Version: HBase: 0.94.3 HDFS: 0.20.* There are too many CLOSE_WAIT connection from RS to DN, and I find the number is over 30000. And change the Log-Level of 'org.apache.hadoop.ipc.HBaseServer.trace' to DEBUG, and check that the performance:
> Call #2649932; Served: HRegionInterface#get queueTime=0 processingTime=284 > contents=1 Get, 86 bytes > > So the conclusion is that when DataNode server port has been occupied by normal or irregular connection, it will bring read/write performance down. According to principle of TCP/IP protocol, CLOSE_WAIT means that RS cannot close fd which has been opened, and I restart RS gracefully, the problem has been tackled. Ok, My question is : Can someone tell me in which conditions do RS will ignore the file handler? Any ideas will be nice. Thanks! -- Bing Jiang Tel：(86)134-2619-1361 weibo: http://weibo.com/jiangbinglover BLOG: www.binospace.com BLOG: http://blog.sina.com.cn/jiangbinglover Focus on distributed computing, HDFS/HBase
