binlog_space_limit is a variable in Percona server used to limit the total
size of all binary logs.
This implementation is based on code from Percona server 5.7.
In MariaDB we decided to call the variable max-binlog-total-size to be
similar to max-binlog-size. This makes it easier to find in the output
from 'mariadbd --help --verbose'). MariaDB will also support
binlog_space_limit for compatibility with Percona.
Some internal notes to explain implementation notes:
- When running MariaDB does not delete binary logs that are either
used by slaves or have active xid that are not yet committed.
Some implementation notes:
- max-binlog-total-size is by default 0 (no limit).
- max-binlog-total-size can be changed without server restart.
- Binlog file sizes are checked on startup, or if
max-binlog-total-size is set to a value > 0, not for every log write.
The total size of all binary logs is cached and dynamically updated
when updating the binary log on binary log rotation.
- max-binlog-total-size is checked against existing log files during
serverstart, binlog rotation, FLUSH LOGS, when writing to binary log
or when max-binlog-total-size changes value.
- Option --slave-connections-needed-for-purge with 1 as default added.
This allows one to ensure that we do not delete binary logs if there
is less than 'slave-connections-needed-for-purge' connected.
Without this option max-binlog-total-size would potentially delete
binlogs needed by slaves on server startup or when a slave disconnects
as there are then no connected slaves to protect active binlogs.
- PURGE BINARY LOGS TO ... will be executed as if
slave-connectitons-needed-for-purge would be zero. In other words
it will do the purge even if there is no slaves connected. If there
are connected slaves working on the logs, these will be protected.
- If binary log is on and max-binlog-total_size <> 0 then the status
variable 'Binlog_disk_use' shows the current size of all old binary
logs + the state of the current one.
- Removed test of strcmp(log_file_name, log_info.log_file_name) in
purge_logs_before_date() as this is tested in can_purge_logs()
- To avoid expensive calls of log_in_use() we cache the result for the
last log that is in use by a slave. Future calls to can_purge_logs()
for this binary log will be quickly detected and false will be returned
until a slave starts working on a new log.
- Note that after a binary log rotation caused by max_binlog_size,
the last log will not be purged directly as it is still in use
internally. The next binary log write will purge binlogs if needed.
Reviewer:Kristian Nielsen <knielsen@knielsen-hq.org>
This reverts commit c37b2087b4.
In c37b20887, when re-binlogging a GTID event on a replica,
it will overwrite the thread_id from the primary to be the
value of the slave applier (SQL thread or parallel worker).
This should be the value of the original thread_id on the
master connection though, to both help track temporary
tables, and be consistent with Query_log_event.
Reverting the commit to re-target 11.5, so we can re-test
with the corrected thread_id.
enable ssl + ssl_verify_server_cert in the internal client too
* fix replication tests to disable master_ssl_verify_server_cert
because accounts are passwordless - except rpl.rpl_ssl1
* fix federated/federatedx/connect to disable SSL_VERIFY_SERVER_CERT
because they cannot configure an ssl connection
* fix spider to disable ssl_verify_server_cert, if configuration
says so, as spider _can_ configure an ssl connection
* memory leak in embedded test-connect
not default_mysqld.cnf. The latter has only server settings,
it misses mtr-specific client configuration
Except for spider, that doesn't use mysqld.1 server
and default_my.cnf starts it automatically.
Spider tests have to include both default_mysqld.cnf and
default_client.cnf
Improve the performance of slave connect using B+-Tree indexes on each binlog
file. The index allows fast lookup of a GTID position to the corresponding
offset in the binlog file, as well as lookup of a position to find the
corresponding GTID position.
This eliminates a costly sequential scan of the starting binlog file
to find the GTID starting position when a slave connects. This is
especially costly if the binlog file is not cached in memory (IO
cost), or if it is encrypted or a lot of slaves connect simultaneously
(CPU cost).
The size of the index files is generally less than 1% of the binlog data, so
not expected to be an issue.
Most of the work writing the index is done as a background task, in
the binlog background thread. This minimises the performance impact on
transaction commit. A simple global mutex is used to protect index
reads and (background) index writes; this is fine as slave connect is
a relatively infrequent operation.
