diff --git a/lbry/wallet/server/block_processor.py b/lbry/wallet/server/block_processor.py
index 69a57a2eb..437b24f18 100644
--- a/lbry/wallet/server/block_processor.py
+++ b/lbry/wallet/server/block_processor.py
@@ -183,6 +183,7 @@ class BlockProcessor:
         self.state_lock = asyncio.Lock()
 
         self.search_cache = {}
+        self.history_cache = {}
 
     async def run_in_thread_with_lock(self, func, *args):
         # Run in a thread to prevent blocking.  Shielded so that
@@ -213,6 +214,7 @@ class BlockProcessor:
             await self.run_in_thread_with_lock(self.advance_blocks, blocks)
             for cache in self.search_cache.values():
                 cache.clear()
+            self.history_cache.clear()
             await self._maybe_flush()
             processed_time = time.perf_counter() - start
             self.block_count_metric.set(self.height)
diff --git a/lbry/wallet/server/session.py b/lbry/wallet/server/session.py
index 186755b73..55820fdda 100644
--- a/lbry/wallet/server/session.py
+++ b/lbry/wallet/server/session.py
@@ -135,7 +135,7 @@ class SessionManager:
         "docker_tag": DOCKER_TAG,
         'version': lbry.__version__,
         "min_version": util.version_string(VERSION.PROTOCOL_MIN),
-        "cpu_count": os.cpu_count()
+        "cpu_count": str(os.cpu_count())
     })
     session_count_metric = Gauge("session_count", "Number of connected client sessions", namespace=NAMESPACE,
                                       labelnames=("version",))
@@ -177,7 +177,7 @@ class SessionManager:
         self.cur_group = SessionGroup(0)
         self.txs_sent = 0
         self.start_time = time.time()
-        self.history_cache = pylru.lrucache(256)
+        self.history_cache = self.bp.history_cache
         self.notified_height: typing.Optional[int] = None
         # Cache some idea of room to avoid recounting on each subscription
         self.subs_room = 0
@@ -608,26 +608,20 @@ class SessionManager:
 
     async def limited_history(self, hashX):
         """A caching layer."""
-        hc = self.history_cache
-        if hashX not in hc:
+        if hashX not in self.history_cache:
             # History DoS limit.  Each element of history is about 99
             # bytes when encoded as JSON.  This limits resource usage
             # on bloated history requests, and uses a smaller divisor
             # so large requests are logged before refusing them.
             limit = self.env.max_send // 97
-            hc[hashX] = await self.db.limited_history(hashX, limit=limit)
-        return hc[hashX]
+            self.history_cache[hashX] = await self.db.limited_history(hashX, limit=limit)
+        return self.history_cache[hashX]
 
     async def _notify_sessions(self, height, touched):
         """Notify sessions about height changes and touched addresses."""
         height_changed = height != self.notified_height
         if height_changed:
             await self._refresh_hsub_results(height)
-            # Invalidate our history cache for touched hashXs
-            hc = self.history_cache
-            for hashX in set(hc).intersection(touched):
-                del hc[hashX]
-
         if self.sessions:
             await asyncio.wait([
                 session.notify(touched, height_changed) for session in self.sessions