Ok, looks fair enough. Thanks guys. I would be great to be able to add disks when amount of data raises and add nodes when throughput increases... :)
2014-06-19 5:27 GMT+02:00 Ben Bromhead <b...@instaclustr.com>: > > http://www.datastax.com/documentation/cassandra/1.2/cassandra/architecture/architecturePlanningEC2_c.html > > From the link: > > EBS volumes are not recommended for Cassandra data volumes for the > following reasons: > > * EBS volumes contend directly for network throughput with standard > packets. This means that EBS throughput is likely to fail if you saturate a > network link. > * EBS volumes have unreliable performance. I/O performance can be > exceptionally slow, causing the system to back load reads and writes until > the entire cluster becomes unresponsive. > * Adding capacity by increasing the number of EBS volumes per host does > not scale. You can easily surpass the ability of the system to keep > effective buffer caches and concurrently serve requests for all of the data > it is responsible for managing. > > Still applies, especially the network contention and latency issues. > > Ben Bromhead > Instaclustr | www.instaclustr.com | @instaclustr > <http://twitter.com/instaclustr> | +61 415 936 359 > > On 18 Jun 2014, at 7:18 pm, Daniel Chia <danc...@coursera.org> wrote: > > While they guarantee IOPS, they don't really make any guarantees about > latency. Since EBS goes over the network, there's so many things in the > path of getting at your data, I would be concerned with random latency > spikes, unless proven otherwise. > > Thanks, > Daniel > > > On Wed, Jun 18, 2014 at 1:58 AM, Alain RODRIGUEZ <arodr...@gmail.com> > wrote: > >> In this document it is said : >> >> >> - Provisioned IOPS (SSD) - Volumes of this type are ideal for the >> most demanding I/O intensive, transactional workloads and large relational >> or NoSQL databases. This volume type provides the most consistent >> performance and allows you to provision the exact level of performance you >> need with the most predictable and consistent performance. With this type >> of volume you provision exactly what you need, and pay for what you >> provision. Once again, you can achieve up to 48,000 IOPS by connecting >> multiple volumes together using RAID. >> >> >> >> 2014-06-18 10:57 GMT+02:00 Alain RODRIGUEZ <arodr...@gmail.com>: >> >> Hi, >>> >>> I just saw this : >>> http://aws.amazon.com/fr/blogs/aws/new-ssd-backed-elastic-block-storage/ >>> >>> Since the problem with EBS was the network, there is no chance that this >>> hardware architecture might be useful alongside Cassandra, right ? >>> >>> Alain >>> >> >> > >
