Aaron,
Thanks a lot for your answer,
I had in mind something more generic that I am currently working on.
The idea is to have a tool with GUI screens where you can feed-in the
various column families you are using with column (names and values) sizes.
Then it will have anotehr screen withh applicat
http://pixs.ru/showimage/17jpg_9670866_1622744.jpg
It is initialized after processing Thrift connections
2011/2/1 ruslan usifov
>
> Hello
>
> I launch single node cassandra daemon (v 0.7.0 - from official site), а
> connect to it throw jconsole, and found that three is no StorageProxy Mbean.
> Is it normal?
>
> Here is my screenshot of jconsole
Hi,
I'm getting an exception when doing many writes to a column with an
empty column name (i.e. empty byte buffer). The exception occurs during
compactation. It is reproducable given enough writes (around 130).
Is this a known issue? After the problem occurs cassandra will no longer
start up.
Thanks for the insight, Jonathan!
As it turns out using single threaded clients with Hector's
LeastActiveBalancingPolicy leads to the first node always winning :-)
Is StorageProxy bean the only way to detect this, considering that all nodes are
evenly loaded?
Oleg
You should bring this up in the Hector user group. It sounds like in the
case of a tie, a random winner should be chosen, instead of taking the first
one.
On Tue, Feb 1, 2011 at 5:50 PM, Oleg Proudnikov wrote:
> Thanks for the insight, Jonathan!
>
> As it turns out using single threaded clients w
What is the type of a Row Key? Can you define how they are compared?
I ask because I'm using TimeUUIDs as my row keys, but when I make a
call to get a range of row keys (get_range in phpcassa) I have to
specify the UTF8 range of '' to '----'
instead of the TimeUUID
Is there a way to query for column names or super column names without
also pulling down the data they contain? (Besides keeping a second
index) I don't see an obvious way to do it from the Thrift API, but
maybe I'm missing something.
Thanks!
-Jeremiah
Jeremiah
Hey,
I am currently investigating Cassandra for storing what are
effectively web sessions. Our production environment has about 10 high
end servers behind a load balancer, and we'd like to add distributed
session support. My main concerns are performance, consistency, and
the ability to create uniq
I asked this on the hector list last week. Its possible but remember, each
row can have a different set of associated columns.
On 1 Feb 2011 18:16, "Jeremiah Jordan"
wrote:
> Is there a way to query for column names or super column names without
> also pulling down the data they contain? (Besides
I am working on this tonight with jetty as front end and cassandra as
backend session store. Hopefully.
On 1 Feb 2011 18:19, "Kallin Nagelberg" wrote:
> Hey,
> I am currently investigating Cassandra for storing what are
> effectively web sessions. Our production environment has about 10 high
> en
Cool, maybe we can help each other out. I'm using multiple web-apps,
all running in Resin containers. Have you thought about schema or how
to generate sessionIds for cookies?
-Kal
On Tue, Feb 1, 2011 at 12:22 PM, Sasha Dolgy wrote:
> I am working on this tonight with jetty as front end and cassa
Please do keep this discussion on the mailing list and not take it offline.
:-)
I will be in the same boat very soon, I think.
It will be great to hear from people who have already gone down this road
and used Cassandra as a session store in a clustered environment.
On Tue, Feb 1, 2011 at 10:56
Are you going to use TTLs to expire the session columns automagically? (we're
working on something similar as well)
On 2/1/11 12:30 PM, "Roshan Dawrani" wrote:
Please do keep this discussion on the mailing list and not take it offline. :-)
I will be in the same boat very soon, I think.
It wi
Most if not all modern web application frameworks support sessions. This
applies to Django (with which I have most experience and also run it with
X.509 security layer) but also to Ruby on Rails and Pylons.
So, why would you re-invent the wheel? Too messy. It's all out there for you
to use.
Rega
The problem is where to store the session data. If the session need to be
accessible by more than one web servers, the external storage is needed.
Cassandra only supports eventual consistency. If web server w1 saves the
session at node 1 of cassendra while web server w2 retrieve the session from
We're using servlets which also support sessions, but you have to rely
on the servlet container to offer any sort of distributed session
handling and this produces scalability issues past a certain point.
