Re: Why does Cassandra recommends Oracle JVM instead of OpenJDK?

by saying Oracle just has lot of self interest but I really hope that I am wrong since I am a big fan of JVM. On Fri, Dec 23, 2016 at 7:15 PM, Edward Capriolo <edlinuxg...@gmail.com> wrote: > > On Fri, Dec 23, 2016 at 6:01 AM, Kant Kodali <k...@peernova.com> wrote: > >>

Re: Why does Cassandra recommends Oracle JVM instead of OpenJDK?

; > > -- Brice > > On Mon, Dec 26, 2016 at 3:55 PM, Edward Capriolo <edlinuxg...@gmail.com> > wrote: > >> >> >> On Sat, Dec 24, 2016 at 5:58 AM, Kant Kodali <k...@peernova.com> wrote: >> >>> @Edward Agreed JVM is awesome and it is a wo

Re: Why does Cassandra recommends Oracle JVM instead of OpenJDK?

ess I'm >> misreading) is that all the stuff that was never free is still not free - >> the change is that Oracle may actually be interested in the fact that some >> are using non-free products for free. >> >> Pretty much a non-story, it seems like. >>

Re: scylladb

I dont think ScyllaDB performance is because of C++. The design decisions in scylladb are indeed different from Cassandra such as getting rid of SEDA and moving to TPC and so on. If someone thinks it is because of C++ then just show the benchmarks that proves it is indeed the C++ which gave 10X

Re: scylladb

and control. > > None of this is new btw, it's pretty common in the storage world. > > Avi > > > On 03/11/2017 11:18 PM, Kant Kodali wrote: > > Here is the Java version http://docs.paralleluniverse.co/quasar/ but I > still don't see how user level scheduling can be beneficial

Re: scylladb

e aren't available as > transparent hugepages). > > > On 03/11/2017 10:26 PM, Kant Kodali wrote: > > @Dor > > 1) You guys have a CPU scheduler? you mean user level thread Scheduler > that maps user level threads to kernel level threads? I thought C++ by > default creates native k

Re: scylladb

@Dor 1) You guys have a CPU scheduler? you mean user level thread Scheduler that maps user level threads to kernel level threads? I thought C++ by default creates native kernel threads but sure nothing will stop someone to create a user level scheduling library if that's what you are talking

Re: scylladb

> If you have thread-per-core and N (logical) cores, and have M tasks > running concurrently where M > N, then you need a scheduler to decide which > of those M tasks gets to run on those N kernel threads. Whether those M > tasks are user-level threads, or callbacks, or a mix of the two is >

Re: scylladb

One more thing. Pretty much every database that is written in C++ or Java uses native kernel threads for non-blocking I/O as well. They didn't use Seaster or Quasar but anyways I am going to read up on Seaster and see what it really does. On Sun, Mar 12, 2017 at 3:48 AM, Kant Kodali &l

Re: scylladb

se [1] and documentation [2] > to see how we handled those problems. I'll also comment a bit below. > > > [1] https://github.com/scylladb/seastar > > [2] http://www.seastar-project.org/ > > On 03/12/2017 11:07 AM, Kant Kodali wrote: > > @Avi > > "User-level sc

Re: scylladb

On Sun, Mar 12, 2017 at 12:23 AM, Avi Kivity <a...@scylladb.com> wrote: > > > On 03/12/2017 12:19 AM, Kant Kodali wrote: > > My response is inline. > > On Sat, Mar 11, 2017 at 1:43 PM, Avi Kivity <a...@scylladb.com> wrote: > >> There are several issues

Re: scylladb

threading/scheduling (Hyperthreading, NUMA, many-core), the second order nature seriously limits the ability of M:N threading. On Sun, Mar 12, 2017 at 1:33 AM, Kant Kodali <k...@peernova.com> wrote: > Sorry I made some typo's here is a better version. > > @Avi > > "Use

Re: scylladb

to > overprovision your node and then you mostly underutilize it. > > On 03/12/2017 10:23 AM, Avi Kivity wrote: > > > > On 03/12/2017 12:19 AM, Kant Kodali wrote: > > My response is inline. > > On Sat, Mar 11, 2017 at 1:43 PM, Avi Kivity <a...@scylladb.com> wrote:

