It looks like your datanode is overloaded. You can scale your system by adding more datanodes.
You can also try tighten the admission control to recover. You can lower the number of dfs.datanode.max.transfer.threads so that the datanode accepts fewer concurrent requests (but which also means that it serves less number of clients). ~Haohui On Thu, Feb 20, 2014 at 8:44 AM, lei liu <liulei...@gmail.com> wrote: > I use Hbase0.94 and CDH4. There are 25729 tcp connections in one > machine,example: > hadoop@apayhbs081 ~ $ netstat -a | wc -l > 25729 > > The linux configration is : > soft core 0 > hard rss 10000 > hard nproc 20 > soft nproc 20 > hard nproc 50 > hard nproc 0 > maxlogins 4 > nproc 20480 > nofile 204800 > > > When there are 25729 tcp connections in one machine, the datanode is very > slow. > How can I resolve the question? > > > > -- CONFIDENTIALITY NOTICE NOTICE: This message is intended for the use of the individual or entity to which it is addressed and may contain information that is confidential, privileged and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are hereby notified that any printing, copying, dissemination, distribution, disclosure or forwarding of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and delete it from your system. Thank You.