with existing connection information
- * is not changed. However its index position in node pool is changed
- * according to the alphabetical order of the node name in new
- * cluster configuration.
- * Backend sessions are responsible to reconnect to the pooler to update
- * their agent with newest connection information.
- * The session invocating connection information reload is reconnected
- * and uploaded automatically after database pool reload.
- * Other server sessions are signaled to reconnect to pooler and update
- * their connection information separately.
- * During reload process done internally on pooler, pooler is locked
- * to forbid new connection requests.
- */
pool_getmessage(&agent->port, s, 4);
pq_getmsgend(s);
break;
case 'R': /* Refresh connection info */
/*
- * Connection information refresh concerns all the database pools.
- * A database pool is refreshed as follows for each remote node:
- * - node pool is deleted if its port or host information is changed.
- * Subsequently all its connections are dropped.
- *
- * If any other type of activity is found, we error out
*/
pool_getmessage(&agent->port, s, 4);
pq_getmsgend(s);
- /* Refresh the pools */
- res = refresh_database_pools(agent);
-
- /* Send result */
- pool_sendres(&agent->port, res);
+ pool_sendres(&agent->port, refresh_database_pools(agent));
break;
case 'P': /* Ping connection info */
/*
pq_getmsgend(s);
/* Check cached info consistency */
- res = node_info_check(agent);
-
- /* Send result */
- pool_sendres(&agent->port, res);
+ pool_sendres(&agent->port, node_info_check(agent));
break;
case 'r': /* RELEASE CONNECTIONS */
{
agent_release_connections(agent, destroy);
}
break;
- default: /* EOF or protocol violation */
+ case EOF: /* EOF */
+ agent_destroy(agent);
+ return;
+ default: /* protocol violation */
agent_destroy(agent);
+ ereport(WARNING,
+ (errmsg("agent protocol violation, received byte %c", qtype)));
return;
}
- /* avoid reading from connection */
+
+ /*
+ * check if there are more data in the buffer (but don't recv
+ * additional data), to avoid reading from a closed connection
+ *
+ * XXX I wonder whether this is correct, because it means we
+ * won't call agent_destroy() in this case (unlike when handling
+ * the message in the switch above).
+ */
if ((qtype = pool_pollbyte(&agent->port)) == EOF)
break;
}
}
/*
- * Rebuild information of database pools
+ * reload_database_pools
+ * rebuild connection information for all database pools
+ *
+ * A database pool is reloaded as follows for each remote node:
+ *
+ * - node pool is deleted if the node has been deleted from catalog.
+ * Subsequently all its connections are dropped.
+ *
+ * - node pool is deleted if its port or host information is changed.
+ * Subsequently all its connections are dropped.
+ *
+ * - node pool is kept unchanged with existing connection information
+ * is not changed. However its index position in node pool is changed
+ * according to the alphabetical order of the node name in new
+ * cluster configuration.
+ *
+ * Backend sessions are responsible to reconnect to the pooler to update
+ * their agent with newest connection information.
+ *
+ * The session invocating connection information reload is reconnected
+ * and uploaded automatically after database pool reload. Other server
+ * sessions are signaled to reconnect to pooler and update their
+ * connection information separately.
+ *
+ * During reload process done internally on pooler, pooler is locked
+ * to forbid new connection requests.
*/
static void
reload_database_pools(PoolAgent *agent)
}
/*
- * Refresh information of database pools
+ * refresh_database_pools
+ * refresh information for all database pools
+ *
+ * Connection information refresh concerns all the database pools.
+ * A database pool is refreshed as follows for each remote node:
+ *
+ * - node pool is deleted if its port or host information is changed.
+ * Subsequently all its connections are dropped.
+ *
+ * If any other type of activity is found, we error out.
+ *
+ * XXX I don't see any cases that would error out. Isn't the comment
+ * simply obsolete?
*/
static int
refresh_database_pools(PoolAgent *agent)
projects / postgres-xl.git / commitdiff