Merge pull request #2601 from mirgee/fix-2490

Persist and restore routing table

lbry/lbry/dht/node.py

@@ -2,6 +2,7 @@ import logging
 import asyncio
 import typing
 import binascii
+import socket
 from lbry.utils import resolve_host
 from lbry.dht import constants
 from lbry.dht.peer import make_kademlia_peer
@@ -19,7 +20,8 @@ log = logging.getLogger(__name__)
 class Node:
     def __init__(self, loop: asyncio.AbstractEventLoop, peer_manager: 'PeerManager', node_id: bytes, udp_port: int,
                  internal_udp_port: int, peer_port: int, external_ip: str, rpc_timeout: float = constants.rpc_timeout,
-                 split_buckets_under_index: int = constants.split_buckets_under_index):
+                 split_buckets_under_index: int = constants.split_buckets_under_index,
+                 storage: typing.Optional['SQLiteStorage'] = None):
         self.loop = loop
         self.internal_udp_port = internal_udp_port
         self.protocol = KademliaProtocol(loop, peer_manager, node_id, external_ip, udp_port, peer_port, rpc_timeout,
@@ -28,6 +30,7 @@ class Node:
         self.joined = asyncio.Event(loop=self.loop)
         self._join_task: asyncio.Task = None
         self._refresh_task: asyncio.Task = None
+        self._storage = storage
 
     async def refresh_node(self, force_once=False):
         while True:
@@ -67,6 +70,8 @@ class Node:
             to_ping = [peer for peer in set(total_peers) if self.protocol.peer_manager.peer_is_good(peer) is not True]
             if to_ping:
                 self.protocol.ping_queue.enqueue_maybe_ping(*to_ping, delay=0)
+            if self._storage:
+                await self._storage.save_kademlia_peers(self.protocol.routing_table.get_peers())
             if force_once:
                 break
 
@@ -111,7 +116,7 @@ class Node:
         self.listening_port = None
         log.info("Stopped DHT node")
 
-    async def start_listening(self, interface: str = '') -> None:
+    async def start_listening(self, interface: str = '0.0.0.0') -> None:
         if not self.listening_port:
             self.listening_port, _ = await self.loop.create_datagram_endpoint(
                 lambda: self.protocol, (interface, self.internal_udp_port)
@@ -121,56 +126,53 @@ class Node:
         else:
             log.warning("Already bound to port %s", self.listening_port)
 
-    async def join_network(self, interface: typing.Optional[str] = '',
+    async def join_network(self, interface: str = '0.0.0.0',
                            known_node_urls: typing.Optional[typing.List[typing.Tuple[str, int]]] = None):
+        def peers_from_urls(urls: typing.Optional[typing.List[typing.Tuple[bytes, str, int, int]]]):
+            peer_addresses = []
+            for node_id, address, udp_port, tcp_port in urls:
+                if (node_id, address, udp_port, tcp_port) not in peer_addresses and \
+                        (address, udp_port) != (self.protocol.external_ip, self.protocol.udp_port):
+                    peer_addresses.append((node_id, address, udp_port, tcp_port))
+            return [make_kademlia_peer(*peer_address) for peer_address in peer_addresses]
+
         if not self.listening_port:
             await self.start_listening(interface)
         self.protocol.ping_queue.start()
         self._refresh_task = self.loop.create_task(self.refresh_node())
 
-        # resolve the known node urls
-        known_node_addresses = []
-        url_to_addr = {}
-
-        if known_node_urls:
-            for host, port in known_node_urls:
-                address = await resolve_host(host, port, proto='udp')
-                if (address, port) not in known_node_addresses and\
-                        (address, port) != (self.protocol.external_ip, self.protocol.udp_port):
-                    known_node_addresses.append((address, port))
-                    url_to_addr[address] = host
-
-        if known_node_addresses:
-            peers = [
-                make_kademlia_peer(None, address, port)
-                for (address, port) in known_node_addresses
-            ]
         while True:
-                if not self.protocol.routing_table.get_peers():
-                    if self.joined.is_set():
-                        self.joined.clear()
-                    self.protocol.peer_manager.reset()
-                    self.protocol.ping_queue.enqueue_maybe_ping(*peers, delay=0.0)
-                    peers.extend(await self.peer_search(self.protocol.node_id, shortlist=peers, count=32))
             if self.protocol.routing_table.get_peers():
+                if not self.joined.is_set():
                     self.joined.set()
                     log.info(
-                            "Joined DHT, %i peers known in %i buckets", len(self.protocol.routing_table.get_peers()),
-                            self.protocol.routing_table.buckets_with_contacts())
+                        "joined dht, %i peers known in %i buckets", len(self.protocol.routing_table.get_peers()),
+                        self.protocol.routing_table.buckets_with_contacts()
+                    )
             else:
+                if self.joined.is_set():
+                    self.joined.clear()
+                seed_peers = peers_from_urls(
+                    await self._storage.get_persisted_kademlia_peers()
+                ) if self._storage else []
+                if not seed_peers:
+                    try:
+                        seed_peers.extend(peers_from_urls([
+                            (None, await resolve_host(address, udp_port, 'udp'), udp_port, None)
+                            for address, udp_port in known_node_urls or []
+                        ]))
+                    except socket.gaierror:
+                        await asyncio.sleep(30, loop=self.loop)
                         continue
+
+                self.protocol.peer_manager.reset()
+                self.protocol.ping_queue.enqueue_maybe_ping(*seed_peers, delay=0.0)
+                await self.peer_search(self.protocol.node_id, shortlist=seed_peers, count=32)
+
             await asyncio.sleep(1, loop=self.loop)
 
