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author | Sujatha <sujatha.sivakumar@mariadb.com> | 2021-04-30 18:12:43 +0530 |
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committer | Sujatha <sujatha.sivakumar@mariadb.com> | 2021-04-30 20:34:31 +0530 |
commit | abe6eb10a65d5c28c221d756357b4e7f392ad13d (patch) | |
tree | 4a919ed0baed61bb442397e7f6c1f6a33999cafe /sql/log_event.cc | |
parent | 13b9af50e42e9de9d8e540b2c59f763cc8041a42 (diff) | |
download | mariadb-git-abe6eb10a65d5c28c221d756357b4e7f392ad13d.tar.gz |
MDEV-16146: MariaDB slave stops with following errors.
Problem:
========
180511 11:07:58 [ERROR] Slave I/O: Unexpected master's heartbeat data:
heartbeat is not compatible with local info;the event's data: log_file_name
mysql-bin.000009 log_pos 1054262041, Error_code: 1623
Analysis:
=========
In replication setup when master server doesn't have any events to send to
slave server it sends an 'Heartbeat_log_event'. This event carries the
current binary log filename and offset details. The offset values is stored
within 4 bytes of event header. When the size of binary log is higher than
UINT32_MAX the log_pos values will not fit in 4 bytes memory. It overflows
and hence slave stops with an error.
Fix:
===
Since we cannot extend the common_header of Log_event class, a greater than
4GB value of Log_event::log_pos is made to be transported with a HeartBeat
event's sub-header. Log_event::log_pos in such case is set to zero to
indicate that the 8 byte sub-header is allocated in the event.
In case of cross version replication following behaviour is expected
OLD - Server without fix
NEW - Server with fix
OLD<->NEW : works bidirectionally as long as the binlog offset is
(normally) within 4GB.
When log_pos > UINT32_MAX
OLD->NEW : The 'log_pos' is bound to overflow and NEW slave may report
an invalid event/incompatible heart beat event error.
NEW->OLD : Since patched server sets log_pos=0 on overflow, OLD slave will
report invalid event error.
Diffstat (limited to 'sql/log_event.cc')
-rw-r--r-- | sql/log_event.cc | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/sql/log_event.cc b/sql/log_event.cc index c32f31db1f6..94b2af20354 100644 --- a/sql/log_event.cc +++ b/sql/log_event.cc @@ -14324,14 +14324,23 @@ st_print_event_info::st_print_event_info() #endif #if defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT) -Heartbeat_log_event::Heartbeat_log_event(const char* buf, uint event_len, +Heartbeat_log_event::Heartbeat_log_event(const char* buf, ulong event_len, const Format_description_log_event* description_event) :Log_event(buf, description_event) { uint8 header_size= description_event->common_header_len; - ident_len = event_len - header_size; - set_if_smaller(ident_len,FN_REFLEN-1); - log_ident= buf + header_size; + if (log_pos == 0) + { + log_pos= uint8korr(buf + header_size); + log_ident= buf + header_size + HB_SUB_HEADER_LEN; + ident_len= event_len - (header_size + HB_SUB_HEADER_LEN); + } + else + { + log_ident= buf + header_size; + ident_len = event_len - header_size; + } + } #endif |