I use nodetool to set cache capacity on a certain node but the settings are
"forgotten" after a few minutes.
I run:
$ nodetool -h localhost -p 9004 setcachecapacity outbrain_kvdb KvImpressions
1000 100
And then run nodetool cfstats immediately after and the settings are
effective, I see t
fixed for 0.6.2 in https://issues.apache.org/jira/browse/CASSANDRA-1079
On Mon, May 24, 2010 at 7:14 AM, Ran Tavory wrote:
> I use nodetool to set cache capacity on a certain node but the settings are
> "forgotten" after a few minutes.
> I run:
> $ nodetool -h localhost -p 9004 setcachecapacity o
50% of 0 will be rounded up to 1.
-Original Message-
From: "Ran Tavory"
Sent: Monday, May 24, 2010 12:34am
To: user@cassandra.apache.org
Subject: Key cache capacity: 1 when using KeysCached="50%"
I've noticed that when defining KeysCached="50%" (or KeysCached="100%" and I
didn't test ot
If you really want a cache capacity of 0 then you need to use 0
explicitly, otherwise the % versions will give you at least 1.
On Mon, May 24, 2010 at 12:34 AM, Ran Tavory wrote:
> I've noticed that when defining KeysCached="50%" (or KeysCached="100%" and I
> didn't test other values with %) then
Can anyone with Moin experience tell us what our options are here?
On Sun, May 23, 2010 at 10:09 PM, Yuki Morishita wrote:
> Hi all,
>
> I'm currently working on translating cassandra wiki to Japanese.
> Cassandra is gaining attention in Japan, too. :)
>
> I noticed that for those who have browse
I am evaluating Cassandra as a candidate for our next-gen database. One of
my colleagues told me that "it's not recommended to use it as your system of
Record because it CAN lose data". Can someone with architecture
understanding shed some light on under what circumstance Cassandra cluster
can eith
This is largely FUD. Cassandra let's you choose how consistent you want writes
to be. The more consistency you choose, the slower the writes, but it's very
unlikely with high consistency that you'll lose data.
That being said, if you write with a consistency level of 0 then, yes, you
could lose
So if I set it up to be strongly consistent, I should have the same level of
consistency as traditional relational DB ?
On the other hand, what will happen if I set it up as eventual consistent?
Will the data become inconsistent after a crash/reboot, similar to the case
of asynchronous replication
On May 24, 2010, at 10:01 AM, Steve Lihn wrote:
> So if I set it up to be strongly consistent, I should have the same level of
> consistency as traditional relational DB ?
If you do, say, QUORUM on the consistency level it will ensure at least 2 out
of the 3 replicants have responded back that
Ryan King actually has a very nice, short and sweet explanation that cuts
through the FUD:
http://theryanking.com/entries/2010/04/29/potential-consistency/
On Mon, May 24, 2010 at 12:01 PM, Steve Lihn wrote:
> So if I set it up to be strongly consistent, I should have the same level
> of consis
I'd like to have 100% keys cached. Sorry if my example of Super2 wasn't
correct, but I do think there's a problem. Here's with my own data:
When using actual numbers (in this case for RowsCached) it works as
expected, however when specifying KeysCached="100%" I get only 1.
You also need to set CommitLogSync to batch instead of periodic if you
Absolutely Cannot Lose Data.
On Mon, May 24, 2010 at 10:51 AM, Joe Stump wrote:
> This is largely FUD. Cassandra let's you choose how consistent you want
> writes to be. The more consistency you choose, the slower the writes,
I can think of at least 2 clusters running 32GB boxes with single
Cassandra processes on each. (16 seems to be more common.) At 64 I
would seriously consider multiple processes per machine. You'd want
to configure a Snitch such that same-machine boxes were considered the
same rack, there is no s
My data disks on two of my nodes are RAID-5, just because of circumstances.
My other nodes are JBOD. I don't notice any real difference, but I haven't
strongly benched it.
Ian
On Mon, May 24, 2010 at 2:45 PM, Jonathan Ellis wrote:
> I can think of at least 2 clusters running 32GB boxes with sin
We have an application that stores session data in Cassandra. The
session data needs to be deleted after, say, one hour of inactivity. The
CASSANDRA-699 TTL update in 0.7 looks like it will work very well for
that.
However, we have a few scenarios where some session data will be
retrieved frequent
Thanks, a lot! So for RAID 10, is the thought that the node can survive a
single disk failure and keep going until a normal maintain cycle? Also are
you saying that you would configure a single RAID 10 for the whole box? OS
included? I have 8 x 500 Gig drives, so that would leave me with 2T per
(a) cassandra does not use update-in-place storage so doing the update
as part of the get call isn't much of an efficiency gain
(b) I don't think it's a common enough use case to warrant special treatment
On Mon, May 24, 2010 at 2:19 PM, Omer van der Horst Jansen
wrote:
> We have an application t
I have the same issue in my cluster: 0,5% of requests are extremely
slow because the time it takes to read the data from the socket.
However in my case it is not related to the load. Actually the
percentage of anomalies drop as the load increases.
