here comes an MySQL bug between MySQL 5.6.20 & MySQL5.6.34

[pengan1990]

for MySQL5.6.20 have not compatible with MySQL5.5, so it will no kill zombie thread without the slave uuid

[pengan1990]

fix this bug for using set @slave_uuid="${uuid}" command before dump

[agapple]

我看一下，可能也是因为这个很多用户反馈链接异常断开的一个问题

[yangdehua]

可以参考下MySQL源码的实现,在建立IO线程到Master的时候,会设置一下uuid

/**
Set user variables after connecting to the master.

@param mysql MYSQL to request uuid from master.
@param mi Master_info to set master_uuid

@return 0: Success, 1: Fatal error, 2: Network error.
*/
int io_thread_init_commands(MYSQL *mysql, Master_info *mi)
{
char query[256];
int ret= 0;

sprintf(query, "SET @slave_uuid= '%s'", server_uuid);
if (mysql_real_query(mysql, query, strlen(query))
&& !check_io_slave_killed(mi->info_thd, mi, NULL))
goto err;

[agapple]

看了mysql5.6的源码，它应该是兼容了mysql5.5 client的serverId的dump，如果没有设置slave_uuid默认也会是基于serverId进行判断. 增加slave_uuid之后可以避免对于slaveId不同的强依赖