ORA-12516, TNS:listener could not find available handler with matching protocol stackThe Connection descriptor used by the client was:localhost:1521/XE

Caused by: java.sql.SQLException: Listener refused the connection with the following error:

ORA-12516, TNS:listener could not find available handler with matching protocol stack

The Connection descriptor used by the client was:

localhost:1521/XE

 

or

ORA-12516, TNS:listener could not find available handler with matching protocol stack

The Connection descriptor used by the client was:

localhost:1521/XE

 

18:46:48,468 ERROR [STDERR] org.hibernate.exception.GenericJDBCException: Cannot open connection

    at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:103)

    at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:91)

    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)

    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:29)

    at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:426)

    at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:144)

    at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:119)

    at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:57)

    at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1326)

    at sun.reflect.GeneratedMethodAccessor155.invoke(Unknown Source)

    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

    at java.lang.reflect.Method.invoke(Unknown Source)

    at org.hibernate.context.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:301)

    at $Proxy61.beginTransaction(Unknown Source)

    at com.paging.classes.DAO.getTotalData(DAO.java:40)

    at org.apache.jsp.paging_jsp._jspService(paging_jsp.java:85)

    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)

    at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373)

    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:336)

    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)

    at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

    at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)

    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)

    at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:182)

    at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)

    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)

    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)

    at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)

    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262)

    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)

    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)

    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446)

    at java.lang.Thread.run(Unknown Source)

 

Ans: This exception will be raised by crossing the number of processes or requests to the database. .We have to handle either in application or by increasing no of processes in oracle database file init.ora.

C:\oraclexe\app\oracle\product\10.2.0\server\config\scripts\init.ora

 

##############################################################################

# Copyright (c) 1991, 2005, Oracle. All rights reserved.

##############################################################################

 

###########################################

# Cursors and Library Cache

###########################################

open_cursors=300

 

###########################################

# Database Identification

###########################################

db_name=XE

 

###########################################

# Diagnostics and Statistics

###########################################

background_dump_dest=C:\oraclexe\app\oracle\admin\XE\bdump

core_dump_dest=C:\oraclexe\app\oracle\admin\XE\cdump

user_dump_dest=C:\oraclexe\app\oracle\admin\XE\udump

 

###########################################

# File Configuration

###########################################

control_files=("C:\oraclexe\oradata\XE\control.dbf")

 

###########################################

# Job Queues

###########################################

job_queue_processes=10

 

###########################################

# Miscellaneous

###########################################

compatible=10.2.0.1.0

 

###########################################

# Processes and Sessions

###########################################

sessions=20

 

###########################################

# SGA Memory

###########################################

sga_target=570M

 

###########################################

# Security and Auditing

###########################################

audit_file_dest=C:\oraclexe\app\oracle\admin\XE\adump

remote_login_passwordfile=EXCLUSIVE

 

###########################################

# Shared Server

###########################################

dispatchers="(PROTOCOL=TCP) (SERVICE=XEXDB)"

shared_servers=4

 

###########################################

# Sort, Hash Joins, Bitmap Indexes

###########################################

pga_aggregate_target=190M

 

###########################################

# System Managed Undo and Rollback Segments

###########################################

undo_management=AUTO

undo_tablespace=UNDO

 

###########################################

# Backup and Recovery

###########################################

DB_RECOVERY_FILE_DEST_SIZE = 10G

DB_RECOVERY_FILE_DEST = C:\oraclexe\app\oracle\flash_recovery_area

 

os_authent_prefix=""

 

by increasing job queues we can overcome this exception. Default value for instance server is 4.

Here I have increased this value to 10.

We can change other properties if your application needs additional .