MySQL bug：server-id默認被自動置爲1

昨天同事在做主從時，從庫報如下錯誤：

<span style="font-family: Comic Sans MS; font-size: 18px;">Got fatal error 1236 from master when reading data from binary log: 'Misconfigured master - server id was not set'</span>

<span style="font-family:Comic Sans MS;font-size:18px;">Got fatal error 1236 from master when reading data from binary log: 'Misconfigured master - server id was not set'</span>

粗粗看好像是master的server-id沒有設置，但同事做如下查詢：

<span style="font-family: Comic Sans MS; font-size: 18px;">備庫採集：
root@localhost Fri May 23 14:18:59 2014 14:18:59 [(none)]> show variables like '%server_id%';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id     | 2     |
+---------------+-------+

主庫採集：

mysql> show variables like '%server%';
+----------------------+-------------------+
| Variable_name        | Value             |
+----------------------+-------------------+
| character_set_server | latin1            |
| collation_server     | latin1_swedish_ci |
| server_id            | 1                 |
+----------------------+-------------------+</span>

<span style="font-family:Comic Sans MS;font-size:18px;">備庫採集：
root@localhost Fri May 23 14:18:59 2014 14:18:59 [(none)]> show variables like '%server_id%';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id     | 2     | 
+---------------+-------+

主庫採集：

mysql> show variables like '%server%';
+----------------------+-------------------+
| Variable_name        | Value             |
+----------------------+-------------------+
| character_set_server | latin1            |
| collation_server     | latin1_swedish_ci |
| server_id            | 1                 |
+----------------------+-------------------+</span>

此時，複製環境的server-id確實是全局唯一的。爲何報錯？

由於業務是用於存儲hadoop的元數據，之前MySQL版本較低，同事用了比master版本高的slave，本以爲是這個原因，但在MySQL 的bug列表上發現：

該發現否定了我們之前的判斷，經過同事那邊的測試，也確實是這個bug :-)

祝週末愉快，

Good Luck！