Amazon EBS volumes come with a very cool feature called "lazy
loading". In a nutshell: if a volume is created from an existing
snapshot, it can become available almost immediately without
waiting for all data to be restored. This allows for extremely
fast provisioning of large data sets as long as you don't
explicitly require the entire data set to be present before you
start using it.
When an EBS volume is restored from snapshot, its blocks are
fetched from Amazon S3. It happens either lazily in the
background or explicitly on demand (think of a pagefault-like
mechanism) and of course, fetching pieces of data from Amazon S3
is going to be one-two orders of magnitude slower than reading
blocks directly from a volume.
In this short article, I will try to give you an idea of how this
may impact the crash recovery time of your MySQL databases. Why
talk about this? Depending on the workload and data set layout,
crash recovery of a MySQL …
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Nov
18
2015
Showing entries 1 to 1