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From Dmitriy Setrakyan <dsetrak...@apache.org>
Subject Re: Cache preloading
Date Tue, 01 Sep 2015 01:33:51 GMT
On Mon, Aug 31, 2015 at 5:56 PM, vkulichenko <valentin.kulichenko@gmail.com>

> Andrey,
> Loading from cache store is usually used only for initial data load, so
> it's
> safe to do it only after nodes started and before any other cache
> operations
> (puts, transactions, etc.) are performed. Topology should be also stable -
> if a node joins or fails during the process, most likely you will have to
> restart it to make sure data is consistent. It works this way because
> loading from store is supposed to run only once. After it's completed, you
> can safely change topology - rebalancing will guarantee data consistency
> even if it happens concurrently with cache updates.
> If this doesn't work for you, I would recommend to use IgniteDataStreamer
> instead and load data from a designated client node. This approach is more
> centralized and allows to load the data concurrently with updates and
> topology changes.

Valya, it would be great if you added a blurb in the documentation about
this. Perhaps a Note or a Tip paragraph.

> To trigger preloading from store simply execute IgniteCache.loadCache()
> method, it will initiate the process on all nodes.
> The process itself is the same for partitioned and replicated caches.d When
> loading data, a node stores entries that are primary OR backup for this
> node. Since replicated cache always has as many backups as many nodes in
> topology, nothing is discarded, while with partitioned cache a node will
> save only part of the data.
> Makes sense?
> -Val
> --
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