Re: How to throttle up/down compactions without a restart

[Jeff Jirsa]

You can also set concurrent compactors through JMX – in the CompactionManager 
mbean, you have CoreCompactionThreads and MaxCompactionThreads – you can adjust 
them at runtime, but do it in an order such that Max is always higher than Core

 

 

 

From: kurt Greaves <k...@instaclustr.com>
Reply-To: "user@cassandra.apache.org" <user@cassandra.apache.org>
Date: Thursday, October 20, 2016 at 9:54 PM
To: "user@cassandra.apache.org" <user@cassandra.apache.org>, 
"thomasjul...@zoho.com" <thomasjul...@zoho.com>
Subject: Re: How to throttle up/down compactions without a restart

 

You can throttle compactions using nodetool setcompactionthroughput .

Where x is in mbps. If you're using 2.2 or later this applies immediately to 
all running compactions, otherwise it applies on any "new" compactions.  You 
will want to be careful of allowing compactions to utilise too much disk 
bandwidth. If you're needing to alter this in peak periods you may be starting 
to overload your nodes with writes, or potentially something else is not ideal 
like memtables flushing too frequently. 


Kurt Greaves 

k...@instaclustr.com

www.instaclustr.com

 

On 21 October 2016 at 04:41, Thomas Julian <thomasjul...@zoho.com> wrote:

Hello,

 

I was going through this presentation and the Slide-55 caught my attention. 

 

i.e) "Throttled down compactions during high load period, throttled up during 
low load period"

 

Can we throttle down compactions without a restart? 

 

If this can be done, what are all the parameters(JMX?) to work with? How to 
implement this for below Compaction Strategies. 

Size Tiered Compaction Strategy.
Leveled Compaction Strategy
Any help is much appreciated.

 

Best Regards,

Julian.

 

 

 

 

 


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Re: How to throttle up/down compactions without a restart

[kurt Greaves]

You can throttle compactions using nodetool setcompactionthroughput .
Where x is in mbps. If you're using 2.2 or later this applies immediately
to all running compactions, otherwise it applies on any "new" compactions.
You will want to be careful of allowing compactions to utilise too much
disk bandwidth. If you're needing to alter this in peak periods you may be
starting to overload your nodes with writes, or potentially something else
is not ideal like memtables flushing too frequently.

Kurt Greaves
k...@instaclustr.com
www.instaclustr.com

On 21 October 2016 at 04:41, Thomas Julian  wrote:

> Hello,
>
>
> I was going through this
> 
> presentation and the Slide-55 caught my attention.
>
> i.e) "Throttled down compactions during high load period, throttled up
> during low load period"
>
> Can we throttle down compactions without a restart?
>
> If this can be done, what are all the parameters(JMX?) to work with? How
> to implement this for below Compaction Strategies.
>
>1. Size Tiered Compaction Strategy.
>2. Leveled Compaction Strategy
>
> Any help is much appreciated.
>
> Best Regards,
> Julian.
>
>
>
>
>