cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ali Hubail <>
Subject Re: Compaction Strategy
Date Thu, 20 Sep 2018 17:53:00 GMT
Hello Rajasekhar,

It's not really clear to me what your workload is. As I understand it, you 
do heavy writes, but what about reads?
So, could you:

1) execute 
nodetool tablestats 
nodetool tablehistograms
nodetool compactionstats

we should be able to see the latency, workload type, and the # of sstable 
used for reads

2) specify your hardware specs. i.e., memory size, cpu, # of drives (for 
data sstables), and type of harddrives (ssd/hdd)
3) cassandra.yaml (make sure to sanitize it)

You have a lot of updates, and your data is most likely scattered across 
different sstables. size compaction strategy (STCS) is much less expensive 
than level compaction strategy (LCS). 

Stopping the background compaction should be approached with caution, I 
think your problem is more to do with why STCS compaction is taking more 
resources than you expect.


Ali Hubail

Petrolink International Ltd
Confidentiality warning: This message and any attachments are intended 
only for the persons to whom this message is addressed, are confidential, 
and may be privileged. If you are not the intended recipient, you are 
hereby notified that any review, retransmission, conversion to hard copy, 
copying, modification, circulation or other use of this message and any 
attachments is strictly prohibited. If you receive this message in error, 
please notify the sender immediately by return email, and delete this 
message and any attachments from your system. Petrolink International 
Limited its subsidiaries, holding companies and affiliates disclaims all 
responsibility from and accepts no liability whatsoever for the 
consequences of any unauthorized person acting, or refraining from acting, 
on any information contained in this message. For security purposes, staff 
training, to assist in resolving complaints and to improve our customer 
service, email communications may be monitored and telephone calls may be 

rajasekhar kommineni <> 
09/19/2018 04:44 PM
Please respond to


Re: Compaction Strategy


Can any one respond to my questions. Is it a good idea to disable auto 
compaction and schedule it every 3 days. I am unable to control compaction 
and it is causing timeouts. 

Also will reducing or increasing compaction_throughput_mb_per_sec 
eliminate timeouts ?


> On Sep 17, 2018, at 9:38 PM, rajasekhar kommineni <> 
> Hello Folks,
> I need advice in deciding the compaction strategy for my C cluster. 
There are multiple jobs that will load the data with less inserts and more 
updates but no deletes. Currently I am using Size Tired compaction, but 
seeing auto compactions after the data load kicks, and also read timeouts 
during compaction.
> Can anyone suggest good compaction strategy for my cluster which will 
reduce the timeouts.
> Thanks,

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message