Ah, looking more closely at your request. You are wondering if the
pre-read list is seen by the proxy. Yes, but it does nothing as we had
nothing to hook it to. Implementations are welcome. Look at
read(offset, length)
which means I want this data here but I don't have anywhere to deliver it
to yet.
Andy
On Tue, 23 Oct 2012, Matevz Tadel wrote:
> Hi,
>
> Is there a way for a client to issue an advisory prefetch request to a
> server?
> The scenario I have in mind is:
> 1. The client knows it will need to access a specific part of the file but
> it will take it a while to plow through, with many small read requests.
> 2. It suspects (or knows) it is actually talking to a proxy server that
> needs to fetch data over WAN.
> 3. It knows it will NOT need any other part of the file.
> The request would be ignored by normal (non-proxy) servers.
>
> The use case is populating proxy-cache with known missing blocks from hadoop,
> 64 or 128MB in size ... but doing it on demand, when the "broken" file is
> actually accessed, and still trying to minimize latency in retrieval.
>
> Cheers,
> Matevz
>
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