ORA-16198: LGWR received timedout error from KSR

ORA-16198: LGWR received timedout error from KSR
------- 1

LGWR: Attempting destination LOG_ARCHIVE_DEST_2 network reconnect (16198) --------2

LGWR: Destination LOG_ARCHIVE_DEST_2 network reconnect abandoned

Error 16198 for archive log file 9 to 'q9histstd'

Destination LOG_ARCHIVE_DEST_2 is UNSYNCHRONIZED

Destination LOG_ARCHIVE_DEST_2 no longer supports SYNCHRONIZATION

LGWR: Failed to archive log 9 thread 1 sequence 50218 (16198)

Thread 1 advanced to log sequence 50218 (LGWR switch) --------3

Current log# 9 seq# 50218 mem# 0: /oradata/q9histdb/group_9.1546.818724549

Tue Nov 04 23:06:14 2014

Archived Log entry 97790 added for thread 1 sequence 50217 ID 0x35fb63c9 dest 1:

Tue Nov 04 23:10:13 2014

Destination LOG_ARCHIVE_DEST_2 is UNSYNCHRONIZED

Thread 1 advanced to log sequence 50219 (LGWR switch)

Current log# 10 seq# 50219 mem# 0: /oradata/q9histdb/group_10.1545.818724547

Tue Nov 04 23:10:27 2014

Archived Log entry 97791 added for thread 1 sequence 50218 ID 0x35fb63c9 dest 1:

Tue Nov 04 23:11:03 2014

ARC6: Standby redo logfile selected for thread 1 sequence 50218 for destination LOG_ARCHIVE_DEST_2 ------4

Tue Nov 04 23:11:04 2014

NSS2 started with pid=63, OS id=21261

Tue Nov 04 23:11:11 2014

LGWR: Standby redo logfile selected for thread 1 sequence 50220 for destination LOG_ARCHIVE_DEST_2

Thread 1 advanced to log sequence 50220 (LGWR switch)

上面是生产环境中主库的一段日志，该段日志证实了最近自己看的一本书--(Oracle Data Guard 11g完全参考手册Oracle Data Guard 11g完全参考手册)中理论知识。

下面参数文件中对于日志传输的配置：

*.log_archive_dest_2='SERVICE=****** lgwr sync valid_for=(online_logfile,primary_role) db_unique_name=******'（为了信息保密，将数据库名字掩盖了）

采用的是同步传输，我们按告警日志中标示示的步骤来解析

1、收不到备库的确认消息，传输连接断开

2、重连备库失败

3、由于重连失败，只好进行日志切换

4、ARCH使用ping的形式尝试重建连接，连接成功，将归档传输到备库。

引起这问题的可能原因有很多，建议将net_timeout设置为默认值（30s），由于后面重建了连接，后续关注该问题。