Re: Patch: Implement failover on libpq connect level.

On Mon, Sep 5, 2016 at 4:33 PM, Aleksander Alekseev <
a(dot)alekseev(at)postgrespro(dot)ru> wrote:
>After a brief examination I've found following ways to improve the patch.
Adding to above comments.

1)
+ /*
+ * consult connection options and check if RO connection is OK
+ * RO connection is OK if readonly connection is explicitely
+ * requested or if replication option is set, or just one
+ * host is specified in the connect string.
+ */
+ if ((conn->pghost==NULL || strchr(conn->pghost,',')==NULL) ||
+ ((conn->read_only && conn->read_only[0] > '0'))
+ ||(conn->replication && conn->replication[0])
+ )
+ {

Now if only one host is in connection string and it ask for read_write
connection(connect to master) I mean read_only is set 0 explicitly. With
above logic we will allow it to connect to standby?. I still think psql
connection to standby should be handled by changing the default value of
readonly to 1 (which means connect to any). Thinking further probably
replacing readonly parameter with targetServerType=any|master (with default
being any) should clear some confusions and bring consistency since same is
used in JDBC multi host connection string.

2)
@@ -1460,33 +1538,80 @@ connectDBStart(PGconn *conn)
portstr,
(int) (UNIXSOCK_PATH_BUFLEN - 1));
conn->options_valid = false;
+ free(nodes->port);

nodes->port was not allocated at this point.

--
Thanks and Regards
Mithun C Y
EnterpriseDB: http://www.enterprisedb.com