I don't have the thread handy but I thought we decided to do this already
and it would just be a doc change.
Either way, I'm +1 on removing experimental flag.
Jon
On Tue, Jul 8, 2025 at 1:38 PM Geremy Cohen wrote:
> Hi all, just curious as to when docs will be updated to signify official
> JDK
ries about there being
>> additional hidden nuances to implementing the same level of functionality
>> and reliability in ECS and even K8s. We agree that the K8ssandra operator
>> would be the most advantageous and desired aspect of switching to a
>> container-based solu
I agree that managing Cassandra on Kubernetes can be challenging without
prior experience, as understanding all the nuances of Kubernetes takes time.
However, there are ways to address the rescheduling issues, node placement,
and local disk concerns that were mentioned. You can pin pods to specifi
I've got 1K nodes in various clusters running on Java 17. I've had great
results with Shenandoah, 30GB heap, and off heap trie memtables.
Pauses are as advertised, between 1-3ms. With smaller heaps or high
throughput you might see the JVM apply pacing - to ensure it can keep up
with allocations.
Just a reminder!
The deadline to submit a proposal closes at 6:59 PM 21 Apr 2025 in Central
Daylight Time (UTC-05:00) timezone.
Jon
On Mon, Mar 10, 2025 at 6:51 AM Paulo Motta wrote:
> Hi,
>
> Please see message below with instructions on submitting talk proposals
> for Community Over Code 202
Thanks for bringing this up. I've been meaning to for a while now.
I'm at the early stages of doing some testing of Java 11 G1GC vs 17 w/ G1GC
vs 17 w/ Shenandoah. I plan on sharing my results with the wider
community, and if things look good I'll be proposing we remove the
experimental label.
I’m not sure if i shared this to the user list… I’m doing a massive series
on C* 5.0 performance and how it relates to node density and cost. First
post is up now.
http://rustyrazorblade.com/post/2025/03-streaming/
The benefit any given feature depends on a lot of factors. Hardware and
workload v
There's several options for load testing. I'll admit that I'm massively
biased as I wrote one of them.
* easy-cass-stress offers a variety of customizable workloads out of the
box and can stress many features without writing any code or learning new
config. I wrote this with the goal of getting
Can you explain a bit more what you mean by memory spikes?
The defaults we ship use the same settings for min and max JVM heap size,
so you should see all the memory allocated to the JVM at startup. Did you
change anything here? I don't recommend doing so.
If you're referring to files in the pa
ch had very good automation for this sort of thing, I can
>> still see this process taking 3 times as long to complete as a normal
>> upgrade, and this does take up operators time.
>>
>> I can see the advantages of 3 stage process, and all things being equal I
>> would r
fficulty of upgrading in general? I'm all for
improving it. It's just not what this thread is about.
Jon
On Wed, Dec 18, 2024 at 10:01 AM Eric Evans
wrote:
>
>
> On Wed, Dec 18, 2024 at 11:43 AM Jon Haddad
> wrote:
>
>> > We (Wikimedia) have had more
thing, I can
>> still see this process taking 3 times as long to complete as a normal
>> upgrade, and this does take up operators time.
>>
>> I can see the advantages of 3 stage process, and all things being equal I
>> would recommend that process as being safe
#x27;s question - clients (i.e. java driver, etc) should be able to
> handle disconnects gracefully and route to other coordinators leaving the
> application-facing symptom being a blip on latency. Are you seeing
> something else more painful, or is it more just not having the built-in
&
age process, and all things being equal I
> would recommend that process as being safer, however I am getting a lot of
> push back whenever we discuss the upgrade process.
>
> Thanks
>
> Paul
>
> > On 17 Dec 2024, at 19:24, Jon Haddad wrote:
> >
> > Just cu
Just curious, why is a rolling restart difficult? Is it a tooling issue,
stability, just overall fear of messing with things?
You *should* be able to do a rolling restart without it being an issue. I look
at this as a fundamental workflow that every C* operator should have available,
and you
It sounds like enabling the JDK's vector preview api could significantly
improve Vector search. I haven't verified this myself, but it might be
worth trying Java 17 + this flag:
--add-modules jdk.incubator.vector
I'd love to hear how much of a difference this makes.
