Re: how to access data only on specific node

Oh, I finally understand. As I read records one by one they aren't necessarily read from a single node, so if I got 965 records out of 1000, some of them could be read from other nodes which have all of 1000 records. And about range scan - as far as I understand, range scan could be done only with

Re: How to add new DC to cluster when GossipingPropertyFileSnitch is used

If I understand you correctly, GossipingPropertyFileSnitch is useful for manipulations with nodes within a single DC, but to add a new DC without having to restart every node in all DCs (because seeds are specified in cassandra.yaml and I need to restart a node after addition of a new seed from new

Re: How to add new DC to cluster when GossipingPropertyFileSnitch is used

I see no reason to restart all nodes. You can continue to use seed from first DC - seed used for loading ring configuration(locations, token ranges, etc), not data. On 05/17/2013 10:34 AM, Sergey Naumov wrote: If I understand you correctly, GossipingPropertyFileSnitch is useful for manipulatio

Re: How to add new DC to cluster when GossipingPropertyFileSnitch is used

But I've read in some sources (for example http://www.datastax.com/docs/1.0/initialize/cluster_init_multi_dc) that seed list MUST include at least one seed from each DC and seed lists should be the same for each node. Or it is fine if nodes from new DC have all seeds specified and nodes from old D

Re: How to add new DC to cluster when GossipingPropertyFileSnitch is used

On 05/17/2013 11:19 AM, Sergey Naumov wrote: But I've read in some sources (for example http://www.datastax.com/docs/1.0/initialize/cluster_init_multi_dc) that seed list MUST include at least one seed from each DC and seed lists should be the same for each node. Or it is fine if nodes from ne

update does not apply to any replica if consistency = ALL and one replica is down

As described here ( http://maxgrinev.com/2010/07/12/update-idempotency-why-it-is-important-in-cassandra-applications-2/), if consistency level couldn't be met, updates are applied anyway on functional replicas, and they could be propagated later to other replicas using repair mechanisms or by issui

Re: Announcing Mutagen

Hi Blair-- Thanks for digging into the code. I did indeed experiment with longer timeouts and the result was that trying to obtain the lock hung for whatever amount of time I set the timeout for. I am not an expert on Astyanax and haven't debugged my use of that recipe yet; I don't even know if I'

Re: Announcing Mutagen

Now that comparators can be changed I am internally wondering if every column, rowkey,value in c* should be a dynamic composite and then everything can "evolve" On Fri, May 17, 2013 at 5:35 AM, Todd Fast wrote: > Hi Blair-- > > Thanks for digging into the code. I did indeed experiment with long

C language - cassandra

Hello, new here, What are my options in using cassandra from a program written in c? A) Thrift has no documentation, so it will take me time to understand. Thrift also doesnt have a balancing pool, asking different nodes every time, which is a big problem. B) Should I use the hector (java) client

Logging Cassandra queries

Hi! For quite time I've been having some unexpected loadavg in the cassandra servers. I suspect there are lots of uncontrolled queries to the cassandra servers causing this load, but the developers say that there are none, and the load is due to cassandra internal processes. Trying to get to the

Re: C language - cassandra

Hi Apostolis I'm the author of libcassie, a C library for cassandra that wraps the C++ libcassandra library. It's in use in production where I work, however it has not received much traction elsewhere as far as I know. You can get it here: https://github.com/minaguib/libcassandra/tree/kicks

Re: best practices on EC2 question

> b) do people skip backups altogether except for huge outages and just let > rebooted server instances come up empty to repopulate via C*? This one. Bootstrapping a new node into the cluster has a small impact on the existing nodes and the new nodes to have all the data they need when the fini

Re: update does not apply to any replica if consistency = ALL and one replica is down

I think you're conflating "may" with "must". That article says that updates "may" still be applied to some replicas when there is a failure and I believe that still is the case. However, if the coordinator knows that the CL can't be met before even attempting the write, I don't think it will atte

Re: C language - cassandra

Thanks Mina for your work. One other option could be to use pycassa and link the code with my c program, but I have no experience with python at all. Maybe this will be better since pycassa seems to have a strong community. 2013/5/17 Mina Naguib > > Hi Apostolis > > I'm the author of libcassie

