problems getting cache working with laravel app

[tormodmacleod]

hello,

we have a batch application that runs for several hours and is very read heavy. we used to get good mileage out of the query cache on mysql 5.7 but when they removed that feature we saw that the documentation suggested proxysql. i've configured proxysql to run as a sidecar container in the pod next to the batch process. essentially i want all my reads going through proxysql and to be cached for a very long time. my writes i will probably just send to the mysql host

please see my configuration below

$ cat proxysql.cnf 
datadir="/var/lib/proxysql"

admin_variables=
{
  admin_credentials="sensitive:sensitive;sensitive:sensitive"
  mysql_ifaces="0.0.0.0:6032"
}

mysql_variables=
{
  threads=4
  max_connections=2048
  default_query_delay=0
  default_query_timeout=36000000
  have_compress=true
  poll_timeout=2000
  interfaces="0.0.0.0:3306"
  default_schema="myschema"
  stacksize=1048576
  server_version="5.5.30"
  connect_timeout_server=3000
  monitor_enabled = false
  commands_stats=true
  sessions_sort=true
  connect_retries_on_failure=10
  query_cache_size_MB=256
}

mysql_servers=
(
  {
    address="mysql"
    port=3306
    hostgroup=0
    max_connections=200
  }
)

mysql_users=
(
  {
    username="sensitive"
    password="sensitive"
    default_hostgroup=0
    default_schema="myschema"
    active=1
  }
)

mysql_query_rules=
(
  {
    rule_id=1
    active=1
    match_pattern="^SELECT .*"
    cache_ttl=21600000
    destination_hostgroup=0
    apply=0
  },
)

all my reads are being routed through proxysql as expected but nothing is being cached

mysql> SELECT hostgroup, COUNT(*) AS query_count FROM stats_mysql_query_digest GROUP BY hostgroup;
+-----------+-------------+
| hostgroup | query_count |
+-----------+-------------+
| 0         | 90          |
+-----------+-------------+
1 row in set (0.01 sec)

i understand that proxysql is able to work with prepared statements and i can see that there are entries in the stats_mysql_prepared_statements_info table

mysql> SELECT count(*) FROM stats_mysql_prepared_statements_info;
+----------+
| count(*) |
+----------+
| 842      |
+----------+
1 row in set (0.01 sec)

i'm wondering if i've perhaps misconfigured something and would be grateful for any help or advice