Jon
On Fri, Nov 8, 2024 at
I think this is the correct explanation. It's very similar to
CASSANDRA-19576, where compaction is unable to finish because we can't
insert into compaction history.
Really good analysis, Jaydeep.
Jon
On Sun, Nov 10, 2024 at 1:51 PM Jaydeep Chovatia
wrote:
> Upon further studying the thread d
#x27;s a large number of snapshots. These can
> have significant impact on file deletion performance on ZFS. Also worth
> checking the disks, I have seen broken disks that stuck on some operations,
> e.g. when a specific sector is being read, and this will certainly affect
> the filesyste
I ran into this a few months ago, and in my case I tracked it down to an
issue with ZFS not unlinking commitlogs properly.
https://issues.apache.org/jira/browse/CASSANDRA-19564
On Tue, Nov 5, 2024 at 6:05 AM Dmitry Konstantinov
wrote:
> I am speaking about a thread dump (stack traces for all th
Overwriting non collections does not generate tombstones on compaction.
—
Jon Haddad
Rustyrazorblade Consulting
rustyrazorblade.com
On Wed, Oct 9, 2024 at 9:57 AM James Shaw wrote:
> Hi, Naman:
> How does the client side load large amounts of data ? Most
> likely it ha
I've worked with a few hundred teams now, including the major ones that
used single token (Apple, Netflix, Spotify), and pretty much all the rest
used some form of vnodes.
Jeff did a good job of summarizing the tradeoffs and I don't have anything
to add.
I would never, ever, recommend > 4 tokens.
Are you using collections?
—
Jon Haddad
Rustyrazorblade Consulting
rustyrazorblade.com
On Tue, Oct 8, 2024 at 10:52 PM Naman kaushik
wrote:
> Hi Community,
>
> We are currently using Cassandra version 4.1.3 and have encountered an
> issue related to tombstone generation. We hav
Thank you both for the recommendation!
Jon
On Fri, Sep 27, 2024 at 5:12 AM Aaron Ploetz wrote:
> Casting a second vote for Jon Haddad. You can reach out to him on
> LinkedIn: https://www.linkedin.com/in/rustyrazorblade/
>
> Thanks,
>
> Aaron
>
>
> On Fri, Sep 27,
Hey Matthias,
Somehow this slipped by me. Here's the video:
https://youtube.com/live/-i-ox-8q0nI
Jon
On Thu, Aug 29, 2024 at 3:31 AM Matthias Pfau via user <
user@cassandra.apache.org> wrote:
> Hey Jon,
> just saw this and wondered if a recording is available?
>
> Thanks!
>
> Matthias
>
>
> Au
Riding on the coattails of the release...
If folks are interested in trying this release but you don't have the
tooling to spin it up, I've already released an update to easy-cass-lab [1]
to support 4.1.6. It's my tooling that lets you get started with Apache
Cassandra in AWS in under 15 minutes.
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
your time doing other things instead.
ARE YOU KIDDING ME?!?!?! THIS RELEASE IS HUGE.
Come join me as I take an hour to cover some of t
Hey everyone!
If you've already seen the news that 5.0 RC-1 is out, you might be
wondering how you can kick the tires without investing a ton of time into
changing your tooling around. I've got you covered :)
I've just released an update to easy-cass-lab [1], my tooling to spin up
Cassandra envi
Yes, 5.0 already works with 17 and I’ve been running it almost exclusively
in my tests.
—
Jon Haddad
Rustyrazorblade Consulting
rustyrazorblade.com
On Mon, Jun 17, 2024 at 1:08 PM manish khandelwal <
manishkhandelwa...@gmail.com> wrote:
> Thans Erick, Jon and Stefan for the respons
Erick, that blanket statement about it “never” going in 5.1 is incorrect.
We could absolutely add Java 21 support in 5.1 if we wanted to.
—
Jon Haddad
Rustyrazorblade Consulting
rustyrazorblade.com
On Mon, Jun 17, 2024 at 11:26 AM Erick Ramirez
wrote:
> Cassandra 5.0 will only work with J
As an aside, if you're not putting a TTL on your data, it's a good idea to
be proactive and use multiple tables. For example, one per month or year.
