Tables are created but the data is not populated . followed the below steps https://docs.wso2.com/display/AM170/Publishing+API+Runtime+Statistics this link is used to configure
below is the error i see in the wso2carbon.log on wso2 api manager
TID: [0] [AM] [2014-10-16 20:15:50,544] ERROR {JAGGERY.modules.statistics.usage:jag} - java.lang.NullPointerException: null {JAGGERY.modules.statistics.usage:jag}
TID: [0] [AM] [2014-10-16 20:15:59,210] ERROR {JAGGERY.modules.statistics.usage:jag} - java.lang.NullPointerException: null {JAGGERY.modules.statistics.usage:jag}
TID: [0] [AM] [2014-10-16 20:16:01,473] ERROR {JAGGERY.modules.statistics.usage:jag} - java.lang.NullPointerException: null {JAGGERY.modules.statistics.usage:jag}