slowing down sync after some time #4886

I recently installed Bitcoin Core v0.9.2.1 on Ubuntu. Started synchronizing with network and started up system monitor (not using internet with other applications). So it quickly starts going at max download speed, but after some time (maybe an hour or so) it slows down to like 10%. After restarting it does same thing. So I have to restart Bitcoin Core every hour or so. Don't know what could be the problem, maybe connections start turning slower for some reason (other peers syncing maybe), but it doesn't look for better connections ( unless restarted when it looks for best connections).

@tunnelman this is a known problem, and there doesn't appear to be a fix coming any time soon, since the core developers are waiting for #4468 to be ready, which currently breaks core features, so isn't ready to merge yet. I did raise a pull request that fixes the problem you mention, pull request #4431, but this has been closed, so it doesn't look like this is going to be merged either. If you want to test it, and you're familiar with compiling, git merging etc, then feel free to use it - it doesn't download as fast as #4468 (which downloads from multiple nodes concurrently), but it certainly does download faster than the current v0.9.2.1 available for download.

It wouldn't take much to get #4468 working in a way that doesn't break re-indexing - e.g. the ability to store orphans could be re-introduced, and with the new logic that #4468 provides, not so many orphans would end up being downloaded, and neither would duplicate blocks be downloaded (as is one of the current problems with v0.9.2.1).

Until headers-first is merged I'd suggest to use the bootstrap.dat torrent (https://bitcointalk.org/index.php?topic=145386.0) for initial sync.

Thanks. All synced up now.

@tunnelman Can you close your issue then?