This allows you the flexibility to delete your data by dropping old tables.
Storing old data in Cassandra is expensive. Once you get to a certain
p
I strongly suggest you don't use materialized views at all. There are edge
cases that in my opinion make them unsuitable for production, both in terms
of cluster stability as well as data integrity.
Jon
On Fri, May 17, 2024 at 8:58 AM Gábor Auth wrote:
> Hi,
>
> I know, I know, the materialize
Unless your cluster is very small, using the method of adding / removing
nodes will eventually result in putting a much larger portion of your
dataset on a very few number of nodes. I *highly* discourage this.
The only correct, safe path is Bowen's suggestion of adding another DC and
decommission
Thanks Aaron!
Just realized I made a mistake, the 4th week's URL is
https://www.youtube.com/watch?v=MAxQ0QygcKk.
Jon
On Tue, Apr 30, 2024 at 4:58 AM Aaron Ploetz wrote:
> Nice! This sounds awesome, Jon.
>
> On Mon, Apr 29, 2024 at 6:25 PM Jon Haddad wrote:
>
>> Hey ev
Hey everyone,
I'm doing a 4 week YouTube series on the C* storage engine. My first video
was last week where I gave an overview into some of the storage engine
internals [1].
The next 3 weeks are looking at the new Trie indexes coming in 5.0 [2],
running Cassandra on EBS [3], and finally looking
Hey all,
Tomorrow at 10:30am PDT I'm taking a look at Trie Memtables tomorrow on my
live stream. I'll do some performance comparisons between it and the
legacy SkipListMemtable implementation and see what I can learn.
https://www.youtube.com/live/Jp5R_-uXORQ?si=NnIoV3jqjHFoD8nF
or if you prefer
You shouldn’t decom an entire DC before removing it from replication.
—
Jon Haddad
Rustyrazorblade Consulting
rustyrazorblade.com
On Mon, Apr 8, 2024 at 6:26 AM Michalis Kotsiouros (EXT) via user <
user@cassandra.apache.org> wrote:
> Hello community,
>
> In our deployments, we
Try changing the chunk length parameter on the compression settings to 4kb,
and reduce read ahead to 16kb if you’re using EBS or 4KB if you’re using
decent local ssd or nvme.
Counters read before write.
—
Jon Haddad
Rustyrazorblade Consulting
rustyrazorblade.com
On Fri, Apr 5, 2024 at 9:27 AM
Hi,
Unfortunately, the numbers you're posting have no meaning without context.
The speculative retries could be the cause of a problem, or you could
simply be executing enough queries and you have a fairly high variance in
latency which triggers them often. It's unclear how many queries / second
Hey folks,
I'm doing a working session tomorrow at 10am PDT, testing LWTs in C* 5.0.
I'll be running benchmarks and doing some performance analysis. Come hang
out and bring your questions!
Jon
YouTube: https://www.youtube.com/watch?v=IoWh647LRQ0
LinkedIn:
https://www.linkedin.com/events/cassan
Hey everyone,
Today starting at 10am PT I'm going to be streaming my session messing with
5.0, looking at UCS. I'm doing this with my easy-cass-lab and
easy-cass-stress tools using a build of C* from last night. I'll also show
some of the cool things you can do with my tools.
I'll be running th
Hey Chris - this looks pretty interesting! It looks like there's a lot of
functionality in here.
* What aspects of Mission Control are dependent on using K8ssandra?
* Can Mission Control work without K8ssandra?
* Is mission control open source?
* I'm not familiar with Vector - does it require an
Hey everyone,
Over the last several months I've put a lot of work into 2 projects I
started back at The Last Pickle, for stress testing Cassandra and for
building labs in AWS. You may know them as tlp-stress and tlp-cluster.
Since I haven't worked at TLP in almost half a decade, and am the prima
I can't think of a reason to keep empty directories around, seems like a
reasonable change, but I don't think you're butting up against a thing that
most people would run into, as snapshots are enabled by default (auto_snapshot:
true) and almost nobody changes it.
The use case you described i
I haven't found chunk cache to be particularly useful. It's a fairly small
cache that could only help when you're dealing with a small hot dataset. I
wouldn't bother increasing memory for it.
