--
-- failure_connection_establishment.sql tests some behaviour of connection management when
-- it fails to connect.
--
-- Failure cases covered:
--  - timeout
--
SELECT citus.mitmproxy('conn.allow()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

CREATE SCHEMA fail_connect;
SET search_path TO 'fail_connect';
SET citus.shard_count TO 4;
SET citus.max_cached_conns_per_worker TO 0;
ALTER SEQUENCE pg_catalog.pg_dist_shardid_seq RESTART 1450000;
ALTER SEQUENCE pg_catalog.pg_dist_placement_placementid_seq RESTART 1450000;
CREATE TABLE products (
    product_no integer,
    name text,
    price numeric
);
SELECT create_distributed_table('products', 'product_no');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

-- Can only add primary key constraint on distribution column (or group of columns
-- including distribution column)
-- Command below should error out since 'name' is not a distribution column
ALTER TABLE products ADD CONSTRAINT p_key PRIMARY KEY(name);
ERROR:  cannot create constraint on "products"
DETAIL:  Distributed relations cannot have UNIQUE, EXCLUDE, or PRIMARY KEY constraints that do not include the partition column (with an equality operator if EXCLUDE).
-- we will insert a connection delay here as this query was the cause for an investigation
-- into connection establishment problems
SET citus.node_connection_timeout TO 400;
SELECT citus.mitmproxy('conn.delay(500)');
 mitmproxy
---------------------------------------------------------------------

(1 row)

ALTER TABLE products ADD CONSTRAINT p_key PRIMARY KEY(product_no);
WARNING:  could not establish connection after 400 ms
ERROR:  connection to the remote node localhost:xxxxx failed
SELECT citus.mitmproxy('conn.allow()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

CREATE TABLE r1 (
    id int PRIMARY KEY,
    name text
);
INSERT INTO r1 (id, name) VALUES
(1,'foo'),
(2,'bar'),
(3,'baz');
SELECT create_reference_table('r1');
NOTICE:  Copying data from local table...
NOTICE:  copying the data has completed
DETAIL:  The local data in the table is no longer visible, but is still on disk.
HINT:  To remove the local data, run: SELECT truncate_local_data_after_distributing_table($$fail_connect.r1$$)
 create_reference_table
---------------------------------------------------------------------

(1 row)

SELECT citus.clear_network_traffic();
 clear_network_traffic
---------------------------------------------------------------------

(1 row)

SELECT citus.mitmproxy('conn.delay(500)');
 mitmproxy
---------------------------------------------------------------------

(1 row)

-- we cannot control which replica of the reference table will be queried and there is
-- only one specific client we can control the connection for.
-- by using round-robin task_assignment_policy we can force to hit both machines.
-- and in the end, dumping the network traffic shows that the connection establishment
-- is initiated to the node behind the proxy
SET client_min_messages TO ERROR;
SET citus.task_assignment_policy TO 'round-robin';
-- suppress the warning since we can't control which shard is chose first. Failure of this
-- test would be if one of the queries does not return the result but an error.
SELECT name FROM r1 WHERE id = 2;
 name
---------------------------------------------------------------------
 bar
(1 row)

SELECT name FROM r1 WHERE id = 2;
 name
---------------------------------------------------------------------
 bar
(1 row)

-- verify a connection attempt was made to the intercepted node, this would have cause the
-- connection to have been delayed and thus caused a timeout
SELECT * FROM citus.dump_network_traffic() WHERE conn=0;
 conn |   source    |      message
---------------------------------------------------------------------
    0 | coordinator | [initial message]
(1 row)

SELECT citus.mitmproxy('conn.allow()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

-- similar test with the above but this time on a
-- distributed table instead of a reference table
-- and with citus.force_max_query_parallelization is set
SET citus.force_max_query_parallelization TO ON;
SELECT citus.mitmproxy('conn.delay(500)');
 mitmproxy
---------------------------------------------------------------------

(1 row)

-- suppress the warning since we can't control which shard is chose first. Failure of this
-- test would be if one of the queries does not return the result but an error.
SELECT count(*) FROM products;
 count
---------------------------------------------------------------------
     0
(1 row)

