oracle 经常报Fatal NI connect error 12537,connecting to:和TNS-12537:TNS:connecti
连接数据数据很慢，alert报大量的这样日志：
Fatal NI connect error 12537, connecting to:
 (LOCAL=NO)

  VERSION INFORMATION:
TNS for Linux: Version 11.2.0.1.0 - Production
Oracle Bequeath NT Protocol Adapter for Linux: Version 11.2.0.1.0 - Production
TCP/IP NT Protocol Adapter for Linux: Version 11.2.0.1.0 - Production
  Time: 05-APR-2011 22:10:00
  Tracing not turned on.
  Tns error struct:
  ns main err code: 12537
   
TNS-12537: TNS:connection closed
  ns secondary err code: 12560
  nt main err code: 0
  nt secondary err code: 0
  nt OS err code: 0
opiodr aborting process unknown ospid (32106) as a result of ORA-609
Tue Apr 05 22:10:00 2011


***********************************************************************
这是一些系统文件：
[sshuser@database1 etc]$ cat resolv.conf 
nameserver 61.139.2.69
search localdomain

[sshuser@database1 etc]$ cat hosts
192.168.10.54 database1.localdomain database1
127.0.0.1 localhost.localdomain localhost

# listener.ora Network Configuration File: /usrapp/oracleapp/product/11.2.0/dbhome_1/network/admin/listener.ora
# Generated by Oracle configuration tools.
SID_LIST_LISTENER =
  (SID_LIST =
  (SID_DESC =
  (SID_NAME = kszxorcl)
  (ORACLE_HOME = /usrapp/oracleapp/product/11.2.0/dbhome_1)
  )
  )
LISTENER =
  (DESCRIPTION_LIST =
  (DESCRIPTION =
  (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
  (ADDRESS = (PROTOCOL = TCP)(HOST = database1.localdomain)(PORT = 1521))
  )
  )

ADR_BASE_LISTENER = /usrapp/oracleapp




------解决方案--------------------
TNS-12537: TNS:connection closed
Cause: "End of file" condition has been reached; partner has disconnected.
Action: None needed; this is an information message.
------解决方案--------------------
好像是BUG，查看解决方法

http://tolywang.itpub.net/post/48/406624
------解决方案--------------------
TNS-12537: TNS:connection closed
 会话过多，造成连接关闭，

 增加会话限制。。。