Key cache can be helpful, but it depends on the workload. I generally
recommend optimizing for your
I worked on a handful of large clusters (> 200 nodes) using vnodes, and
there were some serious issues with both performance and availability. We
had to put in a LOT of work to fix the problems.
I agree with Jeff - it's way better to manage multiple clusters than a
really large one.
On Fri, Jul
You could also pull TWCS out of the version of Cassandra you want to
deploy, fix the imports and change the package name. Then you've got the
same version as OSS, just under the name you're using in 2.1. Once you've
moved to 3.11, you can switch to the OSS version.
On Thu, Jul 9, 2020 at 9:09 AM
Generally speaking, don't run mixed versions longer than you have to, and
don't upgrade that way.
Why?
* We don't support it.
* We don't even test it.
* If you run into trouble and ask for help, the first thing people will
tell you is to get all nodes on the same version.
Anyone that's doing so
I'm on mobile now so I might be mistaken, but I don't think nodetool move
works with multiple tokens
On Fri, May 29, 2020, 1:48 PM Kornel Pal wrote:
> Hi Anthony,
>
> Thank you very much for looking into using the script for initial token
> generation and for providing multiple detailed methods
It's not going to matter at all.
On Fri, Mar 6, 2020, 2:15 AM Hanauer, Arnulf, Vodacom South Africa
(External) wrote:
> Hi Cassandra folks,
>
>
>
> Is there any difference in performance of general operations if using a
> TEXT based Primary key versus a BIGINT Primary key.
>
>
>
> Our use-case r
You can issue a delete using a future timestamp.
http://cassandra.apache.org/doc/latest/cql/dml.html#grammar-token-update-parameter
Look for USING TIMESTAMP.
Jon
On Mon, Mar 2, 2020, 3:28 AM Furkan Cifci wrote:
> Greetings,
> In our C* cluster, one node lost time sync and it went to future(16
I also recommend avoiding them. I've seen too many clusters fall over as a
result of their usage.
On Fri, Feb 28, 2020 at 9:52 AM Max C. wrote:
> The general view of the community is that you should *NOT* use them in
> production, due to multiple serious outstanding issues (see Jira). We used
Seeds don't bootstrap, don't list new nodes as seeds.
On Thu, Feb 13, 2020 at 5:23 PM Sergio wrote:
> Hi guys!
>
> I don't know how but this is the first time that I see such behavior. I
> wanted to add a new node in the cluster and it looks to be working fine but
> instead to wait for 2-3 hours
A while ago, on my first cluster, I decided to do an upgrade by adding
nodes running 1.2 to an existing cluster running version 1.1. This was a
bad decision, and at that point I decided to always play it safe and always
stick to a single version, and never bootstrap in a node running different
ver
Thanks for handling this, Mick!
On Fri, Feb 7, 2020 at 12:02 PM Mick Semb Wever wrote:
>
>
> The Cassandra team is pleased to announce the release of Apache Cassandra
> version 4.0-alpha3.
>
> Apache Cassandra is a fully distributed database. It is the right choice
> when you need scalability an
There's a few things you can do here that might help.
First off, if you're using the default heap settings, that's a serious
problem. If you've got the head room, my recommendation is to use 16GB
heap with 12 GB new gen and pin your memtable heap space to 2GB. Set your
max tenuring threshold to
I suggest checking out Aaron Morton's post on the 3.0 storage engine.
https://thelastpickle.com/blog/2016/03/04/introductiont-to-the-apache-cassandra-3-storage-engine.html
On Tue, Dec 31, 2019 at 11:20 AM Subroto Barua
wrote:
> I have a table ---
>
> create Table mytable (
>
> Id text,
>
> cdat
n,
>
> Yes we will upgrade it soon. But before we can upgrade shouldn’t we get
> this lost node in the cluster to be replaced ?
>
>
>
>
>
>
>
> *From:* Jon Haddad
> *Sent:* Friday, December 20, 2019 2:13 PM
> *To:* user@cassandra.apache.org
> *Subject:* Re:
You should upgrade to Cassandra 3.11.5 before doing anything else. You're
running a pretty old and buggy version. There's been hundreds (maybe
thousands) of bugs fixed between 3.3 and 3.11.5.