SELECT count(*) FROM products;
 count
---------------------------------------------------------------------
     0
(1 row)

SELECT citus.mitmproxy('conn.allow()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SET citus.shard_replication_factor TO 1;
CREATE TABLE single_replicatated(key int);
SELECT create_distributed_table('single_replicatated', 'key');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

-- this time the table is single replicated and we're still using the
-- the max parallelization flag, so the query should fail
SET citus.force_max_query_parallelization TO ON;
SELECT citus.mitmproxy('conn.delay(500)');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT count(*) FROM single_replicatated;
ERROR:  could not establish any connections to the node localhost:xxxxx after 400 ms
SET citus.force_max_query_parallelization TO OFF;
-- one similar test, and this time on modification queries
-- to see that connection establishement failures could
-- fail the transaction (but not mark any placements as INVALID)
SELECT citus.mitmproxy('conn.allow()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

BEGIN;
SELECT
	count(*) as invalid_placement_count
FROM
	pg_dist_shard_placement
WHERE
	shardstate = 3 AND
	shardid IN (SELECT shardid from pg_dist_shard where logicalrelid = 'single_replicatated'::regclass);
 invalid_placement_count
---------------------------------------------------------------------
                       0
(1 row)

SELECT citus.mitmproxy('conn.delay(500)');
 mitmproxy
---------------------------------------------------------------------

(1 row)

INSERT INTO single_replicatated VALUES (100);
ERROR:  could not establish any connections to the node localhost:xxxxx after 400 ms
COMMIT;
SELECT
	count(*) as invalid_placement_count
FROM
	pg_dist_shard_placement
WHERE
	shardstate = 3 AND
	shardid IN (SELECT shardid from pg_dist_shard where logicalrelid = 'single_replicatated'::regclass);
 invalid_placement_count
---------------------------------------------------------------------
                       0
(1 row)

-- show that INSERT failed
SELECT citus.mitmproxy('conn.allow()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT count(*) FROM single_replicatated WHERE key = 100;
 count
---------------------------------------------------------------------
     0
(1 row)

RESET client_min_messages;
-- verify get_global_active_transactions works when a timeout happens on a connection
SELECT * FROM get_global_active_transactions() WHERE transaction_number != 0;
 datid | process_id | initiator_node_identifier | worker_query | transaction_number | transaction_stamp | global_pid
---------------------------------------------------------------------
(0 rows)

-- tests for connectivity checks
SET client_min_messages TO ERROR;
-- kill the connection after authentication is ok
SELECT citus.mitmproxy('conn.onAuthenticationOk().kill()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_connection_to_node('localhost', :worker_2_proxy_port);
 citus_check_connection_to_node
---------------------------------------------------------------------
 f
(1 row)

-- cancel the connection after authentication is ok
SELECT citus.mitmproxy('conn.onAuthenticationOk().cancel(' || pg_backend_pid() || ')');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_connection_to_node('localhost', :worker_2_proxy_port);
ERROR:  canceling statement due to user request
-- kill the connection after connectivity check query is sent
SELECT citus.mitmproxy('conn.onQuery(query="^SELECT 1$").kill()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_connection_to_node('localhost', :worker_2_proxy_port);
 citus_check_connection_to_node
---------------------------------------------------------------------
 f
(1 row)

-- cancel the connection after connectivity check query is sent
SELECT citus.mitmproxy('conn.onQuery(query="^SELECT 1$").cancel(' || pg_backend_pid() || ')');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_connection_to_node('localhost', :worker_2_proxy_port);
ERROR:  canceling statement due to user request
-- kill the connection after connectivity check command is complete
SELECT citus.mitmproxy('conn.onCommandComplete(command="SELECT 1").kill()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_connection_to_node('localhost', :worker_2_proxy_port);
 citus_check_connection_to_node
---------------------------------------------------------------------
 f
(1 row)

-- cancel the connection after connectivity check command is complete
SELECT citus.mitmproxy('conn.onCommandComplete(command="SELECT 1").cancel(' || pg_backend_pid() || ')');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_connection_to_node('localhost', :worker_2_proxy_port);
ERROR:  canceling statement due to user request
-- verify that the checks are not successful when timeouts happen on a connection
SELECT citus.mitmproxy('conn.delay(500)');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_connection_to_node('localhost', :worker_2_proxy_port);
 citus_check_connection_to_node
---------------------------------------------------------------------
 f
(1 row)

