Oracle_ORA-12518故障_处理

TROUBLESHOOTING GUIDE TNS-12518 TNS listener could not hand off client connection [ID 550859.1]

修改时󳯅 29-SEP-2011 类型 TROUBLESHOOTING 状态 PUBLISHED

In this Document

Purpose

Last Review Date

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Error: Connection Pooling limit reached

Error: 2: No such file or directory

Section III: Errors Specific to Windows

Error: 233: Unknown error

Error: 54: Unknown error

Applies to:

Oracle Net Services - Version: 9.2.0.1.0 to 11.2.0.3 - Release: 9.2 to 11.2

Information in this document applies to any platform.

Purpose

This article discusses about how to approach ORA-12518/TNS-12518 and troubleshoot it for the resolution.

Section I: Steps to approach ORA-12518/TNS-12518 Error:

ORA-12518/TNS-12518 indicates a problem while listener hands off the client connection to the server process or dispatcher process.TNS-12518 is

logged in the listener log. The client might receive ORA-12518 or some other disconnection errors like ORA-12537. Once TNS-12518 is noted in the

listener log, follow the below steps to approach and resolve this error.

Let us have a small discussion about how actually database connections are made:

In Dedicated mode, database client contacts listener and supplies the SERVICE NAME of the database. Then listener spawns a dedicated server

process and hands off the client connection to this dedicated server process. TNS-12518 indicates a problem while handing off the client connection to

the server process.

In Shared Server mode, database client contacts listener and supplies the SERVICE NAME of the database. Then listener hands off the client

connection to one of the dispatcher configured for that service. TNS-12518 indicates a problem while handing off the client connection to the dispatcher

For 9i databases, 9i or 10g listeners can be used.

For 10g databases, only 10g listeners can be used.