The incoming mutations are written per column in a Memtable (an in memory
cache) . The default size for this table is 64MB if I can recall correctly.
For more information take a look here:
https://wiki.apache.org/cassandra/MemtableSSTable
http://wiki.apache.org/cassandra/MemtableThresholds
-Original Message-
From: Oleg Dulin [mailto:oleg.du...@gmail.com]
Sent: Wednesday, April 09, 2014 10:42 AM
To: user@cassandra.apache.org
Subject: Re: Commitlog questions
Parag:
To answer your questions:
1) Default is just that, a default. I wouldn't advise raising it though. The
bigger
talking about
before it even hits any disk. This has to be in memory, correct?
Parag
-Original Message-
From: Oleg Dulin [mailto:oleg.du...@gmail.com]
Sent: Wednesday, April 09, 2014 10:42 AM
To: user@cassandra.apache.org
Subject: Re: Commitlog questions
Parag:
To answer your
1) Why is the default 4GB? Has anyone changed this? What are some aspects
to consider when determining the commitlog size?
2) If the commitlog is in periodic mode, there is a property to set a time
interval to flush the incoming mutations to disk. This implies that there is a
Parag:
To answer your questions:
1) Default is just that, a default. I wouldn't advise raising it
though. The bigger it is the longer it takes to restart the node.
2) I think they juse use fsync. There is no queue. All files in
cassandra use java.nio buffers, but they need to be fsynced
On Wed, Apr 9, 2014 at 3:06 AM, Parag Patel ppa...@clearpoolgroup.comwrote:
some questions about the commitlog and related assumptions
https://issues.apache.org/jira/browse/CASSANDRA-6764
You might wish to get in contact with the reporter here, who has similar
questions!
=Rob
