Hi, I'm evaluating Hbase as a NoSql DB for a large scale, interactive, web service with very high uptime requirements, and have a few questions to the community.
1. I assume you've seen this benchmark by Yahoo ( http://www.brianfrankcooper.net/pubs/ycsb-v4.pdf and http://www.brianfrankcooper.net/pubs/ycsb.pdf). They show three main problems: latency goes up quite significantly when doing more operations, operations/sec are capped at about half of the other tested platforms and adding new nodes interrupts the normal operation of the cluster for a while. Do you consider these results a problem and if so are there any plans to address them? 2. While running our tests (most were done using 0.20.2) we've had a few incidents where a table went into "transition" without ever going out of it. We had to restart the cluster to release the stuck tables. Is this a common issue? 3. If I understand correctly then any major upgrade requires completely shutting down the cluster while doing the upgrade as well as deploying a new version of the application compiled with the new version client? Did I get it correctly? Is there any strategy for upgrading while the cluster is still running? 4. This is more a bug report than a question but it seems that in 0.20.3 the master server doesn't stop cleanly and has to be killed manually. Is someone else seeing it too? 5. Are there any performance benchmarks for the Thrift gateway? Do you have an estimate of the performance penalty of using the gateway compared to using the native API? 6. Right now, my biggest concern about HBase is its administration complexity and cost. If anyone can share their experience that would be a huge help. How many serves do you have in the cluster? How much ongoing effort does it take to administrate it? What uptime levels are you seeing (including upgrades)? Do you have any good strategy for running one cluster across two data centers, or replicating between two clusters in two different DCs? Did you have any serious problems/crashes/downtime with HBase? Thanks a lot, Eran Kutner