Same thing for persistent sessions (survive restart). We also want a
mechanism that can operat
Is there anyone working with current chef recipes for Cassandra?
For completeness:
http://stackoverflow.com/questions/3746685/running-django-site-in-multiserver-environment-how-to-handle-sessions
http://docs.djangoproject.com/en/dev/topics/http/sessions/#using-cached-sessions
I guess your approach does make sense, one only wishes that the servlet in
question
Not a concern - and here is why:-
>From the wiki arch section captioned below - eventual consistency does not
have to mean inconsistent reads. The concern is the overhead for consistent
reads. But remember in the use case being cited, the expensive read will
happen only during failover, not all th
FWIW we used Memcached for session data at Digg without any major issues. The
one thing we did end up doing to reduce the LRU on sessions was to modify the
slab size and put sessions in their own Memcached cluster. Probably not an
issue for you though.
+1 on Memcached.
On Feb 1, 2011, at 9:57
In my scenario all i need is simple session management. That's all. Quick
and useful for what i need. Why i'm creating a wheel...
On 1 Feb 2011 18:42, "buddhasystem" wrote:
>
> Most if not all modern web application frameworks support sessions. This
> applies to Django (with which I have most e
On Tue, Feb 1, 2011 at 12:57 PM, Anthony John wrote:
> Not a concern - and here is why:-
> From the wiki arch section captioned below - eventual consistency does not
> have to mean inconsistent reads. The concern is the overhead for consistent
> reads. But remember in the use case being cited, the
If it is a really session data, which will be active for a short time, a few
hours, and it is OK to lose them, memcached is a better solution. I were using
it when I was in Yahoo.
Tong
-Original Message-
From: buddhasystem [mailto:potek...@bnl.gov]
Sent: Tuesday, February 01, 2011 9:57
Wouldn't something like Redis be a better fit than Cassandra?
On Tue, Feb 1, 2011 at 6:16 PM, Tong Zhu wrote:
> If it is a really session data, which will be active for a short time, a few
> hours, and it is OK to lose them, memcached is a better solution. I were
> using it when I was in Yahoo.
Hmm, looking at redis now. The built in time to live functionality
would be nice to have..
On Tue, Feb 1, 2011 at 1:34 PM, Colin Vipurs wrote:
> Wouldn't something like Redis be a better fit than Cassandra?
>
> On Tue, Feb 1, 2011 at 6:16 PM, Tong Zhu wrote:
>> If it is a really session data, wh
I'm running Cassandra 0.7 and I'm trying to get Pig integration to work
correctly. I'm using Pig 0.8 running against Hadoop 20.2, I've also tried this
running against CDH2.
I can log into the grunt shell, and execute scripts, but when they run, they
don't read all of the data from Cassandra.
Version: Cassandra 0.7.1 (build from trunk)
Setup:
- Cluster of 2 nodes (Say A and B)
- HH enabled
- Using the default Keyspace definition in cassandra.yaml
- Using SuperCounter1 CF
Client:
- Using CL of ONE
I started the two Cassandra nodes, created schema and then shutdown one of
the instances
Version: Cassandra 0.7.1 (build from trunk)
Setup:
- Cluster of 2 nodes (Say A and B)
- HH enabled
- Using the default Keyspace definition in cassandra.yaml
- Using SuperCounter1 CF
Steps:
- Started the two nodes, loaded schema using nodetool
- Executed counter update and read operations on A wit
How they are compared depends on the partitioner you are using. For
BOP, it is lexical by byte order.
On Tue, Feb 1, 2011 at 8:47 AM, Bill Speirs wrote:
> What is the type of a Row Key? Can you define how they are compared?
>
> I ask because I'm using TimeUUIDs as my row keys, but when I make a
Reddis seems neat, but a couple issues:
- It's 'persistence' is more of a timed backup. You are not guaranteed
the latest results on disk.
- no real 'clustering'. It has a master/slave system.
Hard to say if those are deal breakers at this point, but the API for
it seems nice.
