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Posted to dev@cassandra.apache.org by Jonathan Ellis <jb...@gmail.com> on 2010/06/11 17:29:36 UTC
Re: Handoff on failure.
repartitioning is expensive. you don't want to do it as soon as a
node goes down (which may be temporary, cassandra has no way of
knowing). so repartitioning happens when decommission is done by a
human.
On Thu, Jun 10, 2010 at 10:37 PM, Sriram Srinivasan <sr...@malhar.net> wrote:
> I am looking at Cassandra 0.6.2's source code, and am unable to figure out
> where, if at all, repartitioning happens in the case of failure. The
> Gossiper's onDead message is ignored. Can someone please clarify this for
> me?
--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com
Re: Handoff on failure.
Posted by Jonathan Ellis <jb...@gmail.com>.
>From that page:
To bootstrap a node, turn AutoBootstrap on in the configuration file,
and start it.
If you explicitly specify an InitialToken in the configuration, the
new node will bootstrap to that position on the ring. Otherwise, it
will pick a Token that will give it half the keys from the node with
the most disk space used, that does not already have another node
bootstrapping into its Range.
On Fri, Jun 11, 2010 at 8:24 PM, Sriram Srinivasan <sr...@malhar.net> wrote:
> I saw the operations page, but didn't get what I was looking for. What I
> meant by my earlier statement was that it is not clear to me who assigns the
> token to a new node; if a node goes down, and another process comes up, is
> (a) the token assigned to it automatically by consensus (and the bootstrap
> process gives it a place in the ring where it needs most load balancing),
> or, (b) it is an external script's responsibility to bootstrap every node
> with a new initialtoken?
>
>
> On Jun 12, 2010, at 8:46 AM, Jonathan Ellis wrote:
>
>> I'm not sure what you mean, but
>> http://wiki.apache.org/cassandra/Operations may clear some things up.
>>
>> On Fri, Jun 11, 2010 at 7:49 PM, Sriram Srinivasan <sr...@malhar.net>
>> wrote:
>>>
>>> Fair enough. But doesn't that mean that the node that comes up has the
>>> same
>>> token? I suppose the answer is that the auto bootstrap process is smart
>>> enough to figure out which range needs help.
>>>
>
>
--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com
Re: Handoff on failure.
Posted by Sriram Srinivasan <sr...@malhar.net>.
I saw the operations page, but didn't get what I was looking for. What
I meant by my earlier statement was that it is not clear to me who
assigns the token to a new node; if a node goes down, and another
process comes up, is (a) the token assigned to it automatically by
consensus (and the bootstrap process gives it a place in the ring
where it needs most load balancing), or, (b) it is an external
script's responsibility to bootstrap every node with a new initialtoken?
On Jun 12, 2010, at 8:46 AM, Jonathan Ellis wrote:
> I'm not sure what you mean, but
> http://wiki.apache.org/cassandra/Operations may clear some things up.
>
> On Fri, Jun 11, 2010 at 7:49 PM, Sriram Srinivasan
> <sr...@malhar.net> wrote:
>> Fair enough. But doesn't that mean that the node that comes up has
>> the same
>> token? I suppose the answer is that the auto bootstrap process is
>> smart
>> enough to figure out which range needs help.
>>
Re: Handoff on failure.
Posted by Jonathan Ellis <jb...@gmail.com>.
I'm not sure what you mean, but
http://wiki.apache.org/cassandra/Operations may clear some things up.
On Fri, Jun 11, 2010 at 7:49 PM, Sriram Srinivasan <sr...@malhar.net> wrote:
> Fair enough. But doesn't that mean that the node that comes up has the same
> token? I suppose the answer is that the auto bootstrap process is smart
> enough to figure out which range needs help.
>
> Thanks much, Jonathan.
> --sriram.
>
>
> On Jun 11, 2010, at 8:59 PM, Jonathan Ellis wrote:
>
>> repartitioning is expensive. you don't want to do it as soon as a
>> node goes down (which may be temporary, cassandra has no way of
>> knowing). so repartitioning happens when decommission is done by a
>> human.
>>
>> On Thu, Jun 10, 2010 at 10:37 PM, Sriram Srinivasan <sr...@malhar.net>
>> wrote:
>>>
>>> I am looking at Cassandra 0.6.2's source code, and am unable to figure
>>> out
>>> where, if at all, repartitioning happens in the case of failure. The
>>> Gossiper's onDead message is ignored. Can someone please clarify this for
>>> me?
>>
>>
>>
>> --
>> Jonathan Ellis
>> Project Chair, Apache Cassandra
>> co-founder of Riptano, the source for professional Cassandra support
>> http://riptano.com
>
>
--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com
Re: Handoff on failure.
Posted by Sriram Srinivasan <sr...@malhar.net>.
Fair enough. But doesn't that mean that the node that comes up has the
same token? I suppose the answer is that the auto bootstrap process is
smart enough to figure out which range needs help.
Thanks much, Jonathan.
--sriram.
On Jun 11, 2010, at 8:59 PM, Jonathan Ellis wrote:
> repartitioning is expensive. you don't want to do it as soon as a
> node goes down (which may be temporary, cassandra has no way of
> knowing). so repartitioning happens when decommission is done by a
> human.
>
> On Thu, Jun 10, 2010 at 10:37 PM, Sriram Srinivasan
> <sr...@malhar.net> wrote:
>> I am looking at Cassandra 0.6.2's source code, and am unable to
>> figure out
>> where, if at all, repartitioning happens in the case of failure. The
>> Gossiper's onDead message is ignored. Can someone please clarify
>> this for
>> me?
>
>
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of Riptano, the source for professional Cassandra support
> http://riptano.com