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From Daryn Sharp <da...@yahoo-inc.com>
Subject Re: is time sync required among all nodes?
Date Thu, 06 Jun 2013 13:38:47 GMT
Time sync is always a good idea if for no other reason than being able to collate logs when
debugging.  Issues may also result if a client is expecting to reliably compare timestamps,
ex. checking if a file has been modified.  NTP is very easy to use.

Also of note: kerberos is very sensitive to clock skew if you intend to enable security.


On Jun 5, 2013, at 12:59 AM, Harsh J wrote:

> Skew in time between nodes is highly confusing, even if not a problem
> to the runtime. I'd strongly recommend running a time sync service for
> operational sanity.
> On Wed, Jun 5, 2013 at 8:41 AM, Chris Embree <cembree@gmail.com> wrote:
>> Yes, NTPD is your best option.
>> On 6/4/13, Ben Kim <benkimkimben@gmail.com> wrote:
>>> Hi,
>>> This is very basic & fundamental question.
>>> Is time among all nodes needs to be synced?
>>> I've never even thought of timing in hadoop cluster but recently
>>> experienced my servers going out of sync with time. I know hbase requires
>>> time to by synced due to its timestamp action. But I wonder any of hadoop
>>> functionality requires time sync. Perhaps checkpoint, namenode HA, or
>>> datanode report, etc... hmm
>>> --
>>> *Benjamin Kim*
>>> *benkimkimben at gmail*
> --
> Harsh J

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