Aha.

So what's the way to a "clean" (as in, robust/non-leaky) feedback
mechanism for making earlier parts degrade gracefully and stop adding
more work, when the buffer is full/close to full?

Again thank you for the libbitcoin, it's basically essential to the
Bitcoin world and may be the primary implementation if you look at it
really.

On 2014-01-08 11:42, Amir Taaki wrote:

> Not really, and it doesn't seem like a good solution (more of a
> workaround) now I'm thinking.
>
> The problem (if this is it), is that the block writer is IO bound, and
> blocks are being queued such that memory is exhausted before writes can
> complete.
>
> I'm not sure if it is the problem, but certainly should be something
> along these lines if it's only caused by HDD.
>
> Only 500 blocks are downloaded at a time and attempted to be stored.