hi, all.

If i update my conf/zoo.cfg config, must i restart my zk server?

In my case, we have 3 servers in production environment, now, we want to
upgrade to 5 server.
Any problem will happen if a kill one of three servers.
*[EMAIL PROTECTED]*

On Tue, Nov 29, 2011 at 1:08 PM, nileader <[EMAIL PROTECTED]> wrote:
>
> hi, all.
>
> If i update my conf/zoo.cfg config, must i restart my zk server?
>
> In my case, we have 3 servers in production environment, now, we want to
> upgrade to 5 server.

Take a look at http://wiki.apache.org/hadoop/ZooKeeper/FAQ#A6 where it says
how to upgrade ZooKeeper.
>
>
> Any problem will happen if a kill one of three servers.
>
>
> *[EMAIL PROTECTED]*
--
Thanks,
Pubudu

To expand on that FAQ, the detailed process should be to

- configure the new servers

- update the configuration on the old servers

- restart each old server one at a time

- start the new servers

- have your applications reconnect with the full set of servers in the
connection string.  This can be done whenever you like.

Your clients will receive a disconnect message when the server that they
are talking to is restarted, but they should reconnect immediately and
transparently.  You may have a problem if your applications don't handle
transient disconnections properly.

On Tue, Nov 29, 2011 at 3:10 AM, pubudu gunawardena <[EMAIL PROTECTED]>wrote:

> On Tue, Nov 29, 2011 at 1:08 PM, nileader <[EMAIL PROTECTED]> wrote:
> >
> > hi, all.
> >
> > If i update my conf/zoo.cfg config, must i restart my zk server?
> >
> > In my case, we have 3 servers in production environment, now, we want to
> > upgrade to 5 server.
>
> Take a look at http://wiki.apache.org/hadoop/ZooKeeper/FAQ#A6 where it
> says
> how to upgrade ZooKeeper.
> >
> >
> > Any problem will happen if a kill one of three servers.
> >
> >
> > *[EMAIL PROTECTED]*
>
>
>
>
> --
> Thanks,
> Pubudu
>

Thanks Ted, I also met the same problem. Your solution sounds so good.

>From Davy

2011/11/29 Ted Dunning <[EMAIL PROTECTED]>

> To expand on that FAQ, the detailed process should be to
>
> - configure the new servers
>
> - update the configuration on the old servers
>
> - restart each old server one at a time
>
> - start the new servers
>
> - have your applications reconnect with the full set of servers in the
> connection string.  This can be done whenever you like.
>
> Your clients will receive a disconnect message when the server that they
> are talking to is restarted, but they should reconnect immediately and
> transparently.  You may have a problem if your applications don't handle
> transient disconnections properly.
>
>
>
> On Tue, Nov 29, 2011 at 3:10 AM, pubudu gunawardena <[EMAIL PROTECTED]
> >wrote:
>
> > On Tue, Nov 29, 2011 at 1:08 PM, nileader <[EMAIL PROTECTED]> wrote:
> > >
> > > hi, all.
> > >
> > > If i update my conf/zoo.cfg config, must i restart my zk server?
> > >
> > > In my case, we have 3 servers in production environment, now, we want
> to
> > > upgrade to 5 server.
> >
> > Take a look at http://wiki.apache.org/hadoop/ZooKeeper/FAQ#A6 where it
> > says
> > how to upgrade ZooKeeper.
> > >
> > >
> > > Any problem will happen if a kill one of three servers.
> > >
> > >
> > > *[EMAIL PROTECTED]*
> >
> >
> >
> >
> > --
> > Thanks,
> > Pubudu
> >
>

Hi，ted，you mean restart old server before new servers?
Let's see the case:

In my cluster, there are three zk server, A,B and C each config three
server address.
Once, i want to upgrade my cluster to five server.
You say:

> configure the new servers
>
> - update the configuration on the old servers
>
> - restart each old server one at a time
>
> - start the new servers
>
>

So,  when i config Server C's serverlist, it will be five server in it's
zoo.cfg, and restart it.
Then make change on server b. Once i restart server b, there will be only
two server work in cluster,
and  2< 5/2+1.

