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• cache partition files (primary, backup, SQL index)
• cache configuration
• binary meta-information
• marshaller meta information

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Copy binary, marshaller metas

Binary meta, marshaller meta , configurations still stored in on-heap, so it is easy to collect and keep this persistent user information consistent under the checkpoint write-lock (no changes allowed).

Copy cache configurations

Cache configuration files may be changed during, for instance, concurrent SQL ADD[DROP] COLUMN  operations or SQL CREATE[DROP] INDEX  operations. These changes always happen through the exchange thread. 

Partitions copy strategy

Another strategy must be used for cache partition files. The checkpoint process will write dirty pages from PageMemory to the cache partition files simultaneously with another process copy them to the target directory. Each cache partition file is consistent only at checkpoint end. So, to avoid long-time transaction blocks during the cluster-wide snapshot process it should not wait when checkpoint ends on each node. The process of copying cache partition files must do the following:

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