Last Imelda I faced a problem with log4j was because a 3rd party library we used *coughalfrescocough* had log4j that turned debug logging on. Hibernate logs every property of every entity it persists at debug level. One of our entities has a byte array... A very large byte array.
End result: log4j coverts the byte array into a base64 encoded
string. App OOM. heap dump showed log4j. WTF