So, how the leader will be elect and how the cluster will work ok?

*nileader* ni掌櫃的個人郵箱
*MSN*： [EMAIL PROTECTED]
*Weibo*：http://weibo.com/nileader
————————————————————————————————————————————————————————————————————————
This email (including any attachments) is confidential and may be legally
privileged, private information of correct recipient and nileader. If you
received this email in error, please delete it immediately and do not copy
it or use it for any purpose or disclose its contents to any other person.
Thank you.
*
本電郵(包括任何附件)可能含有機密資料並受法律保護，屬於ni掌櫃和正確收件人之間的私有信息。如您不是正確的收件人，請您立即刪除本郵件。請不要將本電郵進行複製並用作任何其它用途，或透露本郵件之內容。謝謝。
*

2011/11/29 Ted Dunning <[EMAIL PROTECTED]>

> To expand on that FAQ, the detailed process should be to
>
> - configure the new servers
>
> - update the configuration on the old servers
>
> - restart each old server one at a time
>
> - start the new servers
>
> - have your applications reconnect with the full set of servers in the
> connection string.  This can be done whenever you like.
>
> Your clients will receive a disconnect message when the server that they
> are talking to is restarted, but they should reconnect immediately and
> transparently.  You may have a problem if your applications don't handle
> transient disconnections properly.
>
>
>
> On Tue, Nov 29, 2011 at 3:10 AM, pubudu gunawardena <[EMAIL PROTECTED]
> >wrote:
>
> > On Tue, Nov 29, 2011 at 1:08 PM, nileader <[EMAIL PROTECTED]> wrote:
> > >
> > > hi, all.
> > >
> > > If i update my conf/zoo.cfg config, must i restart my zk server?
> > >
> > > In my case, we have 3 servers in production environment, now, we want
> to
> > > upgrade to 5 server.
> >
> > Take a look at http://wiki.apache.org/hadoop/ZooKeeper/FAQ#A6 where it
> > says
> > how to upgrade ZooKeeper.
> > >
> > >
> > > Any problem will happen if a kill one of three servers.
> > >
> > >
> > > *[EMAIL PROTECTED]*
> >
> >
> >
> >
> > --
> > Thanks,
> > Pubudu
> >
>

I personal think zookeeper team need to add the feature of changing
zookeeper cluster server list in runtime---without restart server.

