block scribe-hub and scribe-elastic-sync startup on scribe initially catching up

fixes https://github.com/lbryio/scribe/issues/1

scribe/blockchain/service.py

@@ -1540,10 +1540,12 @@ class BlockchainProcessorService(BlockchainService):
         """Loop forever processing blocks as they arrive."""
         self._caught_up_event = caught_up_event
         try:
+            if self.height != self.daemon.cached_height() and not self.db.catching_up:
+                await self._need_catch_up()  # tell the readers that we're still catching up with lbrycrd/lbcd
             while not self._stopping:
                 if self.height == self.daemon.cached_height():
                     if not self._caught_up_event.is_set():
-                        await self._first_caught_up()
+                        await self._finished_initial_catch_up()
                         self._caught_up_event.set()
                 try:
                     await asyncio.wait_for(self.blocks_event.wait(), self.wait_for_blocks_duration)
@@ -1558,25 +1560,27 @@ class BlockchainProcessorService(BlockchainService):
                         await self.refresh_mempool()
                     except asyncio.CancelledError:
                         raise
-                    except Exception:
-                        self.log.exception("error while updating mempool txs")
-                        raise
+                    except Exception as err:
+                        self.log.exception("error while updating mempool txs: %s", err)
+                        raise err
                 else:
                     try:
                         await self.check_and_advance_blocks(blocks)
                     except asyncio.CancelledError:
                         raise
-                    except Exception:
-                        self.log.exception("error while processing txs")
-                        raise
+                    except Exception as err:
+                        self.log.exception("error while processing txs: %s", err)
+                        raise err
+        except asyncio.CancelledError:
+            raise
+        except Exception as err:
+            self.log.exception("error in block processor loop: %s", err)
+            raise err
         finally:
             self._ready_to_stop.set()
 
-    async def _first_caught_up(self):
-        self.log.info(f'caught up to height {self.height}')
-        # Flush everything but with first_sync->False state.
-        first_sync = self.db.first_sync
-        self.db.first_sync = False
+    async def _need_catch_up(self):
+        self.db.catching_up = True
 
         def flush():
             assert len(self.db.prefix_db._op_stack) == 0
@@ -1586,10 +1590,18 @@ class BlockchainProcessorService(BlockchainService):
 
         await self.run_in_thread_with_lock(flush)
 
-        if first_sync:
-            self.log.info(f'{__version__} synced to '
-                             f'height {self.height:,d}, halting here.')
-            self.shutdown_event.set()
+    async def _finished_initial_catch_up(self):
+        self.log.info(f'caught up to height {self.height}')
+        # Flush everything but with catching_up->False state.
+        self.db.catching_up = False
+
+        def flush():
+            assert len(self.db.prefix_db._op_stack) == 0
+            self.db.write_db_state()
+            self.db.prefix_db.unsafe_commit()
+            self.db.assert_db_state()
+
+        await self.run_in_thread_with_lock(flush)
 
     def _iter_start_tasks(self):
         self.height = self.db.db_height

scribe/db/db.py

@@ -1045,10 +1045,10 @@ class HubDB:
         if self.db_height > 0:
             self.prefix_db.db_state.stage_delete((), self.prefix_db.db_state.get())
         self.prefix_db.db_state.stage_put((), (
-                self.genesis_bytes, self.db_height, self.db_tx_count, self.db_tip,
-                self.utxo_flush_count, int(self.wall_time), self.first_sync, self.db_version,
-                self.hist_flush_count, self.hist_comp_flush_count, self.hist_comp_cursor,
-                self.es_sync_height
+            self.genesis_bytes, self.db_height, self.db_tx_count, self.db_tip,
+            self.utxo_flush_count, int(self.wall_time), self.catching_up, self.db_version,
+            self.hist_flush_count, self.hist_comp_flush_count, self.hist_comp_cursor,
+            self.es_sync_height
             )
         )
 
@@ -1062,7 +1062,7 @@ class HubDB:
             self.db_version = max(self.DB_VERSIONS)
             self.utxo_flush_count = 0
             self.wall_time = 0
-            self.first_sync = True
+            self.catching_up = True
             self.hist_flush_count = 0
             self.hist_comp_flush_count = -1
             self.hist_comp_cursor = -1
@@ -1083,7 +1083,7 @@ class HubDB:
             self.db_tip = state.tip
             self.utxo_flush_count = state.utxo_flush_count
             self.wall_time = state.wall_time
-            self.first_sync = state.first_sync
+            self.catching_up = state.catching_up
             self.hist_flush_count = state.hist_flush_count
             self.hist_comp_flush_count = state.comp_flush_count
             self.hist_comp_cursor = state.comp_cursor
@@ -1097,7 +1097,7 @@ class HubDB:
         assert self.db_height == state.height, f"{self.db_height} != {state.height}"
         assert self.db_tx_count == state.tx_count, f"{self.db_tx_count} != {state.tx_count}"
         assert self.db_tip == state.tip, f"{self.db_tip} != {state.tip}"
-        assert self.first_sync == state.first_sync, f"{self.first_sync} != {state.first_sync}"
+        assert self.catching_up == state.catching_up, f"{self.catching_up} != {state.catching_up}"
         assert self.es_sync_height == state.es_sync_height, f"{self.es_sync_height} != {state.es_sync_height}"
 
