Hello,
The current trunk limit the value of phi_convict_threshold from 5 to 16
in DatabaseDescriptor.java.
And phi value is calculated in FailureDetector.java as
PHI_FACTOR x time_since_last_gossip / mean_heartbeat_interval
And the PHI_FACTOR is a predefined value:
PHI_FACTOR = 1 / Log(10) =~ 0
We're running a 8 node cluster with different CFs for different applications.
One of the application uses 1.5TB out of 1.8TB in total, but only because we
started out with a deletion mechanism and implemented one later on. So there is
probably a high amount of old data in there, that we don't ev
Is there any way that you could do that lookup in reverse where you pull
the records from your SQL database, figure out which keys aren't necessary,
and then delete any unnecessary keys that may or may not exist in
cassandra?
If that's not a possibility, then what about creating the same Cassandra
Anyway, I can't find any reason to limit minimum value of
phi_convict_threshold to 5. maki
In real world you often want to have 9 because cassandra is too much
sensitive to overloaded LAN and nodes are flipping up/down often and
creating chaos in cluster if you have larger number of nodes (let s
I'd also add that one of the biggest complications to arise from having
multiple clusters is that read biased client applications would need to be
aware of all clusters and either aggregate result sets or involve logic to
choose the right cluster based on a particular query.
And from a more operat
Thanks for your suggestions, Eric!
> One of the application uses 1.5TB out of 1.8TB
I'm sorry, maybe that statment was slightly ambiguous. I meant to say, that one
application uses 1.5TB, while the others use 300GB, totalling in 1.8TB of data.
Our total disk capacity, however, is at about 7 TB,
Great! I'm glad at least one of those ideas was helpful for you.
That's a road we've travelled before and as one last suggestion that might
help, you could alter all client writers to cassandra beforehand so that
they write to BOTH keyspaces BEFORE beginning the SQL based transfer. This
might he
Hi Brian,
We're trying to do the exact same thing and I find myself asking very
similar questions.
Our solution though has been to find what kind of queries we need to
satisfy on a preemptive basis and leverage cassandra's built-in indexing
features to build those result sets beforehand. The who
A couple of days ago I came across Countandra ( http://countandra.org/ ).
It seems that it might be a solution for you.
Gr. Robin
2012/1/20 Tamar Fraenkel
> **
>
> Hi!
>
> I am a newbie to Cassandra and seeking some advice regarding the data
> model I should use to best address my needs.
>
>
I thought about our issue again and was thinking, maybe the describeOwnership
should take into account, if a token is outside the partitioners maximum token
range?
To recap our problem: we had tokens, that were apart by 12.5% of the token
range 2**127, however, we had an offset on each token, w
Thanks for the responses! We'll definitely go for powerful servers to
reduce the total count. Beyond a dozen servers there really doesn't seem
to be much point in trying to increase count anymore for
replication/redundancy. I'm assuming we will use level compaction, which
means that we'll most like
> Thanks for the responses! We'll definitely go for powerful servers to
> reduce the total count. Beyond a dozen servers there really doesn't seem
> to be much point in trying to increase count anymore for
Just be aware that if "big" servers imply *lots* of data (especially
in relation to memory s
But What about: Rainbird?
On Sat, Jan 21, 2012 at 10:52 AM, R. Verlangen wrote:
>
> A couple of days ago I came across Countandra ( http://countandra.org/ ). It
> seems that it might be a solution for you.
>
> Gr. Robin
>
>
> 2012/1/20 Tamar Fraenkel
>>
>> Hi!
>>
>> I am a newbie to Cassandra a
I used rainbird as inspiration for Countandra (& some of publicly available
data structures from rainbird preso). That said, there are significant
differences between the two architectures. Additiomally as Cassandra begins
to provide triggets, some very interesting things will become possible in
Co
Good point. One thing I'm wondering about cassandra is what happens when
there is a massive failure. For example, if 1/3 of the nodes go down or
become unreachable. This could happen in EC2 if an AZ has a failure, or
in a datacenter if a whole rack or UPS goes dark. I'm not so concerned
about the t
Milind Parikh, Rainbird is back by Twitter... My worry is that you
might not be around in the future... Also, do you have evidence that
your system is better? Because Rainbird is used by Twitter.
On Sat, Jan 21, 2012 at 6:55 PM, Milind Parikh wrote:
>
> I used rainbird as inspiration for Countand
Hi
It may be my lack of knowledge but both has to do with counting, which is not
what I need.
What is wrong with the two models I suggested?
Tamar
Sent from my iPod
On Jan 22, 2012, at 2:49 AM, Jean-Nicolas Boulay Desjardins
wrote:
> Milind Parikh, Rainbird is back by Twitter... My worry is
On Sat, Jan 21, 2012 at 7:49 PM, Jean-Nicolas Boulay Desjardins <
jnbdzjn...@gmail.com> wrote:
> Milind Parikh, Rainbird is back by Twitter... My worry is that you
> might not be around in the future... Also, do you have evidence that
> your system is better? Because Rainbird is used by Twitter.
>
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