2011/11/30 nileader <[EMAIL PROTECTED]>

> Hi，ted，you mean restart old server before new servers?
> Let's see the case:
>
> In my cluster, there are three zk server, A,B and C each config three
> server address.
> Once, i want to upgrade my cluster to five server.
> You say:
>
>> configure the new servers
>>
>> - update the configuration on the old servers
>>
>> - restart each old server one at a time
>>
>> - start the new servers
>>
>>
>
> So,  when i config Server C's serverlist, it will be five server in it's
> zoo.cfg, and restart it.
> Then make change on server b. Once i restart server b, there will be only
> two server work in cluster,
> and  2< 5/2+1.
>
> So, how the leader will be elect and how the cluster will work ok?
>
>
>
>
>
> *nileader* ni掌櫃的個人郵��
> *MSN*： [EMAIL PROTECTED]
> *Weibo*：http://weibo.com/nileader
> ————————————————���———————��————————————————���———————��————————————————���—————
> This email (including any attachments) is confidential and may be legally
> privileged, private information of correct recipient and nileader. If you
> received this email in error, please delete it immediately and do not copy
> it or use it for any purpose or disclose its contents to any other person.
> Thank you.
> *
> 本電郵(包括任何附件)可能含有機密資料並受法律保護，���於ni掌櫃和正確收���人之間的私有信��。如您不是正確的收件人，請您立即���除本郵件。請不��將本電郵進行複製並用作任何其它用���，或透露本郵件��內容。謝謝。
> *
>
>
>
> 2011/11/29 Ted Dunning <[EMAIL PROTECTED]>
>
>> To expand on that FAQ, the detailed process should be to
>>
>> - configure the new servers
>>
>> - update the configuration on the old servers
>>
>> - restart each old server one at a time
>>
>> - start the new servers
>>
>> - have your applications reconnect with the full set of servers in the
>> connection string.  This can be done whenever you like.
>>
>> Your clients will receive a disconnect message when the server that they
>> are talking to is restarted, but they should reconnect immediately and
>> transparently.  You may have a problem if your applications don't handle
>> transient disconnections properly.
>>
>>
>>
>> On Tue, Nov 29, 2011 at 3:10 AM, pubudu gunawardena <[EMAIL PROTECTED]
>> >wrote:
>>
>> > On Tue, Nov 29, 2011 at 1:08 PM, nileader <[EMAIL PROTECTED]> wrote:
>> > >
>> > > hi, all.
>> > >
>> > > If i update my conf/zoo.cfg config, must i restart my zk server?
>> > >
>> > > In my case, we have 3 servers in production environment, now, we want
>> to
>> > > upgrade to 5 server.
>> >
>> > Take a look at http://wiki.apache.org/hadoop/ZooKeeper/FAQ#A6 where it
>> > says
>> > how to upgrade ZooKeeper.
>> > >
>> > >
>> > > Any problem will happen if a kill one of three servers.
>> > >
>> > >
>> > > *[EMAIL PROTECTED]*
>> >
>> >
>> >
>> >
>> > --
>> > Thanks,
>> > Pubudu
>> >
>>
>
>

We've been looking at that, see:
https://issues.apache.org/jira/browse/ZOOKEEPER-107

It'll take some evaluation though. Hopefully 3.5?

C

On Tue, Nov 29, 2011 at 10:21 PM, nileader <[EMAIL PROTECTED]> wrote:
> I personal think zookeeper team need to add the feature of changing
