migrate to datastore-backed peerstore

[raulk]

The datastore-backed libp2p peerstore is now production ready. Let's roll it out.

Could someone enumerate a few tests in go-ipfs land that would make intensive use of the peerstore? I'd like to benchmark memory and gc before we merge.

EDIT: do we want to make the peerstore choice and options configurable?

[Stebalien]

🎉 Awesome! 🎉

1. How will this interact with the default non-block datastore, leveldb? IIRC, most testing was against badger. Answer: Just fine (on my machine, that is).
2. This is going to write a lot of data (over time). We may need to look into GC: Data may remain after garbage collecting everything go-ds-badger#54. However, badger isn't the default so this may be fine.
3. We definitely need to fix Periodically garbage collect go-ds-badger#51 first.

For now, we should probably add an experimental option to the config (https://github.com/ipfs/go-ipfs-config/blob/master/experiments.go).

Concretely:

• Experimental config option.
• Fix Periodically garbage collect go-ds-badger#51.

[raulk]

Makes sense, @Stebalien. Will look into those when I get some spare cycles. Thanks for the quick follow-up!

[whyrusleeping]

@raulk i'm getting a panic:

14:55:18.225 ERROR peerstore/: failed to update ttls for peer QmfDqERcEewXnrM8pD2QCsw9XrGQ8KerHPgG66y1A9fFvC: open /home/whyrusleeping/.ipfs/datastore/1597823.ldb: too many open files
 addr_book.go:266
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0xfb79de]

goroutine 7754831 [running]:
github.com/libp2p/go-libp2p-peerstore/pstoreds.(*dsAddrBook).UpdateAddrs(0xc00012a200, 0xc00ecba180, 0x22, 0x7ffffffffffffffe, 0x8bb2c97000)
        /home/whyrusleeping/gopkg/pkg/mod/github.com/libp2p/[email protected]/pstoreds/addr_book.go:269 +0x7e
github.com/libp2p/go-libp2p/p2p/protocol/identify.(*netNotifiee).Disconnected(0xc000126690, 0x1a26760, 0xc00010c000, 0x1a20860, 0xc008d07ec0)
        /home/whyrusleeping/gopkg/pkg/mod/github.com/libp2p/[email protected]/p2p/protocol/identify/id.go:457 +0x145
github.com/libp2p/go-libp2p-swarm.(*Conn).doClose.func1.1(0x1a16a80, 0xc000126690)
        /home/whyrusleeping/gopkg/pkg/mod/github.com/libp2p/[email protected]/swarm_conn.go:75 +0x5b
github.com/libp2p/go-libp2p-swarm.(*Swarm).notifyAll.func1(0xc002c649d4, 0xc01c20be00, 0x1a16a80, 0xc000126690)
        /home/whyrusleeping/gopkg/pkg/mod/github.com/libp2p/[email protected]/swarm.go:448 +0x60
created by github.com/libp2p/go-libp2p-swarm.(*Swarm).notifyAll
        /home/whyrusleeping/gopkg/pkg/mod/github.com/libp2p/[email protected]/swarm.go:446 +0x119

[whyrusleeping]

@raulk could you rebase this on latest master? There are a few conflicts and i'd like to continue testing with some changes that landed in master.