<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Just FYI,<div><br></div><div>RabbitMQ does not use Mnesia as message storage. It has it's own persister module.</div><div><br></div><div>AFAIK Mnesia is only used for storing routing tables, Exchanges and Queues meta information.</div><div><br></div><div>-Alvaro</div><div><br><div><div>On Jun 3, 2011, at 1:35 PM, Alex Lovell-Troy wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">There are a handful of approaches to this problem which all seem to follow a similar pattern. Until there is a way to replace mnesia with a replicable back end, we've all written something on our own that wraps each amqp transaction with a transactional write to the datastore of our choice and. I've seen this done with MySQL, MongoDB, and riak personally. <div>
<br></div><div>@jbrisbin has done some interesting work with implementing a specific queue that sends messages to riak that looks intriguing. I believe there is also a piece that pushes messages from riak into rabbitmq.</div>
<div><br><div class="gmail_quote">At least, that was the state of the art the last time I looked</div><div class="gmail_quote"><br></div><div class="gmail_quote">Anyone else?</div><div class="gmail_quote"><br></div><div class="gmail_quote">
-alex</div><div class="gmail_quote"><br></div><div class="gmail_quote">On Fri, Jun 3, 2011 at 12:21 PM, Ozan Seymen <span dir="ltr"><<a href="mailto:Ozan.Seymen@tdpg.com">Ozan.Seymen@tdpg.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div lang="EN-GB" link="blue" vlink="purple">
<div><p class="MsoNormal">Hi all,</p><div> <br class="webkit-block-placeholder"></div><p class="MsoNormal">Can someone please explain the scenarios where we might have Rabbit message storage (is it mnesia?) corrupted in a way that it is not recoverable?</p><div> <br class="webkit-block-placeholder"></div><p class="MsoNormal">In the solution I am working on, I simply cannot afford to lose any messages. In order to secure this, I will:</p><div> <br class="webkit-block-placeholder"></div><p><span style="font-family:Symbol"><span>�<span style="font:7.0pt "Times New Roman"">
</span></span></span>Rely on publisher confirms. This should ensure that broker will always confirm whether it assumed responsibility and persisted the message.
</p><p><span style="font-family:Symbol"><span>�<span style="font:7.0pt "Times New Roman"">
</span></span></span>Implement durable queues/exchanges.</p><p><span style="font-family:Symbol"><span>�<span style="font:7.0pt "Times New Roman"">
</span></span></span>Ack enabled in consumers to prevent losing messages if consumer dies halfway. I will solve the ordering problem on the consumer side.</p><div> <br class="webkit-block-placeholder"></div><p class="MsoNormal">Even though all of these above prevent message loss in normal conditions, none of them covers the case where data gets corrupted in the broker. There is a window (albeit small) that things might go wrong: broker assumes responsibility (message
is in the disk) and before message is sent to the consumer, broker experiences problems which corrupts the storage. If I can�t bring the broker up with all data previously persisted, I�ve lost messages � producer forgot about the message as broker accepts
responsibility and consumers have no idea about the message as it hasn�t been delivered to it.</p><div> <br class="webkit-block-placeholder"></div><p class="MsoNormal">Am I a total paranoid that is beyond help? Even so, I would really appreciate any info you guys can share.</p><div> <br class="webkit-block-placeholder"></div><p class="MsoNormal">Cheers,</p><p class="MsoNormal">oseymen</p><div> <br class="webkit-block-placeholder"></div><div> <br class="webkit-block-placeholder"></div><div> <br class="webkit-block-placeholder"></div><div> <br class="webkit-block-placeholder"></div>
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