Here are the user-visible options and status variables. The feature is on by
default and is expected to need no tuning or configuration for most users.
binlog_gtid_index
On by default. Can be used to disable the indexes for testing purposes.
binlog_gtid_index_page_size (default 4096)
Page size to use for the binlog GTID index. This is the size of the nodes
in the B+-tree used internally in the index. A very small page-size (64 is
the minimum) will be less efficient, but can be used to stress the
BTree-code during testing.
binlog_gtid_index_span_min (default 65536)
Control sparseness of the binlog GTID index. If set to N, at most one
index record will be added for every N bytes of binlog file written.
This can be used to reduce the number of records in the index, at
the cost only of having to scan a few more events in the binlog file
before finding the target position
Two status variables are available to monitor the use of the GTID indexes:
Binlog_gtid_index_hit
Binlog_gtid_index_miss
The "hit" status increments for each successful lookup in a GTID index.
The "miss" increments when a lookup is not possible. This indicates that the
index file is missing (eg. binlog written by old server version
without GTID index support), or corrupt.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
rpl_semi_sync_slave_enabled_consistent.test and the first part of
the commit message comes from Brandon Nesterenko.
A test to show how to induce the "Read semi-sync reply magic number
error" message on a primary. In short, if semi-sync is turned on
during the hand-shake process between a primary and replica, but
later a user negates the rpl_semi_sync_slave_enabled variable while
the replica's IO thread is running; if the io thread exits, the
replica can skip a necessary call to kill_connection() in
repl_semisync_slave.slave_stop() due to its reliance on a global
variable. Then, the replica will send a COM_QUIT packet to the
primary on an active semi-sync connection, causing the magic number
error.
The test in this patch exits the IO thread by forcing an error;
though note a call to STOP SLAVE could also do this, but it ends up
needing more synchronization. That is, the STOP SLAVE command also
tries to kill the VIO of the replica, which makes a race with the IO
thread to try and send the COM_QUIT before this happens (which would
need more debug_sync to get around). See THD::awake_no_mutex for
details as to the killing of the replica’s vio.
Notes:
- The MariaDB documentation does not make it clear that when one
enables semi-sync replication it does not matter if one enables
it first in the master or slave. Any order works.
Changes done:
- The rpl_semi_sync_slave_enabled variable is now a default value for
when semisync is started. The variable does not anymore affect
semisync if it is already running. This fixes the original reported
bug. Internally we now use repl_semisync_slave.get_slave_enabled()
instead of rpl_semi_sync_slave_enabled. To check if semisync is
active on should check the @@rpl_semi_sync_slave_status variable (as
before).
- The semisync protocol conflicts in the way that the original
MySQL/MariaDB client-server protocol was designed (client-server
send and reply packets are strictly ordered and includes a packet
number to allow one to check if a packet is lost). When using
semi-sync the master and slave can send packets at 'any time', so
packet numbering does not work. The 'solution' has been that each
communication starts with packet number 1, but in some cases there
is still a chance that the packet number check can fail. Fixed by
adding a flag (pkt_nr_can_be_reset) in the NET struct that one can
use to signal that packet number checking should not be done. This
is flag is set when semi-sync is used.
- Added Master_info::semi_sync_reply_enabled to allow one to configure
some slaves with semisync and other other slaves without semisync.
Removed global variable semi_sync_need_reply that would not work
with multi-master.
- Repl_semi_sync_master::report_reply_packet() can now recognize
the COM_QUIT packet from semisync slave and not give a
"Read semi-sync reply magic number error" error for this case.
The slave will be removed from the Ack listener.
- On Windows, don't stop semisync Ack listener just because one
slave connection is using socket_id > FD_SETSIZE.
- Removed busy loop in Ack_receiver::run() by using
"Self-pipe trick" to signal new slave and stop Ack_receiver.
- Changed some Repl_semi_sync_slave functions that always returns 0
from int to void.
- Added Repl_semi_sync_slave::slave_reconnect().
- Removed dummy_function Repl_semi_sync_slave::reset_slave().
- Removed some duplicate semisync notes from the error log.
- Add test of "if (get_slave_enabled() && semi_sync_need_reply)"
before calling Repl_semi_sync_slave::slave_reply().
(Speeds up the code as we can skip all initializations).
