Re: vnodes: high availability

Not necessarily. It depends on how the token ranges for the vNodes are assigned to them. For example take a look at this diagram http://docs.datastax.com/en/archived/cassandra/2.0/cassandra/architecture/architectureDataDistributeDistribute_c.html In the vNode part of the diagram, you will see

Re: Data sync between 2 clusters in single DC

Why wouldnt you set it up as a single cluster that spans 2 DCs? On Mon, Oct 30, 2017 at 4:09 PM, Vincent Lee wrote: > For high availability in a single DC region, I would like to install one > Cassandra cluster on one AZ and a second cluster on a different AZ. > The data

Re: calculation of disk size

Here is a calculator someone has put together http://btoddb-cass-storage.blogspot.com/2012/01/ive-been-asked-for-spreadsheet-to-help.html?m=1 Rahul On Apr 30, 2015, at 12:53 AM, arun sirimalla arunsi...@gmail.com wrote: Hi Rahul, If you are expecting 15 GB of data per day, here is the

Re: How to use nodetool ring only for one data center

Do you want this for some sort of reporting requirement? If so you may be able to write a quick she'll script using grep to remove the unwanted data Rahul On Apr 28, 2015, at 7:24 PM, Surbhi Gupta surbhi.gupt...@gmail.com wrote: Hi, I wanted to know, how can we get the information of the

Re: Drawbacks of Major Compaction now that Automatic Tombstone Compaction Exists

Rob, Does that mean once you split it back into small ones, automatic compaction a will continue to happen on a more frequent basis now that it's no longer a single large monolith? Rahul On Apr 13, 2015, at 3:23 PM, Robert Coli rc...@eventbrite.com wrote: On Mon, Apr 13, 2015 at 10:52 AM,

Re: Adding new node to Cassandra cluster is too slow

You won't lose data unless you have run nodetool cleanup on the existing nodes. Rahul On Mar 19, 2015, at 9:16 PM, Pranay Agarwal agarwalpran...@gmail.com wrote: Also, the new nodes (3 of them, in UJ state) are showing some data size (~10g). Is there any data loss chances with stopping the

Re: best way to measure repair times?

Wouldn't GC Grace set to 34 days increase the bloat in the DB? Rahul On Mar 19, 2015, at 3:02 PM, Robert Coli rc...@eventbrite.com wrote: On Thu, Mar 19, 2015 at 10:30 AM, Ian Rose ianr...@fullstory.com wrote: I'd like to (a) monitor how long my repairs are taking, and (b) know when a

Re: 2 Cassandra nodes slow

Is the data distribution OK? Have you tried running repairs? Rahul On Jan 13, 2015, at 5:01 AM, Batranut Bogdan batra...@yahoo.com wrote: Hello, I have a cluster of 6 C* nodes. All machines have the same hardware. I have noticed in opscenter that when I start reading a lot from the

Re: problem in exporting large table

Why can't you use sstable2json? Rahul On Jan 12, 2015, at 11:24 PM, Rahul Bhardwaj rahul.bhard...@indiamart.com wrote: Hi All, We are using C* 2.1. we need to export data of one table (consist 10 lacs records) using COPY command. After executing copy command cqlsh hangs and get

Re: nodetool compact cannot remove tombstone in system keyspace

I am not sure about the tombstone_failure_threshold, but the tombstones will only get removed during compaction if they are older than GC_Grace_Seconds for that CF. How old are these tombstones? Rahul On Jan 12, 2015, at 11:27 PM, Xu Zhongxing xu_zhong_x...@163.com wrote: Hi, When I

Re: Hinted handoff not working

http://www.datastax.com/documentation/cassandra/2.0/cassandra/configuration/configCassandra_yaml_r.html?scroll=reference_ds_qfg_n1r_1k__hinted_handoff_enabled Rahul On Dec 14, 2014, at 9:46 AM, Robert Wille rwi...@fold3.com wrote: I have a cluster with RF=3. If I shut down one node, add a

Data not replicating consistently

I have a setup that looks like this Dc1: 9 nodes Dc2: 9 nodes Dc3: 9 nodes C* version: 2.0.10 RF: 2 in each DC Empty CF with no data at the beginning of the test Scenario 1 (happy path): I connect to a node in DC1 using CQLsh, validate that I am using CL=1, insert 10 rows. Then using CQLsh

Re: Force purging of tombstones

the normal compaction and repair processes Rahul On Nov 17, 2014, at 6:57 PM, Robert Coli rc...@eventbrite.com wrote: On Mon, Nov 17, 2014 at 3:10 PM, Rahul Neelakantan ra...@rahul.be wrote: Doesn't repair also get rid of tombstones? Repair is a non-destructive activity, and therefore cannot

