From 7bd6efd8482b6106a080c265ac38dbf995bc7704 Mon Sep 17 00:00:00 2001
From: Micaiah Reid <4290054+vabanaerytk@users.noreply.github.com>
Date: Tue, 19 Mar 2024 11:14:09 -0400
Subject: [PATCH] fix: log errors on block download failure; implement max
 retries (#503)

### Description

Before this PR, Chainhook would loop infinitely if there is a problem
downloading a BTC block, and it wouldn't log much information as to what
was causing the failure. This PR implements better logging, and breaks
out of the loop at 10 failed attempts.
---
 .../chainhook-sdk/src/indexer/bitcoin/mod.rs   | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/components/chainhook-sdk/src/indexer/bitcoin/mod.rs b/components/chainhook-sdk/src/indexer/bitcoin/mod.rs
index 44c999b..997c2c0 100644
--- a/components/chainhook-sdk/src/indexer/bitcoin/mod.rs
+++ b/components/chainhook-sdk/src/indexer/bitcoin/mod.rs
@@ -153,18 +153,21 @@ pub async fn download_and_parse_block_with_retry(
     ctx: &Context,
 ) -> Result<BitcoinBlockFullBreakdown, String> {
     let mut errors_count = 0;
+    let max_retries = 10;
     let block = loop {
         match download_and_parse_block(http_client, block_hash, bitcoin_config, ctx).await {
             Ok(result) => break result,
-            Err(_e) => {
+            Err(e) => {
                 errors_count += 1;
-                if errors_count > 3 {
+                if errors_count > 3 && errors_count < max_retries {
                     ctx.try_log(|logger| {
                         slog::warn!(
                             logger,
-                            "unable to fetch and parse block #{block_hash}: will retry in a few seconds (attempt #{errors_count}).",
+                            "unable to fetch and parse block #{block_hash}: will retry in a few seconds (attempt #{errors_count}). Error: {e}",
                         )
                     });
+                } else if errors_count == max_retries {
+                    return Err(format!("unable to fetch and parse block #{block_hash} after {errors_count} attempts. Error: {e}"));
                 }
                 std::thread::sleep(std::time::Duration::from_secs(1));
             }
@@ -180,18 +183,21 @@ pub async fn retrieve_block_hash_with_retry(
     ctx: &Context,
 ) -> Result<String, String> {
     let mut errors_count = 0;
+    let max_retries = 10;
     let block_hash = loop {
         match retrieve_block_hash(http_client, block_height, bitcoin_config, ctx).await {
             Ok(result) => break result,
-            Err(_e) => {
+            Err(e) => {
                 errors_count += 1;
-                if errors_count > 3 {
+                if errors_count > 3 && errors_count < max_retries {
                     ctx.try_log(|logger| {
                         slog::warn!(
                             logger,
-                            "unable to retrieve block hash #{block_height}: will retry in a few seconds (attempt #{errors_count}).",
+                            "unable to retrieve block hash #{block_height}: will retry in a few seconds (attempt #{errors_count}). Error: {e}",
                         )
                     });
+                } else if errors_count == max_retries {
+                    return Err(format!("unable to retrieve block hash #{block_height} after {errors_count} attempts. Error: {e}"));
                 }
                 std::thread::sleep(std::time::Duration::from_secs(2));
             }