slave is running slow in another data center

Hello All,



I've 4 slaves of a master. of 4, 3 are in same data center and have
no issues. The fourth one is in another data center and some time that
slave sql_thread lag behind more then 5000 sec. It's only sql_thread,
which slow down. All H/W, S/W and my.cnf files are same for all slaves.



I ran the mysqladmin extended-status in iterative mode and following
kind of results are there in my log file



| Variable_name | Value |



| Bytes_received | 2117975 |

| Com_insert | 39 |

| Com_show_slave_status | 4 |

| Com_show_status | 1 |

| Com_update | 49 |

| Connections | 1 |

| Handler_read_key | 49 |

| Handler_read_next | 2 |

| Handler_update | 3629 |

| Key_blocks_not_flushed | 1 |

| Key_blocks_unused | -21 |

| Key_blocks_used | 21 |

| Key_reads | 21 |

| Key_write_requests | 94 |

| Key_writes | 75 |

| Max_used_connections | 1 |

| Questions | 93 |

| Table_locks_immediate | 88 |

| Threads_connected | 1 |

| Threads_created | 1 |







| Variable_name | Value |



| Bytes_received | 1469626 |

| Bytes_sent | 3837 |

| Com_delete | 2 |

| Com_insert | 143 |

| Com_show_status | 1 |

| Com_update | 1247 |

| Handler_delete | 5 |

| Handler_read_key | 1249 |

| Handler_read_next | 73 |

| Handler_read_rnd | 8379 |

| Handler_update | 9625 |

| Handler_write | 8492 |

| Key_blocks_not_flushed | 1 |

| Key_blocks_unused | -158 |

| Key_blocks_used | 158 |

| Key_read_requests | 52672 |

| Key_reads | 158 |

| Questions | 1394 |

| Table_locks_immediate | 1392 |

| Threads_cached | 1 |

| Threads_connected | -1 |









Any idea any one, that what can be tunned here for keeping sql_thread
running same as other slaves. My key_buffers are set to 1G in cnf file.
Also on this slave, no binary logging is enabled or no slow log is
enabled. And no application is connected. This is purely stand alone
slave for disaster recovery.



Regards,