Speed up getting last event

.env.example

@@ -13,5 +13,9 @@ CONSENSUS_ENDPOINT=https://hoodi-lighthouse
 
 PUBLIC_KEYS_FILE=public_keys.csv
 
+# Validators manager
 VALIDATORS_MANAGER_KEY_FILE=validators-manager-key.json
 VALIDATORS_MANAGER_PASSWORD_FILE=validators-manager-password.txt
+
+# Maximum number of parallel event scan queries
+# EVENT_LOGS_MAX_CONCURRENCY=4

src/common/contracts.py

@@ -1,3 +1,5 @@
+import asyncio
+import itertools
 import json
 import os
 from functools import cached_property
@@ -50,15 +52,28 @@ async def _get_last_event(
     ) -> EventData | None:
         blocks_range = self.events_blocks_range_interval
 
-        while to_block >= from_block:
-            events = await event.get_logs(
-                from_block=BlockNumber(max(to_block - blocks_range, from_block)),
-                to_block=to_block,
+        # Build all chunk ranges from newest to oldest
+        ranges: list[tuple[BlockNumber, BlockNumber]] = []
+        chunk_to = to_block
+        while chunk_to >= from_block:
+            chunk_from = BlockNumber(max(chunk_to - blocks_range + 1, from_block))
+            ranges.append((chunk_from, chunk_to))
+            chunk_to = BlockNumber(chunk_to - blocks_range)
+
+        # from_block and to_block are both inclusive
+        async def fetch_chunk(chunk_from: BlockNumber, chunk_to: BlockNumber) -> list[EventData]:
+            return await event.get_logs(
+                from_block=chunk_from,
+                to_block=chunk_to,
                 argument_filters=argument_filters,
             )
-            if events:
-                return events[-1]
-            to_block = BlockNumber(to_block - blocks_range - 1)
+
+        # Process chunks in batches (newest-first), abort on first hit
+        for batch in itertools.batched(ranges, settings.event_logs_max_concurrency):
+            batch_results = await asyncio.gather(*[fetch_chunk(f, t) for f, t in batch])
+            for chunk_events in batch_results:
+                if chunk_events:
+                    return chunk_events[-1]
         return None
 
 

src/config/settings.py

@@ -45,6 +45,8 @@
 
 validator_lifetime: int = config('VALIDATOR_LIFETIME', default=3600, cast=int)
 
+event_logs_max_concurrency: int = config('EVENT_LOGS_MAX_CONCURRENCY', default=4, cast=int)
+
 validators_manager_key_file: str = config('VALIDATORS_MANAGER_KEY_FILE')
 validators_manager_password_file: str = config('VALIDATORS_MANAGER_PASSWORD_FILE')