Hi, I have event-processing system which uses hbase + a pack of tomcat web-apps as front-end. tomcat web-apps are similar and used for front-end load-balancing. tomcat apps write events to hbase.
What is good pattern to show last 10/100/1000 events? events table schema is: row_key=user_id each user_id has 128 versions. So I keep history for the last 128 user events. There is no way to get last events, I can get last event only for concrete user. I had an idea to create separate table named 'last_events' and force all tomcats write there copy of event with the same key and set versions count to 1000. HBase would automatically delete old events. Drawbacks are: 1. x2 traffic 2. x2 write ops on hbase to single region Solution is bad. Are they any good patterns to resolve such problem. The other option is to use some kind of memcache or stuff like that.