> zookeeper cluster server list in runtime---without restart server.
>
> 2011/11/30 nileader <[EMAIL PROTECTED]>
>
>> Hi，ted，you mean restart old server before new servers?
>> Let's see the case:
>>
>> In my cluster, there are three zk server, A,B and C each config three
>> server address.
>> Once, i want to upgrade my cluster to five server.
>> You say:
>>
>>> configure the new servers
>>>
>>> - update the configuration on the old servers
>>>
>>> - restart each old server one at a time
>>>
>>> - start the new servers
>>>
>>>
>>
>> So,  when i config Server C's serverlist, it will be five server in it's
>> zoo.cfg, and restart it.
>> Then make change on server b. Once i restart server b, there will be only
>> two server work in cluster,
>> and  2< 5/2+1.
>>
>> So, how the leader will be elect and how the cluster will work ok?
>>
>>
>>
>>
>>
>> *nileader* ni掌櫃的個人郵箱
>> *MSN*： [EMAIL PROTECTED]
>> *Weibo*：http://weibo.com/nileader
>> ------------------------------------------------------------------------------------------------------------------------------------------------
>> This email (including any attachments) is confidential and may be legally
>> privileged, private information of correct recipient and nileader. If you
>> received this email in error, please delete it immediately and do not copy
>> it or use it for any purpose or disclose its contents to any other person.
>> Thank you.
>> *
>> 本電郵(包括任何附件)可能含有�
鰼K資料並受法律保護，屬於ni掌櫃和正確收件人之間的私有信息。�
p您不是正確的收件人，請您立即刪除本郵件。請不要將本電郵進行�
しs並用作任何其它用途，或透露本郵件之內容。謝謝。
>> *
>>
>>
>>
>> 2011/11/29 Ted Dunning <[EMAIL PROTECTED]>
>>
>>> To expand on that FAQ, the detailed process should be to
>>>
>>> - configure the new servers
>>>
>>> - update the configuration on the old servers
>>>
>>> - restart each old server one at a time
>>>
>>> - start the new servers
>>>
>>> - have your applications reconnect with the full set of servers in the
>>> connection string.  This can be done whenever you like.
>>>
>>> Your clients will receive a disconnect message when the server that they
>>> are talking to is restarted, but they should reconnect immediately and
>>> transparently.  You may have a problem if your applications don't handle
>>> transient disconnections properly.
>>>
>>>
>>>
>>> On Tue, Nov 29, 2011 at 3:10 AM, pubudu gunawardena <[EMAIL PROTECTED]
>>> >wrote:
>>>
>>> > On Tue, Nov 29, 2011 at 1:08 PM, nileader <[EMAIL PROTECTED]> wrote:
>>> > >
>>> > > hi, all.
>>> > >
>>> > > If i update my conf/zoo.cfg config, must i restart my zk server?
>>> > >
>>> > > In my case, we have 3 servers in production environment, now, we want
>>> to
>>> > > upgrade to 5 server.
>>> >
>>> > Take a look at http://wiki.apache.org/hadoop/ZooKeeper/FAQ#A6 where it
>>> > says
>>> > how to upgrade ZooKeeper.
>>> > >
>>> > >
>>> > > Any problem will happen if a kill one of three servers.
>>> > >
>>> > >
>>> > > *[EMAIL PROTECTED]*
>>> >
>>> >
>>> >
>>> >
>>> > --
>>> > Thanks,
>>> > Pubudu
>>> >
>>>
>>
>>

