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Posted to common-user@hadoop.apache.org by lei liu <li...@gmail.com> on 2014/02/20 17:44:19 UTC
datanode is slow
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?
Re: datanode is slow
Posted by Haohui Mai <hm...@hortonworks.com>.
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 <li...@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?
>
>
>
>
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Re: datanode is slow
Posted by Haohui Mai <hm...@hortonworks.com>.
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 <li...@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.
Re: datanode is slow
Posted by Haohui Mai <hm...@hortonworks.com>.
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 <li...@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.
Re: datanode is slow
Posted by Haohui Mai <hm...@hortonworks.com>.
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 <li...@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.