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Posted to mapreduce-user@hadoop.apache.org by Jianhui Zhang <jh...@gmail.com> on 2013/01/06 08:41:06 UTC
Can I switch the IP/host of NN without losing the filesystem?
Hadoop version: hadoop-0.20.205.0
My NN machine has 2 IP addresses and 2 hostnames assigned to them
respectively. I have configured "fs.default.name" using one of the
hostnames and used the cluster for a while.
Now, I may have to move the "fs.default.name" to the other IP/hostname of
the same machine. If no other configurations change (such as the
directories), can I simply change "fs.default.name" to the new hostname,
restart the NN and expect the same filesystem is intact?
Thanks,
James
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by 周梦想 <ab...@gmail.com>.
Hi Jianhui,
If you only has hadoop and not HBase, maybe there is no problem.
Last time we changed IP addresses but not hostname. Our hadoop version is
hadoop 1.0.2, HBase is 0.92. At beginning, it's ok. But after about 2
hours, the second name node exited and couldn't start , reported
NullPointException. Then we restarted all nodes, but NN couldn't start and
reported the same error.
So you can just have a test. Before your test, REMEMBER to BACKUP ALL YOUR
DATA, especially the name node data and HBase -META-,-ROOT- table.
Good Luck!
Andy Zhou
2013/1/6 Jianhui Zhang <jh...@gmail.com>
> Hadoop version: hadoop-0.20.205.0
>
> My NN machine has 2 IP addresses and 2 hostnames assigned to them
> respectively. I have configured "fs.default.name" using one of the
> hostnames and used the cluster for a while.
>
> Now, I may have to move the "fs.default.name" to the other IP/hostname of
> the same machine. If no other configurations change (such as the
> directories), can I simply change "fs.default.name" to the new hostname,
> restart the NN and expect the same filesystem is intact?
>
> Thanks,
> James
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by 周梦想 <ab...@gmail.com>.
Hi Jianhui,
If you only has hadoop and not HBase, maybe there is no problem.
Last time we changed IP addresses but not hostname. Our hadoop version is
hadoop 1.0.2, HBase is 0.92. At beginning, it's ok. But after about 2
hours, the second name node exited and couldn't start , reported
NullPointException. Then we restarted all nodes, but NN couldn't start and
reported the same error.
So you can just have a test. Before your test, REMEMBER to BACKUP ALL YOUR
DATA, especially the name node data and HBase -META-,-ROOT- table.
Good Luck!
Andy Zhou
2013/1/6 Jianhui Zhang <jh...@gmail.com>
> Hadoop version: hadoop-0.20.205.0
>
> My NN machine has 2 IP addresses and 2 hostnames assigned to them
> respectively. I have configured "fs.default.name" using one of the
> hostnames and used the cluster for a while.
>
> Now, I may have to move the "fs.default.name" to the other IP/hostname of
> the same machine. If no other configurations change (such as the
> directories), can I simply change "fs.default.name" to the new hostname,
> restart the NN and expect the same filesystem is intact?
>
> Thanks,
> James
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by 周梦想 <ab...@gmail.com>.
Hi Jianhui,
If you only has hadoop and not HBase, maybe there is no problem.
Last time we changed IP addresses but not hostname. Our hadoop version is
hadoop 1.0.2, HBase is 0.92. At beginning, it's ok. But after about 2
hours, the second name node exited and couldn't start , reported
NullPointException. Then we restarted all nodes, but NN couldn't start and
reported the same error.
So you can just have a test. Before your test, REMEMBER to BACKUP ALL YOUR
DATA, especially the name node data and HBase -META-,-ROOT- table.
Good Luck!
Andy Zhou
2013/1/6 Jianhui Zhang <jh...@gmail.com>
> Hadoop version: hadoop-0.20.205.0
>
> My NN machine has 2 IP addresses and 2 hostnames assigned to them
> respectively. I have configured "fs.default.name" using one of the
> hostnames and used the cluster for a while.
>
> Now, I may have to move the "fs.default.name" to the other IP/hostname of
> the same machine. If no other configurations change (such as the
> directories), can I simply change "fs.default.name" to the new hostname,
> restart the NN and expect the same filesystem is intact?
>
> Thanks,
> James
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by 周梦想 <ab...@gmail.com>.
Hi Jianhui,
If you only has hadoop and not HBase, maybe there is no problem.
