database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-08-07 00:04:31 +03:00
Code Activity

MDEV-6156: Parallel replication incorrectly caches charset between worker threads

Browse Source 
Replication caches the character sets used in a query, to be able to quickly
reuse them for the next query in the common case of them not having changed.

In parallel replication, this caching needs to be per-worker-thread. The
code was not modified to handle this correctly, so the caching in one worker
could cause another worker to run a query using the wrong character set,
causing replication corruption.
This commit is contained in:
unknown
2014-04-23 16:06:06 +02:00
parent f9e5f237f0
commit 010971a761
7 changed files with 186 additions and 47 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
sql/rpl_rli.h
View File

@@ -295,7 +295,6 @@ public:
/* Condition for UNTIL master_gtid_pos. */
slave_connection_state until_gtid_pos;
char cached_charset[6];
/*
retried_trans is a cumulative counter: how many times the slave
has retried a transaction (any) since slave started.
@@ -371,15 +370,6 @@ public:
group_relay_log_pos);
}
/*
Last charset (6 bytes) seen by slave SQL thread is cached here; it helps
the thread save 3 get_charset() per Query_log_event if the charset is not
changing from event to event (common situation).
When the 6 bytes are equal to 0 is used to mean "cache is invalidated".
*/
void cached_charset_invalidate();
bool cached_charset_compare(char *charset) const;
/**
Helper function to do after statement completion.
@@ -546,6 +536,8 @@ struct rpl_group_info
mysql_mutex_t sleep_lock;
mysql_cond_t sleep_cond;
char cached_charset[6];
/*
trans_retries varies between 0 to slave_transaction_retries and counts how
many times the slave has retried the present transaction; gets reset to 0
@@ -679,6 +671,15 @@ struct rpl_group_info
return false;
}
/*
Last charset (6 bytes) seen by slave SQL thread is cached here; it helps
the thread save 3 get_charset() per Query_log_event if the charset is not
changing from event to event (common situation).
When the 6 bytes are equal to 0 is used to mean "cache is invalidated".
*/
void cached_charset_invalidate();
bool cached_charset_compare(char *charset) const;
void clear_tables_to_lock();
void cleanup_context(THD *, bool);
void slave_close_thread_tables(THD *);