Re: 5.0 webinar - Thursday August 22 9am PDT

Hey Jon, just saw this and wondered if a recording is available? Thanks! Matthias Aug 14, 2024, 00:38 by j...@jonhaddad.com: > Hey everyone!! > > With 5.0 right around the corner I'm sure you're wondering if there's a good > reason for you to upgrade, or if you should just ignore it and spend

Re: null values injected while drop compact storage was executed

This happened with version 3.11.10. We were analyzing impact until now as this happened only on our production systems. There was probably not enough concurrency on our staging environments so it did not happen there. We will start to write a reproducer and file an issue afterwards. Thanks for

null values injected while drop compact storage was executed

Hi there, we just ran drop compact storage in order to prepare for the upgrade to version 4. We observed that column values have been written as null, if they where inserted while the drop compact storage statement was running. This just happened for the couple seconds the drop compact storage

Re: Performance drop of current Java drivers

ely release a fixed version very soon. > > Many thanks again, > Erik > > On Mon, May 4, 2020 at 6:58 AM Matthias Pfau > wrote: > >> Hi Chris and Adam, >> thanks for looking into this! >> >> You can find my tests for old/new client here: &

Re: Performance drop of current Java drivers

Hi Chris and Adam, thanks for looking into this! You can find my tests for old/new client here: https://gist.github.com/mpfau/7905cea3b73d235033e4f3319e219d15 https://gist.github.com/mpfau/a62cce01b83b56afde0dbb588470bc18 May 1, 2020, 16:22 by adam.holmb...@datastax.com: > Also, if you can shar

Performance drop of current Java drivers

Hi there, I just did some testing with latest 3.x and 4.x version of the java driver. While async performance seems to be fine, sync performance degraded significantly with version 4.x. Reading 10.000 small columns from a local cassandra instance took: * around 5 seconds with the old driver * a

Re: Ram & Space...

Did you check nodetool status and logs? If so, what is reported? Regarding that more and more memory is used. This might be a problem with your table design. I would start analyzing nodetool tablestats output. It reports how much memory (especially off heap) is used by which table. Best, Matthi

How to retrieve disk boundaries

Hi there, we are using cassandra 3.11.4 with multiple data dirs on separate disks. If one disk fails, we would like to run a repair for the ranges of the vnodes assigned to the disks. Does anyone know how to retrieve the disk boundaries from cassandra? Best, Matthias --

Re: Multiple compactions to same disk with 3.11.4

r... Best, Matthias Oct 1, 2019, 23:16 by elli...@backblaze.com: > There's a concurrent_compactors parameter in cassandra.yml that does exactly > what the name says.  You may also find compaction_throughput_mb_per_sec > useful. > > On Tue, Oct 1, 2019 at 8:16 AM Matthias Pfau

Multiple compactions to same disk with 3.11.4

Hi there, we recently upgraded from 2.2 to 3.11.4. Unfortunately, we are running into problems with the compaction scheduling, now. From time to time, a bunch of compactions (e.g. 6) are scheduled for the same data dir. This makes no sense for spinning disks as it will slow down all compaction

Re: Drastic increase of bloom filter sizer after upgrading from 2.2.14 to 3.11.4

Just a short follow up on this: After running upgradesstables for a CF, off heap memory used by bloom filters increases by a factor between 6 and 12 in our case. This is a cassandra bug. Bloom filters are obviously calculated before splitting the sstable for multiple data dirs. When you delete

Re: Drastic increase of bloom filter sizer after upgrading from 2.2.14 to 3.11.4

A few more details: 1. bloom_filter_fp_chance is set to 0.01 2. I reviewed CASSANDRA-8413 (https://github.com/apache/cassandra/commit/23fd75f27c40462636f09920719b5dcbef5b8f36 ) and this should not have lead t

Drastic increase of bloom filter sizer after upgrading from 2.2.14 to 3.11.4

Hi there, we just finished upgrading sstables on a single node after upgrading from  2.2.14 to 3.11.4. Since then, we noted a drastic increase of off heap memory consumption. This is due to increased bloom filter size. According to cfstats output "Bloom filter off heap memory used" increased by a

Re: 2.2 eats memory

eeded. Have you checked the output of free? If > available memory is still high you're perfectly fine and everything is > working as expected.  > > On 27 August 2018 at 21:32, Matthias Pfau <> matthias.p...@tutao.de > <mailto:matthias.p...@tutao.de>> > wrote:

2.2 eats memory

Hi there, after upgrading from 2.1 to 2.2.13, Cassandra eats up all available memory within one week. The following is a diagram of the left available RAM of a single node over the course of a week: https://imgur.com/a/H9BDBxC Nodes are bare metal, 12 cores with 64G

