Bug Fix: MyRocks locking scan with RC may not return full result sets (…

…percona#916)

Upstream commit ID : fb-mysql-5.6.35/b939510e2d1ecff961d1c1aee50a2fdd2bcb223a
PS-5577 : Merge fb-prod201901

Summary:
With Read Committed isolation level, MyRocks locking full/range scan
(updates/deletes with Seek) may end up GetForUpdate returning kNotFound,
if other transactions delete the same key after Seek and before
GetForUpdate. MyRocks was expected to skip to next row in that case.
However, under certain conditions (locking range scan with equal predicates,
and locking range/full scan with secondary index),
MyRocks stops scanning records further and end up not updating after
that, even if further rows may match.
From caller's perspective, the update succeeds with updating
zero/fewer rows.
This diff catches the cases and preventing from stopping scanning.
Pull Request resolved: facebook/mysql-5.6#916

Differential Revision: D13545942

Pulled By: yoshinorim

fbshipit-source-id: 76285a06a05

mysql-test/suite/rocksdb/include/rocksdb_concurrent_delete.inc

@@ -1,3 +1,8 @@
+--source include/have_rocksdb.inc
+--source include/have_debug_sync.inc
+
+--source include/count_sessions.inc
+
 # Usage:
 #
 # let $order = ASC;  # or DESC
@@ -8,21 +13,30 @@ let $first_row = -1; # Error this should never happen
 if ($order == 'ASC')
 {
   let $first_row = 1;
+  let $middle_row = 3;
+  let $end_row = 5;
 }
 if ($order == 'DESC')
 {
-  let $first_row = 3;
+  let $first_row = 5;
+  let $middle_row = 3;
+  let $end_row = 1;
 }
 
 connect (con, localhost, root,,);
 connection default;
+eval SET SESSION TRANSACTION ISOLATION LEVEL $isolation_level;
 
-eval CREATE TABLE t1 (pk INT PRIMARY KEY COMMENT '$comment', a INT) ENGINE=ROCKSDB;
-INSERT INTO t1 VALUES(1,1), (2,2), (3,3);
+SET debug_sync='RESET';
+
+eval CREATE TABLE t1 (pk INT PRIMARY KEY COMMENT '$comment', a INT) ENGINE=RocksDB;
+INSERT INTO t1 VALUES(1,1), (2,2), (3,3), (4,4), (5,5);
 
 # This will cause the SELECT to block after finding the first row, but
 # before locking and reading it.
+--echo --PK first row delete
 connection con;
+eval SET SESSION TRANSACTION ISOLATION LEVEL $isolation_level;
 SET debug_sync='rocksdb_concurrent_delete SIGNAL parked WAIT_FOR go';
 send_eval SELECT * FROM t1 order by t1.pk $order FOR UPDATE;
 
@@ -41,8 +55,52 @@ SET debug_sync='now SIGNAL go';
 connection con;
 reap;
 
+# Deleting a middle row
+--echo --PK middle row delete
+SET debug_sync='rocksdb_concurrent_delete SIGNAL parked WAIT_FOR go';
+send_eval SELECT * FROM t1 order by t1.pk $order FOR UPDATE;
+
+connection default;
+SET debug_sync='now WAIT_FOR parked';
+eval DELETE FROM t1 WHERE pk = $middle_row;
+SET debug_sync='now SIGNAL go';
+
+connection con;
+if ($isolation_level == "REPEATABLE READ")
+{
+  --error ER_LOCK_DEADLOCK
+  reap;
+}
+if ($isolation_level == "READ COMMITTED")
+{
+  reap;
+}
+
+# Deleting the end row
+--echo --PK end row delete
+SET debug_sync='rocksdb_concurrent_delete SIGNAL parked WAIT_FOR go';
+send_eval SELECT * FROM t1 order by t1.pk $order FOR UPDATE;
+
+connection default;
+SET debug_sync='now WAIT_FOR parked';
+eval DELETE FROM t1 WHERE pk = $end_row;
+SET debug_sync='now SIGNAL go';
+
+connection con;
+if ($isolation_level == "REPEATABLE READ")
+{
+  --error ER_LOCK_DEADLOCK
+  reap;
+}
+if ($isolation_level == "READ COMMITTED")
+{
+  reap;
+}
+
+
 # Cleanup
 connection default;
 disconnect con;
 set debug_sync='RESET';
 drop table t1;
+--source include/wait_until_count_sessions.inc