-- tests for citus_check_cluster_node_health
-- kill all connectivity checks that originate from this node
SELECT citus.mitmproxy('conn.onQuery(query="^SELECT citus_check_connection_to_node").kill()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_cluster_node_health();
 from_nodename | from_nodeport | to_nodename | to_nodeport | result
---------------------------------------------------------------------
 localhost     |          9060 | localhost   |        9060 |
 localhost     |          9060 | localhost   |       57637 |
 localhost     |         57637 | localhost   |        9060 | t
 localhost     |         57637 | localhost   |       57637 | t
(4 rows)

-- suggested summary queries for connectivity checks
SELECT bool_and(coalesce(result, false)) FROM citus_check_cluster_node_health();
 bool_and
---------------------------------------------------------------------
 f
(1 row)

SELECT result, count(*) FROM citus_check_cluster_node_health() GROUP BY result ORDER BY 1;
 result | count
---------------------------------------------------------------------
 t      |     2
        |     2
(2 rows)

-- cancel all connectivity checks that originate from this node
SELECT citus.mitmproxy('conn.onQuery(query="^SELECT citus_check_connection_to_node").cancel(' || pg_backend_pid() || ')');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_cluster_node_health();
ERROR:  canceling statement due to user request
-- kill all but first connectivity checks that originate from this node
SELECT citus.mitmproxy('conn.onQuery(query="^SELECT citus_check_connection_to_node").after(1).kill()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_cluster_node_health();
 from_nodename | from_nodeport | to_nodename | to_nodeport | result
---------------------------------------------------------------------
 localhost     |          9060 | localhost   |        9060 | t
 localhost     |          9060 | localhost   |       57637 |
 localhost     |         57637 | localhost   |        9060 | t
 localhost     |         57637 | localhost   |       57637 | t
(4 rows)

-- cancel all but first connectivity checks that originate from this node
SELECT citus.mitmproxy('conn.onQuery(query="^SELECT citus_check_connection_to_node").after(1).cancel(' || pg_backend_pid() || ')');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_cluster_node_health();
ERROR:  canceling statement due to user request
-- kill all connections to this node
SELECT citus.mitmproxy('conn.onAuthenticationOk().kill()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_cluster_node_health();
 from_nodename | from_nodeport | to_nodename | to_nodeport | result
---------------------------------------------------------------------
 localhost     |          9060 | localhost   |        9060 |
 localhost     |          9060 | localhost   |       57637 |
 localhost     |         57637 | localhost   |        9060 | f
 localhost     |         57637 | localhost   |       57637 | t
(4 rows)

-- cancel all connections to this node
SELECT citus.mitmproxy('conn.onAuthenticationOk().cancel(' || pg_backend_pid() || ')');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_cluster_node_health();
ERROR:  canceling statement due to user request
-- kill connection checks to this node
SELECT citus.mitmproxy('conn.onQuery(query="^SELECT 1$").kill()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_cluster_node_health();
 from_nodename | from_nodeport | to_nodename | to_nodeport | result
---------------------------------------------------------------------
 localhost     |          9060 | localhost   |        9060 | f
 localhost     |          9060 | localhost   |       57637 | t
 localhost     |         57637 | localhost   |        9060 | f
 localhost     |         57637 | localhost   |       57637 | t
(4 rows)

-- cancel connection checks to this node
SELECT citus.mitmproxy('conn.onQuery(query="^SELECT 1$").cancel(' || pg_backend_pid() || ')');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SELECT * FROM citus_check_cluster_node_health();
ERROR:  canceling statement due to user request
RESET client_min_messages;
SELECT citus.mitmproxy('conn.allow()');
 mitmproxy
---------------------------------------------------------------------

(1 row)

SET citus.node_connection_timeout TO DEFAULT;
DROP SCHEMA fail_connect CASCADE;
NOTICE:  drop cascades to 3 other objects
DETAIL:  drop cascades to table products
drop cascades to table r1
drop cascades to table single_replicatated
SET search_path TO default;