Re: Is HEAP_NEWSIZE configuration is no more useful from cassandra 2.1 ?

G1GC still has an Eden size, however, it's strongly recommended *NOT* to set the new gen size G1GC and just let it figure it out based on your target pause time. Thanks, Daniel On Sun, Oct 4, 2015 at 4:11 PM, Tushar Agrawal wrote: > If you are using CMS garbage collector then you still have to

Re: Question about how to remove data

t; > Daniel, I am using Size Tiered compaction. > > My concern is that as I do not have a TTL defined on the Column family, > and I do not have the possibility to create it. Perhaps, the "deleted > data" is never actually going to be removed? > > Thanks a lot! > >

Re: Question about how to remove data

Is this a LCS family, or Size Tiered? Manually running compaction on LCS doesn't do anything until C* 2.2 ( https://issues.apache.org/jira/browse/CASSANDRA-7272) Thanks, Daniel On Wed, Aug 19, 2015 at 6:56 PM, Analia Lorenzatto < analialorenza...@gmail.com> wrote: > Hello Michael, > > Thanks for

Re: Deserialize the collection type data from the SSTable file

Hi Yong, Glad the code was helpful. I believe it serializes using List> for maps so that it can store the Key of the map as well. Thanks for pointing out the edge case! Thanks, Daniel On Wed, Jun 10, 2015 at 6:39 AM, java8964 wrote: > Thanks, Daniel. > > I didn't realize that Cassandra will s

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: Less frequent flushing with LCS

Do the tables look like they're being flushed every hour? It seems like the setting memtable_flush_after_mins which I believe defaults to 60 could also affect how often your tables are flushed. Thanks, Daniel On Mon, Mar 2, 2015 at 11:49 AM, Dan Kinder wrote: > I see, thanks for the input. Comp

Re: Controlling the MAX SIZE of sstables after compaction

They have an experimental 2.0 that works (we're using it). Thanks, Daniel On Tue, Jan 27, 2015 at 11:50 AM, Mikhail Strebkov wrote: > It is open sourced but works only with C* 1.x as far as I know. > > Mikhail > > > On Tuesday, January 27, 2015, Mohammed Guller > wrote: > >> I believe Aegisth

Re: efficiently generate complete database dump in text format

You might also want to consider tools like https://github.com/Netflix/aegisthus for the last step, which can help you deal with tombstones and de-duplicate data. Thanks, Daniel On Thu, Oct 9, 2014 at 12:19 AM, Gaurav Bhatnagar wrote: > Hi, >We have a Cassandra database column family contain

Re: Adjusting readahead for SSD disk seeks

Cassandra only reads a small part of each SSTable during normal operation (not compaction), in fact Datastax recommends lowering readahead - http://www.datastax.com/documentation/cassandra/2.1/cassandra/install/installRecommendSettings.html There are also blogposts where people have improved their

Re: CPU consumption of Cassandra

If I had to guess, it might be in part i could be due to inefficiencies in 2.0 with regards to CompositeType (which is used in CQL3 tables) - https://issues.apache.org/jira/browse/CASSANDRA-5417?focusedCommentId=13821243&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-

Re: EBS SSD <-> Cassandra ?

While they guarantee IOPS, they don't really make any guarantees about latency. Since EBS goes over the network, there's so many things in the path of getting at your data, I would be concerned with random latency spikes, unless proven otherwise. Thanks, Daniel On Wed, Jun 18, 2014 at 1:58 AM, A

Re: Is the updating compaction strategy from 'sized tiered' to 'leveled' automatic or need to be done manually?

If you want to trigger a conversion to LCS of the on-disk sstables, doing "nodetool compact " should achieve what you want. Be warned, if you have a lot of data in the CF, this could potentially take a while depending on your compaction throttling. Thanks, Daniel On Sun, May 4, 2014 at 11:54 PM

Re: Multiget performance

Are you making the 100 calls in serial, or in parallel? Thanks, Daniel On Tue, Apr 8, 2014 at 11:22 PM, Allan C wrote: > Hi all, > > I've always been told that multigets are a Cassandra anti-pattern for > performance reasons. I ran a quick test tonight to prove it to myself, and, > sure enough

Re: Cassandra Data Model and Surrogate Keys

g cql3 with the Datastax java driver > > Thanks > *From: *Daniel Chia > *Sent: *Tuesday, February 25, 2014 2:02 PM > *To: *user@cassandra.apache.org > *Reply To: *user@cassandra.apache.org > *Subject: *Re: Cassandra Data Model and Surrogate Keys > > Hi John, > > Sin

Re: Cassandra Data Model and Surrogate Keys

Hi John, Since this is presumably for creation of users, which should have low activity per user, you can use a combination of reads / writes to acquire a "lock" on the username. I believe astyanax has a recipe with what you want that works for C1.2 (although you might have to port it to CQL3 if t

Re: DELETE does not delete :)

What is the gc_grace_period for the CF you're deleting from? Thanks, Daniel On Tue, Oct 15, 2013 at 10:12 PM, Alexander Shutyaev wrote: > Hi all, > > Unfortunately, we still have a problem. I've modified my code, so that it > explicitly sets the consistency level to *QUORUM* for each query. > H

Re: What is the best way to install & upgrade Cassandra on Ubuntu ?

Opscenter is a separate package: http://www.datastax.com/documentation/opscenter/3.2/webhelp/index.html?pagename=docs&version=opscenter&file=index#opsc/install/opscInstallDeb_t.html Thanks, Daniel On Tue, Oct 1, 2013 at 8:11 PM, Aaron Morton wrote: > Does DSC include other things like Opscenter