Re: Hbase vs Cassandra

Hi All, Thanks for all the input. I posted the same question in HBase forum and got more response. Posting the consolidated list here. Our case is that a central team builds and maintain the platform (Cassandra as a service). We have couple of usecases which fits Cassandra like time-series data.

Re: Hbase vs Cassandra

Hi, Some minor comments: > 2.terrible!!! Ambari/cloudera manager rulezzz. Netflix has its own tool for Cassandra but it doesn't support vnodes. Not entirely sure what you mean here, but we ran Cloudera for a while and Cloudera Manager was buggy and hard to debug. Overall, our experience wasn't v

Ghost compaction process

Hello, I'm having problem there in 1 node I have continues compaction process running and consuming CPU. nodetool tpstats show 1 compaction in progress, but if I try to query system.compactions_in_progress table, I see 0 records. This never ending compaction does slow down node and it becomes lagg

Re: Hbase vs Cassandra

Hi Jens, All the points listed weren't from me. I posted the HBase Vs Cassandra in both the forums and consolidated here for the discussion. On Mon, Jun 8, 2015 at 2:27 PM, Jens Rantil wrote: > Hi, > > Some minor comments: > > > 2.terrible!!! Ambari/cloudera manager rulezzz. Netflix has its ow

Re: Ghost compaction process

Does `nodetool comactionstats` show nothing running as well? Also, for posterity what are some details of the setup (C* version, etc.)? -Tim -- Tim Heckman Operations Engineer PagerDuty, Inc. On Sun, Jun 7, 2015 at 6:40 PM, Arturas Raizys wrote: > Hello, > > I'm having problem there in 1 node

Re: Ghost compaction process

Hi, > Does `nodetool comactionstats` show nothing running as well? Also, for > posterity what are some details of the setup (C* version, etc.)? `nodetool comactionstats` does not return anything, it just waits. If I do enable DEBUG logging, I see this line poping up while executing `nodetool comp

Re: Ghost compaction process

HI, Is it 2.0.14 or 2.1.4? If you are on 2.1.4 I would recommend an upgrade to 2.1.5 regardless of that issue. >From the data you provide it is difficult to access what is the issue. If you are running with RF=2 you can always add another node and kill that one if that is the only node that shows

Re: Hbase vs Cassandra

On Mon, Jun 8, 2015 at 11:16 AM, Ajay wrote: > >>> If I understand correctly, you mean when we write with QUORUM and > Cassandra writes to few machines and fails to write to few machines and > throws exception if it doesn't satisfy QUORUM, leaving it inconsistent and > doesn't rollback?. Yes.

Re: Avoiding Data Duplication

Some options I can think of: 1 - depending on your data size and stime query frequency, you may use spark to peform queries filtering by server time in the log table, maybe within an device time window to reduce the dataset your spark job will need to go through. more info on the spark connector:

Restoring all cluster from snapshots

Hello all. I need to transfer and start the copy of production cluster in a test environment. My steps: - nodetool snapshot -t `hostname`-#{cluster_name}-#{timestamp} -p #{jmx_port} - nodetool ring -p #{jmx_port} | grep `/sbin/ifconfig eth0 | grep 'inet addr' | awk -F: '{print $2}' | awk '{prin

Re: sstableloader usage doubts

Il 05/06/15 22:40, Robert Coli ha scritto: On Fri, Jun 5, 2015 at 7:53 AM, Sebastian Estevez mailto:sebastian.este...@datastax.com>> wrote: Since you only restored one dc's sstables, you should be able to rebuild them on the second DC. Refresh means pick up new SSTables that have b

[RELEASE] Apache Cassandra 2.1.6 released

The Cassandra team is pleased to announce the release of Apache Cassandra version 2.1.6. We are now calling 2.1 series stable and suitable for production. Apache Cassandra is a fully distributed database. It is the right choice when you need scalability and high availability without compromising

[RELEASE] Apache Cassandra 2.2.0-rc1 released

The Cassandra team is pleased to announce the release of Apache Cassandra version 2.2.0-rc1. Apache Cassandra is a fully distributed database. It is the right choice when you need scalability and high availability without compromising performance. http://cassandra.apache.org/ Downloads of sourc

Re: Cassandra crashes daily; nothing on the log

try checking your system logs (generally /var/log/syslog) to check if the cassandra process was killed by the OS oom-killer 2015-06-06 15:39 GMT-03:00 Brian Sam-Bodden : > Berk, >1 GB is not enough to run C*, the minimum memory we use on Digital > Ocean is 4GB. > > Cheers, > Brian > http://in

