What!! DB connection is full?

What went wrong with this? During the UAT, the WAS console output showing me this long story line. Initially I though I have cause some trouble in the UAT but later my investigation shows that the database connection has been fully utilize.

Caused by: org.hibernate.exception.GenericJDBCException: Cannot open connection
            at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:140)
            at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:128)
            at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
            at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:52)
            at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:449)
            at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
            at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:160)
            at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:81)
            at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1473)
            at org.springframework.orm.hibernate3.HibernateTransactionManager.doBegin(HibernateTransactionManager.java:558)
            ... 89 more
    Caused by: com.ibm.db2.jcc.am.SqlException: DB2 SQL Error: SQLCODE=-1040, SQLSTATE=57030, SQLERRMC=null, DRIVER=3.58.81
            at com.ibm.db2.jcc.am.ed.a(ed.java:679)
            at com.ibm.db2.jcc.am.ed.a(ed.java:60)
            at com.ibm.db2.jcc.am.ed.a(ed.java:127)
            at com.ibm.db2.jcc.am.jb.a(jb.java:4303)
            at com.ibm.db2.jcc.t4.db.q(db.java:703)
            at com.ibm.db2.jcc.t4.db.p(db.java:576)
            at com.ibm.db2.jcc.t4.db.l(db.java:397)
            at com.ibm.db2.jcc.t4.db.d(db.java:142)
            at com.ibm.db2.jcc.t4.b.Qc(b.java:1264)
            at com.ibm.db2.jcc.t4.b.b(b.java:1184)
            at com.ibm.db2.jcc.t4.b.a(b.java:5193)
            at com.ibm.db2.jcc.t4.b.c(b.java:743)
            at com.ibm.db2.jcc.t4.b.b(b.java:686)
            at com.ibm.db2.jcc.t4.b.a(b.java:367)
            at com.ibm.db2.jcc.t4.b.<init>(b.java:307)
            at com.ibm.db2.jcc.DB2SimpleDataSource.getConnection(DB2SimpleDataSource.java:214)
            at com.ibm.db2.jcc.DB2Driver.connect(DB2Driver.java:456)
            at java.sql.DriverManager.getConnection(DriverManager.java:582)
            at java.sql.DriverManager.getConnection(DriverManager.java:154)
            at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:174)
            at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriver(DriverManagerDataSource.java:165)
            at org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnectionFromDriver(AbstractDriverBasedDataSource.java:149)
            at org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnection(AbstractDriverBasedDataSource.java:119)
            at org.springframework.orm.hibernate3.LocalDataSourceConnectionProvider.getConnection(LocalDataSourceConnectionProvider.java:82)
            at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
            ... 94 more