ORA-12516: TNS: 监听程序找不到符合协议堆栈要求的可用处理程

这种错误一般是连接满了，但是被他们重启以后连接又报改错误，感觉增大连接用处不大。登录到后台alert_jscn.log日志，看到如下错误：

Wed Apr 4 15:04:25 2012

WARNING: inboundconnection timed out (ORA-3136)

Wed Apr 4 15:04:25 2012

WARNING: inboundconnection timed out (ORA-3136)

Wed Apr 4 15:04:25 2012

WARNING: inboundconnection timed out (ORA-3136)

Wed Apr 4 15:04:25 2012

WARNING: inboundconnection timed out (ORA-3136)

下面内容参考网络

参考metalink上的345197.1文章，内容如下：

Symptoms

If applications are longer than 60 secs to authenticate with theOracle database, the errors occur.The following may be seen in the alert log:WARNING: inbound connection timed out (ORA-3136)

SQLNET.INBOUND_CONNECT_TIMEOUT is set to a value in seconds anddetermines how long a client has to provide the necessary authenticationinformation to a database.

INBOUND_CONNECT_TIMEOUT_listenernameis set to a value in seconds and determines how long a client has to completeits connect request to the listener after the network connection has beenestablished.

To protect both the listener and the database server, OracleCorporation recommends setting INBOUND_CONNECT_TIMEOUT_listenername incombination with the SQLNET.INBOUND_CONNECT_TIMEOUT parameter.

Cause

Whenever default timeouts are assigned to a parameter, there may becases where this default does not work well with a particular application.However, some type of timeout on the connection establishment is necessary tocombat Denial of Service attacks on the database. In this case, SQLNET.INBOUND_CONNECT__TIMEOUTand INBOUND_CONNECT_TIMEOUT_listenername were given default values of 60seconds in Oracle 10.2. It is thesetimeout values that can cause the errors described in this note.

Also note thatit is possilbe the reason the database is slow to authenticate, may be due toan overloaded Oracle database or node.

Solution

Set theparameters SQLNET.INBOUND_CONNECT_TIMEOUT andINBOUND_CONNECT_TIMEOUT_listenername to 0 (indefinite) or to an approprateva lue for the application yet still combat DOS attacks (120 for example).

Theseparameters are set on the SERVER side:

listener.ora:INBOUND_CONNECT_TIMEOUT_listenername

sqlnet.ora: SQLNET.INBOUND_CONNECT_TIMEOUT

Further tuning of these parameters may beneeded is the problem persists

Metalink上给出的解决方案如下:

1. set INBOUND_CONNECT_TIMEOUT_=0 inlistener.ora

2. set SQLNET.INBOUND_CONNECT_TIMEOUT = 0in sqlnet.ora of server.

3. stop and start both listener anddatabase.

4. Now try to connect to DB and observe thebehaviour

以下是Oracle官方文档的一段：

SQLNET.INBOUND_CONNECT_TIMEOUT

Use theSQLNET.INBOUND_CONNECT_TIMEOUT parameter to specify the time, in seconds, for aclient to connect with the database server and provide the necessaryauthentication information.

If the clientfails to establish a connection and complete authentication in the timespecified, then the database server terminates the connection. In addition, thedatabase server logs the IP address of the client and an ORA-12170: TNS:Connecttimeout occurred error message to the sqlnet.log file. The client receiveseither an ORA-12547: TNS:lost contact or an ORA-12637: Packet receive failederror message.