incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Tyler Hobbs <ty...@datastax.com>
Subject Re: Recommended data size for Reads/Writes in Cassandra
Date Thu, 18 Jul 2013 21:50:29 GMT
The default limit is 16mb, but realistically you should try to keep writes
under 10mb, breaking up large values into multiple columns/rows if
necessary.


On Thu, Jul 18, 2013 at 4:31 PM, Andrey Ilinykh <ailinykh@gmail.com> wrote:

> there is a limit of thrift message ( thrift_max_message_length_in_mb), by
> default it is 64m if I'm not mistaken. This is your limit.
>
>
> On Thu, Jul 18, 2013 at 2:03 PM, hajjat <hajjat@purdue.edu> wrote:
>
>> Hi,
>>
>> Is there a recommended data size for Reads/Writes in Cassandra? I tried
>> inserting 10 MB objects and the latency I got was pretty high. Also, I was
>> never able to insert larger objects (say 50 MB) since Cassandra kept
>> crashing when I tried that.
>>
>> Here is my experiment setup:
>> I used two Large VMs in EC2 within the same data-center. Inserts have ALL
>> consistency (strong consistency).  The latencies were as follows:
>> Data size:      10 MB           1 MB            100 Bytes
>> Latency:        250ms           50ms            8ms
>>
>> I've also done the same for two Large VMs across two data-centers. The
>> latencies were around:
>> Data size:      10 MB           1 MB            100 Bytes
>> Latency:        1200ms          800ms   80ms
>>
>> 1) Ain't the 10 MB latency extremely high?
>> 2) Is there a recommended data size to use with Cassandra (e.g., a few
>> bytes
>> up to 1 MB)?
>> 3) Also, I tried inserting 50 MB data but Cassandra kept crashing. Does
>> anybody know why? I thought the max data size should be up to 2 GB?
>>
>> Thanks,
>> Mohammad
>>
>> PS. Here is my python code I use to insert into Cassandra. I put my
>> stopwatch timers around the insert statement:
>>     fh = open(TEST_FILE,'r')
>>     data = str(fh.read())
>>
>>     POOL = ConnectionPool(keyspace, server_list=['localhost:9160'],
>> timeout=None)
>>     USER = ColumnFamily(POOL, 'User')
>>     USER.insert('Ali', {'data':
>>
>> data},write_consistency_level=pycassa.cassandra.ttypes.ConsistencyLevel.ALL)
>>
>>
>>
>>
>> --
>> View this message in context:
>> http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Recommended-data-size-for-Reads-Writes-in-Cassandra-tp7589141.html
>> Sent from the cassandra-user@incubator.apache.org mailing list archive
>> at Nabble.com.
>>
>
>


-- 
Tyler Hobbs
DataStax <http://datastax.com/>

Mime
View raw message