Re: scylladb

yes. On Sun, Mar 12, 2017 at 2:01 PM, James Carman wrote: > Does all of this Scylla talk really even belong on the Cassandra user > mailing list in the first place? > > > > > On Sun, Mar 12, 2017 at 4:07 PM Jeff Jirsa wrote: > > > > On 2017-03-11

Re: scylladb

te a "drop-in replacement" (use us, not Cassandra) isn't cool, IMHO. > > > On Sun, Mar 12, 2017 at 5:04 PM Kant Kodali <k...@peernova.com> wrote: > > yes. > > On Sun, Mar 12, 2017 at 2:01 PM, James Carman <ja...@carmanconsulting.com> > wrote: > > Does all of

Re: scylladb

ly assigning it to >> memtables, cache, and working memory needed to handle requests in flight. >> Memory is statically partitioned across cores, allowing us to exploit NUMA >> fully. You can't do these things in Java. >> >> I would say the major contributors to Scyl

Re: Attached profiled data but need help understanding it

Hi Romain, We may be able to achieve what we need without LWT but that would require bunch of changes from the application side and possibly introducing caching layers and designing solution around that. But for now, we are constrained to use LWT's for another month or so. All said, I still would

Cassandra 3.10 has partial partition key search but does it result in a table scan?

Hi All, It looks like Cassandra 3.10 has partial partition key search but does it result in a table scan? for example I can have the following create table hello( a text, b int, c text, d text, primary key((a,b), c) ); Now I can do select * from hello where a='foo' allow filtering;// This works

Re: Cassandra 3.10 has partial partition key search but does it result in a table scan?

;> The query you’ve listed here looks like it would also do a full table >> scan (again, I don’t see how it would be avoided). >> >> I recommend firing up a 3 node cluster using CCM, creating a key space >> with RF=1, and seeing what it does. >> >> On May 9, 2

Is there a C* summit this year?

Hi All, I was wondering if there is going to be a C* summit this year? If so, when can we expect? Thanks!

Re: Cassandra & Spark

If you use Containers like Docker Plan A can work provided you do the resource and capacity planning. I tend to think that Plan B is more Standard and easier Although you can wait to hear from others for a second opinion. Caution: Data Locality will make sense if the Disk throughput is

is static column thread safe or only counter column is thread safe?

Hi All, is static column thread safe or only counter column is thread safe? Thanks!

Re: Weird error (unable to start cassandra)

I had to do brew upgrade jemalloc to fix this issue. On Mon, Sep 11, 2017 at 4:25 AM, Kant Kodali <k...@peernova.com> wrote: > Hi All, > > I am trying to start cassandra 3.11 on Mac OS Sierra 10.12.6. when invoke > cassandra binary I get the following error > > java(298

Weird error (unable to start cassandra)

Hi All, I am trying to start cassandra 3.11 on Mac OS Sierra 10.12.6. when invoke cassandra binary I get the following error java(2981,0x7fffedb763c0) malloc: *** malloc_zone_unregister() failed for 0x7fffedb6c000 I have xcode version 8.3.3 installed (latest). Any clue ? Thanks!

Is there a plan for Feature like this in C* ?

https://www.cockroachlabs.com/docs/v2.1/change-data-capture.html

Re: Is there a plan for Feature like this in C* ?

Hi Justin, Thanks, Looks like a very early stage feature and no integration with Kafka yet I suppose. Thanks! On Mon, Jul 2, 2018 at 6:24 PM, Justin Cameron wrote: > yes, take a look at http://cassandra.apache.org/ > doc/latest/operating/cdc.html > > On Tue, 3 Jul 2018 at 01:20

Re: unable to start cassandra 3.11.1

ote: > >> you can try to checkout https://github.com/be >> obal/cassandra/tree/14173-3.11 >> and compile yourself a compatible version (unreleased), in case you are >> bound to >> the latest java runtime for any reason. >> >> Marcus Haarmann >> >>

Re: What happens if multiple processes send create table if not exist statement to cassandra?

t; www.pythian.com > >> On Sat, Jan 27, 2018 at 7:25 PM, Jeff Jirsa <jji...@gmail.com> wrote: >> It’s not LWT. Don’t do programmatic schema changes that can race, it’s >> likely to cause problems >> >> >> -- >> Jeff Jirsa >> >> >&

Re: What happens if multiple processes send create table if not exist statement to cassandra?

