rm_node fixed.

* Cleanup now called only on removed node.
* Node is not deleted from the nodes table to avoid problems with foreign keys.

Author: arssher

membership.sql

@@ -7,7 +7,8 @@
  */
 
 -- active is the normal mode, others needed only for proper node add and removal
-CREATE TYPE worker_node_status AS ENUM ('active', 'add_in_progress', 'rm_in_progress');
+CREATE TYPE worker_node_status AS ENUM (
+	'active', 'add_in_progress', 'rm_in_progress', 'removed');
 
 -- list of nodes present in the cluster
 CREATE TABLE nodes (
@@ -30,7 +31,10 @@ CREATE TABLE nodes (
 -- of transaction. Later we should delete subscriptions fully.
 CREATE FUNCTION rm_node_worker_side() RETURNS TRIGGER AS $$
 BEGIN
-	PERFORM shardman.pg_shardman_cleanup(false);
+	IF OLD.id = (SELECT shardman.get_node_id()) THEN
+		RAISE DEBUG '[SHARDMAN] rm_node_worker_side called';
+		PERFORM shardman.pg_shardman_cleanup(false);
+	END IF;
 	RETURN NULL;
 END
 $$ LANGUAGE plpgsql;

src/pg_shardman.c

@@ -690,11 +690,9 @@ rm_node(Cmd *cmd)
 	 */
 	sql = psprintf(
 		"select shardman.drop_repslot('shardman_meta_sub_%d');"
-		/* keep silent cmd_log fk constraint */
-		"update shardman.cmd_log set node_id = null where node_id = %d;"
-		"delete from shardman.nodes where id = %d;"
+		"update shardman.nodes set worker_status = 'removed' where id = %d;"
 		"update shardman.cmd_log set status = 'success' where id = %ld;",
-		node_id, node_id, node_id, cmd->id);
+		node_id, node_id, cmd->id);
 	void_spi(sql);
 	pfree(sql);
 	elog(INFO, "Node %d successfully removed", node_id);