Andrei Elkin 593c9457cd Bug#11747416 : 32228 A disk full makes binary log corrupt ...

Binary log of master can get a partially logged event if the server
runs out of disk space and, while waiting for some space to be freed,
is shut down (or crashes). If the server is not stopped, it will just
wait endlessly for space to be freed, thus no partial event anomaly
occurs.  The restarted master server has had a dubious policy to send
the incomplete event to slave which it apparently can't handle.
Although an error was printed out the fact of sending with unclear
error message is a source of confusion.
Actually the problem of presence an incomplete event in the binary log
was already fixed by WL 5493 (which was merged to our current trunk
branch, major version 5.6). The fix makes the server truncate the
binary log on server restart and recovery.

However 5.5 master can't do that. So the current issue is a problem of
sending incomplete events to the slave by 5.5 master.

It is fixed in this patch by changing the policy so that only complete
events are pushed by the dump thread to the IO thread. In addition,
the error text that master sends to the slave when an incomplete event
is found, now states that incomplete event may have been caused by an
out-of-disk space situation and provides coordinates of
the first and the last event bytes read.


mysql-test/std_data/bug11747416_32228_binlog.000001:
  a binlog is added with the last event written partly.
mysql-test/suite/rpl/r/rpl_cant_read_event_incident.result:
  new result file is added.
mysql-test/suite/rpl/r/rpl_log_pos.result:
  results updated.
mysql-test/suite/rpl/r/rpl_manual_change_index_file.result:
  results updated.
mysql-test/suite/rpl/r/rpl_packet.result:
  results updated.
mysql-test/suite/rpl/t/rpl_cant_read_event_incident.test:
  regression test for bug#11747416 : 32228 A disk full makes binary log corrupt
  is added.
sql/share/errmsg-utf8.txt:
  Increasing the explanatory part of ER_MASTER_FATAL_ERROR_READING_BINLOG error message twice
  in order to fit to the updated version which carries some more info.
sql/sql_repl.cc:
  Error text indicating a failure of reading from binlog that master delivers to the slave 
  is made more clear;
  A policy to regard a partial event to send it out to the slave anyway is removed.

2011-09-29 14:14:43 +03:00

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