- If epl_semisync_slave.slave_reply() fails, we disable semisync
for that connection.
- We do not call semisync.switch_off() if there are no active slaves.
Instead we check in Repl_semi_sync_master::commit_trx() if there are
no active threads. This simplices the code.
- Changed assert() to DBUG_ASSERT() to ensure that the DBUG log is
flushed in case of asserts.
- Removed the internal rpl_semi_sync_slave_status as it is not needed
anymore. The @@rpl_semi_sync_slave_status status variable is now
mapped to rpl_semi_sync_enabled.
- Removed rpl_semi_sync_slave_enabled as it is not needed anymore.
Repl_semi_sync_slave::get_slave_enabled() contains the active status.
- Added checking that we do not add a slave twice with
Ack_receiver::add_slave(). This could happen with old code.
- Removed Repl_semi_sync_master::check_and_switch() as it is not
needed anymore.
- Ensure that when we call Ack_receiver::remove_slave() that the slave
is removed from the listener before function returns.
- Call listener.listen_on_sockets() outside of mutex for better
performance and less contested mutex.
- Ensure that listening is ignoring newly added slaves when checking for
responses.
- Fixed the master ack_receiver listener is not killed if there are no
connected slaves (and thus stop semisync handling of future
connections). This could happen if all slaves sockets where would be
marked as unreliable.
- Added unlink() to base_ilist_iterator and remove() to
I_List_iterator. This enables us to remove 'dead' slaves in
Ack_recever::run().
- kill_zombie_dump_threads() now does killing of dump threads properly.
- It can now kill several threads (should be impossible but could
happen if IO slaves reconnects very fast).
- We now wait until the dump thread is done before starting the
dump.
- Added an error if kill_zombie_dump_threads() fails.
- Set thd->variables.server_id before calling
kill_zombie_dump_threads(). This simplies the code.
- Added a lot of comments both in code and tests.
- Removed DBUG_EVALUATE_IF "failed_slave_start" as it is not used.
Test changes:
- rpl.rpl_session_var2 added which runs rpl.rpl_session_var test with
semisync enabled.
- Some timings changed slight with startup of slave which caused
rpl_binlog_dump_slave_gtid_state_info.text to fail as it checked the
error log file before the slave had started properly. Fixed by
adding wait_for_pattern_in_file.inc that allows waiting for the
pattern to appear in the log file.
- Tests have been updated so that we first set
rpl_semi_sync_master_enabled on the master and then set
rpl_semi_sync_slave_enabled on the slaves (this is according to how
the MariaDB documentation document how to setup semi-sync).
- Error text "Master server does not have semi-sync enabled" has been
replaced with "Master server does not support semi-sync" for the
case when the master supports semi-sync but semi-sync is not
enabled.
Other things:
- Some trivial cleanups in Repl_semi_sync_master::update_sync_header().
- We should in 11.3 changed the default value for
rpl-semi-sync-master-wait-no-slave from TRUE to FALSE as the TRUE
does not make much sense as default. The main difference with using
FALSE is that we do not wait for semisync Ack if there are no slave
threads. In the case of TRUE we wait once, which did not bring any
notable benefits except slower startup of master configured for
using semisync.
Co-author: Brandon Nesterenko <brandon.nesterenko@mariadb.com>
This solves the problem reported in MDEV-32960 where a new
slave may not be registered in time and the master disables
semi sync because of that.
This patch augments Gtid_log_event with the user thread-id.
In particular that compensates for the loss of this info in
Rows_log_events.
Gtid_log_event::thread_id gets visible in mysqlbinlog output like
#231025 16:21:45 server id 1 end_log_pos 537 CRC32 0x1cf1d963 GTID 0-1-2 ddl thread_id=10
as 64 bit unsigned integer.
While the size of Gtid event has grown by 8-9 bytes
replication from OLD <-> NEW is not affected by it.
This work was started by the late Sujatha Sivakumar.
Brandon Nesterenko took it over, reviewed initial patches and extended
the work.
Reviewed-by: <andrei.elkin@mariadb.com>
Item::val_str() sets the Item::null_value flag, so call it before checking
the flag, not after.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Fix some random test failures following MDEV-32168 push.
