I think it would be really cool to be able to rename a column, or, more
generally, a move command to move data from one column to another in the
same CF without the client having to read and resend the column value.
This would be *extremely* powerful, imo. I suspect the execution would
be q
On Fri, Jul 8, 2011 at 9:22 AM, AJ wrote:
>
> I think it would be really cool to be able to rename a column, or, more
> generally, a move command to move data from one column to another in the
> same CF without the client having to read and resend the column value. This
> would be extremely power
On 7/8/2011 2:18 AM, Sylvain Lebresne wrote:
On Fri, Jul 8, 2011 at 9:22 AM, AJ wrote:
I think it would be really cool to be able to rename a column, or, more
generally, a move command to move data from one column to another in the
same CF without the client having to read and resend the column
Questions like this seem to come up a lot:
http://stackoverflow.com/questions/6033888/cassandra-atomicity-isolation-of-column-updates-on-a-single-row-on-on-single-no
http://stackoverflow.com/questions/2055037/cassandra-atomic-reads-writes-within-a-single-columnfamily
http://www.mail-archive.com/use
Disregard most of my post (already). I forgot that reads aren't isolated.
That means A and B are states cassandra will *eventually* be in, but at any
point in time a read might see a "partial B" (where some columns are still
A, and others are B). Though, I'm sure someone else will confirm if I'm
Not quite, its more limited and specific
The order of operations is all within the Cassandra node server and looks
like this this...
We have one row, A. Thats the only row being operated on.
Client -> submits A'
Server does the following:
(1) Validate function reads current A
(2) Validate f
I think node repair involves some compaction too. See the issue:
https://issues.apache.org/jira/browse/CASSANDRA-2811
It talks of 'validation compaction' being triggered concurrently
during node repair.
On Thu, Jun 30, 2011 at 8:51 PM, Watanabe Maki wrote:
> Repair doesn't compact. Those are diff
It doesn't look like that at all.
Row A exists.
Client submits mutation Am. This is not necessarily a full row.
Coordinator validates Am.
If validation succeeds, coordinator sends Am to the replica owners,
effectively creating A'.
Neither A nor A' is ever explicitly assembled on the write pat
I think you need to look into Zookeeper, or other distributed coordinator,
as you have little/no guarantees from cassandra between 1-3 (in terms of the
guarantees you want and need).
And my terminology in my post is different than yours. My "client" == your
"server". Specifically, I was thinking
that's an internal term meaning "background i/o," not sstable merging per se.
On Fri, Jul 8, 2011 at 9:24 AM, A J wrote:
> I think node repair involves some compaction too. See the issue:
> https://issues.apache.org/jira/browse/CASSANDRA-2811
> It talks of 'validation compaction' being triggered
Also, one point of early confusion for me is there is a slightly different
definition of "atomicity" depending on if your talking software vs.
database, and I'm a "software guy". From wikipedia:
Software = Atomicity is a guarantee of isolation from concurrent processes.
Additionally, atomic opera
On Thu, 2011-07-07 at 19:34 -0400, A J wrote:
> Does a 'select * from ' with no filter still use the primary
> index on the key or do a 'full table scan' ?
It's the equivalent of a range slice with no starting or ending keys,
and no starting or ending columns. Indexing cannot save you; This is
I am confused by what you mean by "Cassandra client code." Is this part of
the Cassnadra server?
My architecture is my "user" talks thrift to Cassandra.
Where does a custom validation method run?
Given that it is validating a row update, my assumption was that it ran on
the node that "owns" the row. That would make sense to me as it would
fulfill the NoSql philosophy of taking computation to data, rather then data
to computation.
I don't follow
I use a language specific wrapper around thrift as my "client", but yes, I
guess I fundamentally mean thrift == client, and the cassandra server ==
server.
will
On Fri, Jul 8, 2011 at 11:08 AM, Jeffrey Kesselman wrote:
> I am confused by what you mean by "Cassandra client code." Is this part o
Alright,
So are you saying the column validator, as specified
by conf/storage-conf.xml is checked in the client interface library and not
on the server side? That seems odd to me on a number of levels, not the
least being I cant see how thrift could autogenerate that
for different languages or ho
I haven't ever written my own org.apache.cassandra.db.marshal.AbstractType
(which is I think what your talking about), so I have no idea.