Re: Force purging of tombstones

Doesn't repair also get rid of tombstones? Rahul Neelakantan On Nov 17, 2014, at 5:53 PM, Robert Coli rc...@eventbrite.com wrote: On Mon, Nov 17, 2014 at 1:40 PM, Ken Hancock ken.hanc...@schange.com wrote: You can use the JMX forceUserDefinedCompaction operation to compact each SSTable

Re: Did not get positive replies from all endpoints error on incremental repair

It appears to come from the ActiveRepairService.prepareForRepair portion of the Code. Are you sure all nodes are reachable from the node you are initiating repair on, at the same time? Any Node up/down/died messages? Rahul Neelakantan On Oct 30, 2014, at 6:37 AM, Juho Mäkinen juho.maki

Re: opscenter with community cassandra

You can turn off the phone home function in the opscenterd.conf file [stat_reporter] interval = 0 Rahul Neelakantan On Oct 28, 2014, at 11:08 AM, Colin colpcl...@gmail.com wrote: I cant run opscenter in a secure environment for a couple of reasons, one - it phones home, two - lack

Re: Looking for a cassandra web interface

It is not web based, you can try Helenos, but I don't think it is ready for newer versions. Rahul Neelakantan On Oct 21, 2014, at 12:26 AM, Vishanth Balasubramaniam vishan...@wso2.com wrote: I believe DevCenter is not a 'web' interface, isn't it? On Mon, Oct 20, 2014 at 11:40 PM, Jared

Deleting data in 1.2.8 based on time stamp

Does anyone know of a way to delete rows from C* 1.2.8 based on the timestamp (time from epoch) that is present on each column in the triplet of name, value and timestamp? (I do not have a separate date/timestamp column that I insert) Rahul Neelakantan

Re: Deleting data in 1.2.8 based on time stamp

So this would need me to know the partition keys, what if I simply wanted to say delete all rows where the timestamp was older than 123456789? Rahul Neelakantan On Oct 16, 2014, at 6:27 PM, Tyler Hobbs ty...@datastax.com wrote: For each partition in the table, run: DELETE FROM mytable

Re: Repair taking long time

What is the recommendation on the number of tokens value? I am asking because of the issue with sequential repairs on token range after token range. Rahul Neelakantan On Sep 29, 2014, at 2:29 PM, Robert Coli rc...@eventbrite.com wrote: On Fri, Sep 26, 2014 at 9:52 AM, Gene Robichaux

Re: ava.lang.OutOfMemoryError: unable to create new native thread

What is your sstable size set to for each of the sstables, using LCS? Are you at the default of 5 MB? Rahul Neelakantan On Sep 17, 2014, at 10:58 AM, Yatong Zhang bluefl...@gmail.com wrote: sorry, about 300k+ On Wed, Sep 17, 2014 at 10:56 PM, Yatong Zhang bluefl...@gmail.com wrote

Re: Questions about cleaning up/purging Hinted Handoffs

Will try... Thank you Rahul Neelakantan On Sep 10, 2014, at 12:01 AM, Rahul Menon ra...@apigee.com wrote: I use jmxterm. http://wiki.cyclopsgroup.org/jmxterm/ attach it to your c* process and then use the org.apache.cassandra.db:HintedHandoffManager bean and run deleteHintsforEndpoint

Re: hardware sizing for cassandra

Why not more than 32gb of RAM/node? Rahul Neelakantan On Sep 9, 2014, at 3:52 PM, Paolo Crosato paolo.cros...@targaubiest.com wrote: Every node should have at least 4 cores, with a maximum of 8. Memory shouldn't be higher than 32g, 16gb is good for a start. Every node should

Re: Questions about cleaning up/purging Hinted Handoffs

, Robert Coli rc...@eventbrite.com wrote: On Fri, Sep 5, 2014 at 3:20 PM, Rahul Neelakantan ra...@rahul.be wrote: The reason I asked about he hints is because I see hints being replayed but the large compacted hints stable still sticks around, perhaps it is a bug with that version . I've

Questions about cleaning up/purging Hinted Handoffs

The questions are for Cassandra 1.0.8 but may apply to later versions too. 1) When the coordinator notices that a node it is collecting hints for is down for more than the max hint window, it stops collecting hints for that node - Does it automatically purge the hints it collected so far, or

Re: Questions about cleaning up/purging Hinted Handoffs

Yup... Upgrades are in the works.. Thanks for the response. The reason I asked about he hints is because I see hints being replayed but the large compacted hints stable still sticks around, perhaps it is a bug with that version . Rahul Neelakantan On Sep 5, 2014, at 1:03 PM, Robert Coli rc

Re: Question about EC2 and SSDs

With SSD one drive should be sufficient for both data and commitLogs. Rahul Neelakantan On Sep 4, 2014, at 8:05 PM, Steve Robenalt sroben...@highwire.org wrote: Hi all, We are migrating a small cluster on AWS from instances based on spinning disks (using instance store) to SSD-backed

Re: disk space and tombstones

Is that GC_grace 300 days? Rahul Neelakantan On Aug 18, 2014, at 5:51 AM, Dimetrio dimet...@flysoft.ru wrote: In our Twitter-like application users have their own timelines with news from subscriptions. To populate timelines we're using fanout on write. But we forced to trim it to keep

Re: A question about using 'update keyspace with strategyoptions' command

Try running describe cluster from Cassandra-CLI to see if all nodes have the same schema version. Rahul Neelakantan On Aug 5, 2014, at 6:13 AM, Sylvain Lebresne sylv...@datastax.com wrote: On Tue, Aug 5, 2014 at 11:40 AM, Lu, Boying boying...@emc.com wrote: What I want to know

Re: How to get rid of stale info in gossip

It no longer shows up, but I will definitely investigate that option. What exactly does it do? Rahul Neelakantan On Aug 4, 2014, at 7:49 PM, Patricia Gorla patri...@thelastpickle.com wrote: Rahul, If the removed node is still showing up in gossip state, you can remove

Authentication for Mx4j

Does anyone know how to enable basic authentication of MX4J with Cassandra? Mx4j supports it but not sure how to pass the variables to enable it. I was able to set the listen address and port for the http server, but can't get authentication to work. Rahul Neelakantan

Re: Measuring WAN replication latency

Rob, Any ideas you can provide on how to do this will be appreciated, we would like to build a latency monitoring tool/dashboard that shows how long it takes for data to get sent across various DCs. Rahul Neelakantan On Jul 29, 2014, at 8:53 PM, Robert Coli rc...@eventbrite.com wrote

Re: Measuring WAN replication latency

Agreed... This is what we are trying right now. Rahul Neelakantan On Jul 30, 2014, at 1:43 PM, Jeremy Jongsma jer...@barchart.com wrote: Yes, the results should definitely not be relied on as a future performance indicator for key app functionality. but knowing roughly what your current

Question about Vnodes

? Do I just reduce it in the cassandra.yaml and start removing tokens via nodetool? Rahul Neelakantan

Re: unable to load data using sstableloader

Is SStable loader being run on the same host as the Cassandra node 127.0.0.1 (I see your ring is made up of all loop back IPs). Rahul Neelakantan 678-451-4545 On Jul 29, 2014, at 4:55 AM, Akshay Ballarpure akshay.ballarp...@tcs.com wrote: Thanks Duncan for quick help now i am trying

Re: unable to load data using sstableloader

-to-cassandra-using.html?m=1 Rahul Neelakantan On Jul 29, 2014, at 4:55 AM, Akshay Ballarpure akshay.ballarp...@tcs.com wrote: Thanks Duncan for quick help now i am trying sstableloader but its not loading data...any suggestion ? [root@CSL-simulation conf]# ps -eaf | grep -i

Measuring WAN replication latency

Does anyone know of a way to measure/monitor WAN replication latency for Cassandra? For example I make a write to DC 1 of a multi DC setup using local_quorum , how long before that write is available for a read either locally in DC1 or remotely in DC2 using local_quorum. Rahul Neelakantan

Re: Measuring WAN replication latency

to increase the time it takes for writes to be acknowledged. What I am looking for is a way to monitor either using some statistic exposed by Cassandra or using some sort of synthetic transaction of how my Cassandra replication looks and alert if there is slowness noticed. Rahul Neelakantan

Cassandra version upgrade path

version while upgrading Rahul Neelakantan 678-451-4545

How to get rid of stale info in gossip

Is there a way to get rid of stale information that shows up for removed/dead nodes in gossip, without a complete cluster bounce? Rahul Neelakantan

Re: How to get rid of stale info in gossip

Yes, and this is a really old version of casandra 1.0.8. Rahul Neelakantan 678-451-4545 On Jul 25, 2014, at 7:29 AM, Mark Reddy mark.re...@boxever.com wrote: After removing a node, it's information can persist in the Gossiper for up to 3 days, after which time it should be removed

Changing IPs of all nodes in a ring

All, I need to change the IPs of all nodes in my ring in a flash cut, at the same time. Any recommendations on how to do this? Rahul Neelakantan

Re: Changing IPs of all nodes in a ring

I am ok with taking upto 2 hours of planned downtime. The problem is all the IPs will change at the same time and the previous IPs will no longer be available. So it's either all old IPs or all new IPs. Rahul Neelakantan 678-451-4545 On Jul 25, 2014, at 7:23 PM, Robert Coli rc

Re: Changing IPs of all nodes in a ring

of Normal. Rahul Neelakantan 678-451-4545 On Jul 25, 2014, at 9:06 PM, Robert Coli rc...@eventbrite.com wrote: On Fri, Jul 25, 2014 at 4:42 PM, Rahul Neelakantan ra...@rahul.be wrote: I am ok with taking upto 2 hours of planned downtime. The problem is all the IPs will change at the same time