Inconsistent dependencies

Hi there, we just noticed that cassandra is currently published with inconsistent dependencies. The inconsistencies exist between the published pom and the published distribution (tar.gz). I compared hashes of the libs of several versions and the inconsistencies are different each time. Howeve

Re: Second Cassandra users survey

It took some time to gather our requirements and to check what are our most important needs. However, here they are: * Column position range queries: We would like to access columns not by their name, but by their position in the row. Example: row("A":v1, "B":v2, "C":v3, "D":v4); ; ordered by

Re: Storing pre-sorted data

Hi David, yes, what we are working on could be referenced as "encrypted database service". Thanks for your insights. We will continue to work on this topic! Kind regards Matthias On 10/21/2011 02:31 AM, David Jeske wrote: If I understand you correctly, you are saying that you will never have

Re: Storing pre-sorted data

list are not a sequence of natural numbers. Kind regards Matthias On 10/18/2011 10:30 AM, David Jeske wrote: On Tue, Oct 18, 2011 at 12:14 AM, Matthias Pfau mailto:p...@l3s.de>> wrote: we want to sort completely on the client-side (where the data is encrypted). But that requi

Re: Storing pre-sorted data

/2011 08:53 AM, David Jeske wrote: On Mon, Oct 17, 2011 at 2:39 AM, Matthias Pfau mailto:p...@l3s.de>> wrote: We would be very happy if cassandra would give us an option to maintain the sort order on our own (application logic). That is why it would be interesting to hear from any

Re: Storing pre-sorted data

ation, would be troublesome at CL ONE. Hope that helps. - Aaron Morton Freelance Cassandra Developer @aaronmorton http://www.thelastpickle.com On 17/10/2011, at 10:39 PM, Matthias Pfau wrote: David, thanks for your nice summary on this topic. We would be very happy if cassandr

Re: Storing pre-sorted data

shrink it sufficiently and give nice buckets in near sequential order (http://en.wikipedia.org/wiki/Soundex) On 13 October 2011 21:21, Matthias Pfau wrote: Hi Stephen, we are hashing the first 8 byte (8 US-ASCII characters) of text that has been written by humans. Wouldn't it be easy fo

Re: Storing pre-sorted data

David, thanks for your nice summary on this topic. We would be very happy if cassandra would give us an option to maintain the sort order on our own (application logic). That is why it would be interesting to hear from any of the developers if it would be easily possible to add such a feature

Re: Storing pre-sorted data

es, random nonsense words and other nonsense are a direct result of using swype to type on the screen On 13 Oct 2011 17:57, "Matthias Pfau" mailto:p...@l3s.de>> wrote: Hi Stephen, this sounds very reasonable. But wouldn't this enable an attacker to execute dictiona

Re: Storing pre-sorted data

you've said your data is not uniformly distributed, so a linear hash function sounds like your best bet. your hash function should have the property that hash(A)>= hash(B) if and only if A>= B On 13 October 2011 08:47, Matthias Pfau wrote: Hi Stephen, this is a great idea but unfortu

Re: Storing pre-sorted data

also needed but used very rare. Kind regards Matthias On 10/13/2011 04:49 PM, Zach Richardson wrote: Matthias, Answers below. On Thu, Oct 13, 2011 at 9:03 AM, Matthias Pfau wrote: Hi Zach, thanks for that good idea. Unfortunately, our list needs to be rewritten often because our data is far

Re: Storing pre-sorted data

small enough, then you could use ints to save space, but will then have to re-write the list more often. Thanks, Zach On Thu, Oct 13, 2011 at 2:47 AM, Matthias Pfau wrote: Hi Stephen, this is a great idea but unfortunately doesn't work for us either as we can not store the data in an unencr

Re: Storing pre-sorted data

a? it wouldn't be a perfect sort, but you'd have less of a range to query to get the sorted values? - Stephen --- Sent from my Android phone, so random spelling mistakes, random nonsense words and other nonsense are a direct result of using swype to type on the screen On 12 Oct 2011 17:57,

Re: Storing pre-sorted data

rings are lengthy you could run into additional issues. On Wed, Oct 12, 2011 at 11:34 AM, Matthias Pfau mailto:p...@l3s.de>> wrote: Hi there, we are currently building a prototype based on cassandra and came into problems on implementing sorted lists containing millions of item

Storing pre-sorted data

Hi there, we are currently building a prototype based on cassandra and came into problems on implementing sorted lists containing millions of items. The special thing about the items of our lists is, that cassandra is not able to sort them as the data is stored in a binary format which is not