On Fri, Dec 20, 2019 at 10:46 AM Nethi, Manoj
wrote:
> Hi,
>
>
>
> We are seeing the following error w
I'm not sure how you're measuring this - could you share your benchmarking
code?
I ask because execute calls execute_async under the hood:
https://github.com/datastax/python-driver/blob/master/cassandra/cluster.py#L2316
I tested the python driver a ways back and found some weird behavior due to
t
I'm not sure how closely the driver maintainers are following this list.
You might want to ask on the Java Driver mailing list:
https://groups.google.com/a/lists.datastax.com/forum/#!forum/java-driver-user
On Tue, Dec 10, 2019 at 5:10 PM Caravaggio, Kevin <
kevin.caravag...@lowes.com> wrote:
>
You can easily do this with bcache or LVM
http://rustyrazorblade.com/post/2018/2018-04-24-intro-to-lvm/.
Medusa might be a good route to go down if you want to do backups instead:
https://thelastpickle.com/blog/2019/11/05/cassandra-medusa-backup-tool-is-open-source.html
On Thu, Dec 5, 2019 at 1
A new thing like this would be much better served by the community through
several iterations. For instance, over the last year I've developed a tool
for spinning up lab clusters, it's here:
https://thelastpickle.com/tlp-cluster/
I had to make a *lot* of tradeoffs here. Everything Jeff mentioned
What artifact did you use and what OS are you on?
On Thu, Oct 31, 2019 at 12:40 PM Abdul Patel wrote:
> Hey Everyone
>
> Did anyone was successfull to install either alpha or alpha2 version for
> cassandra 4.0?
> Found 2 issues :
> 1> cassandra-env.sh:
> JAVA_VERSION varianle is not defined.
> J
table on a regular basis as any
> other?
>
>
>
> ‐‐‐ Original Message ‐‐‐
> On Wednesday, 30 October 2019 16:26, Jon Haddad wrote:
>
> Counters are good for things like page views, bad for money. Yes they can
> under or overcount in certain situations. If your cluster is
Archives are here: http://archive.apache.org/dist/cassandra/
For example, the RPM for 3.11.x you can find here:
http://archive.apache.org/dist/cassandra/redhat/311x/
The old releases are removed by Apache automatically as part of their
policy, it's not specific to Cassandra.
On Wed, Oct 30, 201
Counters are good for things like page views, bad for money. Yes they can
under or overcount in certain situations. If your cluster is stable,
you'll see very little of it in practice.
I've done quite a bit of tuning of counters. Here's the main takeaways:
* They do a read before a write, so u
My coworker Radovan wrote up a post on the relationship between gc grace
and hinted handoff:
https://thelastpickle.com/blog/2018/03/21/hinted-handoff-gc-grace-demystified.html
Jon
On Sat, Oct 26, 2019 at 6:45 AM Hossein Ghiyasi Mehr
wrote:
> It needs to change gc_grace_seconds carefully because
There's some major warning signs for me with your environment. 4GB heap is
too low, and Cassandra 3.7 isn't something I would put into production.
Your surface area for problems is massive right now. Things I'd do:
1. Never use incremental repair. Seems like you've already stopped doing
them,
Probably not beneficial, I wouldn't do it. Not a fan of multi-tenancy with
Cassandra unless the use cases are so small that your noisy neighbor
problem is not very noisy at all. For those cases I don't know what you
get from Cassandra other than a cool resume.
On Wed, Oct 23, 2019 at 12:41 PM Re
t-1a
>- 4 write TWO us-east-1b 5 write TWO us-east-1b
>- 6 write TWO us-east-1b
>
>
> Here we have 2 DC read and write
> One Rack per DC
> One Availability Zone per DC
>
> Thanks,
>
> Sergio
>
>
> On Wed, Oct 23, 2019, 1:11 PM Jon Haddad wr
Personally, I wouldn't ever do this. I recommend separate DCs if you want
to keep workloads separate.