3.4.1 <= pushing the curve =8^)

/*
Joe Stein
http://www.medialets.com
Twitter: @allthingshadoop
*/

On Nov 29, 2011, at 10:44 PM, Camille Fournier <[EMAIL PROTECTED]> wrote:

> We've been looking at that, see:
> https://issues.apache.org/jira/browse/ZOOKEEPER-107
>
> It'll take some evaluation though. Hopefully 3.5?
>
> C
>
> On Tue, Nov 29, 2011 at 10:21 PM, nileader <[EMAIL PROTECTED]> wrote:
>> I personal think zookeeper team need to add the feature of changing
>> zookeeper cluster server list in runtime---without restart server.
>>
>> 2011/11/30 nileader <[EMAIL PROTECTED]>
>>
>>> Hi，ted，you mean restart old server before new servers?
>>> Let's see the case:
>>>
>>> In my cluster, there are three zk server, A,B and C each config three
>>> server address.
>>> Once, i want to upgrade my cluster to five server.
>>> You say:
>>>
>>>> configure the new servers
>>>>
>>>> - update the configuration on the old servers
>>>>
>>>> - restart each old server one at a time
>>>>
>>>> - start the new servers
>>>>
>>>>
>>>
>>> So,  when i config Server C's serverlist, it will be five server in it's
>>> zoo.cfg, and restart it.
>>> Then make change on server b. Once i restart server b, there will be only
>>> two server work in cluster,
>>> and  2< 5/2+1.
>>>
>>> So, how the leader will be elect and how the cluster will work ok?
>>>
>>>
>>>
>>>
>>>
>>> *nileader* ni掌櫃的個人郵��
>>> *MSN*： [EMAIL PROTECTED]
>>> *Weibo*：http://weibo.com/nileader
>>> ------------------------------------------------------------------------------------------------------------------------------------------------
>>> This email (including any attachments) is confidential and may be legally
>>> privileged, private information of correct recipient and nileader. If you
>>> received this email in error, please delete it immediately and do not copy
>>> it or use it for any purpose or disclose its contents to any other person.
>>> Thank you.
>>> *
>>> 本電郵(包括任何附件)可能含有機密資���並受法律保護，屬於ni掌櫃和正確收件���之間的私有信息。如您不是正確的收��人，請您立即刪除���郵件。請不要將本電郵進行複製並用��任何其它用途，或���露本郵件之內容。謝謝。
>>> *
>>>
>>>
>>>
>>> 2011/11/29 Ted Dunning <[EMAIL PROTECTED]>
>>>
>>>> To expand on that FAQ, the detailed process should be to
>>>>
>>>> - configure the new servers
>>>>
>>>> - update the configuration on the old servers
>>>>
>>>> - restart each old server one at a time
>>>>
>>>> - start the new servers
>>>>
>>>> - have your applications reconnect with the full set of servers in the
>>>> connection string.  This can be done whenever you like.
>>>>
>>>> Your clients will receive a disconnect message when the server that they
>>>> are talking to is restarted, but they should reconnect immediately and
>>>> transparently.  You may have a problem if your applications don't handle
>>>> transient disconnections properly.
>>>>
>>>>
>>>>
>>>> On Tue, Nov 29, 2011 at 3:10 AM, pubudu gunawardena <[EMAIL PROTECTED]
>>>>> wrote:
>>>>
>>>>> On Tue, Nov 29, 2011 at 1:08 PM, nileader <[EMAIL PROTECTED]> wrote:
>>>>>>
>>>>>> hi, all.
>>>>>>
>>>>>> If i update my conf/zoo.cfg config, must i restart my zk server?
>>>>>>
>>>>>> In my case, we have 3 servers in production environment, now, we want
>>>> to
>>>>>> upgrade to 5 server.
>>>>>
>>>>> Take a look at http://wiki.apache.org/hadoop/ZooKeeper/FAQ#A6 where it
>>>>> says
>>>>> how to upgrade ZooKeeper.
>>>>>>
>>>>>>
>>>>>> Any problem will happen if a kill one of three servers.
>>>>>>
>>>>>>
>>>>>> *[EMAIL PROTECTED]*
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Thanks,
>>>>> Pubudu
>>>>>
>>>>
>>>
>>>

Oh，good. It is a perfect feature.

Not only in the case of upgrade, many time, when want to change our zk
server....
在 2011年11月30日 上午11:44��Camille Fournier <[EMAIL PROTECTED]>写道：