mysql-test/suite/rocksdb/include/rocksdb_concurrent_delete_main.inc

@@ -0,0 +1,30 @@
+--source include/have_rocksdb.inc
+--source include/have_debug_sync.inc
+
+# This validates the fix for Issue #144.  The problem was that with more
+# than one client accessing/deleting the same row there was a possibility
+# of client A finding a row (through Next() or Prev()) but the row being
+# deleted before the GetForUpdate() call could occur.  When this happened
+# a nearly useless error was being returned.
+
+let $order=ASC;
+let $comment="";
+--source rocksdb_concurrent_delete.inc
+--source rocksdb_concurrent_delete_sk.inc
+
+let $order=DESC;
+let $comment="";
+--source rocksdb_concurrent_delete.inc
+
+let $order=ASC;
+let $comment="rev:cf2";
+--source rocksdb_concurrent_delete.inc
+
+let $order=DESC;
+let $comment="rev:cf2";
+--source rocksdb_concurrent_delete.inc
+
+let $index=PRIMARY;
+--source rocksdb_concurrent_delete_range.inc
+let $index=sk;
+--source rocksdb_concurrent_delete_range.inc

mysql-test/suite/rocksdb/include/rocksdb_concurrent_delete_range.inc

@@ -0,0 +1,85 @@
+--source include/have_rocksdb.inc
+--source include/have_debug_sync.inc
+
+--source include/count_sessions.inc
+
+# This is a test case to reproduce https://github.com/facebook/mysql-5.6/issues/162
+# Expected output of the last select for update was (1,2,100) and (1,3,100), but
+# currently it returns (1,2,1) and (1,3,1), which must be fixed.
+
+connect (con, localhost, root,,);
+connection default;
+
+set debug_sync='RESET';
+eval SET SESSION TRANSACTION ISOLATION LEVEL $isolation_level;
+create table t1 (id1 int, id2 int, value int, primary key (id1, id2), index sk (id1, value)) ENGINE=RocksDB;
+insert into t1 values (1, 1, 1),(1, 2, 1),(1, 3, 1),(1, 4, 1),(1, 5, 1),(2, 2, 2);
+
+# deleting a first row
+--echo --First row delete with $index
+connection con;
+eval SET SESSION TRANSACTION ISOLATION LEVEL $isolation_level;
+set debug_sync='rocksdb.get_row_by_rowid SIGNAL parked WAIT_FOR go';
+send_eval update t1 force index ($index) set value=100 where id1=1;
+
+connection default;
+set debug_sync='now WAIT_FOR parked';
+delete from t1 where id1=1 and id2=1;
+set debug_sync='now SIGNAL go';
+
+connection con;
+reap;
+select * from t1 where id1=1;
+
+# deleting a middle row
+--echo --Middle row delete with $index
+eval SET SESSION TRANSACTION ISOLATION LEVEL $isolation_level;
+set debug_sync='rocksdb.get_row_by_rowid SIGNAL parked WAIT_FOR go';
+send_eval update t1 force index ($index) set value=200 where id1=1;
+
+connection default;
+set debug_sync='now WAIT_FOR parked';
+delete from t1 where id1=1 and id2=3;
+set debug_sync='now SIGNAL go';
+
+connection con;
+if ($isolation_level == "REPEATABLE READ")
+{
+  --error ER_LOCK_DEADLOCK
+  reap;
+}
+if ($isolation_level == "READ COMMITTED")
+{
+  reap;
+}
+select * from t1 where id1=1;
+
+# deleting the end row
+--echo --End row delete with $index
+eval SET SESSION TRANSACTION ISOLATION LEVEL $isolation_level;
+set debug_sync='rocksdb.get_row_by_rowid SIGNAL parked WAIT_FOR go';
+send_eval update t1 force index ($index) set value=300 where id1=1;
+
+connection default;
+set debug_sync='now WAIT_FOR parked';
+delete from t1 where id1=1 and id2=5;
+set debug_sync='now SIGNAL go';
+
+connection con;
+if ($isolation_level == "REPEATABLE READ")
+{
+  --error ER_LOCK_DEADLOCK
+  reap;
+}
+if ($isolation_level == "READ COMMITTED")
+{
+  reap;
+}
+select * from t1 where id1=1;
+
+# Cleanup
+connection default;
+disconnect con;
+set debug_sync='RESET';
+drop table t1;
+--source include/wait_until_count_sessions.inc

