I wonder if there is known performance limitation running HBase in the standalone-mode? In particular, is there an upper bound to the resource usage (e.g., total number of HTables, column families, number row records per HTable) in a single region server that is not backed by an HDFS?
I'm experiencing a strange HBase server behavior. After running a Java HBase client program for 6+ hours, the HBase server randomly dies. The machine is a Linux box, dual core with 6G of physical memory and 4G swap. I'm running a standalone HBase server and a single Java client. I start the HBase server using the default "start_hbase.sh" BASH script. The Java client runs on the same host as the HBase server. Because the Java client is called by a separate BASH program that feeds the client with different data files, the Java program is periodically started and stopped. I have been very careful about the closing and releasing HTable connections in the client code. In the program, there is a singleton HBaseAdmin, which is responsible for creating different HTable objects. Whenever I'm done using an HTable object, I explicitly call HTable.close, and whenever I'm done using ResutlScanner, I explicit call ResultScanner.close. In additional, because I expect the program to creates a lot of HTable (300+), I also carefully manage the number of active HTable instances. The client program explicitly calls HBaseAdmin to disable HTables when its done using them. I used the HBase SHELL to monitor the HBase server status (status 'detailed'). I saw that at all time, there is no more than 5 active HTable instances. When using the "status 'detailed'" command to monitor my system health, I saw the number of "heapUsed" keeps increasing. I have set the HBASE_HEAPSIZE BASH environment variable to 4G. Because the Java client program is a long running program, eventually the HBase server dies. I wonder if it's caused by an internal OOM exception. I look around the HBase log files and didn't find any obvious Java exceptions. System Information: - HBase version: 0.20.4 - Java version "1.6.0_20" Java(TM) SE Runtime Environment (build 1.6.0_20-b02) Java HotSpot(TM) 64-Bit Server VM (build 16.3-b01, mixed mode) - HBase runs with the following JVM args -Xmx4000m -XX:+HeapDumpOnOutOfMemoryError -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode Thanks J.
