the relay log before flushing master.info.
Doing 'before' leads to duplicate event, doing after leads to missing event.
Both can be as destructive, but 'duplicate' enables us to later add detection
code to catch it. Whereas 'missing' can't be caught (it can't, because
the I/O thread can produce legal position jumps, for example if it has
ignored an event coming from this slave (rememember that starting from 4.1.1,
the I/O thread filters the server id).
Now the I/O thread (in flush_master_info()) flushes the relay log to disk
after reading every event. Slower but provides additionnal safety in case
of brutal crash.
I had to make the flush optional (i.e. add a if(some_bool_argument) in the function)
because sometimes flush_master_info() is called when there is no usable
relay log (the relay log's IO_CACHE is not initialized so can't be flushed).
(Initial caps for each word.) For example, instead of writing
Until_condition, Until_Log_File, and Until_log_pos, write
Until_Condition, Until_Log_File, and Until_Log_pos.
rli->save_temporary_tables and slave_open_temp_tables
(in old 4.0 you could make "SHOW STATUS LIKE 'slave_open_temp_tables'" grow
indefinitely by doing RESET SLAVE and replicating always the same CREATE
TEMPORARY TABLE).
It's critical to reset save_temporary_tables to 0 (otherwise you may later
read memory which has been freed) so this changeset should go into 4.1.
- when we don't have in_addr_t, use uint32.
- a forgotten initialization of slave_proxy_id in sql/log_event.cc (was not really "forgot", was
"we needn't init it there", but there was one case where we needed...).
- made slave_proxy_id always meaningful in THD and Log_event, so we can
rely more on it (no need to test if it's meaningful). THD::slave_proxy_id
is equal to THD::thread_id except for the slave SQL thread.
- clean up the slave's temporary table (i.e. free their memory) when slave
server shuts down.
"If 2 master threads with same-name temp table, slave makes bad binlog"
and (two birds with one stone) for
BUG#1240 "slave of slave breaks when STOP SLAVE was issud on parent slave
and temp tables".
Here is the design change:
in a slave running with --log-slave-updates, events are now logged with the
thread id they had on the master. So no more id conflicts between master threads,
but introduces id conflicts between one master thread and one normal
client thread connected to the slave. This is solved by storing the server id
in the temp table's name.
New test which requires mysql-test-run to be run with --manager,
otherwise it will be skipped.
Undoing a Monty's change (hum, a chill runs down my spine ;) which was
"Cleanup temporary tables when slave ends" in ChangeSet 1.1572.1.1.
a Format_description_log_event (or maybe it will be named
Description_log_event) which is not recognized by 4.0, so
a 4.0 can't be a slave of 5.0. We detect it early to produce
a helpful message instead of "corrupted relay log" later.
"Add a column "Timestamp_of_last_master_event_executed" in SHOW SLAVE STATUS".
Finally this is adding
- Slave_IO_State (a copy of the State column of SHOW PROCESSLIST for the I/O thread,
so that the users, most of the time, has enough info with only SHOW SLAVE STATUS).
- Seconds_behind_master. When the slave connects to the master it does SELECT UNIX_TIMESTAMP()
on the master, computes the absolute difference between the master's and the slave's clock.
It records the timestamp of the last event executed by the SQL thread, and does a
small computation to find the number of seconds by which the slave is late.
Now LOAD DATA FROM MASTER does not drop the database, instead it only tries to
create it, and drops/creates table-by-table.
* replicate_wild_ignore_table='db1.%' is now considered as "ignore the 'db1'
database as a whole", as it already works for CREATE DATABASE and DROP DATABASE.
Added proper options to CHANGE MASTER TO, new fields to SHOW SLAVE STATUS,
Honoring this parameters during connection to master.
Introduced new format of master.info file
For example the Binlog_dump thread (on the master) sometimes showed "Slave:".
And there were confusing messages where "binlog" was employed instead
of "relay log".
when the SQL thread stops, set rli->inside_transaction to 0. This is needed if the user
later restarts replication from a completely different place where there are only autocommit
statements.
* Detect the case where the master died while flushing the binlog cache to the binlog
and stop with error. Cannot add a testcase for this in 4.0 (I tested it manually)
as the slave always runs with --skip-innodb.
Let's say the lack of comments did not help me ;)
Copying it back again and adding comments; now 3.23->4.0
replication of LOAD DATA INFILE works again.
"LOAD DATA INFILE is badly filtered by binlog-*-db rules".
There will probably be a second final one to merge Dmitri's changes
to rpl_log.result and mine.
2 new tests:
rpl_loaddata_rule_m : test of logging of LOAD DATA INFILE when the master has binlog-*-db rules,
rpl_loaddata_rule_s : test of logging of LOAD DATA INFILE when the slave has binlog-*-db rules and --log-slave-updates.
log-slave-updates since this causes unexpected values in
Exec_master_log_pos in A->B->C replication setup, synchronization
problems in master_pos_wait()...
Still this brokes some functionality in sql/repl_failsafe.cc
(but this file is not used now)
- Bug #985: "Between RESET SLAVE and START SLAVE, SHOW SLAVE STATUS is wrong."
Now RESET SLAVE puts correct info in mi->host etc. A new test rpl_reset_slave
for that.
- Bug #986: "CHANGE MASTER & START SLAVE do not reset error columns in SHOW
SLAVE STATUS". Now these reset the errors.
I extended the task to cleaning error messages, making them look nicer,
and making the output of SHOW SLAVE STATUS (column Last_error) be as complete
as what's printed on the .err file;
previously we would have, for a failure of a replicated LOAD DATA INFILE:
- in the .err, 2 lines:
"duplicate entry 2708 for key 1"
"failed loading SQL_LOAD-5-2-2.info"
- and in SHOW SLAVE STATUS, only:
"failed loading SQL_LOAD-5-2-2.info".
Now SHOW SLAVE STATUS will contain the concatenation of the 2 messages.
and other replicate-*-table options in SHOW SLAVE STATUS.
Seems like it had not been done, so I push it now:
there's 4 new columns to SHOW SLAVE STATUS.
