参考metalink的文档：Doc ID: Note:3136.1 and 465043.1
WARNING: inbound connection timed out (ORA-3136)
1.参数含义：
SQLNET.INBOUND_CONNECT_TIMEOUT is set to a value in seconds and determines how long a client has to
provide the necessary authentication information to a database.
INBOUND_CONNECT_TIMEOUT_listenername is set to a value in seconds and determines how long a client has
to complete its connect request to the listener after the network connection has been established.
2.参数意义：
在oracle 10.2以后的版本当中将SQLNET.INBOUND_CONNECT_TIMEOUT 和 INBOUND_CONNECT_TIMEOUT_listenername参
数设置缺省为60s，之前的版本当中默认为0（即关闭此功能）。这两个参数用于防止恶意client通过网络攻击db
server
Note: This timeout restriction was introduced to combat Denial of Service (DoS) attack whereby
malicious clients attempt to flood database servers with connect requests that consumes resources.
3.报出此warning的原因如下：
a.server收到一个从恶意client发来的连接请求，在这种情况下抛出的错误将是预期的和可取的。（客户端反复输错
username/password）
b.服务器接收到一个有效的客户端连接请求,但客户需要很长时间来验证超过默认60秒。（客户端网络延迟）
c.DB服务器负载很高导致它无法在指定时间内完成客户端登录请求。（数据库服务器高负载）
4.解决办法：
a.验证db server端，本地连接是否成功（listener是否可用）
b.验证本地连接是否延迟（本地网络是否高效可用）
c.验证数据库性能（db server是否高负载）
d.告警日志是否在之前报过ORA-600或ORA-7445
e.检查是否有client反复尝试登录密码（这是目前最有可能的原因）
f.关闭此功能（将2参数设置为0，设置方法参照步骤5）也可将2参数设置为适当值。
5.修改这两个参数的方法如下：
Edit the server side sqlnet.ora file and add this parameter:
SQLNET.INBOUND_CONNECT_TIMEOUT=<n> Where <n> is the value in seconds.
E.g.:
SQLNET.INBOUND_CONNECT_TIMEOUT = 120
Edit the listener.ora file and add this parameter:
INBOUND_CONNECT_TIMEOUT_<listenername> = <n> Again, where <n> is the timeout value in seconds.
For example if the listener name is LISTENER then use:
INBOUND_CONNECT_TIMEOUT_LISTENER = 110
6.总结：
此warning提示，极有可能是有客户端在不知道密码的情况下，反复尝试连接数据库或登录延迟导致，个人认为可以
忽略，重启监听并不会解决该问题，只是暂时清空了监听的告警信息，也可观察一段时间，或抓取性能分析报告，确
认是否为负载过高导致性能下降从而引起的告警。
:ORA-3136 错误解决
:ORA-3136 错误解决
1、首先通过后台alter日志发现报如下错误:
Mon May 20 12:44:19 2013
WARNING: inbound connection timed out (ORA-3136)
Mon May 20 12:44:19 2013
WARNING: inbound connection timed out (ORA-3136)
Mon May 20 12:44:19 2013
WARNING: inbound connection timed out (ORA-3136)
2、观察sqlnet.log中记录如下错误:
Fatal NI connect error 12514, connecting to:
(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=XXXXX)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)
(SERVICE_NAME=XXXXXXXX)(INSTANCE_NAME=XXXX)(CID=(PROGRAM=XXXXXX)(HOST=XXXXXX)
(USER=oracle))))
VERSION INFORMATION:
TNS for Linux: Version 10.2.0.1.0 - Production
TCP/IP NT Protocol Adapter for Linux: Version 10.2.0.1.0 - Production
Time: 28-11月-2008 14:10:42
Tracing not turned on.
Tns error struct:
ns main err code: 12564
TNS-12564: TNS:connection refused
ns secondary err code: 0
nt main err code: 0
nt secondary err code: 0
nt OS err code: 0
3、重新reload一下Listner:
[oracle@XXX ~]$ lsnrctl
LSNRCTL for Linux: Version 10.2.0.4.0 - Production on 20-5月 -2013 12:54:56
Copyright (c) 1991, 2007, Oracle. All rights reserved.
Welcome to LSNRCTL, type "help" for information.
LSNRCTL> reload
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
The command completed successfully
LSNRCTL> services
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
Services Summary...
Service "+ASM" has 1 instance(s).
Instance "+ASM2", status BLOCKED, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0 state:ready
LOCAL SERVER
Service "+ASM_XPT" has 1 instance(s).
Instance "+ASM2", status BLOCKED, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0 state:ready
LOCAL SERVER
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0
LOCAL SERVER
Service "XXXXXXXX" has 2 instance(s).
Instance "XXXXXX", status READY, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:16 refused:0 state:ready
REMOTE SERVER
(ADDRESS=(PROTOCOL=tcp)(HOST=XXXXXXXX)(PORT=1521))
Instance "XXXXXX", status READY, has 2 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0 state:ready
REMOTE SERVER
(ADDRESS=(PROTOCOL=tcp)(HOST=XXXXXX)(PORT=1521))
"DEDICATED" established:31 refused:0 state:ready
LOCAL SERVER
Service "XXXXXXXXX" has 2 instance(s).
Instance "XXXXXX", status READY, has 1 handler(s) for this service...
Handler(s):
"D000" established:0 refused:0 current:0 max:972 state:ready
DISPATCHER <machine: XXXXXXX, pid: 28579>
(ADDRESS=(PROTOCOL=tcp)(HOST=XXXXXX)(PORT=6661))
Instance "XXXXXX", status READY, has 1 handler(s) for this service...
Handler(s):
"D000" established:0 refused:0 current:0 max:1022 state:ready
DISPATCHER <machine: XXXX, pid: 28800>
(ADDRESS=(PROTOCOL=tcp)(HOST=XXXXX)(PORT=51924))
Service "XXXXXXXX" has 2 instance(s).
Instance "XXXXXXX", status READY, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:16 refused:0 state:ready
REMOTE SERVER
(ADDRESS=(PROTOCOL=tcp)(HOST=XXXXX)(PORT=1521))
Instance "XXXXXXX", status READY, has 2 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0 state:ready
REMOTE SERVER
(ADDRESS=(PROTOCOL=tcp)(HOST=XXXXXXX)(PORT=1521))
"DEDICATED" established:31 refused:0 state:ready
LOCAL SERVER
The command completed successfully
LSNRCTL> show inbound_connect_timeout
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
LISTENER parameter "inbound_connect_timeout" set to 60
The command completed successfully
4、修改之后观察一段时间系统恢复正常。