Re: [PATCH proxmox-backup 1/2] fix #6373: HTTP level reader heartbeat for proxy connection keepalive

[Christian Ebner <c.ebner@proxmox.com>]

On 4/15/26 12:59 PM, Fabian Grünbichler wrote:
> On April 15, 2026 10:45 am, Christian Ebner wrote:
>> On 4/15/26 10:32 AM, Fabian Grünbichler wrote:
>>> On January 29, 2026 1:26 pm, Christian Ebner wrote:
>>>> Backup readers can have long periods of idle connections, e.g. if a
>>>> backup snapshot has been mounted and all relevant chunks are locally
>>>> cached or a backup session with previous metadata archive not needing
>>>> to fetch new contents while the backup is ongoing.
>>>>
>>>> Proxies like e.g. HAProxy might however close idle connections for
>>>> better resource handling [0,1], even multiplexed HTTP/2 connections as
>>>> are being used for the Proxmox Backup Sever backup/reader protocol.
>>>>
>>>> This mainly affects the backup reader, while the backup writer will
>>>> do indexing and chunk uploads anyways.
>>>
>>> but if the storage is slow, there might not be chunk traffic for a few
>>> seconds as well?
>> So you suggest to implement the same for the backup writer as well?
> 
> I am wondering whether it wouldn't make sense (though I guess 5s is
> quite agressive anyway, and higher idle timeouts make it unlikely to
> trigger in practice?)


Yes, I think for the writer this is way less relevant.
Only the super slow storage case where the chunk is uploaded quickly, 
but then the storage takes ages to write it.

OTOH the heartbeat does not interfere much with the current request 
logic, and is guarded behind the environment variable.

So this would be enabled under very specific conditions anyways? After 
all it is mostly only a way out if one has no control over the proxy to 
increase the timeout values there?