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Posted to user@hadoop.apache.org by ch huang <ju...@gmail.com> on 2013/07/31 03:33:14 UTC
some questions about HA and secondary name node
hi,all :
i have two questions ,hope any one can answer for me
1, if i use 2name nodes for HA ,the secondary name node still need?
2,the secondary name node use to merge fsimage and edits file,if secondary
name node is not needed for HA ,what if the name node edits file become
very long?
Re: some questions about HA and secondary name node
Posted by Harsh J <ha...@cloudera.com>.
Hi,
On Wed, Jul 31, 2013 at 7:03 AM, ch huang <ju...@gmail.com> wrote:
> hi,all :
> i have two questions ,hope any one can answer for me
> 1, if i use 2name nodes for HA ,the secondary name node still need?
With HA setup, you do not need to run the SecondaryNameNode daemon.
> 2,the secondary name node use to merge fsimage and edits file,if secondary
> name node is not needed for HA ,what if the name node edits file become very
> long?
The Standby state NameNode automatically behaves as a checkpoint
service. Therefore, just ensure its liveliness and it will continue to
checkpoint your cluster fine.
--
Harsh J
Re: some questions about HA and secondary name node
Posted by Harsh J <ha...@cloudera.com>.
Hi,
On Wed, Jul 31, 2013 at 7:03 AM, ch huang <ju...@gmail.com> wrote:
> hi,all :
> i have two questions ,hope any one can answer for me
> 1, if i use 2name nodes for HA ,the secondary name node still need?
With HA setup, you do not need to run the SecondaryNameNode daemon.
> 2,the secondary name node use to merge fsimage and edits file,if secondary
> name node is not needed for HA ,what if the name node edits file become very
> long?
The Standby state NameNode automatically behaves as a checkpoint
service. Therefore, just ensure its liveliness and it will continue to
checkpoint your cluster fine.
--
Harsh J
Re: some questions about HA and secondary name node
Posted by Daisuke Kobayashi <da...@cloudera.com>.
Hi,
On Wed, Jul 31, 2013 at 10:33 AM, ch huang <ju...@gmail.com> wrote:
> hi,all :
> i have two questions ,hope any one can answer for me
> 1, if i use 2name nodes for HA ,the secondary name node still need?
>
No, you don't need to run a secondary NN if you configure HA.
> 2,the secondary name node use to merge fsimage and edits file,if secondary
> name node is not needed for HA ,what if the name node edits file become
> very long?
>
The standby NN also checkpoints the namespace state, and that's the reason
why it is not necessary to run a secondary NN.
Re: some questions about HA and secondary name node
Posted by Daisuke Kobayashi <da...@cloudera.com>.
Hi,
On Wed, Jul 31, 2013 at 10:33 AM, ch huang <ju...@gmail.com> wrote:
> hi,all :
> i have two questions ,hope any one can answer for me
> 1, if i use 2name nodes for HA ,the secondary name node still need?
>
No, you don't need to run a secondary NN if you configure HA.
> 2,the secondary name node use to merge fsimage and edits file,if secondary
> name node is not needed for HA ,what if the name node edits file become
> very long?
>
The standby NN also checkpoints the namespace state, and that's the reason
why it is not necessary to run a secondary NN.
Re: some questions about HA and secondary name node
Posted by Harsh J <ha...@cloudera.com>.
Hi,
On Wed, Jul 31, 2013 at 7:03 AM, ch huang <ju...@gmail.com> wrote:
> hi,all :
> i have two questions ,hope any one can answer for me
> 1, if i use 2name nodes for HA ,the secondary name node still need?
With HA setup, you do not need to run the SecondaryNameNode daemon.
> 2,the secondary name node use to merge fsimage and edits file,if secondary
> name node is not needed for HA ,what if the name node edits file become very
> long?
The Standby state NameNode automatically behaves as a checkpoint
service. Therefore, just ensure its liveliness and it will continue to
checkpoint your cluster fine.
--
Harsh J
Re: some questions about HA and secondary name node
Posted by Daisuke Kobayashi <da...@cloudera.com>.
Hi,
On Wed, Jul 31, 2013 at 10:33 AM, ch huang <ju...@gmail.com> wrote:
> hi,all :
> i have two questions ,hope any one can answer for me
> 1, if i use 2name nodes for HA ,the secondary name node still need?
>
No, you don't need to run a secondary NN if you configure HA.
> 2,the secondary name node use to merge fsimage and edits file,if secondary
> name node is not needed for HA ,what if the name node edits file become
> very long?
>
The standby NN also checkpoints the namespace state, and that's the reason
why it is not necessary to run a secondary NN.
Re: some questions about HA and secondary name node
Posted by Harsh J <ha...@cloudera.com>.
Hi,
On Wed, Jul 31, 2013 at 7:03 AM, ch huang <ju...@gmail.com> wrote:
> hi,all :
> i have two questions ,hope any one can answer for me
> 1, if i use 2name nodes for HA ,the secondary name node still need?
With HA setup, you do not need to run the SecondaryNameNode daemon.
> 2,the secondary name node use to merge fsimage and edits file,if secondary
> name node is not needed for HA ,what if the name node edits file become very
> long?
The Standby state NameNode automatically behaves as a checkpoint
service. Therefore, just ensure its liveliness and it will continue to
checkpoint your cluster fine.
--
Harsh J
Re: some questions about HA and secondary name node
Posted by Daisuke Kobayashi <da...@cloudera.com>.
Hi,
On Wed, Jul 31, 2013 at 10:33 AM, ch huang <ju...@gmail.com> wrote:
> hi,all :
> i have two questions ,hope any one can answer for me
> 1, if i use 2name nodes for HA ,the secondary name node still need?
>
No, you don't need to run a secondary NN if you configure HA.
> 2,the secondary name node use to merge fsimage and edits file,if secondary
> name node is not needed for HA ,what if the name node edits file become
> very long?
>
The standby NN also checkpoints the namespace state, and that's the reason
why it is not necessary to run a secondary NN.