Data replication

After a data has been added to the DAGDA hierarchy, the users can choose to replicate it explicitely on one or several DIET nodes. With the current DAGDA version, we allow to choose the nodes where the data will be replicated by hostname or DAGDA component ID. In future developments, it will be possible to select the nodes differently. To maintain backward compatibility, the replication function uses a C-string to define the replication rule.

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dagda_replicate_data(const char* id, const char* rule)

The replication rule is defined as follows:
“Pattern target:identification pattern:Capacity overflow behavior”

• The pattern target can be “ID” or “host”.
• The identification pattern can contain some wildcards characters. (for example “*.lyon.grid5000.fr” is a valid pattern.
• The capacity overflow behavior can be “replace” or “noreplace”. “replace” means the cache replacement algorithm will be used if available on the target node (a data could be deleted from the node to leave space to store the new one). “noreplace” means that the data will be replicated on the node if and only if there is enough storage capacity on it.

For example, “host:capricorne-*.lyon.*:replace” is a valid replication rule.