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Always send a fake Rotate event (this is roughly 70 bytes) when starting binlog_dump.

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This way 3.23.58 slaves will always detect a 4.0.14 master (and stop)
immediately. BUG#198.


mysql-test/r/rpl_log.result:
  result update (the relay log now contains a fake Rotate_log_event).
mysql-test/r/rpl_log_pos.result:
  result update (the relay log now contains a fake Rotate_log_event).
This commit is contained in:
unknown
2003-06-21 18:10:59 +02:00
parent 070f4fbb95
commit 5c9b87ce08
3 changed files with 31 additions and 16 deletions
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43
sql/sql_repl.cc
View File

@@ -51,7 +51,7 @@ int check_binlog_magic(IO_CACHE* log, const char** errmsg)
}
static int fake_rotate_event(NET* net, String* packet, char* log_file_name,
const char**errmsg)
ulonglong position, const char**errmsg)
{
char header[LOG_EVENT_HEADER_LEN], buf[ROTATE_HEADER_LEN];
memset(header, 0, 4); // when does not matter
@@ -69,7 +69,7 @@ static int fake_rotate_event(NET* net, String* packet, char* log_file_name,
packet->append(header, sizeof(header));
/* We need to split the next statement because of problem with cxx */
int4store(buf,4); // tell slave to skip magic number
int4store(buf,position);
int4store(buf+4,0);
packet->append(buf, ROTATE_HEADER_LEN);
packet->append(p,ident_len);
@@ -382,17 +382,30 @@ impossible position";
*/
packet->set("\0", 1);
// if we are at the start of the log
if (pos == BIN_LOG_HEADER_SIZE)
/*
Before 4.0.14 we called fake_rotate_event below only if
(pos == BIN_LOG_HEADER_SIZE), because if this is false then the slave
already knows the binlog's name.
Now we always call fake_rotate_event; if the slave already knew the log's
name (ex: CHANGE MASTER TO MASTER_LOG_FILE=...) this is useless but does not
harm much. It is nice for 3.23 (>=.58) slaves which test Rotate events
to see if the master is 4.0 (then they choose to stop because they can't
replicate 4.0); by always calling fake_rotate_event we are sure that 3.23.58
and newer will detect the problem as soon as replication starts (BUG#198).
Always calling fake_rotate_event makes sending of normal
(=from-binlog) Rotate events a priori unneeded, but it is not so simple: the
2 Rotate events are not equivalent, the normal one is before the Stop event,
the fake one is after. If we don't send the normal one, then the Stop event
will be interpreted (by existing 4.0 slaves) as "the master stopped", which
is wrong. So for safety, given that we want minimum modification of 4.0, we
send the normal and fake Rotates.
*/
if (fake_rotate_event(net, packet, log_file_name, pos, &errmsg))
{
// tell the client log name with a fake rotate_event
if (fake_rotate_event(net, packet, log_file_name, &errmsg))
{
my_errno= ER_MASTER_FATAL_ERROR_READING_BINLOG;
goto err;
}
packet->set("\0", 1);
my_errno= ER_MASTER_FATAL_ERROR_READING_BINLOG;
goto err;
}
packet->set("\0", 1);
while (!net->error && net->vio != 0 && !thd->killed)
{
@@ -585,10 +598,12 @@ Increase max_allowed_packet on master";
end_io_cache(&log);
(void) my_close(file, MYF(MY_WME));
// fake Rotate_log event just in case it did not make it to the log
// otherwise the slave make get confused about the offset
/*
Even if the previous log contained a Rotate_log_event, we still fake
one.
*/
if ((file=open_binlog(&log, log_file_name, &errmsg)) < 0 ||
fake_rotate_event(net, packet, log_file_name, &errmsg))
fake_rotate_event(net, packet, log_file_name, BIN_LOG_HEADER_SIZE, &errmsg))
{
my_errno= ER_MASTER_FATAL_ERROR_READING_BINLOG;
goto err;