set command ‘set transaction_read_only = 0;‘ routed to standby node and execute failed.

[liujinyang-highgo]

Hi,
I have met an issue:

envionment
pgpool 4.6.2 + three backend nodes(one primary and two standby nodes, weight=0:1:1)

reproduce

1. start pgpool
2. run following command:
   begin;
   set transaction_read_only = 0;
   commit;
3. 'set transaction_read_only = 0;' would be routed to standby node and execute failed.

analyze
when node is VariableSetStmt and the value is integer, it should be 'if (!v->val.ival.ival)' but not 'if (v->val.ival.ival)'

in function static POOL_DEST send_to_where(Node *node)
{
     ......
     else if (IsA(node, VariableSetStmt))
    {
                ListCell   *list_item;
                bool            ret = POOL_BOTH;

                /*
                 * SET transaction_read_only TO off
                 */
                if (((VariableSetStmt *) node)->kind == VAR_SET_VALUE &&
                        !strcmp(((VariableSetStmt *) node)->name, "transaction_read_only"))
                {
                        List       *options = ((VariableSetStmt *) node)->args;

                        foreach(list_item, options)
                        {
                                A_Const    *v = (A_Const *) lfirst(list_item);

                                switch (nodeTag(&v->val))
                                {
                                        case T_String:
                                                if (!strcasecmp(v->val.sval.sval, "off") ||
                                                        !strcasecmp(v->val.sval.sval, "f") ||
                                                        !strcasecmp(v->val.sval.sval, "false"))
                                                        ret = POOL_PRIMARY;
                                                break;
                                        case T_Integer:
                                                if (v->val.ival.ival)
                                                        ret = POOL_PRIMARY;
                                        default:
                                                break;
                                }
                        }
                        return ret;
                }
     }

}

4. attachment is the patch , verified has been passed.

0001-fix-issue-set-transaction_read_only-0-was-routed-to-.patch

[pengbo0328]

Thank you as always for your report and patch.
I have committed your fix here:
https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=3862188187f1b61d732189dc473daea30498c669

And I also replaced incorrect bool ret = POOL_BOTH with the proper enum type in this comit.