ORA-16198: LGWR received timedout error from KSR

ORA-16198 意味着主库上的LOG_ARCHIVE_DEST_2的NET_TIMEOUT设置的太小，导致LNS不能在设置的时间内将日志传输到备库。

解决方法是提高NET_TIMEOUT的值到15-20 秒，

SQL>ALTER SYSTEM SET LOG_ARCHIVE_DEST_2 SERVICE=xyz_STANDBY LGWR SYNC DB_UNIQUE_NAME=xyz_STANDBY NET_TIMEOUT=30 VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE)；

但是查看数据库中的NET_TIMEOUT 值的设置。

09:33:47 ops$admin@rac1>select DEST_NAME,NET_TIMEOUT FROM V$ARCHIVE_DEST;

DEST_NAME NET_TIMEOUT

------------------------- -----------

LOG_ARCHIVE_DEST_1 0

LOG_ARCHIVE_DEST_2 30

LOG_ARCHIVE_DEST_3 30

NET_TIMEOUT 为30 秒。查看metalink ：

Note: If NET_TIMEOUT attribute has already been set to 30, and you still get ORA-16198, that means LNS couldn't finish sending redo block in 30 seconds.

The slowness may caused by:

1. Operating System. Please keep track of OS usage (like iostat).

2. Network. Please keep track network flow (like tcpdump).

不过也有可能是bug

Bug 9259587 Multiple LGWR reconnect attempts in Data Guard MAXIMUM_AVAILABILITY

This note gives a brief overview bug 9259587.

Affects:

Product (Component) Oracle Server (Rdbms)

Range of versions believed to be affected Versions BELOW 12.1

Versions confirmed as being affected 11.2.0.1 10.2.0.4

Platforms affected Generic (all / most platforms affected)

Fixed:

This issue is fixed in 12.1 (Future Release) 11.2.0.2 (Server Patch Set)

Symptoms:

Related To:

Hang (Process Spins)

Active Dataguard (ADG)

Physical Standby Database / Dataguard

Description

In a Data Guard configuration using LGWR SYNC transport on one or more LOG_ARCHIVE_DEST_n parameters, and using a protection mode of MAXIMUM_AVAILABILITY, then if the primary database becomes disconnected from the standby database, LGWR continues to attempt to reconnect to the standby database. It should instead avoid attempts to reconnect until an ARCH process has re-established communication with the standby database.

Rediscovery Notes:

Alert log contains messages like:

ORA-16198: LGWR received timedout error from KSR

LGWR: Attempting destination LOG_ARCHIVE_DEST_2 network reconnect (16198)

LGWR: Destination LOG_ARCHIVE_DEST_2 network reconnect abandoned

Errors in file

/app/oracle/diag/rdbms/ora11g_dga/ora11g/trace/ora11g_lgwr_290838.trc:

ORA-16198: Timeout incurred on internal channel during remote archival

LGWR: Network asynch I/O wait error 16198 log 2 service 'ora11g_DGb'

LGWR: Error 16198 disconnecting from destination LOG_ARCHIVE_DEST_2 standby

host 'ora11g_DGb'

Destination LOG_ARCHIVE_DEST_2 is UNSYNCHRONIZED