Re: [libvirt] [PATCH v2] lib: Add note that bulk stats API queries may overrun RPC buffers

On Tue, May 23, 2017 at 05:07:40PM +0200, Michal Privoznik wrote: > Because: > > https://www.redhat.com/archives/libvir-list/2017-May/msg00088.html I don't think this is a reason at all. Libguestfs uses an RPC system which was modelled on the libvirt one, and has exactly the same problem with message size limits, except smaller -- 4MB and we've never had to increase it. We get around this by batching operations over messages as necessary (eg [1]). This adds a little complexity in the implementation of the API, but the point is that the complexity is entirely hidden to users of the APIs. Rich. [1] https://github.com/libguestfs/libguestfs/blob/master/lib/file.c#L375-L415 In this code, ‘guestfs_impl_lstatnslist’ is the publicly visible API (it's the implementation of the public API guestfs_lstatnslist). ‘guestfs_internal_lstatnslist’ is the message which travels over the RPC. The batching of 1000 requests per message was chosen based on pathname limits on Linux so that each request will always fit into a single message.

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