Re: best practices on EC2 question

On Fri, May 17, 2013 at 11:13 AM, aaron morton wrote: > Bootstrapping a new node into the cluster has a small impact on the existing > nodes and the new nodes to have all the data they need when the finish the > process. Sorry for the pedantry, but bootstrapping from existing replicas cannot guar

Re: pycassa failures in large batch cycling

IMHO you are going to have more success breaking up your work load to work with the current settings. The buffers created by thrift are going to eat up the server side memory. They grow dynamically but persist for the life of the connection. Cheers - Aaron Morton Freelance C

Re: how to access data only on specific node

> And about range scan - as far as I understand, range scan could be done only > with Order Preserving Partitioner, but not with Random Partitioner. Range scan can be used with any partitioner. If you use it with the RP the order of the rows will be ranged. Cheers - Aaron Morto

[BLOG] : Cassandra as a Deep Storage Mechanism for Druid Real-Time Analytics Engine

FWIW, we were able to integrate Druid and Cassandra. Its only in PoC right now, but it seems like a powerful combination: http://brianoneill.blogspot.com/2013/05/cassandra-as-deep-storage-mechanism-for.html -brian -- Brian ONeill Lead Architect, Health Market Science (http://healthmarketscience

Re: How to add new DC to cluster when GossipingPropertyFileSnitch is used

> But I've read in some sources (for example > http://www.datastax.com/docs/1.0/initialize/cluster_init_multi_dc) that seed > list MUST include at least one seed from each DC and seed lists should be the > same for each node. That article is about creating a new cluster, to add an a DC to an ex

Re: Logging Cassandra queries

> And... could I be more precise when enabling logging? Because right now, with > log4j.rootLogger=DEBUG,stdout,R I'm getting a lot of information I won't use > ever, and I'd like to enable just what I need to see gets and seds…. see the example at the bottom of this file about setting the log l

Re: update does not apply to any replica if consistency = ALL and one replica is down

> one node in DC1 is deliberately down - and, as RF for DC1 is 3, this down > node is a replica node for 100% of records), when I try to insert one record > with consistency level of ALL, this insert does not appear on any replica This insert will fail to start and the client will get an Unava

Re: C language - cassandra

Mina, Could you update this page with your client library ? https://wiki.apache.org/cassandra/ClientOptions Thanks Aaron - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 18/05/2013, at 6:00 AM, Mina Naguib wrote:

Re: best practices on EC2 question

I was considering that when bootstrapping starts the nodes receive writes so that when the process is complete they have both the data from the streaming process and all writes from the time they started. So that a repair is not needed. Compared to bootstrapping a node from a backup where a (non

Re: C++ Thrift client

Aaron, whenever I get a GCInspector event log, will it means that I'm having a GC pause? *Atenciosamente,* *Víctor Hugo Molinar - *@vhmolinar On Thu, May 16, 2013 at 8:53 PM, aaron morton wrote: > (Assuming you have enabled tcp_nodelay on the client socket) >

Re: pycassa failures in large batch cycling

IMHO you are going to have more success breaking up your work load to work with the current settings.  The buffers created by thrift are going to eat up the server side memory. They grow dynamically but persist for the life of the connection.  Amen to that. Already refactoring our workload to

Re: C++ Thrift client

On 2013-05-16 02:58, Bill Hastings wrote: Hi All I am doing very small inserts into Cassandra in the range of say 64 bytes. I use a C++ Thrift client and seem consistently get latencies anywhere between 35-45 ms. Could some one please advise as to what might be happening? Sniff the network tra

Re: C language - cassandra

On 2013-05-17 16:42, Apostolis Xekoukoulotakis wrote: Hello, new here, What are my options in using cassandra from a program written in c? A) Thrift has no documentation, so it will take me time to understand. Thrift also doesnt have a balancing pool, asking different nodes every time, which is

Re:

On Thu, May 16, 2013 at 8:49 PM, wrote: > > hi [attack_url] Is there anyone taking care of removing these attack spammers from this list? This is the second such mail in two days. =Rob