From 356e613b248fe2b251ca441230e04ca28aa47751 Mon Sep 17 00:00:00 2001
From: Jack Robison <jackrobison@lbry.io>
Date: Tue, 22 Mar 2022 21:12:02 -0400
Subject: [PATCH] partial fix for https://github.com/lbryio/scribe/issues/2

---
 scribe/hub/mempool.py | 16 +++++++++++++---
 scribe/service.py     |  6 +++---
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/scribe/hub/mempool.py b/scribe/hub/mempool.py
index ab9f88d..eb32224 100644
--- a/scribe/hub/mempool.py
+++ b/scribe/hub/mempool.py
@@ -5,6 +5,8 @@ import typing
 import logging
 from collections import defaultdict
 from prometheus_client import Histogram
+
+import rocksdb.errors
 from scribe import PROMETHEUS_NAMESPACE
 from scribe.common import HISTOGRAM_BUCKETS
 from scribe.blockchain.transaction.deserializer import Deserializer
@@ -53,9 +55,17 @@ class MemPool:
 
     def refresh(self) -> typing.Set[bytes]:  # returns list of new touched hashXs
         prefix_db = self._db.prefix_db
-        new_mempool = {k.tx_hash: v.raw_tx for k, v in prefix_db.mempool_tx.iterate()}  # TODO: make this more efficient
-        self.raw_mempool.clear()
-        self.raw_mempool.update(new_mempool)
+        try:
+            new_mempool = {k.tx_hash: v.raw_tx for k, v in prefix_db.mempool_tx.iterate()}  # TODO: make this more efficient
+        except rocksdb.errors.RocksIOError as err:
+            # FIXME: why does this happen? can it happen elsewhere?
+            if err.args[0].startswith(b'IO error: No such file or directory: While open a file for random read:'):
+                self.logger.error("failed to process mempool, retrying later")
+                return set()
+            raise err
+        else:
+            self.raw_mempool.clear()
+            self.raw_mempool.update(new_mempool)
 
         # hashXs = self.hashXs  # hashX: [tx_hash, ...]
         touched_hashXs = set()
diff --git a/scribe/service.py b/scribe/service.py
index 62faf8b..054544d 100644
--- a/scribe/service.py
+++ b/scribe/service.py
@@ -191,9 +191,9 @@ class BlockchainReaderService(BlockchainService):
     def _detect_changes(self):
         try:
             self.db.prefix_db.try_catch_up_with_primary()
-        except:
-            self.log.exception('failed to update secondary db')
-            raise
+        except Exception as err:
+            self.log.exception('failed to update secondary db: %s', err)
+            raise err
         state = self.db.prefix_db.db_state.get()
         if not state or state.height <= 0:
             return