Don't blindly set $rpl_only_running_threads in many places. Instead explicit
stop only the IO or SQL thread, as appropriate. Setting it interfered with
rpl_end.inc in some cases. Rather than clearing it afterwards, better to
not set it at all when it is not needed, removing ambiguity in the test
about the state of the replication threads.
Don't fail the test if include/stop_slave_io.inc finds an error in the IO
thread after stop. Such errors can be simply because slave stop happened in
the middle of the IO thread's initial communication with the master.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Compute binlog checksums (when enabled) already when writing events
into the statement or transaction caches, where before it was done
when the caches are copied to the real binlog file. This moves the
checksum computation outside of holding LOCK_log, improving
scalabitily.
At stmt/trx cache write time, the final end_log_pos values are not
known, so with this patch these will be set to 0. Events that are
written directly to the binlog file (not through stmt/trx cache) keep
the correct end_log_pos value. The GTID and COMMIT/XID events at the
start and end of event groups are written directly, so the zero
end_log_pos is only for events in the middle of event groups, which
do not negatively affect replication.
An option --binlog-legacy-event-pos, off by default, is provided to
disable this behavior to provide backwards compatibility with any
external applications that might rely on end_log_pos in events in the
middle of event groups.
Checksums cannot be pre-computed when binlog encryption is enabled, as
encryption relies on correct end_log_pos to provide part of the
nonce/IV.
Checksum pre-computation is also disabled for WSREP/Galera, as it uses
events differently in its write-sets and so on. Extending pre-computation of
checksums to Galera where it makes sense could be added in a future patch.
The current --binlog-checksum configuration is saved in
binlog_cache_data at transaction start and used to pre-compute
checksums in cache, if applicable. When the cache is later copied to
the binlog, a check is made if the saved value still matches the
configured global value; if so, the events are block-copied directly
into the binlog file. If --binlog-checksum was changed during the
transaction, events are re-written to the binlog file one-by-one and
the checksums recomputed/discarded as appropriate.
Reviewed-by: Monty <monty@mariadb.org>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
remove old deprecation helpers that were not used anywhere.
create new deprecation helpers and enforce their usage
this also removes inconsistencies in reporting deprecation:
sometimes it was ER_WARN_DEPRECATED_SYNTAX (1287),
sometimes ER_WARN_DEPRECATED_SYNTAX_NO_REPLACEMENT (1681),
sometimes a warning, sometimes a note.
it should always be
* ER_WARN_DEPRECATED_SYNTAX
* a warning (because it's something actionable, not purely informational)
Restore code to make InnoDB choose the second transaction as a deadlock
victim if two transactions deadlock that need to commit in-order for
parallel replication. This code was erroneously removed when VATS was
implemented in InnoDB.
Also add a test case for InnoDB choosing the right deadlock victim.
Also fixes this bug, with testcase that reliably reproduces:
MDEV-28776: rpl.rpl_mark_optimize_tbl_ddl fails with timeout on sync_with_master
Note: This should be null-merged to 10.6, as a different fix is needed
there due to InnoDB locking code changes.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
A simple "SET SESSION gtid_seq_no= DEFAULT" did not work, it would straight
up crash the server! Also, explicitly setting gtid_seq_no to 0 gave an error
in --gtid-strict-mode=1.
Setting to DEFAULT or 0 should disable any prior setting of
gtid_seq_no, so that the next transaction is allocated the next GTID
in sequence, as normal.
Reviewed-by: Monty <monty@mariadb.org>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Problem:
========
A master can segfault if it can't set up decryption for its binary
log during a binlog dump with Using_Gtid=Slave_Pos. If slave
connects using GTID mode, the master will call into
log.cc::get_gtid_list_event(), which iterate through binlog events
looking for a Gtid_list_log_event. On an encrypted binlog that the
master cannot decrypt, the first event will be a
START_ENCRYPTION_EVENT which will call into the following decryption branch
if (fdle->start_decryption((Start_encryption_log_event*) ev))
errormsg= ‘Could not set up decryption for binlog.’;
The event iteration however, does not stop in spite of this error.
The master will try to read the next event, but segfault while
trying to decrypt it because decryption failed to initialize.
Solution:
========
Break the event iteration if decryption cannot be set up.
Reviewed By:
============
Andrei Elkin <andrei.elkin@mariadb.com>