On the other hand the nio is actually slow than b
For those interested in Cassandra training, I'll be giving a 3-hour
tutorial[1] at OSCON this year entitled Hands-on Cassandra.
[1]: http://www.oscon.com/oscon2010/public/schedule/detail/14283
The tutorial will cover setup, configuration, and management of
clusters, and will include some Python
with C# you need to be sure to tell thrift to use client-side
buffering. http://wiki.apache.org/cassandra/ThriftExamples#C.23 shows
this (but didn't until recently)
On Mon, May 24, 2010 at 4:09 PM, Carlos Alvarez wrote:
> I have the same issue in my cluster: 0,5% of requests are extremely
> slow
On Mon, May 24, 2010 at 7:43 PM, Jonathan Ellis wrote:
> with C# you need to be sure to tell thrift to use client-side
> buffering. http://wiki.apache.org/cassandra/ThriftExamples#C.23 shows
> this (but didn't until recently)
Yes, I am unsing TBufferedTransport. However the high times continues.
Greetings,
Is it possible to spread the particular keyspace only to the part of the
ring?
For example:
Node| Keyspaces
node1 | KS1
node2 | KS2
node3 | KS1, KS2
Each KeySpace has ReplicationFactor == 2, so, node3 would store data
from all keyspaces.
DatacenterShardSnitch in 0.7 allows something like this:
# DatacenterShardStrategy is a generalization of RackAwareStrategy.
# For each datacenter, you can specify (in `datacenter.properties`)
# how many replicas you want on a per-keyspace basis. Replicas are
# placed on different racks w
Hi Jonatan,
Will it be possible to have datacenter replication factor == 0? (do not
replicate keyspace to that DC)
Jonathan Ellis wrote:
> DatacenterShardSnitch in 0.7 allows something like this:
>
> # DatacenterShardStrategy is a generalization of RackAwareStrategy.
> # For each datacenter,
Hi All,
This may have been answered already, but I did a [quick] Google search and
didn't find much. Which is the better Java client to use? Hector or
cassandra-java-client or neither?
it seems Hector is more fully featured and more active as a project in general.
What are user experiences w
I think hector is better, and seems the author of
cassandra-java-client does not continue work on it.
On Tue, May 25, 2010 at 10:21 AM, Peter Hsu wrote:
> Hi All,
>
> This may have been answered already, but I did a [quick] Google search and
> didn't find much. Which is the better Java client
Yes.
On Mon, May 24, 2010 at 8:56 PM, Mishail wrote:
> Hi Jonatan,
>
> Will it be possible to have datacenter replication factor == 0? (do not
> replicate keyspace to that DC)
>
> Jonathan Ellis wrote:
>> DatacenterShardSnitch in 0.7 allows something like this:
>>
>> # DatacenterShardStrategy i
For small clusters Hinted Handoff cost is not negligible. I'd like to test
its effect.
Is there a way to turn it off for my cluster?
https://issues.apache.org/jira/browse/CASSANDRA-894
On Mon, May 24, 2010 at 11:30 PM, Ran Tavory wrote:
> For small clusters Hinted Handoff cost is not negligible. I'd like to test
> its effect.
> Is there a way to turn it off for my cluster?
--
Jonathan Ellis
Project Chair, Apache Cassandra
yes, I would do raid1 on 2 commitlog disks and raid10 on the 6
remaining for OS + data
On Mon, May 24, 2010 at 2:27 PM, Aaron McCurry wrote:
> Thanks, a lot! So for RAID 10, is the thought that the node can survive a
> single disk failure and keep going until a normal maintain cycle? Also are
>
Hi all,
Am running "Cassandra" on Windows XP (single node) machine.
I have made insertion of about "10 million" records into "Cassandra" , and
it took around 90 minutes to insert and 8GB of space.
For the same number of records MySQL will take "3 GB" space.
Could you please tell me why?
And please
hi Sharan,
what's the replication factor are you using ?
regards,
Cao Jiguang
2010-05-25
casablinca126.com
发件人： sharanabasava raddi
发送时间： 2010-05-25 13:46:38
收件人： user@cassandra.apache.org
抄送：
主题： Why Cassandra is "space inefficient" compared to MySQL?
Hi all,
Am running "Cassan
I think maybe one reason is that Cassandra will also log the operation
into log files, and the log contains the records.
2010/5/25 casablinca126.com :
> hi Sharan,
> what's the replication factor are you using ?
>
> regards,
> Cao Jiguang
>
>
> 2010-05-25
>
> cas
ah, 0.6.2, worth waiting for...
On Tue, May 25, 2010 at 7:52 AM, Jonathan Ellis wrote:
> https://issues.apache.org/jira/browse/CASSANDRA-894
>
> On Mon, May 24, 2010 at 11:30 PM, Ran Tavory wrote:
> > For small clusters Hinted Handoff cost is not negligible. I'd like to
> test
> > its effect.
>
cassandra-java-client is up to cassandra's 0.4.2 version, so you probably
can't use it out of the box.
Hector is active and up to the latest 0.6.1 release with a bunch of
committers, contributors and users. See
http://wiki.github.com/rantav/hector/ and
http://groups.google.com/group/hector-users
O
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