Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
Zookeeper, mail # user - adding/removing a zookeeper server


Copy link to this message
-
Re: adding/removing a zookeeper server
Jordan Zimmerman 2012-04-30, 18:54
Technically, ZK does not support it. However, there is a methodology for
reconfiguring and updated an ensemble. I believe ZK-107 will allow the
changes to be made without needing to restart/reconfigure the cluster.

-JZ

On 4/30/12 11:49 AM, "Mohammad Abdul-Amir (Shamma)"
<[EMAIL PROTECTED]> wrote:

>Alex,
>
>It sounds like you are suggesting that zookeeper keeper does not support
>adding/removing servers non-dynamically. If so, this contradicts with the
>FAQ #6 that Jordan Zimmerman pointed out.
>
>On Sun, Apr 29, 2012 at 11:32 PM, Alexander Shraer
><[EMAIL PROTECTED]>wrote:
>
>> Hi Mohammad,
>>
>> Support for adding/removing servers as well as dynamic changes to
>> other parameters will be added as part of ZOOKEEPER-107, hopefully in
>> the 3.5.0 release.
>>
>> Thanks,
>> Alex
>>
>> On Thu, Apr 26, 2012 at 3:55 PM, Mohammad Abdul-Amir (Shamma)
>> <[EMAIL PROTECTED]> wrote:
>> > On Thu, Apr 26, 2012 at 2:48 PM, Jordan Zimmerman <
>> [EMAIL PROTECTED]>wrote:
>> >
>> >> See #6 in the FAQ: http://wiki.apache.org/hadoop/ZooKeeper/FAQ
>> >>
>> >>
>> > Okay, it seems that a zookeeper "upgrade" is possible according to
>>FAQ.
>> >
>> > Does removing/decommissioning a zookeeper server fall under the
>>notion of
>> > "upgrade" though? Does "upgrade" apply to any zookeeper config update?
>> >
>> >
>> >> Also, FYI, we recently open sourced a ZooKeeper supervisor app that
>> makes
>> >> these kinds of tasks simpler:
>> >>
>> >>        https://github.com/Netflix/exhibitor
>> >>
>> >> -Jordan
>> >>
>> >> On 4/26/12 2:46 PM, "Mohammad Abdul-Amir (Shamma)"
>> >> <[EMAIL PROTECTED]> wrote:
>> >>
>> >> >Hello,
>> >> >
>> >> >I have been searching through the zookeeper documentation and the
>>web
>> for
>> >> >information about reconfiguring a zookeeper ensemble. More
>>precisely I
>> am
>> >> >interested in adding/removing zookeeper servers to/from a zookeeper
>> >> >ensemble. Unfortunately, I could not find much information around,
>> >> >therefore I am bringing up the issue on this list.
>> >> >
>> >> >My questions are:
>> >> >
>> >> >- Is there a safe procedure to add a zookeeper server to a zookeeper
>> >> >ensemble?
>> >> >- Is there a safe procedure to remove a zookeeper server from an
>> existing
>> >> >ensemble?
>> >> >
>> >> >Some posts I have read suggest that these operations are possible.
>>The
>> >> >described procedure is to rewrite a new zookeeper configuration to
>>all
>> >> >involved servers and to restart them. However, given that I could
>>not
>> find
>> >> >any information about how to carry out these two operations in
>> zookeeper's
>> >> >documentation makes me nervous about relying on the described
>> procedure.
>> >> >
>> >> >I would appreciate if anyone can point me to a different procedures
>>to
>> >> >carry out add/remove operations, or convince me that it is safe to
>>use
>> the
>> >> >procedure described above. Safety for me is two-fold: zookeeper
>> database
>> >> >can not get corrupted (unusable), and state updates can not get
>>lost.
>> >> >
>> >> >--
>> >> >Mohammad Abdul-Amir (Shamma)
>> >>
>> >>
>> >
>> >
>> > --
>> > Mohammad Abdul-Amir (Shamma)
>>
>
>
>
>--
>Mohammad Abdul-Amir (Shamma)