[Gluster-devel] [DHT] The myth of two hops for linkto file resolution

Raghavendra Gowdappa rgowdapp at redhat.com
Sun Apr 30 04:03:59 UTC 2017


All,

Its a common perception that the resolution of a file having linkto file on the hashed-subvol requires two hops:

1. client to hashed-subvol.
2. client to the subvol where file actually resides.

While it is true that a fresh lookup behaves this way, the other fact that get's ignored is that fresh lookups on files are almost always prevented by readdirplus. Since readdirplus picks the dentry from the subvolume where actual file (data-file) resides, the two hop cost is most likely never witnessed by the application.

A word of caution is that I've not done any testing to prove this observation :).

regards,
Raghavendra


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