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MDEV-11154: Write_on_release_cache(log_event.cc) function will not wr…
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…ite "COMMIT", if use "mysqlbinlog ... | mysql ..."

Problem:
=======
Executing command, "mysqlbinlog --read-from-remote-server --host='xx.xx.xx.xx'
--port=3306 --user=xxx --password=xxx --database=mysql --to-last-log
mysql-bin.000001 --start-position=1098699 --stop-never |mysql -uxxx -pxxx", we
found that last data read from remote couldn't commit.

Analysis:
========
The purpose of 'Write_on_release_cache' is that the contents of the Cache will
automatically be written to a dedicated result file on destruction. Flush
operation on the result file is controlled by a flag 'FLUSH_F'. Events which
require force flush upon their destruction will have to enable this
'Write_on_release_cache::FLUSH_F'. At present the 'FLUSH_F' flag is defined as
an enum as shown below.

enum flag
{
  FLUSH_F
};

Since 'FLUSH_F' is the first member without initialization it get the default
value '0'. Because of this the following flush condition never succeeds.

if (m_flags & FLUSH_F)
  fflush(m_file);

At present the file gets flushed only during my_fclose(result_file) operation.
When continuous streaming is enabled through --stop-never option it never gets
flushed and hence events are not replicated.

Fix:
===
Initialize the enum value to non zero value.
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sujatha-s committed Jul 15, 2019
1 parent aba2b41 commit 10ebdb7
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16 changes: 16 additions & 0 deletions mysql-test/suite/binlog/r/binlog_mysqlbinlog_stop_never.result
@@ -0,0 +1,16 @@
RESET MASTER;
include/stop_dump_threads.inc
# Step-1: Execute some dummy statements.
CREATE TABLE t1(i int);
INSERT INTO t1 values (1);
# Step-2: Disable binary log temporarily and drop the table 't1'.
set @@SESSION.SQL_LOG_BIN = 0;
DROP TABLE t1;
set @@SESSION.SQL_LOG_BIN = 1;
# Step-3: Execute MYSQL_BINLOG with --stop-never and source it to mysql client.
# Step-4: Wait till dump thread transfer is completed.
# Step-5: Check that the data is there.
# Step-6: Cleanup
# kill the dump thread serving the mysqlbinlog --stop-never process
include/stop_dump_threads.inc
DROP TABLE t1;
66 changes: 66 additions & 0 deletions mysql-test/suite/binlog/t/binlog_mysqlbinlog_stop_never.test
@@ -0,0 +1,66 @@
# ==== Purpose ====
#
# Test verifies that continuous streaming of binary log content using the
# "mysqlbinlog --stop-never" option and sourcing it to mysql client works
# fine.
#
# ==== Implementation ====
#
# Steps:
# 1 - Create a table on a server on which binary log is enabled and insert
# a row.
# 2 - Disable the binary log on the server and drop the table.
# 3 - Capture the binary log output using "mysqlbinlog --stop_never" option
# and source it to mysql client.
# 4 - Query the PROCESSLIST table to ensure that the dump thread which is
# serving "stop_never" option has read entire binlog.
# 5 - Verify that the table is populated on the server.
# 6 - Cleanup.
#
# ==== References ====
#
# MDEV-11154: Write_on_release_cache(log_event.cc) function will not write
# "COMMIT", if use "mysqlbinlog ... | mysql ..."

--source include/not_windows.inc

# Test is not specific to any binlog format. Hence Running only for 'row'.
--source include/have_binlog_format_row.inc

# binlog file name is needed in the test. To use master-bin.000001,
# RESET MASTER is needed.
RESET MASTER;
# kill the dump threads if there any dump threads (may be from previous test)
--source include/stop_dump_threads.inc

--echo # Step-1: Execute some dummy statements.
CREATE TABLE t1(i int);
INSERT INTO t1 values (1);

--echo # Step-2: Disable binary log temporarily and drop the table 't1'.
set @@SESSION.SQL_LOG_BIN = 0;
DROP TABLE t1;
set @@SESSION.SQL_LOG_BIN = 1;

--echo # Step-3: Execute MYSQL_BINLOG with --stop-never and source it to mysql client.
--write_file $MYSQL_TMP_DIR/mysqlbinlog_stop_never.sh
(`$MYSQL_BINLOG --read-from-remote-server --stop-never --user=root --host=127.0.0.1 --port=$MASTER_MYPORT master-bin.000001 | $MYSQL --user=root --protocol=tcp --host=127.0.0.1 --port=$MASTER_MYPORT`) < /dev/null > /dev/null 2>&1 &
EOF
--exec /bin/bash $MYSQL_TMP_DIR/mysqlbinlog_stop_never.sh

--echo # Step-4: Wait till dump thread transfer is completed.
let $wait_condition= SELECT id from information_schema.processlist where processlist.command like '%Binlog%' and state like '%Master has sent%';
--source include/wait_condition.inc

--echo # Step-5: Check that the data is there.
let $count= 1;
let $table= test.t1;
source include/wait_until_rows_count.inc;

--echo # Step-6: Cleanup
--echo # kill the dump thread serving the mysqlbinlog --stop-never process
--source include/stop_dump_threads.inc

DROP TABLE t1;
--remove_file $MYSQL_TMP_DIR/mysqlbinlog_stop_never.sh

2 changes: 1 addition & 1 deletion sql/log_event.cc
Expand Up @@ -296,7 +296,7 @@ class Write_on_release_cache
public:
enum flag
{
FLUSH_F
FLUSH_F= 1
};

typedef unsigned short flag_set;
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