Do nodes always need to restart after backend selection?

Toby Corkindale toby.corkindale at strategicdata.com.au
Mon Apr 8 20:57:36 EDT 2013


I've sent a pull request for a couple of doc changes now.
Cheers,
Toby

On 09/04/13 09:48, Mark Phillips wrote:
> Hi Toby,
>
> Can you take a few minutes to open an issue against the docs to get
> the language clarified?
>
> https://github.com/basho/basho_docs/issues
>
> We'll get it fixed up shortly thereafter.
>
> Thanks,
>
> Mark
>
>
> On Thu, Apr 4, 2013 at 7:42 PM, Toby Corkindale
> <toby.corkindale at strategicdata.com.au> wrote:
>> Answering my own question again, but hopefully that saves you time.
>>
>> So, it appears that if a backend is changed via the JSON REST API, then all
>> keys from the previous backend are now inaccessible. I think this also
>> indicates that now the new backend is in use immediately, without any
>> restarts required.
>>
>> May I suggest that the wording on the API Reference page is improved? Both I
>> and a colleague misunderstood it to mean that *any* change of backend
>> required a restart.
>>
>> Cheers,
>> Toby
>>
>>
>> On 05/04/13 11:27, Toby Corkindale wrote:
>>>
>>> Hi Jared,
>>>
>>> I'm afraid I am still a little confused after reading your reply, so I'd
>>> like to check something.
>>>
>>> If I understand correctly, the reboot of nodes is only required if the
>>> default settings in app.config are changed, and one can change anything
>>> else on-the-fly?
>>>
>>> So therefore, in the following scenario, I could issue these commands
>>> and never need to reboot any nodes?
>>>
>>> Riak backend = Multi, with Bitcask (default) and Leveldb.
>>>
>>> PUT /buckets/myBucket/myKey
>>> # Key is stored in Bitcask
>>>
>>> PUT /buckets/myNewBucket/props
>>> { backend: Leveldb }
>>>
>>> PUT /buckets/myBucket/myOtherKey
>>> # Key is stored in Leveldb backend
>>>
>>>
>>> If I change the backend, do I lose any keys that were previously
>>> available in the original backend or are they migrated? (I'd expect to
>>> lose them)
>>>
>>>
>>> Thanks for your patience,
>>> Toby
>>>
>>>
>>>
>>> On 05/04/13 00:51, Jared Morrow wrote:
>>>>
>>>> Toby,
>>>>
>>>> That particular page is talking about changing the default settings of
>>>> the backend of a bucket.  In that specific case, if you want to change
>>>> the default behavior in your app.config file a restart is necessary.
>>>>    One particularly important detail there is you don't need to restart
>>>> *all* nodes at the same time.  Restarting one node at a time is
>>>> sufficient and recommended so you don't have any cluster downtime.
>>>>
>>>> For setting common bucket properties, you do not need to restart the
>>>> node.  If you want to change the n_val of a bucket for instance, you can
>>>> just change it from your client on all nodes.  That page explains at the
>>>> bottom how to set them on the erlang console or curl, but most people
>>>> use their chosen client to set bucket properties before writing values.
>>>>     Here is an example using the Java Client
>>>> http://docs.basho.com/java/latest/cookbooks/buckets/.  In general it
>>>> doesn't matter if your client supports HTTP or protocol buffers, both
>>>> API's  support bucket
>>>> property changes.
>>>>
>>>> Hope that helps,
>>>> Jared
>>>>
>>>> On Wed, Apr 3, 2013 at 10:14 PM, Toby Corkindale
>>>> <toby.corkindale at strategicdata.com.au
>>>> <mailto:toby.corkindale at strategicdata.com.au>> wrote:
>>>>
>>>>      Hi,
>>>>      According to the docs at the following URL, it is necessary to
>>>>      reboot all Riak nodes after setting the bucket property for backend.
>>>>      This seems really drastic, and we'd like to avoid having to do this!
>>>>      See:
>>>>
>>>> http://docs.basho.com/riak/1.__3.0/tutorials/choosing-a-__backend/Multi/
>>>>
>>>> <http://docs.basho.com/riak/1.3.0/tutorials/choosing-a-backend/Multi/>
>>>>
>>>>      I wondered if the restart of the whole cluster can be avoided?
>>>>      Perhaps we could set the bucket properties prior to setting any keys
>>>>      within it?
>>
>>
>>
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