Major replication test framework cleanup. This does the following:
- Ensure that all tests clean up the replication state when they
finish, by making check-testcase check the output of SHOW SLAVE STATUS.
This implies:
- Slave must not be running after test finished. This is good
because it removes the risk for sporadic errors in subsequent
tests when a test forgets to sync correctly.
- Slave SQL and IO errors must be cleared when test ends. This is
good because we will notice if a test gets an unexpected error in
the slave threads near the end.
- We no longer have to clean up before a test starts.
- Ensure that all tests that wait for an error in one of the slave
threads waits for a specific error. It is no longer possible to
source wait_for_slave_[sql|io]_to_stop.inc when there is an error
in one of the slave threads. This is good because:
- If a test expects an error but there is a bug that causes
another error to happen, or if it stops the slave thread without
an error, then we will notice.
- When developing tests, wait_for_*_to_[start|stop].inc will fail
immediately if there is an error in the relevant slave thread.
Before this patch, we had to wait for the timeout.
- Remove duplicated and repeated code for setting up unusual replication
topologies. Now, there is a single file that is capable of setting
up arbitrary topologies (include/rpl_init.inc, but
include/master-slave.inc is still available for the most common
topology). Tests can now end with include/rpl_end.inc, which will clean
up correctly no matter what topology is used. The topology can be
changed with include/rpl_change_topology.inc.
- Improved debug information when tests fail. This includes:
- debug info is printed on all servers configured by include/rpl_init.inc
- User can set $rpl_debug=1, which makes auxiliary replication files
print relevant debug info.
- Improved documentation for all auxiliary replication files. Now they
describe purpose, usage, parameters, and side effects.
- Many small code cleanups:
- Made have_innodb.inc output a sensible error message.
- Moved contents of rpl000017-slave.sh into rpl000017.test
- Added mysqltest variables that expose the current state of
disable_warnings/enable_warnings and friends.
- Too many to list here: see per-file comments for details.
Some of the test cases reference to binlog position and
these position numbers are written into result explicitly.
It is difficult to maintain if log event format changes.
There are a couple of cases explicit position number appears,
we handle them in different ways
A. 'CHANGE MASTER ...' with MASTER_LOG_POS or/and RELAY_LOG_POS options
Use --replace_result to mask them.
B. 'SHOW BINLOG EVENT ...'
Replaced by show_binlog_events.inc or wait_for_binlog_event.inc.
show_binlog_events.inc file's function is enhanced by given
$binlog_file and $binlog_limit.
C. 'SHOW SLAVE STATUS', 'show_slave_status.inc' and 'show_slave_status2.inc'
For the test cases just care a few items in the result of 'SHOW SLAVE STATUS',
only the items related to each test case are showed.
'show_slave_status.inc' is rebuild, only the given items in $status_items
will be showed.
'check_slave_is_running.inc' and 'check_slave_no_error.inc'
and 'check_slave_param.inc' are auxiliary files helping
to show running status and error information easily.
We cann connect() in a non-blocking mode to be able to specify a
non-standard timeout.
The problem was that we did not fetch the status from the
non-blocking connect(). We assumed that poll() would not return
a POLLIN flag if the connect failed. But on some platforms this
is not true.
After a successful poll() we do now retrieve the status value
from connect() with getsockopt(...SO_ERROR...). Now we do know
if (and how) the connect failed.
The test case for my investigation was rpl.rlp_ssl1 on an
Ubuntu 9.04 x86_64 machine. Both, IPV4 and IPV6 were active.
'localhost' resolved first for IPV6 and then for IPV4. The
connection over IPV6 was blocked. rpl.rlp_ssl1 timed out
as it did not notice the failed connect(). The first read()
failed, which was interpreted as a master crash and the
connection was tried to reestablish with the same result
until the retry limit was reached.
With the fix, the connect() problem is immediately recognized,
and the connect() is retried on the second resolution for
'localhost', which is successful.
Problem 1: The test waits for an error in the slave sql thread,
then resolves the error and issues 'start slave'. However, there
is a gap between when the error is reported and the slave sql
thread stops. If this gap was long, the slave would still be
running when 'start slave' happened, so 'start slave' would fail
and cause a test failure.
Fix 1: Made wait_for_slave_sql_error wait for the slave to stop
instead of wait for error in the IO thread. After stopping, the
error code is verified. If the error code is wrong, debug info
is printed. To print debug info, the debug printing code in
wait_for_slave_param.inc was moved out to a new file,
show_rpl_debug_info.inc.
Problem 2: rpl_stm_mystery22 is a horrible name, the comments in
the file didn't explain anything useful, the test was generally
hard to follow, and the test was essentially duplicated between
rpl_stm_mystery22 and rpl_row_mystery22.
Fix 2: The test is about conflicts in the slave SQL thread,
hence I renamed the tests to rpl_{stm,row}_conflicts. Refactored
the test so that the work is done in
extra/rpl_tests/rpl_conflicts.inc, and
rpl.rpl_{row,stm}_conflicts merely sets some variables and then
sourced extra/rpl_tests/rpl_conflicts.inc.
The tests have been rewritten and comments added.
Problem 3: When calling wait_for_slave_sql_error.inc, you always
want to verify that the sql thread stops because of the expected
error and not because of some other error. Currently,
wait_for_slave_sql_error.inc allows the caller to omit the error
code, in which case all error codes are accepted.
Fix 3: Made wait_for_slave_sql_error.inc fail if no error code
is given. Updated rpl_filter_tables_not_exist accordingly.
Problem 4: rpl_filter_tables_not_exist had a typo, the dollar
sign was missing in a 'let' statement.
Fix 4: Added dollar sign.
Problem 5: When replicating from other servers than the one named
'master', the wait_for_slave_* macros were unable to print debug
info on the master.
Fix 5: Replace parameter $slave_keep_connection by
$master_connection.
Problem 1: tests often fail in pushbuild with a timeout when waiting
for the slave to start/stop/receive error.
Fix 1: Updated the wait_for_slave_* macros in the following way:
- The timeout is increased by a factor ten
- Refactored the macros so that wait_for_slave_param does the work for
the other macros.
Problem 2: Tests are often incorrectly written, lacking a
source include/wait_for_slave_to_[start|stop].inc.
Fix 2: Improved the chance to get it right by adding
include/start_slave.inc and include/stop_slave.inc, and updated tests
to use these.
Problem 3: The the built-in test language command
wait_for_slave_to_stop is a misnomer (does not wait for the slave io
thread) and does not give as much debug info in case of failure as
the otherwise equivalent macro
source include/wait_for_slave_sql_to_stop.inc
Fix 3: Replaced all calls to the built-in command by a call to the
macro.
Problem 4: Some, but not all, of the wait_for_slave_* macros had an
implicit connection slave. This made some tests confusing to read,
and made it more difficult to use the macro in circular replication
scenarios, where the connection named master needs to wait.
Fix 4: Removed the implicit connection slave from all
wait_for_slave_* macros, and updated tests to use an explicit
connection slave where necessary.
Problem 5: The macros wait_slave_status.inc and wait_show_pattern.inc
were unused. Moreover, using them is difficult and error-prone.
Fix 5: remove these macros.
Problem 6: log_bin_trust_function_creators_basic failed when running
tests because it assumed @@global.log_bin_trust_function_creators=1,
and some tests modified this variable without resetting it to its
original value.
Fix 6: All tests that use this variable have been updated so that
they reset the value at end of test.
Problem: show slave status may return different Slave_IO_Running values running some tests.
Fix: wait for a certain slave state if needed to get tests more predictable.
