incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From CASSANDRA learner <cassandralear...@gmail.com>
Subject Re: Memtables stored in which location
Date Thu, 21 Jul 2011 10:55:47 GMT
Thanks Aaron and samal for your quick response. Its going to be helpful....

On Thu, Jul 21, 2011 at 4:15 PM, aaron morton <aaron@thelastpickle.com>wrote:

> Try the project wiki here
> http://wiki.apache.org/cassandra/ArchitectureOverview or the my own blog
> here
> http://thelastpickle.com/2011/04/28/Forces-of-Write-and-Read/
>
> There is also a list of articles on the wiki here
> http://wiki.apache.org/cassandra/ArticlesAndPresentations
>
> in short, writes got to the commit log first, then the memtable in memory,
> which is later flushed to disk. A read is from potentially multiple sstables
> and memtables.
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Cassandra Developer
> @aaronmorton
> http://www.thelastpickle.com
>
> On 21 Jul 2011, at 21:17, CASSANDRA learner wrote:
>
> Hi,
>
> You r right but i too have some concerns...
>
> Any ways , some where memtable has to be stored right, like we say memtable
> data is flushed to create sstable on disk.
> Exactly from which location or memory it will be getting from. is it like
> an objects streams or like it is storing the values in commitlog.
> my next question is , data is written to commit log. all the data is
> available here, and the sstable are getting created on disk, then where and
> when these memtables are coming into picture
>
> On Thu, Jul 21, 2011 at 1:44 PM, samal <samal@wakya.in> wrote:
>
>> SSTable is stored on disk not memtable.
>>
>> Memtable is memory representation of data, which is on flush to create
>> SSTable on disk.
>>
>> This is the location where SSTable is stored
>> https://github.com/apache/cassandra/blob/trunk/conf/cassandra.yaml#L71
>>
>>
>> Where as Commitlog which is back up (log) for memtable replaying store in
>> https://github.com/apache/cassandra/blob/trunk/conf/cassandra.yaml#L75
>> location.
>>
>> Once the all memtable is flushed to disk, new commit log segment is
>> created.
>>
>> On Thu, Jul 21, 2011 at 1:12 PM, Abdul Haq Shaik <
>> abdulsk.cassandra@gmail.com> wrote:
>>
>>> Hi,
>>>
>>> Can you please let me know where exactly the memtables are getting
>>> stored. I wanted to know the physical location
>>>
>>
>>
>
>

Mime
View raw message