Re: Commitlog questions

2014-04-10 Thread Russell Hatch
omewhere for a period of 10 seconds. I'm 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@c

RE: Commitlog questions

2014-04-10 Thread Parag Patel
ct? 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 questions: 1) Default is just that, a default. I wouldn't advise raising it thou

Re: Commitlog questions

2014-04-10 Thread Panagiotis Garefalakis
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 Regards

Re: Commitlog questions

2014-04-09 Thread Robert Coli
On Wed, Apr 9, 2014 at 3:06 AM, Parag Patel wrote: > > https://issues.apache.org/jira/browse/CASSANDRA-6764 You might wish to get in contact with the reporter here, who has similar questions! =Rob

Re: Commitlog questions

2014-04-09 Thread Oleg Dulin
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 perio

Commitlog questions

2014-04-09 Thread Parag Patel
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 queu