-        log.info("Joined DHT, %i peers known in %i buckets", len(self.protocol.routing_table.get_peers()),
-                 self.protocol.routing_table.buckets_with_contacts())
-        self.joined.set()
-
-    def start(self, interface: str, known_node_urls: typing.List[typing.Tuple[str, int]]):
-        self._join_task = self.loop.create_task(
-            self.join_network(
-                interface=interface, known_node_urls=known_node_urls
-            )
-        )
+    def start(self, interface: str, known_node_urls: typing.Optional[typing.List[typing.Tuple[str, int]]] = None):
+        self._join_task = self.loop.create_task(self.join_network(interface, known_node_urls))
 
     def get_iterative_node_finder(self, key: bytes, shortlist: typing.Optional[typing.List['KademliaPeer']] = None,
                                   bottom_out_limit: int = constants.bottom_out_limit,

lbry/lbry/extras/daemon/Components.py

@@ -50,7 +50,7 @@ class DatabaseComponent(Component):
 
     @staticmethod
     def get_current_db_revision():
-        return 13
+        return 14
 
     @property
     def revision_filename(self):
@@ -189,7 +189,7 @@ class BlobComponent(Component):
 
 class DHTComponent(Component):
     component_name = DHT_COMPONENT
-    depends_on = [UPNP_COMPONENT]
+    depends_on = [UPNP_COMPONENT, DATABASE_COMPONENT]
 
     def __init__(self, component_manager):
         super().__init__(component_manager)
@@ -223,6 +223,7 @@ class DHTComponent(Component):
         self.external_peer_port = upnp_component.upnp_redirects.get("TCP", self.conf.tcp_port)
         self.external_udp_port = upnp_component.upnp_redirects.get("UDP", self.conf.udp_port)
         external_ip = upnp_component.external_ip
+        storage = self.component_manager.get_component(DATABASE_COMPONENT)
         if not external_ip:
             external_ip = await utils.get_external_ip()
             if not external_ip:
@@ -237,11 +238,10 @@ class DHTComponent(Component):
             external_ip=external_ip,
             peer_port=self.external_peer_port,
             rpc_timeout=self.conf.node_rpc_timeout,
-            split_buckets_under_index=self.conf.split_buckets_under_index
-        )
-        self.dht_node.start(
-            interface=self.conf.network_interface, known_node_urls=self.conf.known_dht_nodes
+            split_buckets_under_index=self.conf.split_buckets_under_index,
+            storage=storage
         )
+        self.dht_node.start(self.conf.network_interface, self.conf.known_dht_nodes)
         log.info("Started the dht")
 
     async def stop(self):

lbry/lbry/extras/daemon/migrator/dbmigrator.py

@@ -33,6 +33,8 @@ def migrate_db(conf, start, end):
             from .migrate11to12 import do_migration
         elif current == 12:
             from .migrate12to13 import do_migration
+        elif current == 13:
+            from .migrate13to14 import do_migration
         else:
             raise Exception(f"DB migration of version {current} to {current+1} is not available")
         try:

lbry/lbry/extras/daemon/migrator/migrate13to14.py

@@ -0,0 +1,21 @@
+import os
+import sqlite3
+
+
+def do_migration(conf):
+    db_path = os.path.join(conf.data_dir, "lbrynet.sqlite")
+    connection = sqlite3.connect(db_path)
+    cursor = connection.cursor()
+
+    cursor.executescript("""
+        create table if not exists peer (
+            node_id char(96) not null primary key,
+            address text not null,
+            udp_port integer not null,
+            tcp_port integer,
+            unique (address, udp_port)
+        );
+    """)
+
+    connection.commit()
+    connection.close()