Re: Cassandra crashes daily; nothing on the log

It could be the linux kernel killing Cassandra b/c of memory usage. When this happens, nothing is logged in Cassandra. Check the system logs: /var/log/messages Look for a message saying "Out of Memory"... "kill process"... On Mon, Jun 8, 2015 at 1:37 PM, Paulo Motta wrote: > try checking your s

Re: sstableloader usage doubts

On Mon, Jun 8, 2015 at 6:58 AM, ZeroUno wrote: > So you mean that "refresh" needs to be used if the cluster is running, but > if I stopped cassandra while copying the sstables then refresh is useless? > So the error "No new SSTables were found" during my refresh attempt is due > to the fact that

Re: Restoring all cluster from snapshots

On Mon, Jun 8, 2015 at 6:22 AM, Anton Koshevoy wrote: > - sudo rm -rf /db/cassandra/cr/data0*/system/* > This removes the schema. You can't load SSTables for column families which don't exist. =Rob

Deserialize the collection type data from the SSTable file

Hi, Cassandra users: I have a question related to how to Deserialize the new collection types data in the Cassandra 2.x. (The exactly version is C 2.0.10). I create the following example tables in the CQLSH: CREATE TABLE coupon ( account_id bigint, campaign_id uuid, ,

Deserialize the collection type data from the SSTable file

Hi, Cassandra users: I have a question related to how to Deserialize the new collection types data in the Cassandra 2.x. (The exactly version is C 2.0.10). I create the following example tables in the CQLSH: CREATE TABLE coupon ( account_id bigint, campaign_id uuid, ,

Re: Restoring all cluster from snapshots

Rob, thanks for the answer. I just follow instruction from  http://docs.datastax.com/en/cassandra/2.1/cassandra/operations/ops_snapshot_restore_new_cluster.html If not to remove system table data, the test cluster starts interfering to a production cluster. How Can I avoid this situation? On

Re: Restoring all cluster from snapshots

I think you just have to do a "DESC KEYSPACE mykeyspace;" from one node of the production cluster then copy the output and import it in your dev cluster using "cqlsh -f output.cql". Take care at the start of the output you might want to change DC names, RF or strategy. Also, if you don't want to

RE: Restoring all cluster from snapshots

Yes, you shouldn’t delete the system directory. Next steps are …reconfigure the test cluster with new IP addresses, clear the gossiping information and then boot the test cluster. If you are running Cassandra on VMware, then you may also want to look at this solution

Re: Deserialize the collection type data from the SSTable file

I'm not sure why sstable2json doesn't work for collections, but if you're into reading raw sstables we use the following code with good success: https://github.com/coursera/aegisthus/blob/77c73f6259f2a30d3d8ca64578be5c13ecc4e6f4/aegisthus-hadoop/src/main/java/org/coursera/mapreducer/CQLMapper.java

Re: Restoring all cluster from snapshots

On Mon, Jun 8, 2015 at 2:52 PM, Sanjay Baronia < sanjay.baro...@triliodata.com> wrote: > Yes, you shouldn’t delete the system directory. Next steps are > …reconfigure the test cluster with new IP addresses, clear the gossiping > information and then boot the test cluster. > If you don't delete t

Re: DSE 4.7 security

Cassandra authorization is at the keyspace and table level. Click on the GRANT link on the doc page, to get more info: http://docs.datastax.com/en/cql/3.1/cql/cql_reference/grant_r.html Which says "*Permissions to access all keyspaces, a named keyspace, or a table can be granted to a user.*" Ther

auto clear data with ttl

I have C* 2.1.5,store some data with ttl.Reduce the gc_grace_seconds to zero. But it seems has no effect. Did I miss something? -- Ranger Tsao

Re: auto clear data with ttl

So gc_grace zero will remove tombstones without any delay after compaction. So it's possible that tombstones containing SSTs still need to be compacted. So either you can wait for compaction to happen or do a manual compaction depending on your compaction strategy. Manual compaction does have so

Re: auto clear data with ttl

Thank You. I have change unchecked_tombstone_compaction to true . Major compaction will cause a big sstable ，I think is a lot good choice -- Ranger Tsao 2015-06-09 11:16 GMT+08:00 Aiman Parvaiz : > So gc_grace zero will remove tombstones without any delay afte

C* 2.0.15 - java.lang.NegativeArraySizeException

Hi everyone I am running C* 2.0.9 and decided to do a rolling upgrade. Added a node of C* 2.0.15 in the existing cluster and saw this twice: Jun 9 02:27:20 prod-cass23.localdomain cassandra: 2015-06-09 02:27:20,658 INFO CompactionExecutor:4 CompactionTask.runMayThrow - Compacting [SSTableReader(p

Support for ad-hoc query

Hi All, I have an web application running with my backend data stored in cassandra. Now I want to do some analysis on the data stored which requires some ad-hoc queries fired on cassandra. How can I do the same? Regards, Seenu.