Openfire Unable to connect with Database

org.jivesoftware.database.DbConnectionManager - Unable to get a connection from the database pool (attempt 8 out of 10).
java.sql.SQLException: Access denied for user ‘openfire’@‘user’ (using password: YES)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1084)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4232)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4164)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:926)
at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1748)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1288)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2506)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2539)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2321)
at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:832)

Above error we are getting multiple times. i am tried to find solution on this. is this database connection error with pool ? or openfire have internal locked after some times ?