Re: Command Request: rename a column

2011-07-08 Thread Sylvain Lebresne
On Fri, Jul 8, 2011 at 9:22 AM, AJ a...@dude.podzone.net 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

Re: Command Request: rename a column

2011-07-08 Thread AJ
On 7/8/2011 2:18 AM, Sylvain Lebresne wrote: On Fri, Jul 8, 2011 at 9:22 AM, AJa...@dude.podzone.net 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

Re: What does a write lock ?

2011-07-08 Thread William Oberman
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

Re: What does a write lock ?

2011-07-08 Thread Jeffrey Kesselman
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

Re: What does a write lock ?

2011-07-08 Thread Jonathan Ellis
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

Re: What does a write lock ?

2011-07-08 Thread William Oberman
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 in

Re: What does a write lock ?

2011-07-08 Thread William Oberman
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

Re: 'select * from cf' - FTS or Index

2011-07-08 Thread Eric Evans
On Thu, 2011-07-07 at 19:34 -0400, A J wrote: Does a 'select * from cf' 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

Re: What does a write lock ?

2011-07-08 Thread Jeffrey Kesselman
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.

Re: What does a write lock ?

2011-07-08 Thread Jeffrey Kesselman
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

Re: What does a write lock ?

2011-07-08 Thread William Oberman
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 jef...@gmail.com wrote: I am confused by what you mean by Cassandra client code. Is

Re: What does a write lock ?

2011-07-08 Thread Jeffrey Kesselman
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

Re: What does a write lock ?

2011-07-08 Thread William Oberman
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

Re: What does a write lock ?

2011-07-08 Thread Jeffrey Kesselman
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

Re: What does a write lock ?

2011-07-08 Thread Jeffrey Kesselman
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 n...@datastax.com wrote: Validation

Corrupted data

2011-07-08 Thread Héctor Izquierdo Seliva
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

Pre-CassandraSF Happy Hour on Sunday

2011-07-08 Thread Richard Low
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:

Re: Pig pulling an older value from cassandra

2011-07-08 Thread aaron morton
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,

Re: Re : result sorted by keys in reversed

2011-07-08 Thread aaron morton
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

Re: Pig pulling an older value from cassandra

2011-07-08 Thread Jeremy Hanna
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.

Re: List nodes where write was applied to

2011-07-08 Thread aaron morton
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

Re: how large cassandra could scale when it need to do manual operation?

2011-07-08 Thread aaron morton
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.

Re: Corrupted data

2011-07-08 Thread aaron morton
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

Performance deterioration while building secondary index

2011-07-08 Thread Maxim Potekhin
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

node stuck leaving

2011-07-08 Thread Casey Deccio
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

Re: Performance deterioration while building secondary index

2011-07-08 Thread Jonathan Ellis
My guess: index build isn't respecting the background i/o throttle. On Fri, Jul 8, 2011 at 5:55 PM, Maxim Potekhin potek...@bnl.gov 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,

Re: Corrupted data

2011-07-08 Thread Héctor Izquierdo Seliva
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 running