On Tue, Feb 1, 201
nvm on the persistence, it seems like it does support it:
'Since version 1.1 the safer alternative is an append-only file (a
journal) that is written as operations modifying the dataset in memory
are processed. Redis is able to rewrite the append-only file in the
background in order to avoid an in
What I'm still unclear about, and where I think this is suitable, is
Cassandra being used as a data warehouse for current and past sessions tied
to a user. Yes, other things are great for session management, but I want
to provide near real time session information to my users ... quick and
simple
I think the problem here is your test.
The CassandraServer class calls validateColumns() and will not let zero length
columns be inserted. The call would not get to the storage proxy.
Aaron
On 2/02/2011, at 2:27 AM, Mikael Wikblom wrote:
> Hi,
>
> I'm getting an exception when doing many wri
If your sessions are fairly long-lived (more like hours instead of minutes) and
you crank up a suitable row cache and make sure your db is consistent (via
quorum read/writes or write:all, read:1) - sure, why not? Especially if you're
already familiar with Cassandra; possibly even have a deploy
Not that I know of.
Aaron
On 2/02/2011, at 6:21 AM, Sasha Dolgy wrote:
> I asked this on the hector list last week. Its possible but remember, each
> row can have a different set of associated columns.
>
> On 1 Feb 2011 18:16, "Jeremiah Jordan"
> wrote:
> > Is there a way to query for col
I'm still very new to Cassandra, but when I started reading about it the first
thing I thought about was a session store. It's based (in part from what I
understand) on Dynamo which is (again, I could be wrong) used at Amazon as the
session store for your shopping cart.
So I would certainly re
Counters are not yet supported in sstable2json.
(More generally, trunk is not expected to be stable at this point in
the development cycle.)
On Tue, Feb 1, 2011 at 11:32 AM, Narendra Sharma
wrote:
> Version: Cassandra 0.7.1 (build from trunk)
>
> Setup:
> - Cluster of 2 nodes (Say A and B)
> - H
"Cassandra column families are schema-less and like SQL tables, they don't
have a fixed number of columns per row. In the same column family, one row
may have 5 columns, and another row, 10,000 columns. Every row can possibly
have a different number / set of columns."
are you saying the above is
Begin forwarded message:
> From: Viraj Bhat
> Date: February 1, 2011 1:02:23 PM PST
> To: "pig-u...@hadoop.apache.org" ,
> "mapreduce-u...@hadoop.apache.org" ,
> "mapreduce-...@hadoop.apache.org" ,
> "hdfs-...@hadoop.apache.org" ,
> "d...@hive.apache.org" ,
> "mapreduce-...@hadoop.apache.o
Not at all. The question was about retrieving the column name without the column value. That is not possible. AaronOn 02 Feb, 2011,at 10:27 AM, Sasha Dolgy wrote:"Cassandra column families are schema-less and like SQL tables, they don't have a fixed number of columns per row. In the same column f
ah i see ... apologies for the extra bytes
On Tue, Feb 1, 2011 at 10:38 PM, Aaron Morton wrote:
> Not at all.
>
> The question was about retrieving the column name without the column value.
> That is not possible.
>
> Aaron
>
>
2011/2/1 Jonathan Ellis :
> It is initialized after processing Thrift connections
More generally, various MBeans become available at different parts of
the startup process. If, just after startup, one that "should" be
there is "missing," most of the time you probably just have to wait
for it to be
Hi Joe,
On 02/02/2011 02:58 AM, Joe Stump wrote:
FWIW we used Memcached for session data at Digg without any major issues. The
one thing we did end up doing to reduce the LRU on sessions was to modify the
slab size and put sessions in their own Memcached cluster. Probably not an
issue for you
I have posted on Hector ML:
http://thread.gmane.org/gmane.comp.db.hector.user/1690
Oleg
Sent from my iPad
Hi,
I am trying to run CQL from a java client and facing one issue. Keyspace is
passed as null. When I execute "Use Keyspace1" followed by my "Select query" it
is still not working.
Any suggestion will be a great help.
Regards,
Vivek Mishra
For updates on our
Semi colon after the keyspace name?
On 2 Feb 2011 07:58, "Vivek Mishra" wrote:
> Hi,
> I am trying to run CQL from a java client and facing one issue. Keyspace
is passed as null. When I execute "Use Keyspace1" followed by my "Select
query" it is still not working.
>
> Any suggestion will be a grea
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