lbry/lbry/extras/daemon/storage.py

@@ -329,6 +329,14 @@ class SQLiteStorage(SQLiteMixin):
                 timestamp integer,
                 primary key (sd_hash, reflector_address)
             );
+
+            create table if not exists peer (
+                node_id char(96) not null primary key,
+                address text not null,
+                udp_port integer not null,
+                tcp_port integer,
+                unique (address, udp_port)
+            );
     """
 
     def __init__(self, conf: Config, path, loop=None, time_getter: typing.Optional[typing.Callable[[], float]] = None):
@@ -805,3 +813,17 @@ class SQLiteStorage(SQLiteMixin):
             "where r.timestamp is null or r.timestamp < ?",
             int(self.time_getter()) - 86400
         )
+
+    # # # # # # # # # # dht functions # # # # # # # # # # #
+    async def get_persisted_kademlia_peers(self) -> typing.List[typing.Tuple[bytes, str, int, int]]:
+        query = 'select node_id, address, udp_port, tcp_port from peer'
+        return [(binascii.unhexlify(n), a, u, t) for n, a, u, t in await self.db.execute_fetchall(query)]
+
+    async def save_kademlia_peers(self, peers: typing.List['KademliaPeer']):
+        def _save_kademlia_peers(transaction: sqlite3.Connection):
+            transaction.execute('delete from peer').fetchall()
+            transaction.executemany(
+                'insert into peer(node_id, address, udp_port, tcp_port) values (?, ?, ?, ?)',
+                tuple([(binascii.hexlify(p.node_id), p.address, p.udp_port, p.tcp_port) for p in peers])
+            ).fetchall()
+        return await self.db.run(_save_kademlia_peers)

lbry/tests/dht_mocks.py

@@ -48,8 +48,9 @@ def get_time_accelerator(loop: asyncio.AbstractEventLoop,
 
 
 @contextlib.contextmanager
-def mock_network_loop(loop: asyncio.AbstractEventLoop):
-    dht_network: typing.Dict[typing.Tuple[str, int], 'KademliaProtocol'] = {}
+def mock_network_loop(loop: asyncio.AbstractEventLoop,
+                      dht_network: typing.Optional[typing.Dict[typing.Tuple[str, int], 'KademliaProtocol']] = None):
+    dht_network: typing.Dict[typing.Tuple[str, int], 'KademliaProtocol'] = dht_network if dht_network is not None else {}
 
     async def create_datagram_endpoint(proto_lam: typing.Callable[[], 'KademliaProtocol'],
                                        from_addr: typing.Tuple[str, int]):

lbry/tests/integration/test_dht.py

@@ -1,6 +1,8 @@
 import asyncio
 from binascii import hexlify
 
+from lbry.extras.daemon.storage import SQLiteStorage
+from lbry.conf import Config
 from lbry.dht import constants
 from lbry.dht.node import Node
 from lbry.dht import peer as dht_peer
@@ -19,24 +21,32 @@ class DHTIntegrationTest(AsyncioTestCase):
         self.nodes = []
         self.known_node_addresses = []
 
-    async def setup_network(self, size: int, start_port=40000, seed_nodes=1):
-        for i in range(size):
-            node_port = start_port + i
-            node = Node(self.loop, PeerManager(self.loop), node_id=constants.generate_id(i),
-                                   udp_port=node_port, internal_udp_port=node_port,
-                                   peer_port=3333, external_ip='127.0.0.1')
-            self.nodes.append(node)
-            self.known_node_addresses.append(('127.0.0.1', node_port))
-            await node.start_listening('127.0.0.1')
+    async def create_node(self, node_id, port, external_ip='127.0.0.1'):
+        storage = SQLiteStorage(Config(), ":memory:", self.loop, self.loop.time)
+        await storage.open()
+        node = Node(self.loop, PeerManager(self.loop), node_id=node_id,
+                    udp_port=port, internal_udp_port=port,
+                    peer_port=3333, external_ip=external_ip,
+                    storage=storage)
         self.addCleanup(node.stop)
-        for node in self.nodes:
         node.protocol.rpc_timeout = .5
         node.protocol.ping_queue._default_delay = .5
-            node.start('127.0.0.1', self.known_node_addresses[:seed_nodes])
-        await asyncio.gather(*[node.joined.wait() for node in self.nodes])
+        return node
+
+    async def setup_network(self, size: int, start_port=40000, seed_nodes=1, external_ip='127.0.0.1'):
+        for i in range(size):
+            node_port = start_port + i
+            node_id = constants.generate_id(i)
+            node = await self.create_node(node_id, node_port)
+            self.nodes.append(node)
+            self.known_node_addresses.append((external_ip, node_port))
+
+        for node in self.nodes:
+            node.start(external_ip, self.known_node_addresses[:seed_nodes])
 
