Communication link failure

[Glenn Holmer <gholmer@xxxxxxxxxxxxxx>]

Is anyone familiar with this type of exception?  We had a whole storm of
them over a couple days, but our iSeries tech guys can't figure out what
might have caused it.  How to diagnose and/or prevent something like
this?

2009-02-27 08:37:12,590 [ACS Order Thread] ERROR com.weycogroup.service.order.impl.WeycoOrderServiceImpl - *** Error looking up UPC code
org.springframework.dao.DataAccessResourceFailureException: StatementCallback; SQL [SELECT COUNT(*) FROM ACSDBASE3.STYLPU WHERE SUUPC = 23938208324]; Communication link failure. (Connection timed out); nested exception is java.sql.SQLExc
eption: Communication link failure. (Connection timed out)
Caused by: 
java.sql.SQLException: Communication link failure. (Connection timed out)
        at com.ibm.as400.access.JDError.throwSQLException(JDError.java:528)
        at com.ibm.as400.access.AS400JDBCConnection.sendAndReceive(AS400JDBCConnection.java:2839)
        at com.ibm.as400.access.AS400JDBCStatement.commonPrepare(AS400JDBCStatement.java:1568)
        at com.ibm.as400.access.AS400JDBCStatement.executeQuery(AS400JDBCStatement.java:2136)
        at org.apache.tomcat.dbcp.dbcp.DelegatingStatement.executeQuery(DelegatingStatement.java:208)