MVP for #6097
This feature will repeatedly reconnect (with a randomized exponential backoff)
to peers in a set of "peered" peers.
In the future, this should be extended to:
1. Include a CLI for modifying this list at runtime.
2. Include additional options for peers we want to _protect_ but not connect to.
3. Allow configuring timeouts, backoff, etc.
4. Allow groups? Possibly through textile threads.
5. Allow for runtime-only peering rules.
6. Different reconnect policies.
But this MVP should be a significant step forward.
Otherwise, we could end up with only DHT clients and never re-bootstrap.
I've left the default go-ipfs bootstrapping code in for now as it's technically
possible to disable the DHT entirely.
1. Increase broadcast timeout.
2. Fix use of sessions when pinning.
This also includes some bitswap changes to reduce some memory allocations and
optimize some hot spots.
1. Enable AutoNATService on _all_ nodes by default. If it's an issue, we can
disable it in RC3 but this will give us the best testing results.
2. Expose options to configure AutoNAT rate limiting.
And remove retry logic. This was flatfs specific and we've moved the logic down
into flatfs itself.
This update:
* Retries in more cases when we run out of file descriptors.
* Ensures we don't leak temporary files on batch put.
This logic collects a list of known relays by testing every new connection.
It exists so we can dial /p2p-circuit/p2p/QmFoobar addresses (circuit addresses
that don't specify the relay). However, this kind of address is useless outside
of basic demos as a random relay is practically guaranteed to not be connected
to the target peer. Picking a random relay to connect to some peer is almost
_never_ the desired behavior.
Unfortunately, we don't currently have any way to pick out good relays from bad.
That means we keep searching, trying bad relays, searching some more, trying
_the same relays_, etc. until we randomly find 3 good stable relays. In
practice, this means we just keep searching forever and keep thrashing the DHT.
see https://github.com/libp2p/go-libp2p/issues/694