     async def test_replace_bad_nodes(self):
         await self.setup_network(20)
+        await asyncio.gather(*[node.joined.wait() for node in self.nodes])
         self.assertEqual(len(self.nodes), 20)
         node = self.nodes[0]
         bad_peers = []
@@ -57,6 +67,7 @@ class DHTIntegrationTest(AsyncioTestCase):
 
     async def test_re_join(self):
         await self.setup_network(20, seed_nodes=10)
+        await asyncio.gather(*[node.joined.wait() for node in self.nodes])
         node = self.nodes[-1]
         self.assertTrue(node.joined.is_set())
         self.assertTrue(node.protocol.routing_table.get_peers())
@@ -84,6 +95,7 @@ class DHTIntegrationTest(AsyncioTestCase):
 
     async def test_get_token_on_announce(self):
         await self.setup_network(2, seed_nodes=2)
+        await asyncio.gather(*[node.joined.wait() for node in self.nodes])
         node1, node2 = self.nodes
         node1.protocol.peer_manager.clear_token(node2.protocol.node_id)
         blob_hash = hexlify(constants.generate_id(1337)).decode()
@@ -101,6 +113,7 @@ class DHTIntegrationTest(AsyncioTestCase):
         # imagine that you only got bad peers and refresh will happen in one hour
         # instead of failing for one hour we should be able to recover by scheduling pings to bad peers we find
         await self.setup_network(2, seed_nodes=2)
+        await asyncio.gather(*[node.joined.wait() for node in self.nodes])
         node1, node2 = self.nodes
         node2.stop()
         # forcefully make it a bad peer but don't remove it from routing table
@@ -116,3 +129,37 @@ class DHTIntegrationTest(AsyncioTestCase):
         await node1.peer_search(node2.protocol.node_id)
         await asyncio.sleep(.3)  # let pending events settle
         self.assertFalse(node1.protocol.routing_table.get_peers())
+
+    async def test_peer_persistance(self):
+        num_nodes = 6
+        start_port = 40000
+        num_seeds = 2
+        external_ip = '127.0.0.1'
+
+        # Start a node
+        await self.setup_network(num_nodes, start_port=start_port, seed_nodes=num_seeds)
+        await asyncio.gather(*[node.joined.wait() for node in self.nodes])
+
+        node1 = self.nodes[-1]
+        peer_args = [(n.protocol.node_id, n.protocol.external_ip, n.protocol.udp_port, n.protocol.peer_port) for n in
+                     self.nodes[:num_seeds]]
+        peers = [make_kademlia_peer(*args) for args in peer_args]
+
+        # node1 is bootstrapped from the fixed seeds
+        self.assertCountEqual(peers, node1.protocol.routing_table.get_peers())
+
+        # Refresh and assert that the peers were persisted
+        await node1.refresh_node(True)
+        self.assertEqual(len(peer_args), len(await node1._storage.get_persisted_kademlia_peers()))
+        node1.stop()
+
+        # Start a fresh node with the same node_id and storage, but no known peers
+        node2 = await self.create_node(constants.generate_id(num_nodes-1), start_port+num_nodes-1)
+        node2._storage = node1._storage
+        node2.start(external_ip, [])
+        await node2.joined.wait()
+
+        # The peers are restored
+        self.assertEqual(num_seeds, len(node2.protocol.routing_table.get_peers()))
+        for bucket1, bucket2 in zip(node1.protocol.routing_table.buckets, node2.protocol.routing_table.buckets):
+            self.assertEqual((bucket1.range_min, bucket1.range_max), (bucket2.range_min, bucket2.range_max))

lbry/tests/unit/database/test_SQLiteStorage.py

@@ -3,6 +3,7 @@ import tempfile
 import unittest
 import asyncio
 import logging
+import hashlib
 from torba.testcase import AsyncioTestCase
 from lbry.conf import Config
 from lbry.extras.daemon.storage import SQLiteStorage
@@ -10,6 +11,7 @@ from lbry.blob.blob_info import BlobInfo
 from lbry.blob.blob_manager import BlobManager
 from lbry.stream.descriptor import StreamDescriptor
 from tests.test_utils import random_lbry_hash
+from lbry.dht.peer import make_kademlia_peer
 
 log = logging.getLogger()
 