> We've been looking at that, see:
> https://issues.apache.org/jira/browse/ZOOKEEPER-107
>
> It'll take some evaluation though. Hopefully 3.5?
>
> C
>
> On Tue, Nov 29, 2011 at 10:21 PM, nileader <[EMAIL PROTECTED]> wrote:
> > I personal think zookeeper team need to add the feature of changing
> > zookeeper cluster server list in runtime---without restart server.
> >
> > 2011/11/30 nileader <[EMAIL PROTECTED]>
> >
> >> Hi，ted，you mean restart old server before new servers?
> >> Let's see the case:
> >>
> >> In my cluster, there are three zk server, A,B and C each config three
> >> server address.
> >> Once, i want to upgrade my cluster to five server.
> >> You say:
> >>
> >>> configure the new servers
> >>>
> >>> - update the configuration on the old servers
> >>>
> >>> - restart each old server one at a time
> >>>
> >>> - start the new servers
> >>>
> >>>
> >>
> >> So,  when i config Server C's serverlist, it will be five server in it's
> >> zoo.cfg, and restart it.
> >> Then make change on server b. Once i restart server b, there will be
> only
> >> two server work in cluster,
> >> and  2< 5/2+1.
> >>
> >> So, how the leader will be elect and how the cluster will work ok?
> >>
> >>
> >>
> >>
> >>
> >> *nileader* ni掌櫃的個人郵���
> >> *MSN*： [EMAIL PROTECTED]
> >> *Weibo*：http://weibo.com/nileader
> >>
> ------------------------------------------------------------------------------------------------------------------------------------------------
> >> This email (including any attachments) is confidential and may be
> legally
> >> privileged, private information of correct recipient and nileader. If
> you
> >> received this email in error, please delete it immediately and do not
> copy
> >> it or use it for any purpose or disclose its contents to any other
> person.
> >> Thank you.
> >> *
> >>
> 本電郵(包括任何附件)可能含有機密資料並受法律保護，���於ni掌櫃和正確收���人之間的私有信��。如您不是正確的收件人，請您立即���除本郵件。請不��將本電郵進行複製並用作任何其它用���，或透露本郵件��內容。謝謝。
> >> *
> >>
> >>
> >>
> >> 2011/11/29 Ted Dunning <[EMAIL PROTECTED]>
> >>
> >>> To expand on that FAQ, the detailed process should be to
> >>>
> >>> - configure the new servers
> >>>
> >>> - update the configuration on the old servers
> >>>
> >>> - restart each old server one at a time
> >>>
> >>> - start the new servers
> >>>
> >>> - have your applications reconnect with the full set of servers in the
> >>> connection string.  This can be done whenever you like.
> >>>
> >>> Your clients will receive a disconnect message when the server that
> they
> >>> are talking to is restarted, but they should reconnect immediately and
> >>> transparently.  You may have a problem if your applications don't
> handle
> >>> transient disconnections properly.
> >>>
> >>>
> >>>
> >>> On Tue, Nov 29, 2011 at 3:10 AM, pubudu gunawardena <
> [EMAIL PROTECTED]
> >>> >wrote:
> >>>
> >>> > On Tue, Nov 29, 2011 at 1:08 PM, nileader <[EMAIL PROTECTED]>
> wrote:
> >>> > >
> >>> > > hi, all.
> >>> > >
> >>> > > If i update my conf/zoo.cfg config, must i restart my zk server?
> >>> > >
> >>> > > In my case, we have 3 servers in production environment, now, we
> want
> >>> to
> >>> > > upgrade to 5 server.
> >>> >
> >>> > Take a look at http://wiki.apache.org/hadoop/ZooKeeper/FAQ#A6 where
> it
> >>> > says
> >>> > how to upgrade ZooKeeper.
> >>> > >
> >>> > >
> >>> > > Any problem will happen if a kill one of three servers.
> >>> > >
> >>> > >
> >>> > > *[EMAIL PROTECTED]*
> >>> >
> >>> >
> >>> >
> >>> >
> >>> > --
> >>> > Thanks,
> >>> > Pubudu
> >>> >
> >>>
> >>
> >>
>

fyi fix releases only include fixes. We typically put the new features
into minor/major updates. Helps to maintain Operation's sanity. ;-)

Also keep in mind that rolling restart is dead simple and works. 107
will be a nice option to have but is overkill in most scenarios.

