HTTP Client Attributes

[Tom Scavo]

On Thu, May 3, 2018 at 12:15 PM, Brent Putman <putmanb at georgetown.edu> wrote:
>
> On 5/3/18 12:06 PM, Tom Scavo wrote:
>
> On Thu, May 3, 2018 at 11:50 AM, Cantor, Scott <cantor.2 at osu.edu> wrote:
>
> It is 'none', if one is using the default internally-constructed HttpClient.
> Because of the 1) memory requirements of in-memory and 2) disk
> requirements of disk, we didn't want to make assumptions about either of
> those defaults being ok.
>
> And because they do their own caching, I believe. I think there was internal
> logic already to remember a cache tag and use it, just not across restarts
> (whereas the SP actually stores the cache tags on disk, I think). We didn't
> need the HttpClient's support for the batch case.
>
> I'm confused. We know that a FileBackedHTTPMetadataProvider does HTTP
> caching by default (although I don't know the details).
>
> As I said just now in another note, they don't do HTTP caching in the sense
> you mean.  Internally the HTTP metadata providers cache ETag and
> Last-Modified to do conditional GETs.  That's all.

Okay, I understand now.

>  Are you saying
> that the HTTP cache attributes (httpCaching, httpCacheDirectory,
> httpMaxCacheEntries, httpMaxCacheEntrySize) may be used to override
> the default HTTP cache behavior?
>
> Well, yes, for the (internally constructed, non-httpClientRef) HttpClient
> response caching.  That being the whole point of those attributes...
>
> If so, the default shown in the doc
> ("none") is incorrect.
>
> Um, how do the presence of attributes which allow overriding the default
> negate the meaning of the default?  For the FileBacked- batch one, It is
> 'none', I assure you.

Unless I'm missing something, the documentation says nothing about the
default caching behavior of the HTTP metadata providers. Until just
now, I thought the HTTP cache attributes (httpCaching,
httpCacheDirectory, httpMaxCacheEntries, httpMaxCacheEntrySize)
completely controlled the caching behavior.

Are the HTTP cache attributes mutually exclusive of httpClientRef?

Thanks,

Tom