Looking up the JavaDoc for that class, validate says "validate that the byte
array is a valid sequence for the type we are supposed to be comparing",
which soun
hi, all:
I am curious about how large that Cassandra can scale?
from the information I can get, the largest usage is at facebook, which is
about 150 nodes. in the mean time they are using 2000+ nodes with Hadoop,
and yahoo even using 4000 nodes of Hadoop.
I am not understand why is the situation
Validation occurs at the API level, returning an
InvalidRequestException to the caller of the API (a thrift client in
this case). Specifically, a mutation will not be scheduled for the
storage until it has been validated at the API level.
If the intention is to do a read-before-write validation as
Hmm.
Thanks Nate.
I need to think about this and our data store design some. In general I
dislike architecture with large numbers of independent servers, I think it
invites communication latencies and partial failures into the mix. But I'll
cogitate some.
On Fri, Jul 8, 2011 at 12:21 PM, Nate
I should add, Nate, that the intention is to do a read before write
validation and have that occur as close to the data as possible.
if there is a better hook to implement it on I'd love a pointer to it.
JK
On Fri, Jul 8, 2011 at 12:21 PM, Nate McCall wrote:
> Validation occurs at the API leve
Hi everyone,
I'm having thousands of these errors:
WARN [CompactionExecutor:1] 2011-07-08 16:36:45,705
CompactionManager.java (line 737) Non-fatal error reading row
(stacktrace follows)
java.io.IOError: java.io.IOException: Impossible row size
6292724931198053
at
org.apache.cassandra.db.
Hi all,
If you're in San Francisco for CassandraSF on Monday 11th, then come
and join fellow Cassandra users and committers on Sunday evening.
Starting at 6:30pm at ThirstyBear, the famous brewing company. We'll
have drinks, food and more.
RSVP at Eventbrite: http://pre-cassandrasf-happyhour.eve
Jeremy did you get anywhere with this ?
If you are reading at CL ONE Read Repair will run in the background, so it may
only be visible to subsequent reads.
Cheers
-
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelastpickle.com
On 6 Jul 2011, at 20:52, J
> Is it possible to have same results sorting in reversed by another method
> without get_range_slice in JAVA ?
Sorry I don't understand your question.
Cheers
-
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelastpickle.com
On 7 Jul 2011, at 01:56, Monnom
Not yet - we've updated the CassandraStorage with a patch we've done for
CASSANDRA-2869 to see if that might indirectly do something to the inputs, but
not sure it would affect that part of it.
The hadoop default in ConfigHelper is CL ONE. I need to do some more focused
study of that data. We
The logs will give you some idea, but it's not information that is available as
part of a request.
Turn the logging up to DEBUG and watch what happens. You will see the
coordinator log where it is sending messages together with some unique
identifiers that you will also see logged on the repli
AFAIK Facebook Cassandra and Apache Cassandra diverged paths a long time ago.
Twitter is a vocal supporter with a large Apache Cassandra install, e.g.
"Twitter currently runs a couple hundred Cassandra nodes across a half dozen
clusters. "
http://www.datastax.com/2011/06/chris-goffinet-of-twitt
You may not lose data.
- What version and whats the upgrade history?
- What RF / node count / CL ?
- Have you been running repair consistently ?
- Is this on a single node or all nodes ?
Cheers
-
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelastpickle.c
I have roughly 150 million rows in my database, which will grow as I
continue testing. I'm building an index on a particular column, via
cassandra-cli, something of the sort:
update column family jobs with column_metadata = [{column_name : 'DATE',
validation_class : AsciiType, index_type :
I've got a node that is stuck "Leaving" the ring. Running "nodetool
decommission" never terminates. It's been in this state for about a week,
and the load has not decreased:
$ nodetool -h localhost ring
Address DC RackStatus State Load
OwnsToken
Token(bytes[de4075
My guess: index build isn't respecting the background i/o throttle.
On Fri, Jul 8, 2011 at 5:55 PM, Maxim Potekhin wrote:
> I have roughly 150 million rows in my database, which will grow as I
> continue testing. I'm building an index on a particular column, via
> cassandra-cli, something of the
Hi Aaron,
El vie, 08-07-2011 a las 14:47 -0700, aaron morton escribió:
> You may not lose data.
>
> - What version and whats the upgrade history?
all versions from 0.7.1 to 0.8.1. All cfs were in 0.8.1 format though
> - What RF / node count / CL ?
RF=3, node count = 6
> - Have you been runni
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