Patrick

On Tue, Nov 29, 2011 at 7:48 PM, Joe Stein
<[EMAIL PROTECTED]> wrote:
> 3.4.1 <= pushing the curve =8^)
>
> /*
> Joe Stein
> http://www.medialets.com
> Twitter: @allthingshadoop
> */
>
> On Nov 29, 2011, at 10:44 PM, Camille Fournier <[EMAIL PROTECTED]> wrote:
>
>> We've been looking at that, see:
>> https://issues.apache.org/jira/browse/ZOOKEEPER-107
>>
>> It'll take some evaluation though. Hopefully 3.5?
>>
>> C
>>
>> On Tue, Nov 29, 2011 at 10:21 PM, nileader <[EMAIL PROTECTED]> wrote:
>>> I personal think zookeeper team need to add the feature of changing
>>> zookeeper cluster server list in runtime---without restart server.
>>>
>>> 2011/11/30 nileader <[EMAIL PROTECTED]>
>>>
>>>> Hi，ted，you mean restart old server before new servers?
>>>> Let's see the case:
>>>>
>>>> In my cluster, there are three zk server, A,B and C each config three
>>>> server address.
>>>> Once, i want to upgrade my cluster to five server.
>>>> You say:
>>>>
>>>>> configure the new servers
>>>>>
>>>>> - update the configuration on the old servers
>>>>>
>>>>> - restart each old server one at a time
>>>>>
>>>>> - start the new servers
>>>>>
>>>>>
>>>>
>>>> So,  when i config Server C's serverlist, it will be five server in it's
>>>> zoo.cfg, and restart it.
>>>> Then make change on server b. Once i restart server b, there will be only
>>>> two server work in cluster,
>>>> and  2< 5/2+1.
>>>>
>>>> So, how the leader will be elect and how the cluster will work ok?
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> *nileader* ni掌櫃的個人郵箱
>>>> *MSN*： [EMAIL PROTECTED]
>>>> *Weibo*：http://weibo.com/nileader
>>>> ------------------------------------------------------------------------------------------------------------------------------------------------
>>>> This email (including any attachments) is confidential and may be legally
>>>> privileged, private information of correct recipient and nileader. If you
>>>> received this email in error, please delete it immediately and do not copy
>>>> it or use it for any purpose or disclose its contents to any other person.
>>>> Thank you.
>>>> *
>>>> 本電郵(包括任何附件)可能含有機密資料並受法律保護，屬於ni掌櫃和正確收件人之間的私有信息�
C如您不是正確的收件人，請您立即刪除本郵件。請不要將本電郵進行複製並用作任何其它用途，或透露本郵件之內容。謝謝。
>>>> *
>>>>
>>>>
>>>>
>>>> 2011/11/29 Ted Dunning <[EMAIL PROTECTED]>
>>>>
>>>>> To expand on that FAQ, the detailed process should be to
>>>>>
>>>>> - configure the new servers
>>>>>
>>>>> - update the configuration on the old servers
>>>>>
>>>>> - restart each old server one at a time
>>>>>
>>>>> - start the new servers
>>>>>
>>>>> - have your applications reconnect with the full set of servers in the
>>>>> connection string.  This can be done whenever you like.
>>>>>
>>>>> Your clients will receive a disconnect message when the server that they
>>>>> are talking to is restarted, but they should reconnect immediately and
>>>>> transparently.  You may have a problem if your applications don't handle
>>>>> transient disconnections properly.
>>>>>
>>>>>
>>>>>
>>>>> On Tue, Nov 29, 2011 at 3:10 AM, pubudu gunawardena <[EMAIL PROTECTED]
>>>>>> wrote:
>>>>>
>>>>>> On Tue, Nov 29, 2011 at 1:08 PM, nileader <[EMAIL PROTECTED]> wrote:
>>>>>>>
>>>>>>> hi, all.
>>>>>>>
>>>>>>> If i update my conf/zoo.cfg config, must i restart my zk server?
>>>>>>>
>>>>>>> In my case, we have 3 servers in production environment, now, we want
>>>>> to
>>>>>>> upgrade to 5 server.
>>>>>>
>>>>>> Take a look at http://wiki.apache.org/hadoop/ZooKeeper/FAQ#A6 where it
>>>>>> says
>>>>>> how to upgrade ZooKeeper.
>>>>>>>
>>>>>>>
>>>>>>> Any problem will happen if a kill one of three servers.
>>>>>>>
>>>>>>>
>>>>>>> *[EMAIL PROTECTED]*
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Thanks,
>>>>>> Pubudu
>>>>>>
>>>>>
>>

I second this and would add some emphasis.

Rolling restart looks complicated when you write out the steps, but the
fact that anybody who has done it can write down the procedure correctly.
At most, they have to be reminded to make sure that a quorum of machines
stays live.

That implies that the procedure is dead simple and easy to get right in
practice.

2011/11/30 Patrick Hunt <[EMAIL PROTECTED]>

> Also keep in mind that rolling restart is dead simple and works.