Re: Scrub - autocompaction

2018-10-29 Thread Vlad
Hi
>you should reach an end as the scrub is applied to a list of sstables 
>calculated scrub start (I believe).What I observed is that in data folder 
>almost no original SSTables remained, but scrub still ran. So I suspect 
>processing each new appearing table.
 

On Monday, October 29, 2018 8:34 PM, Alain RODRIGUEZ  
wrote:
 

 Hello,

should autocompaction be disabled before running scrub?


I would say the other way around, to be sure to leave some room to regular 
compactions, you could try to run scrub with the following option
`nodetool scrub -j 1` (-j / --jobs allow controlling the number of compactor 
threads to use). Depending on the rhythm you want to give to compaction 
operations, you can tune this number and the ‘concurrent_compactor' option.

It seems that scrub processes each new created table and never ends.

Depending on the command that was run, if nothing was specified, nodetool scrub 
might be running on the whole node (or keyspace?), which can be a lot, so when 
an SSTable finishes, another might well start, for quite a while. But you 
should reach an end as the scrub is applied to a list of sstables calculated 
scrub start (I believe).
Here is what I can share from my understanding. If you believe there might be 
an issue with your version of Cassandra or want to make sure that 'nodetool 
scrub' behaves as described, reading the code and/or observing writ time of the 
files that are getting compacted (SCRUB) is a way to go.
C*heers,---Alain Rodriguez - alain@thelastpickle.comFrance 
/ Spain
The Last Pickle - Apache Cassandra Consultinghttp://www.thelastpickle.com


Le lun. 29 oct. 2018 à 16:18, Vlad  a écrit :

Hi,
should autocompaction be disabled before running scrub?It seems that scrub 
processes each new created table and never ends.
Thanks.



   

Re: Scrub - autocompaction

2018-10-29 Thread Alain RODRIGUEZ
Hello,

should autocompaction be disabled before running scrub?
>

I would say the other way around, to be sure to leave some room to regular
compactions, you could try to run scrub with the following option

`nodetool scrub -j 1` (-j / --jobs allow controlling the number of
compactor threads to use). Depending on the rhythm you want to give to
compaction operations, you can tune this number and the
‘concurrent_compactor' option.

It seems that scrub processes each new created table and never ends.


Depending on the command that was run, if nothing was specified, nodetool
scrub might be running on the whole node (or keyspace?), which can be a
lot, so when an SSTable finishes, another might well start, for quite a
while. But you should reach an end as the scrub is applied to a list of
sstables calculated scrub start (I believe).

Here is what I can share from my understanding. If you believe there might
be an issue with your version of Cassandra or want to make sure that
'nodetool scrub' behaves as described, reading the code and/or observing
writ time of the files that are getting compacted (SCRUB) is a way to go.

C*heers,
---
Alain Rodriguez - al...@thelastpickle.com
France / Spain

The Last Pickle - Apache Cassandra Consulting
http://www.thelastpickle.com



Le lun. 29 oct. 2018 à 16:18, Vlad  a écrit :

> Hi,
>
> should autocompaction be disabled before running scrub?
> It seems that scrub processes each new created table and never ends.
>
> Thanks.
>


Scrub - autocompaction

2018-10-29 Thread Vlad
Hi,
should autocompaction be disabled before running scrub?It seems that scrub 
processes each new created table and never ends.
Thanks.