我在 eclipse 中有一个 JAVA 应用程序，它尝试连接到 Oracle 11G 数据库，但出现以下错误：
Caused by: java.sql.SQLException: Listener refused the connection with the following error:
ORA-12518, TNS:listener could not hand off client connection
The Connection descriptor used by the client was:
127.0.0.1:1521/XE
尽管 listener.ora 和 tnsnames.ora 的主机名为"LP-5CD9296CDZ"，但 lsnrctl 状态显示主机为 LP-5CD9296CDZ.XXX.CORP.XXX.IN
C:WINDOWSsystem32>lsnrctl status
LSNRCTL for 64-bit Windows: Version 11.2.0.2.0 - Production on 14-DEC-2019 18:20:51
Copyright (c) 1991, 2014, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for 64-bit Windows: Version 11.2.0.2.0 - Production
Start Date 14-DEC-2019 17:52:45
Uptime 0 days 0 hr. 28 min. 6 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Default Service XE
Listener Parameter File C:oraclexeapporacleproduct11.2.0servernetworkadminlistener.ora
Listener Log File C:oraclexeapporaclediagtnslsnrLP-5CD9296CDZlisteneralertlog.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\.pipeEXTPROC1ipc)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=LP-5CD9296CDZ.XXX.CORP.XXX.IN)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=LP-5CD9296CDZ.XXX.CORP.XXX.IN)(PORT=8080))(Presentation=HTTP)(Session=RAW))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "XEXDB" has 1 instance(s).
Instance "xe", status READY, has 1 handler(s) for this service...
Service "xe" has 1 instance(s).
Instance "xe", status READY, has 1 handler(s) for this service...
The command completed successfully
我的 JDBC 连接 URL 如下所示：jdbc:oracle:thin:@LP-5CD9296CDZ:1521/XE在SQL Plus上，我可以使用conn系统连接到数据库，但不能通过通过JBOSS7.1服务器部署的应用程序。
Listener.ora 如下：
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = C:oraclexeapporacleproduct11.2.0server)
(PROGRAM = extproc)
)
(SID_DESC =
(SID_NAME = CLRExtProc)
(ORACLE_HOME = C:oraclexeapporacleproduct11.2.0server)
(PROGRAM = extproc)
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
)
)
DEFAULT_SERVICE_LISTENER = (XE)
tnsnames.ora is as follows:
XE =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = XE)
)
)
EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
)
(CONNECT_DATA =
(SID = PLSExtProc)
(PRESENTATION = RO)
)
)
ORACLR_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
)
(CONNECT_DATA =
(SID = CLRExtProc)
(PRESENTATION = RO)
)
)
结果 ：
SQL>select * from v$resource_limit;
RESOURCE_NAME CURRENT_UTIL MAX_UTIL INITIAL_ALLOCAT LIMIT_VALUE
-----------------------------------------------------------------
processes 32 100 100 100
sessions 33 101 176 176
enqueue_locks 16 90 2180 2180
enqueue_resources 15 15 992 UNLIMITED
ges_procs 0 0 0 0
ges_ress 0 0 0 UNLIMITED
ges_locks 0 0 0 UNLIMITED
ges_cache_ress 0 0 0 UNLIMITED
ges_reg_msgs 0 0 0 UNLIMITED
ges_big_msgs 0 0 0 UNLIMITED
ges_rsv_msgs 0 0 0 0
gcs_resources 0 0 0 0
gcs_shadows 0 0 0 0
dml_locks 0 0 772 UNLIMITED
temporary_table_locks 0 0 UNLIMITED UNLIMITED
transactions 0 0 193 UNLIMITED
branches 0 0 193 UNLIMITED
cmtcallbk 0 1 193 UNLIMITED
max_rollback_segments 11 11 193 65535
sort_segment_locks 0 4 UNLIMITED UNLIMITED
k2q_locks 0 0 352 UNLIMITED
max_shared_servers 4 4 UNLIMITED UNLIMITED
parallel_max_serve 0 0 0 3600
23 rows selected.
您的系统负载过重，数据库进程(limit 100 , max_utilisation 100( 和数据库中会话(limit 176, max_utilisation 101( 的最大值已达到。您需要增加数据库进程和会话的最大数量。
>sqlplus / as sysdba
SQL*Plus: Release 11.2.0.3.0 Production on Mon Dec 16 08:48:42 2019
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Release 11.2.0.3.0 - 64bit Production
SQL> show parameter processes
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
aq_tm_processes integer 1
db_writer_processes integer 1
gcs_server_processes integer 0
global_txn_processes integer 1
job_queue_processes integer 1000
log_archive_max_processes integer 4
processes integer 150
SQL> alter system set processes = 500 scope = spfile;
System altered.
重新启动数据库。