What are the restrictions of metadata on Swift Object ?

asked 2019-01-24 04:19:47 -0500

updated 2019-01-24 07:51:59 -0500


I'm looking for some details about the limits of the metadata used by Swift. I found some information on the Constraints section on the Swift's documentation.

max_meta_name_length = 128

The max number of bytes in the utf8 encoding of the name portion of a metadata header.

What's the "name portion" in a header ? I did'nt found any example or explanation.

max_meta_count = 90 / The max number of metadata keys that can be stored on a single account, container, or object.

max_meta_overall_size = 4096 / The max number of bytes in the utf8 encoding of the metadata (keys + values).

Can i change this values (with some performance tests) or is there any limits imposed by the system (XFS, or other) ?

Are object's metadata stored in the same partition as the object itself ?

Are object's metadata replicated like data is ? Did Erasure Coding works with object's metada too ?

Thanks in advance !

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