Canceled queries on hot standby with hot_standby_feedback = on

[Drazen Kacar <drazen.kacar@xxxxxxxxxxx>]

I'm running Postgres 9.3.4 with one hot standby. The standby has hot_standby_feedback = on configured:

SQL> select name, setting from pg_settings where name like '%standby%';
            name             | setting
-----------------------------+---------
 hot_standby                 | on
 hot_standby_feedback        | on
 max_standby_archive_delay   | 0
 max_standby_streaming_delay | 0
 synchronous_standby_names   |

In the standby log I have this:

2015-01-12 07:23:07 UTC ERROR:  canceling statement due to conflict with recovery
2015-01-12 07:23:07 UTC DETAIL:  User was holding a relation lock for too long.
2015-01-12 07:23:07 UTC STATEMENT:  ... JOIN table_t1 ...

2015-01-12 08:53:28 UTC ERROR:  canceling statement due to conflict with recovery
2015-01-12 08:53:28 UTC DETAIL:  User was holding a relation lock for too long.
2015-01-12 08:53:28 UTC STATEMENT:  ... JOIN table_t1 ...

On the primary I have this:

2015-01-12 07:23:07 UTC LOG:  automatic vacuum of table "xxx.xxx.table_t1": index scans: 0
        pages: 0 removed, 273 remain
        tuples: 155 removed, 918 remain
        buffer usage: 131 hits, 78 misses, 16 dirtied
        avg read rate: 5.656 MB/s, avg write rate: 1.160 MB/s
        system usage: CPU 0.00s/0.00u sec elapsed 0.10 sec

2015-01-12 08:53:28 UTC LOG:  automatic vacuum of table "xxx.xxx.table_t1": index scans: 1
        pages: 0 removed, 273 remain
        tuples: 50 removed, 1057 remain
        buffer usage: 168 hits, 48 misses, 13 dirtied
        avg read rate: 6.046 MB/s, avg write rate: 1.637 MB/s
        system usage: CPU 0.00s/0.00u sec elapsed 0.06 sec

I was under impression that setting hot_standby_feedback to on would prevent query cancellation on the standby because of vacuuming on the primary.

Is there something else I should do in order to disable query cancelation on the standby?