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Added checking that row events ends with a proper end block

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Problems --------

The slave io thread did not conduct integrity check
for a group of row-based events. Specifically it tolerates missed
terminal block event that must be flagged with STMT_END. Failure to
react on its loss can confuse the applier thread in various ways.
Another potential issue was that there were no check of impossible
second in row Gtid-log-event while the slave io thread is receiving
to be skipped events after reconnect.

Fixes
-----
The slave io thread is made by this patch to track the rows event
STMT_END status.
Whenever at next event reading the IO thread finds out that a preceding
Rows event did not actually had the flag, an
explicit error is issued.

Replication can be resumed after the source of failure is eliminated,
see a provided test.

Note that currently the row-based group integrity check excludes
the compressed version 2 Rows events (which are not generated by MariaDB
master).
Its uncompressed counterpart is manually tested.

The 2nd issue is covered to produce an error in case the io thread
receives a successive Gtid_log_event while it is post-reconnect
skipping.
This commit is contained in:
Andrei Elkin
2018-01-11 23:56:54 +02:00
committed by Monty
parent 5fce14dad0
commit 3dc3ab1a30
5 changed files with 322 additions and 11 deletions
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21
sql/rpl_mi.h
View File

@ -133,6 +133,19 @@ public:
extern TYPELIB slave_parallel_mode_typelib;
typedef struct st_rows_event_tracker
{
char binlog_file_name[FN_REFLEN];
my_off_t first_seen;
my_off_t last_seen;
bool stmt_end_seen;
void update(const char* file_name, size_t pos,
const char* buf,
const Format_description_log_event *fdle);
void reset();
bool check_and_report(const char* file_name, size_t pos);
} Rows_event_tracker;
/*****************************************************************************
Replication IO Thread
@ -301,6 +314,14 @@ class Master_info : public Slave_reporting_capability
uint64 gtid_reconnect_event_skip_count;
/* gtid_event_seen is false until we receive first GTID event from master. */
bool gtid_event_seen;
/**
The struct holds some history of Rows- log-event reading/queuing
by the receiver thread. Its fields are updated per each such event
at time of queue_event(), and they are checked to detect
the Rows- event group integrity violation at time of first non-Rows-
event gets handled.
*/
Rows_event_tracker rows_event_tracker;
bool in_start_all_slaves, in_stop_all_slaves;
bool in_flush_all_relay_logs;
uint users; /* Active user for object */