Last time we changed IP addresses but not hostname. Our hadoop version is
hadoop 1.0.2, HBase is 0.92. At beginning, it's ok. But after about 2
hours, the second name node exited and couldn't start , reported
NullPointException. Then we restarted all nodes, but NN couldn't start and
reported the same error.
So you can just have a test. Before your test, REMEMBER to BACKUP ALL YOUR
DATA, especially the name node data and HBase -META-,-ROOT- table.
Good Luck!
Andy Zhou
2013/1/6 Jianhui Zhang <jh...@gmail.com>
> Hadoop version: hadoop-0.20.205.0
>
> My NN machine has 2 IP addresses and 2 hostnames assigned to them
> respectively. I have configured "fs.default.name" using one of the
> hostnames and used the cluster for a while.
>
> Now, I may have to move the "fs.default.name" to the other IP/hostname of
> the same machine. If no other configurations change (such as the
> directories), can I simply change "fs.default.name" to the new hostname,
> restart the NN and expect the same filesystem is intact?
>
> Thanks,
> James
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by Jianhui Zhang <jh...@gmail.com>.
Thank everybody for the responses.
James
On Mon, Jan 7, 2013 at 12:49 PM, Robert Molina <rm...@hortonworks.com>wrote:
> Hi James,
> This should be fine, but just wanted to add that you will need to also
> make the change on your other nodes within the cluster, so they know how to
> contact the filesystem.
>
> Regards,
> Robert
>
>
> On Sun, Jan 6, 2013 at 12:18 AM, Jagat Singh <ja...@gmail.com> wrote:
>
>> Yes your data is safe.
>>
>>
>>
>>
>> On Sun, Jan 6, 2013 at 6:41 PM, Jianhui Zhang <jh...@gmail.com>wrote:
>>
>>> Hadoop version: hadoop-0.20.205.0
>>>
>>> My NN machine has 2 IP addresses and 2 hostnames assigned to them
>>> respectively. I have configured "fs.default.name" using one of the
>>> hostnames and used the cluster for a while.
>>>
>>> Now, I may have to move the "fs.default.name" to the other IP/hostname
>>> of the same machine. If no other configurations change (such as the
>>> directories), can I simply change "fs.default.name" to the new
>>> hostname, restart the NN and expect the same filesystem is intact?
>>>
>>> Thanks,
>>> James
>>>
>>
>>
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by Jianhui Zhang <jh...@gmail.com>.
Thank everybody for the responses.
James
On Mon, Jan 7, 2013 at 12:49 PM, Robert Molina <rm...@hortonworks.com>wrote:
> Hi James,
> This should be fine, but just wanted to add that you will need to also
> make the change on your other nodes within the cluster, so they know how to
> contact the filesystem.
>
> Regards,
> Robert
>
>
> On Sun, Jan 6, 2013 at 12:18 AM, Jagat Singh <ja...@gmail.com> wrote:
>
>> Yes your data is safe.
>>
>>
>>
>>
>> On Sun, Jan 6, 2013 at 6:41 PM, Jianhui Zhang <jh...@gmail.com>wrote:
>>
>>> Hadoop version: hadoop-0.20.205.0
>>>
>>> My NN machine has 2 IP addresses and 2 hostnames assigned to them
>>> respectively. I have configured "fs.default.name" using one of the
>>> hostnames and used the cluster for a while.
>>>
>>> Now, I may have to move the "fs.default.name" to the other IP/hostname
>>> of the same machine. If no other configurations change (such as the
>>> directories), can I simply change "fs.default.name" to the new
>>> hostname, restart the NN and expect the same filesystem is intact?
>>>
>>> Thanks,
>>> James
>>>
>>
>>
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by Jianhui Zhang <jh...@gmail.com>.
Thank everybody for the responses.
James
On Mon, Jan 7, 2013 at 12:49 PM, Robert Molina <rm...@hortonworks.com>wrote:
> Hi James,
> This should be fine, but just wanted to add that you will need to also
> make the change on your other nodes within the cluster, so they know how to
> contact the filesystem.
>
> Regards,
> Robert
>
>
> On Sun, Jan 6, 2013 at 12:18 AM, Jagat Singh <ja...@gmail.com> wrote:
>
>> Yes your data is safe.
>>
>>
>>
>>
>> On Sun, Jan 6, 2013 at 6:41 PM, Jianhui Zhang <jh...@gmail.com>wrote:
>>
>>> Hadoop version: hadoop-0.20.205.0
>>>
>>> My NN machine has 2 IP addresses and 2 hostnames assigned to them
>>> respectively. I have configured "fs.default.name" using one of the
>>> hostnames and used the cluster for a while.
