On 8/22/11 6:48 PM, Horacio Sanson wrote:
Thanks for all the answers... very informative and now I am confident
that what the client is asking is too much.
The application is a custom Ad Server (think adSense, iAd, etc) for
mobiles we implemented in Japan. And as some know the mobile market in
Japan is huge. We have three clients and between them we get
300,000,000 (300 million) hits per month. The image data changes
several times a day but the database and log files change hundreds of
times per second. Each record/line in the DB and logs represents lots
of money for advertisers and publishers that cannot be lost.
Our system is hosted in a cloud and they handle virtual machine
snapshots (they say) but I cannot tell how effective or good these
are. For example I understand these snapshots do not guarantee that
the DB is in a stable because they cannot flush the DB memory during
the snapshot and the same may be true for logs.
As many said this 15 min requirement is too much for any backup
solution and instead I will go with high availability options like
redundant DBs (slaves) and remote logging (rsyslog).
thanks for all the answers, very helpful....
Also, note the lessons from the major cloud failures earlier this year.
For serious applications with real financial consequences, people are setting up across more than
one cloud vendor, with replication and failover. If, e.g., Amazon fails and you lose your access for
an extended period, or lose your data, then you flip over to the other vendor. Those who had done
that experienced very little or no outage. Those who were totally dependent on the failed vendor
were out for anywhere from hours to days.
You should be able to google back and find the case studies. I didn't dig into details, but just
made note of the concept for future reference.
--
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Chris Hoogendyk
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O__ ---- Systems Administrator
c/ /'_ --- Biology& Geology Departments
(*) \(*) -- 140 Morrill Science Center
~~~~~~~~~~ - University of Massachusetts, Amherst
<[email protected]>
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Erdös 4
