[BBLISA-announce] Recap from July and no August meeting

[John P. Rouillard]

Hi all:

Just found this in my drafts folder from oh about a month ago 8-/.

Twenty eight people joined us for Jeff Darcy's talk on Cloud storage
options and DFS.

The talk started by noting the passing of Seth Vidal who was friend to
Jeff.

He then started his talk about the requirements for a cloud based
filesystem including:

   * horizontal scaling to increase aggregate performance
   * predictability of performance over a workload
   * durability guarantees fsync/osync (and where some DFS's fail)
   * consistency guarantee: can you write from one client and read
     back old data from another client.

Also discussed were the various replication strategies and their
different tradeoffs:

   * chain replication (higher latency, but full bandwidth use of
     server/replicant connection)
   * fanout replication (lower latency but bandwidth split among all
     replicants)


He also shared the results he ran on Rackspace servers using a worst
performance case of a 4k blocks, random i/o.  This resulted in a
surprising win for gluster which beat ceph on iops using the raw
api's. Ceph's design (block storage with a filesystem layer on top)
would seem to be optimized for this workload compared to gluster
(filesystem layer with block storage on top). Also since ceph has a
kernel driver rather than using fuse (as gluster does), it would be
expected to be better for filesystem (posix semantics) but again
gluster had better performance.

The talk wrapped up with some non-filesystems cloud storage options
including:

  cassandra, bigtables/column data model, brisk (hadoop), CQL, Riak
  document data model (e.g. mongo, couchdb similar data model but
  different consistency/replication)

Then followed by a lively discussion section.

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We have no meeting scheduled for August.


-----------

Also we have no speaker scheduled for September at this point. If we
can't find one, I will be speaking on:

  BackupPC - it's not just for desktops anymore

  Where I will discuss the multi-site multi TB BackupPC installation
  that I use at work to backup the important files and databases
  including a windows server.

--
				-- rouilj
John Rouillard
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My employers don't acknowledge my existence much less my opinions.