[storage/federated] PS-7999: FEDERATED engine not reconnecting on wai…

…t_timeout exceeded https://jira.percona.com/browse/PS-7999 Original commit caused error: percona@14508bbb179 Reconnection is lost because error is produced on reading query result, but reconnect is implemented only in `cli_advanced_command`, which sends commands. So we add reconnection on the full real query, but just for Federated to minimize possible issues. Similar reconnect logic was added for MySQL CLI Client, see mysql_real_query_for_lazy in 14508bb patch.
inikep · Jul 24, 2023 · d218589 · d218589
1 parent 576177e
commit d218589
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Showing 3 changed files with 58 additions and 1 deletion.
diff --git a/mysql-test/suite/federated/r/federated.result b/mysql-test/suite/federated/r/federated.result
@@ -2444,6 +2444,33 @@ SELECT a, b FROM federated.t1;
 a	b
 DROP TABLE federated.t1;
 DROP TABLE federated.t1;
+#
+# Bug#105878: PS-7999: FEDERATED engine not reconnecting on wait_timeout exceeded
+#
+SET @OLD_SLAVE_WAIT_TIMEOUT= @@GLOBAL.WAIT_TIMEOUT;
+SET @@GLOBAL.WAIT_TIMEOUT= 4;
+CREATE TABLE test.t1 (id int PRIMARY KEY);
+INSERT INTO test.t1 VALUES(1);
+CREATE SERVER test FOREIGN DATA WRAPPER test1 OPTIONS(
+user 'root',
+password '',
+host '127.0.0.1',
+port SLAVE_PORT,
+database 'test');
+CREATE TABLE test.t1 (id int PRIMARY KEY) ENGINE=FEDERATED CONNECTION='test';
+SELECT * FROM test.t1;
+id
+1
+SELECT sleep(5);
+sleep(5)
+0
+SELECT * from test.t1;
+id
+1
+DROP TABLE test.t1;
+DROP SERVER test;
+DROP TABLE test.t1;
+SET @@GLOBAL.WAIT_TIMEOUT= @OLD_SLAVE_WAIT_TIMEOUT;
 SET @@GLOBAL.CONCURRENT_INSERT= @OLD_MASTER_CONCURRENT_INSERT;
 SET @@GLOBAL.CONCURRENT_INSERT= @OLD_SLAVE_CONCURRENT_INSERT;
 DROP TABLE IF EXISTS federated.t1;

diff --git a/mysql-test/suite/federated/t/federated.test b/mysql-test/suite/federated/t/federated.test
@@ -2151,6 +2151,35 @@ DROP TABLE federated.t1;
 connection slave;
 DROP TABLE federated.t1;
 
+--echo #
+--echo # Bug#105878: PS-7999: FEDERATED engine not reconnecting on wait_timeout exceeded
+--echo #
+connection slave;
+SET @OLD_SLAVE_WAIT_TIMEOUT= @@GLOBAL.WAIT_TIMEOUT;
+SET @@GLOBAL.WAIT_TIMEOUT= 4;
+CREATE TABLE test.t1 (id int PRIMARY KEY);
+INSERT INTO test.t1 VALUES(1);
+
+connection master;
+--replace_result $SLAVE_MYPORT SLAVE_PORT
+eval CREATE SERVER test FOREIGN DATA WRAPPER test1 OPTIONS(
+  user 'root',
+  password '',
+  host '127.0.0.1',
+  port $SLAVE_MYPORT,
+  database 'test');
+CREATE TABLE test.t1 (id int PRIMARY KEY) ENGINE=FEDERATED CONNECTION='test';
+
+SELECT * FROM test.t1;
+SELECT sleep(5);
+SELECT * from test.t1;
+
+DROP TABLE test.t1;
+DROP SERVER test;
+connection slave;
+DROP TABLE test.t1;
+SET @@GLOBAL.WAIT_TIMEOUT= @OLD_SLAVE_WAIT_TIMEOUT;
+
 connection default;
 SET @@GLOBAL.CONCURRENT_INSERT= @OLD_MASTER_CONCURRENT_INSERT;
 connection slave;

diff --git a/storage/federated/ha_federated.cc b/storage/federated/ha_federated.cc
@@ -500,7 +500,8 @@ static int federated_db_init(void *p) {
   federated_hton->commit = federated_commit;
   federated_hton->rollback = federated_rollback;
   federated_hton->create = federated_create_handler;
-  federated_hton->flags = HTON_ALTER_NOT_SUPPORTED | HTON_NO_PARTITION;
+  federated_hton->flags = HTON_ALTER_NOT_SUPPORTED | HTON_NO_PARTITION |
+                          HTON_SUPPORTS_ONLINE_BACKUPS;
 
   /*
     Support for transactions disabled until WL#2952 fixes it.