     async def all_utxos(self, hashX):

scribe/db/prefixes.py

@@ -422,7 +422,7 @@ class DBState(typing.NamedTuple):
     tip: bytes
     utxo_flush_count: int
     wall_time: int
-    first_sync: bool
+    catching_up: bool
     db_version: int
     hist_flush_count: int
     comp_flush_count: int
@@ -1439,11 +1439,11 @@ class DBStatePrefixRow(PrefixRow):
 
     @classmethod
     def pack_value(cls, genesis: bytes, height: int, tx_count: int, tip: bytes, utxo_flush_count: int, wall_time: int,
-                   first_sync: bool, db_version: int, hist_flush_count: int, comp_flush_count: int,
+                   catching_up: bool, db_version: int, hist_flush_count: int, comp_flush_count: int,
                    comp_cursor: int, es_sync_height: int) -> bytes:
         return super().pack_value(
             genesis, height, tx_count, tip, utxo_flush_count,
-            wall_time, 1 if first_sync else 0, db_version, hist_flush_count,
+            wall_time, 1 if catching_up else 0, db_version, hist_flush_count,
             comp_flush_count, comp_cursor, es_sync_height
         )
 
@@ -1457,10 +1457,10 @@ class DBStatePrefixRow(PrefixRow):
 
     @classmethod
     def pack_item(cls, genesis: bytes, height: int, tx_count: int, tip: bytes, utxo_flush_count: int, wall_time: int,
-                  first_sync: bool, db_version: int, hist_flush_count: int, comp_flush_count: int,
+                  catching_up: bool, db_version: int, hist_flush_count: int, comp_flush_count: int,
                   comp_cursor: int, es_sync_height: int):
         return cls.pack_key(), cls.pack_value(
-            genesis, height, tx_count, tip, utxo_flush_count, wall_time, first_sync, db_version, hist_flush_count,
+            genesis, height, tx_count, tip, utxo_flush_count, wall_time, catching_up, db_version, hist_flush_count,
             comp_flush_count, comp_cursor, es_sync_height
         )
 

scribe/elasticsearch/service.py

@@ -336,7 +336,24 @@ class ElasticSyncService(BlockchainReaderService):
                 self.log.info("reindex (last wrote: %i, db height: %i)", self._last_wrote_height, self.db.db_height)
             await self._reindex()
 
+    async def block_bulk_sync_on_writer_catchup(self):
+        def _check_if_catching_up():
+            self.db.prefix_db.try_catch_up_with_primary()
+            state = self.db.prefix_db.db_state.get()
+            return state.catching_up
+
+        loop = asyncio.get_event_loop()
+
+        catching_up = True
+        while catching_up:
+            catching_up = await loop.run_in_executor(self._executor, _check_if_catching_up)
+            if catching_up:
+                await asyncio.sleep(1)
+            else:
+                return
+
     def _iter_start_tasks(self):
+        yield self.block_bulk_sync_on_writer_catchup()
         yield self.read_es_height()
         yield self.start_index()
         yield self.start_cancellable(self.run_es_notifier)

scribe/hub/service.py

@@ -92,8 +92,9 @@ class HubServerService(BlockchainReaderService):
     def _iter_start_tasks(self):
         yield self.start_status_server()
         yield self.start_cancellable(self.es_notification_client.maintain_connection)
-        yield self.start_cancellable(self.receive_es_notifications)
         yield self.start_cancellable(self.refresh_blocks_forever)
+        yield self.finished_initial_catch_up.wait()
+        yield self.start_cancellable(self.receive_es_notifications)
         yield self.session_manager.search_index.start()
         yield self.start_cancellable(self.session_manager.serve, self.mempool)
 

scribe/service.py

@@ -140,6 +140,7 @@ class BlockchainReaderService(BlockchainService):
         super().__init__(env, secondary_name, thread_workers, thread_prefix)
         self._refresh_interval = 0.1
         self.prometheus_server: typing.Optional[PrometheusServer] = None
+        self.finished_initial_catch_up = asyncio.Event()
 
     async def poll_for_changes(self):
         """
@@ -233,6 +234,8 @@ class BlockchainReaderService(BlockchainService):
             try:
                 async with self.lock:
                     await self.poll_for_changes()
+                    if not self.db.catching_up and not self.finished_initial_catch_up.is_set():
+                        self.finished_initial_catch_up.set()
             except asyncio.CancelledError:
                 raise
             except: