最近客户邮件描述无法从客户端连接到数据库，其错误号为ORA-12537: TNS:connection closed，连接被关闭。直接通过tnsping没有任何问题。listener日志中出现TNS-12518: TNS:listener could not hand off client connection。即Listener无法分发客户端连接。下面是具体的错误信息、分析与解决的过程。
1、前端错误信息
C:\Program Files\VMware\VMware vSphere CLI>sqlplus robinson@sywgmr
SQL*Plus: Release 10.2.0.1.0 - Production on Thu Mar 27 10:49:00 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Enter password:
ERROR:
ORA-12537: TNS:connection closed
oracle@SZDB:/users/oracle/OraHome10g/network/log> tail listener_sywgmr.log
TNS-12547: TNS:lost contact
TNS-12560: TNS:protocol adapter error
TNS-00517: Lost contact
Linux Error: 32: Broken pipe
27-MAR-2014 11:02:38 * (CONNECT_DATA=(SID=SYWGMR)(CID=(PROGRAM=)(HOST=__jdbc__)(USER=))) * (ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=63561)) * establish * SYWGMR * 12518
TNS-12518: TNS:listener could not hand off client connection
TNS-12547: TNS:lost contact
TNS-12560: TNS:protocol adapter error
TNS-00517: Lost contact
Linux Error: 32: Broken pipe
oracle@SZDB:~> oerr ora 12537
12537, 00000, "TNS:connection closed"
// *Cause: "End of file" condition has been reached; partner has disconnected.
// *Action: None needed; this is an information message.
oracle@SZDB:~> oerr ora 12518
12518, 00000, "TNS:listener could not hand off client connection"
// *Cause: The process of handing off a client connection to another process
// failed.
// *Action: Turn on listener tracing and re-execute the operation. Verify
// that the listener and database instance are properly configured for
// direct handoff. If problem persists, call Oracle Support.
// *Comment: The problem can be worked around by configuring dispatcher(s)
// to specifically handle the desired presentation(s), and connecting
// directly to the dispatcher, bypassing the listener.
#根据上面的2个error no，没有获得太多的有用信息
#ora-12518建议作一个trace.其comment说明可以通过配置disaptcher来解决，而当前我们的数据库使用的是dedicate方式
#关于如何配置监听器trace，可参考: http://blog.csdn.net/leshami/article/details/8254720
#此处不做trace，笔者尝试reload以及restart 监听，故障依旧
#下面查看alert log 日志
#下面的日志里表明无法创建m000进程，m000进程是SMON进程的奴隶进程
oracle@SZDB:/users/oracle>
tail /u02/database/SYWGMR/bdump/alert_SYWGMR.log
Thu Mar 27 11:00:28 2014
ksvcreate: Process(m000) creation failed
Thu Mar 27 11:01:29 2014
Process m000 died, see its trace file
Thu Mar 27 11:01:29 2014
ksvcreate: Process(m000) creation failed
Thu Mar 27 11:02:30 2014
Process m000 died, see its trace file
Thu Mar 27 11:02:30 2014
ksvcreate: Process(m000) creation failed
#在06:19:02 2014时有一个Error，无法衍生job 奴隶进程
Thu Mar 27 06:19:02 2014
Process J000 died, see its trace file
Thu Mar 27 06:19:02 2014
kkjcre1p: unable to spawn jobq slave process
Thu Mar 27 06:19:02 2014
Errors in file /u02/database/SYWGMR/bdump/sywgmr_cjq0_7780.trc:
#从上面的alert log可以看出实例无法创建新的进程，推断有可能是由于超出了实例设定进程的最大值
oracle@SZDB:~> export ORACLE_SID=SYWGMR
oracle@SZDB:~> sqlplus / as sysdba
SQL*Plus: Release 11.2.0.3.0 Production on Thu Mar 27 10:56:27 2014
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Release 10.2.0.3.0 - 64bit Production
-- Author : Leshami
-- Blog : http://blog.csdn.net/leshami
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