Unexpected end of input stream

Our server with MySQL has an temporary overload, sometimes answer from MySQL can take 5-30 secs, but only it happens only sometimes (1 time per hour for example).

Other MySQL clients works without any problems.

I uses 'autoReconnect=true' option in database connection.

Note:
When Confluence stops to work (shows only exceptions), I still see connection to the MySQL database. Only 1 connection, not two as usual when Confluence works.

It can be reproduced by restarting MySQL server.

Below short piece of exception which I have a lot.

• • BEGIN NESTED EXCEPTION **

java.io.IOException
MESSAGE: Unexpected end of input stream

STACKTRACE:

java.io.IOException: Unexpected end of input stream
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:1455)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:1826)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1098)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1192)
at com.mysql.jdbc.MysqlIO.sqlQuery(MysqlIO.java:1153)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2048)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2017)
at com.mysql.jdbc.Connection.execSQL(Connection.java:1998)
at com.mysql.jdbc.Connection.commit(Connection.java:1096)
at net.sf.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:63)
at org.springframework.orm.hibernate.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:339)

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