>>>
>>> Now, I may have to move the "fs.default.name" to the other IP/hostname
>>> of the same machine. If no other configurations change (such as the
>>> directories), can I simply change "fs.default.name" to the new
>>> hostname, restart the NN and expect the same filesystem is intact?
>>>
>>> Thanks,
>>> James
>>>
>>
>>
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by Jianhui Zhang <jh...@gmail.com>.
Thank everybody for the responses.
James
On Mon, Jan 7, 2013 at 12:49 PM, Robert Molina <rm...@hortonworks.com>wrote:
> Hi James,
> This should be fine, but just wanted to add that you will need to also
> make the change on your other nodes within the cluster, so they know how to
> contact the filesystem.
>
> Regards,
> Robert
>
>
> On Sun, Jan 6, 2013 at 12:18 AM, Jagat Singh <ja...@gmail.com> wrote:
>
>> Yes your data is safe.
>>
>>
>>
>>
>> On Sun, Jan 6, 2013 at 6:41 PM, Jianhui Zhang <jh...@gmail.com>wrote:
>>
>>> Hadoop version: hadoop-0.20.205.0
>>>
>>> My NN machine has 2 IP addresses and 2 hostnames assigned to them
>>> respectively. I have configured "fs.default.name" using one of the
>>> hostnames and used the cluster for a while.
>>>
>>> Now, I may have to move the "fs.default.name" to the other IP/hostname
>>> of the same machine. If no other configurations change (such as the
>>> directories), can I simply change "fs.default.name" to the new
>>> hostname, restart the NN and expect the same filesystem is intact?
>>>
>>> Thanks,
>>> James
>>>
>>
>>
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by Robert Molina <rm...@hortonworks.com>.
Hi James,
This should be fine, but just wanted to add that you will need to also make
the change on your other nodes within the cluster, so they know how to
contact the filesystem.
Regards,
Robert
On Sun, Jan 6, 2013 at 12:18 AM, Jagat Singh <ja...@gmail.com> wrote:
> Yes your data is safe.
>
>
>
>
> On Sun, Jan 6, 2013 at 6:41 PM, Jianhui Zhang <jh...@gmail.com>wrote:
>
>> Hadoop version: hadoop-0.20.205.0
>>
>> My NN machine has 2 IP addresses and 2 hostnames assigned to them
>> respectively. I have configured "fs.default.name" using one of the
>> hostnames and used the cluster for a while.
>>
>> Now, I may have to move the "fs.default.name" to the other IP/hostname
>> of the same machine. If no other configurations change (such as the
>> directories), can I simply change "fs.default.name" to the new hostname,
>> restart the NN and expect the same filesystem is intact?
>>
>> Thanks,
>> James
>>
>
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by Robert Molina <rm...@hortonworks.com>.
Hi James,
This should be fine, but just wanted to add that you will need to also make
the change on your other nodes within the cluster, so they know how to
contact the filesystem.
Regards,
Robert
On Sun, Jan 6, 2013 at 12:18 AM, Jagat Singh <ja...@gmail.com> wrote:
> Yes your data is safe.
>
>
>
>
> On Sun, Jan 6, 2013 at 6:41 PM, Jianhui Zhang <jh...@gmail.com>wrote:
>
>> Hadoop version: hadoop-0.20.205.0
>>
>> My NN machine has 2 IP addresses and 2 hostnames assigned to them
>> respectively. I have configured "fs.default.name" using one of the
>> hostnames and used the cluster for a while.
>>
>> Now, I may have to move the "fs.default.name" to the other IP/hostname
>> of the same machine. If no other configurations change (such as the
>> directories), can I simply change "fs.default.name" to the new hostname,
>> restart the NN and expect the same filesystem is intact?
>>
>> Thanks,
>> James
>>
>
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by Robert Molina <rm...@hortonworks.com>.
Hi James,
This should be fine, but just wanted to add that you will need to also make
the change on your other nodes within the cluster, so they know how to
contact the filesystem.
Regards,
Robert
On Sun, Jan 6, 2013 at 12:18 AM, Jagat Singh <ja...@gmail.com> wrote:
> Yes your data is safe.
>
>
>
>
> On Sun, Jan 6, 2013 at 6:41 PM, Jianhui Zhang <jh...@gmail.com>wrote:
>
>> Hadoop version: hadoop-0.20.205.0
>>
>> My NN machine has 2 IP addresses and 2 hostnames assigned to them
>> respectively. I have configured "fs.default.name" using one of the
>> hostnames and used the cluster for a while.
>>
>> Now, I may have to move the "fs.default.name" to the other IP/hostname
>> of the same machine. If no other configurations change (such as the
>> directories), can I simply change "fs.default.name" to the new hostname,
>> restart the NN and expect the same filesystem is intact?
>>
>> Thanks,
>> James
>>
>
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by Robert Molina <rm...@hortonworks.com>.
Hi James,
This should be fine, but just wanted to add that you will need to also make
the change on your other nodes within the cluster, so they know how to
contact the filesystem.
Regards,
Robert
On Sun, Jan 6, 2013 at 12:18 AM, Jagat Singh <ja...@gmail.com> wrote:
> Yes your data is safe.
>
>
>
>
> On Sun, Jan 6, 2013 at 6:41 PM, Jianhui Zhang <jh...@gmail.com>wrote:
>
>> Hadoop version: hadoop-0.20.205.0
>>
>> My NN machine has 2 IP addresses and 2 hostnames assigned to them
>> respectively. I have configured "fs.default.name" using one of the
>> hostnames and used the cluster for a while.
>>
>> Now, I may have to move the "fs.default.name" to the other IP/hostname
>> of the same machine. If no other configurations change (such as the
>> directories), can I simply change "fs.default.name" to the new hostname,
>> restart the NN and expect the same filesystem is intact?
>>
>> Thanks,
>> James
>>
>
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by Jagat Singh <ja...@gmail.com>.
Yes your data is safe.
On Sun, Jan 6, 2013 at 6:41 PM, Jianhui Zhang <jh...@gmail.com>wrote:
> Hadoop version: hadoop-0.20.205.0
>
> My NN machine has 2 IP addresses and 2 hostnames assigned to them
> respectively. I have configured "fs.default.name" using one of the
> hostnames and used the cluster for a while.
>
> Now, I may have to move the "fs.default.name" to the other IP/hostname of
> the same machine. If no other configurations change (such as the
> directories), can I simply change "fs.default.name" to the new hostname,
> restart the NN and expect the same filesystem is intact?
>
> Thanks,
> James
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by Jagat Singh <ja...@gmail.com>.
Yes your data is safe.
On Sun, Jan 6, 2013 at 6:41 PM, Jianhui Zhang <jh...@gmail.com>wrote:
> Hadoop version: hadoop-0.20.205.0
>
> My NN machine has 2 IP addresses and 2 hostnames assigned to them
> respectively. I have configured "fs.default.name" using one of the
> hostnames and used the cluster for a while.
>
> Now, I may have to move the "fs.default.name" to the other IP/hostname of
> the same machine. If no other configurations change (such as the
> directories), can I simply change "fs.default.name" to the new hostname,
> restart the NN and expect the same filesystem is intact?
>
> Thanks,
> James
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by Jagat Singh <ja...@gmail.com>.
Yes your data is safe.
On Sun, Jan 6, 2013 at 6:41 PM, Jianhui Zhang <jh...@gmail.com>wrote:
> Hadoop version: hadoop-0.20.205.0
>
> My NN machine has 2 IP addresses and 2 hostnames assigned to them
> respectively. I have configured "fs.default.name" using one of the
> hostnames and used the cluster for a while.
>
> Now, I may have to move the "fs.default.name" to the other IP/hostname of
> the same machine. If no other configurations change (such as the
> directories), can I simply change "fs.default.name" to the new hostname,
> restart the NN and expect the same filesystem is intact?
>
> Thanks,
> James
>
Re: Can I switch the IP/host of NN without losing the filesystem?
Posted by Jagat Singh <ja...@gmail.com>.
Yes your data is safe.
On Sun, Jan 6, 2013 at 6:41 PM, Jianhui Zhang <jh...@gmail.com>wrote:
> Hadoop version: hadoop-0.20.205.0
>
> My NN machine has 2 IP addresses and 2 hostnames assigned to them
> respectively. I have configured "fs.default.name" using one of the
> hostnames and used the cluster for a while.
>
> Now, I may have to move the "fs.default.name" to the other IP/hostname of
> the same machine. If no other configurations change (such as the
> directories), can I simply change "fs.default.name" to the new hostname,
> restart the NN and expect the same filesystem is intact?
>
> Thanks,
> James
>