mysql-test/suite/rocksdb/include/rocksdb_concurrent_delete_sk.inc

@@ -0,0 +1,82 @@
+--source include/have_rocksdb.inc
+--source include/have_debug_sync.inc
+
+--source include/count_sessions.inc
+
+connect (con, localhost, root,,);
+connection default;
+eval SET SESSION TRANSACTION ISOLATION LEVEL $isolation_level;
+
+SET debug_sync='RESET';
+
+eval CREATE TABLE t1 (pk INT PRIMARY KEY, a INT, index a(a)) ENGINE=RocksDB;
+INSERT INTO t1 VALUES(1,1), (2,2), (3,3), (4,4), (5,5);
+
+# This will cause the SELECT to block after finding the first row, but
+# before locking and reading it.
+--echo --SK first row delete
+connection con;
+eval SET SESSION TRANSACTION ISOLATION LEVEL $isolation_level;
+SET debug_sync='rocksdb_concurrent_delete_sk SIGNAL parked WAIT_FOR go';
+send_eval SELECT a FROM t1 FORCE INDEX(a) FOR UPDATE;
+
+# While that connection is waiting, delete the first row (the one con
+# is about to lock and read
+connection default;
+SET debug_sync='now WAIT_FOR parked';
+eval DELETE FROM t1 WHERE pk = 1;
+
+# Signal the waiting select to continue
+SET debug_sync='now SIGNAL go';
+
+connection con;
+reap;
+
+# Deleting a middle row
+--echo --SK middle row delete
+SET debug_sync='rocksdb_concurrent_delete_sk SIGNAL parked WAIT_FOR go';
+send_eval SELECT a FROM t1 FORCE INDEX(a) FOR UPDATE;
+
+connection default;
+SET debug_sync='now WAIT_FOR parked';
+eval DELETE FROM t1 WHERE pk = 3;
+SET debug_sync='now SIGNAL go';
+
+connection con;
+if ($isolation_level == "REPEATABLE READ")
+{
+  --error ER_LOCK_DEADLOCK
+  reap;
+}
+if ($isolation_level == "READ COMMITTED")
+{
+  reap;
+}
+
+# Deleting the end row
+--echo --SK end row delete
+SET debug_sync='rocksdb_concurrent_delete_sk SIGNAL parked WAIT_FOR go';
+send_eval SELECT a FROM t1 FORCE INDEX(a) FOR UPDATE;
+
+connection default;
+SET debug_sync='now WAIT_FOR parked';
+eval DELETE FROM t1 WHERE pk = 5;
+SET debug_sync='now SIGNAL go';
+
+connection con;
+if ($isolation_level == "REPEATABLE READ")
+{
+  --error ER_LOCK_DEADLOCK
+  reap;
+}
+if ($isolation_level == "READ COMMITTED")
+{
+  reap;
+}
+
+# Cleanup
+connection default;
+disconnect con;
+set debug_sync='RESET';
+drop table t1;
+--source include/wait_until_count_sessions.inc