On Wed, Oct 23, 2019 at 4:06 PM Sergio wrote:
> I forgot to comment for
>
>OPTION C)
>1. Node DC RACK AZ 1 read ONE us-east-1a 2 read ONE us-east-1b
>2. 3 read ONE us-east
CPU waiting on memory will look like CPU overhead. There's a good post on
the topic by Brendan Gregg:
http://www.brendangregg.com/blog/2017-05-09/cpu-utilization-is-wrong.html
Regarding GC, I agree with Reid. You're probably not going to saturate
your network card no matter what your settings,
ospel truth that -XX:+UseNUMA is a good
>> thing on AWS (or anything virtualized), you’d have to run your own tests
>> and find out.
>>
>>
>>
>> R
>>
>> *From: *Jon Haddad
>> *Reply-To: *"user@cassandra.apache.org"
>> *Date: *Mo
testing harnesses. It isn’t worth our time. As a previous
> writer mentioned, there is usually better return on our time tuning the
> schema (aka helping developers understand Cassandra’s strengths).
>
>
>
> We use 16 – 32 GB heaps, nothing smaller than that.
>
>
>
I still use ParNew + CMS over G1GC with Java 8. I haven't done a
comparison with JDK 11 yet, so I'm not sure if it's any better. I've heard
it is, but I like to verify first. The pause times with ParNew + CMS are
generally lower than G1 when tuned right, but as Chris said it can be
tricky. If y
It's possible the queries you're normally running are served out of page
cache, and during the latency spike you're hitting your disks. If you're
using read ahead you might be hitting a throughput limit on the disks.
I've got some numbers and graphs I can share later when I'm not on my
phone.
Jon
I agree with Jeff here. Ideally you should be so comfortable with rolling
restarts that they become second nature. Cassandra is designed to handle
them and you should not be afraid to do them regularly.
On Wed, Oct 16, 2019, 8:06 AM Jeff Jirsa wrote:
>
> Personally I encourage you to rolling res
Probably not a great idea unless you're using it sparingly. Using LWTs
without knowing all the caveats is likely to lead to terrible cluster
performance.
On Wed, Sep 11, 2019, 10:59 PM A wrote:
> Is it ok if I do this?
>
> ... where email = em AND company_id = id IF EXISTS
>
>
>
>
>
> Sent fr
Technically, not a problem. Use GossipingPropertyFileSnitch to keep things
simple and you can go across whatever cloud providers you want without
issue.
The biggest issue you're going to have isn't going to be Cassandra, it's
having the expertise in the different cloud providers to understand the
Just to close the loop on this, I did a release of tlp-stress last night,
which now has this workload (AllowFiltering). You can grab a deb, rpm,
tarball or docker image.
Docs are here: http://thelastpickle.com/tlp-stress/
Jon
On Mon, Aug 19, 2019 at 2:21 PM Jon Haddad wrote:
> It'll
This advice hasn't been valid for a long time now for most use cases. The
only time you need to reserve 50% disk space is if you're going to be
running major compactions against a table in your cluster that occupies 50%
of its total disk space. Nowadays, that's far less common than it was when
yo
gt; Jon,
>
> If we expect non of our partition key to have more than 100 records and
> pass partition key in where clause we wouldnt see issues using new column
> and allow filtering? Can you please point me to any doc how allow
> filtering works. I was in assumption of it goes through
If you're giving the partition key you won't scan the whole table. The
overhead will depend on the size or the partition.
Would be an interesting workload for our tlp-stress tool, I'll code
something up for the next release.
On Sun, Aug 18, 2019, 12:58 PM Rahul Reddy wrote:
> Hello,
>
> We have
Any chance you're using NVMe with an older Linux kernel? I've seen a *lot*
filesystem errors from using older CentOS versions. You'll want to be
using a version > 4.15.
On Thu, Aug 8, 2019 at 9:31 AM Philip Ó Condúin
wrote:
> *@Jeff *- If it was hardware that would explain it all, but do you t
I think this might be because the timeout only applied to each request, and
the driver is paginating in the background. Each page is a new request.
On Mon, Aug 5, 2019, 12:08 AM Oleksandr Shulgin <
oleksandr.shul...@zalando.de> wrote:
> On Mon, Aug 5, 2019 at 8:50 AM nokia ceph
> wrote:
>
>> Hi
http://www.brendangregg.com/linuxperf.html
On Sat, Jul 27, 2019 at 2:45 AM Paul Chandler wrote:
> I have always found Amy's Cassandra 2.1 tuning guide great for the Linux
> performance tuning:
> https://tobert.github.io/pages/als-cassandra-21-tuning-guide.html
>
> Sent from my iPhone
>
> On 26 J
If you're thinking about rewriting your data to be more performant when
doing analytics, you might as well go the distance and put it in an
analytics friendly format like Parquet. My 2 cents.