@@ -247,3 +249,13 @@ class ContentClaimStorageTests(StorageTest):
         current_claim_info = await self.storage.get_content_claim(stream_hash)
         # this should still be the previous update
         self.assertDictEqual(current_claim_info, update_info)
+
+
+class UpdatePeersTest(StorageTest):
+    async def test_update_get_peers(self):
+        node_id = hashlib.sha384("1234".encode()).digest()
+        args = (node_id, '73.186.148.72', 4444, None)
+        fake_peer = make_kademlia_peer(*args)
+        await self.storage.save_kademlia_peers([fake_peer])
+        peers = await self.storage.get_persisted_kademlia_peers()
+        self.assertTupleEqual(args, peers[0])

lbry/tests/unit/dht/test_node.py

@@ -2,9 +2,11 @@ import asyncio
 import typing
 from torba.testcase import AsyncioTestCase
 from tests import dht_mocks
+from lbry.conf import Config
 from lbry.dht import constants
 from lbry.dht.node import Node
 from lbry.dht.peer import PeerManager, make_kademlia_peer
+from lbry.extras.daemon.storage import SQLiteStorage
 
 
 class TestNodePingQueueDiscover(AsyncioTestCase):
@@ -84,3 +86,75 @@ class TestNodePingQueueDiscover(AsyncioTestCase):
             # teardown
             for n in nodes.values():
                 n.stop()
+
+
+class TestTemporarilyLosingConnection(AsyncioTestCase):
+
+    async def test_losing_connection(self):
+        async def wait_for(check_ok, insist, timeout=20):
+            start = loop.time()
+            while loop.time() - start < timeout:
+                if check_ok():
+                    break
+                await asyncio.sleep(0)
+            else:
+                insist()
+
+        loop = self.loop
+        loop.set_debug(False)
+
+        peer_addresses = [
+            ('1.2.3.4', 40000+i) for i in range(10)
+        ]
+        node_ids = [constants.generate_id(i) for i in range(10)]
+
+        nodes = [
+            Node(
+                loop, PeerManager(loop), node_id, udp_port, udp_port, 3333, address,
+                storage=SQLiteStorage(Config(), ":memory:", self.loop, self.loop.time)
+            )
+            for node_id, (address, udp_port) in zip(node_ids, peer_addresses)
+        ]
+        dht_network = {peer_addresses[i]: node.protocol for i, node in enumerate(nodes)}
+        num_seeds = 3
+
+        with dht_mocks.mock_network_loop(loop, dht_network):
+            for i, n in enumerate(nodes):
+                await n._storage.open()
+                self.addCleanup(n.stop)
+                n.start(peer_addresses[i][0], peer_addresses[:num_seeds])
+            await asyncio.gather(*[n.joined.wait() for n in nodes])
+
+            node = nodes[-1]
+            advance = dht_mocks.get_time_accelerator(loop, loop.time())
+            await advance(500)
+
+            # Join the network, assert that at least the known peers are in RT
+            self.assertTrue(node.joined.is_set())
+            self.assertTrue(len(node.protocol.routing_table.get_peers()) >= num_seeds)
+
+            # Refresh, so that the peers are persisted
+            self.assertFalse(len(await node._storage.get_persisted_kademlia_peers()) > num_seeds)
+            await advance(4000)
+            self.assertTrue(len(await node._storage.get_persisted_kademlia_peers()) > num_seeds)
+
+            # We lost internet connection - all the peers stop responding
+            dht_network.pop((node.protocol.external_ip, node.protocol.udp_port))
+
+            # The peers are cleared on refresh from RT and storage
+            await advance(4000)
+            self.assertListEqual([], await node._storage.get_persisted_kademlia_peers())
+            await wait_for(
+                lambda: len(node.protocol.routing_table.get_peers()) == 0,
+                lambda: self.assertListEqual(node.protocol.routing_table.get_peers(), [])
+            )
+
+            # Reconnect
+            dht_network[(node.protocol.external_ip, node.protocol.udp_port)] = node.protocol
+
+            # Check that node reconnects at least to them
+            await advance(1000)
+            await wait_for(
+                lambda: len(node.protocol.routing_table.get_peers()) >= num_seeds,
+                lambda: self.assertTrue(len(node.protocol.routing_table.get_peers()) >= num_seeds)
+            )