Re: Log4j vulnerability

[Arvinder Dhillon]

If anyone uses tlp-stress tool, it uses Log4j. It might not be in use most
of the time, you might want to remove/upgrade the jar.

On Mon, Dec 13, 2021 at 3:58 PM Bowen Song  wrote:

> Do you mean the log4j-over-slf4j-#.jar? If so, please read:
> http://slf4j.org/log4shell.html
>
> On 13/12/2021 23:48, Rahul Reddy wrote:
>
> Hello,
>
>
> I see this jar  log4j-over-slf4j-1.7.7.jar does it have any impact on it?
> Why that jar is used for ?
>
>
>
> On Sat, Dec 11, 2021 at 12:45 PM Brandon Williams 
> wrote:
>
>> https://issues.apache.org/jira/browse/CASSANDRA-5883
>>
>> As that ticket shows, Apache Cassandra has never used log4j2.
>>
>> On Sat, Dec 11, 2021 at 11:07 AM Abdul Patel  wrote:
>> >
>> > Hi all,
>> >
>> > Any idea if any of open source Cassandra versions are impacted with
>> log4j vulnerability which was reported on dec 9th
>>
>

Re: about memory problem in write heavy system..

[Eunsu Kim]

Thank you Bowen.

As can be seen from the chart, the memory of existing nodes has increased since 
new nodes were added. And I stopped writing a specific table. Write throughput 
decreased by about 15%. And memory usage began to decrease.
I'm not sure if this was done by natural resolution or by reducing writing.
What is certain is that the addition of new nodes has increased the native 
memory usage of some existing nodes.

After reading the 3.x to 4.x migration guide of DataStax, it seems that more 
than 50% of disk availability is required for upgrade. This is likely to be a 
major obstacle to upgrading the cluster in operation.


Many thanks.

> 2022. 1. 10. 오후 8:53, Bowen Song  작성:
> 
> Anything special about the table you stopped writing to? I'm wondering how 
> did you locate the table was the cause of the memory usage increase.
> 
> > For the latest version (3.11.11) upgrade, can the two versions coexist in 
> > the cluster for a while?
> > 
> > Can the 4.x version coexist as well?
> 
> Yes and yes. It is expected that two different versions of Cassandra will be 
> running in the same cluster at the same time while upgrading. This process is 
> often called zero downtime upgrade or rolling upgrade. You can perform such 
> upgrade from 3.11.4 to 3.11.11 or directly to 4.0.1, both are supported. 
> Surprisingly, I can't find any documentation related to this on the 
> cassandra.apache.org website (if you found it, please send me a link). Some 
> other sites have brief guides on this process, such as DataStax 
> 
>  and Instaclustr 
> ,
>  and you should always read the release notes 
>  which includes 
> breaking changes and new features before you perform an upgrade.
> 
> 
> 
> On 10/01/2022 00:18, Eunsu Kim wrote:
>> Thank you for your response
>> 
>> Fortunately, memory usage came back down over the weekend. I removed the 
>> writing of a specific table last Friday.
>> 
>> <붙여넣은 그래픽-2.png>
>> 
>> 
>> For the latest version (3.11.11) upgrade, can the two versions coexist in 
>> the cluster for a while?
>> 
>> Can the 4.x version coexist as well?
>> 
>>> 2022. 1. 8. 오전 1:26, Jeff Jirsa >> > 작성:
>>> 
>>> 3.11.4 is a very old release, with lots of known bugs. It's possible the 
>>> memory is related to that.
>>> 
>>> If you bounce one of the old nodes, where does the memory end up? 
>>> 
>>> 
>>> On Thu, Jan 6, 2022 at 3:44 PM Eunsu Kim >> > wrote:
>>> 
>>> Looking at the memory usage chart, it seems that the physical memory usage 
>>> of the existing node has increased since the new node was added with 
>>> auto_bootstrap=false.
>>> 
>>> <붙여넣은 그래픽-1.png>
>>> 
>>> 
 
 On Fri, Jan 7, 2022 at 1:11 AM Eunsu Kim >>> > wrote:
 Hi,
 
 I have a Cassandra cluster(3.11.4) that does heavy writing work. (14k~16k 
 write throughput per second per node)
 
 Nodes are physical machine in data center. Number of nodes are 30. Each 
 node has three data disks mounted.
 
 
 A few days ago, a QueryTimeout problem occurred due to Full GC.
 So, referring to this 
 blog(https://thelastpickle.com/blog/2018/04/11/gc-tuning.html 
 ), it seemed to 
 have been solved by changing the memtable_allocation_type to 
 offheap_objects.
 
 But today, I got an alarm saying that some nodes are using more than 90% 
 of physical memory. (115GiB /125GiB)
 
 Native memory usage of some nodes is gradually increasing.
 
 
 
 All tables use TWCS, and TTL is 2 weeks.
 
 Below is the applied jvm option.
 
 -Xms31g
 -Xmx31g
 -XX:+UseG1GC
 -XX:G1RSetUpdatingPauseTimePercent=5
 -XX:MaxGCPauseMillis=500
 -XX:InitiatingHeapOccupancyPercent=70
 -XX:ParallelGCThreads=24
 -XX:ConcGCThreads=24
 …
 
 
 What additional things can I try?
 
 I am looking forward to the advice of experts.
 
 Regards.
>>> 
>> 

Interview opportunity for Cassandra users

[Chris Thornett]

Hello everyone,

My name is Chris, and I provide content support for the Apache Cassandra
project. As part of Apache Cassandra's ongoing content marketing, I'd like
to give Cassandra users the opportunity to participate in a little
interview series called 'Inside Cassandra', which will be published on the
Apache Cassandra blog. Here's an example of something we've done
previously:
https://cassandra.apache.org/_/blog/Inside-Cassandra-an-interview-with-Marcel-Birkner-at-Instana.html

This is an opportunity for you to talk about how you're using Cassandra and
perhaps talk about trends you're seeing in your field and anything topical
around the Cassandra ecosystem (as long as it's open source and not used as
a promo opportunity for a commercial product, please, as we are an Apache
project).

By sharing your experiences, you'll be helping other users learn more about
Cassandra, share your knowledge, and help spread the word
about the database, which everyone in the community would greatly
appreciate!

The interviews themselves would only take half an hour. We'd record them
and then write them up as blog entries and/or potentially offer them to
other press outlets (if you'd be interested in permitting us to do that as
well).

*Case Studies*
Additionally, if you think your company would be happy to be interviewed
for a case study, we're always looking for those to write up and add to the
dedicated case study page here -
https://cassandra.apache.org/_/case-studies.html.

If you're interested in either option, please let me know at
cassan...@constantia.io.

Thanks!

--
Chris Thornett
senior content strategist, Constantia.io