On Thu, Jul 25, 2019 at 11:01 AM ZAIDI, ASAD A wrote:
> Thank you all for your insights.
>
>
>
> When s
for using MV was avoiding updates (delete +
> create) on primaryKey columns because we suppose that cassandra developers
> can manage this unpreferred operation better then us. I'm really confused
> now.
>
>
>
> On Wednesday, July 24, 2019, 11:30:15 PM GMT+3, Jon Haddad
I really, really advise against using MVs. I've had to help a number of
teams move off them. Not sure what list of bugs you read, but if the list
didn't include "will destabilize your cluster to the point of constant
downtime" then the list was incomplete.
Jon
On Wed, Jul 24, 2019 at 6:32 AM me
It's a limit on the total compaction throughput.
On Fri, Jul 19, 2019 at 10:39 AM Vlad wrote:
> Hi,
>
> is 'nodetool setcompactionthroughput' sets limit for all compactions on
> the node, or is it per compaction thread?
>
> Thanks.
>
Yep - not to mention the increased complexity and overhead of going from
ONE to QUORUM, or the increased cost of QUORUM in RF=5 vs RF=3.
If you're in a cloud provider, I've found you're almost always better off
adding a new DC with a higher RF, assuming you're on NTS like Jeff
mentioned.
On Fri,
100% agree with Sean. I would only use Cassandra backups in a case where
you need to restore from full cluster loss. Example: An entire DC burns
down, tornado, flooding.
Your routine node replacement after a failure should be
replace_address_first_boot.
To ensure this goes smoothly, run regular
Yep. I would *never* use mean when it comes to performance to make any
sort of decisions. I prefer to graph all the p99 latencies as well as the
max.
Some good reading on the topic:
https://bravenewgeek.com/everything-you-know-about-latency-is-wrong/
On Thu, May 30, 2019 at 7:35 AM Chris Lohfin
.
>
> Sent using Zoho Mail
>
>
>
> ==== Forwarded message
> From: Jon Haddad
> To:
> Date: Sat, 04 May 2019 22:10:39 +0430
> Subject: Re: How to set up a cluster with allocate_tokens_for_keyspace?
> Forwarded message
>
> That line is only
Do separate queries for each partition you want. There's no benefit
in using the IN() clause here, and performance is significantly worse
with multi-partition IN(), especially if the partitions are small.
On Sun, May 5, 2019 at 4:52 AM Soheil Pourbafrani wrote:
>
> Hi,
>
> I want to run cqlsh qu
That line is only relevant for when you're starting your cluster and
you need to define your initial tokens in a non-random way. Random
token distribution doesn't work very well when you only use 4 tokens.
Once you get the cluster set up you don't need to specify tokens
anymore, you can just use
Just curious - why are you using such large batches? Most of the time
when someone asks this question, it's because they're using batches as
they would in an RDBMS, because larger transactions improve
performance. That doesn't apply with Cassandra.
Batches are OK at keeping multiple tables in sy
Agreed with Jeff here. The whole "community recommends no more than
1TB" has been around, and inaccurate, for a long time.
The biggest issue with dense nodes is how long it takes to replace
them. 4.0 should help with that under certain circumstances.
On Thu, Apr 18, 2019 at 6:57 AM Jeff Jirsa
Let me be more specific - run the async java profiler and generate a
flame graph to determine where CPU time is spent.
On Wed, Apr 17, 2019 at 11:36 AM Jon Haddad wrote:
>
> Run the async java profiler on the node to determine what it's doing:
> https://github.com/jvm-profili
Run the async java profiler on the node to determine what it's doing:
https://github.com/jvm-profiling-tools/async-profiler
On Wed, Apr 17, 2019 at 11:31 AM Carl Mueller
wrote:
>
> No, we just did the package upgrade 2.1.9 --> 2.2.13
>
> It definitely feels like some indexes are being recalculate
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