May I know why? Sent from my iPhone > On Jan 27, 2018, at 12:36 PM, Jeff Jirsa <jji...@gmail.com> wrote: > > Yes it causes issues > > > -- > Jeff Jirsa > > >> On Jan 27, 2018, at 12:17 PM, Kant Kodali <k...@peernova.com> wrote: >> &g

What happens if multiple processes send create table if not exist statement to cassandra?

Hi All, What happens if multiple processes send create table if not exist statement to cassandra? will there be any data corruption or any other issues if I send "create table if not exist" request often? I dont see any entry in system.paxos table so is it fair to say "IF NOT EXISTS" doesn't

Re: unable to start cassandra 3.11.1

You'll need to either downgrade to Java 1.8.0.151-5 or wait for C* 3.11.2 > (see https://issues.apache.org/jira/browse/CASSANDRA-14173 for details) > > On Fri, 2 Feb 2018 at 09:35 Kant Kodali <k...@peernova.com> wrote: > >> Hi All, >> >> I am unable to start c

unable to start cassandra 3.11.1

Hi All, I am unable to start cassandra 3.11.1. Below is the stack trace. Exception (java.lang.AbstractMethodError) encountered during startup:

Re: unable to start cassandra 3.11.1

Ok I saw the ticket looks like this java version "1.8.0_162" wont work! On Thu, Feb 1, 2018 at 2:43 PM, Kant Kodali <k...@peernova.com> wrote: > Hi Justin, > > I am using > > java version "1.8.0_162" > > Java(TM) SE Runtime Environment (build 1.8.0

Re: What happens if multiple processes send create table if not exist statement to cassandra?

ely for 4.0, > but doesn’t exist in any released version now > > So again, don’t programmatically create tables if there’s a race possible, it > may work fine most of the time, but there’s a risk of ugly failure. > > -- > Jeff Jirsa > > >> On Jan 27, 2018,

Re: How to Parse raw CQL text?

a query and split it into several actions? > > Did you look into this unit test folder? > > https://github.com/apache/cassandra/blob/trunk/test/ > unit/org/apache/cassandra/cql3/CQLTester.java > > -- > Rahul Singh > rahul.si...@anant.us > > Anant Corporation > > On F

Re: How to Parse raw CQL text?

etColumnMetadata() .values() .stream() .forEach(cd -> System.out.println(cd)); } } } On Mon, Feb 5, 2018 at 2:13 PM, Kant Kodali <k...@peernova.com> wrote: > Hi Anant, > > I just have CQL create table statement as a string I wa

How to Parse raw CQL text?

Hi All, I have a need where I get a raw CQL create table statement as a String and I need to parse the keyspace, tablename, columns and so on..so I can use it for various queries and send it to C*. I used the example below from this link . I get

Re: How to Parse raw CQL text?

de/rustyrazorblade-examples/blob/ > master/privatevaraccess/src/main/kotlin/com/rustyrazorblade/ > privatevaraccess/CreateTableParser.kt > [2] http://rustyrazorblade.com/post/2018/2018-02-25- > accessing-private-variables-in-jvm/ > > On Mon, Feb 5, 2018 at 2:27 PM Kant Kodali <

Re: Jon Haddad on Diagnosing Performance Problems in Production

+1 That was a nice talk! I don't know why I haven't come across that video before! On Tue, Feb 27, 2018 at 9:12 AM, Jonathan Haddad wrote: > There isn't a ton from that talk I'd consider "wrong" at this point, but > some of it is a little stale. I always start off looking

UDF related question

Hi All, I was reading the article below and I was wondering how did one manage to block all I/O calls given that there is no byte code instruction for I/O in java instead all the I/O calls in java will go through *invokevirtual *byte code instruction. But this can call a C function that just add

Re: Cassandra/Spark failing to process large table

The fact that cqlsh itself gives different results tells me that this has nothing to do with spark. Moreover, spark results are monotonically increasing which seem to be more consistent than cqlsh. so I believe spark can be taken out of the equation. Now, while you are running these queries is

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