mempool update stuck retrieving missing tx #165
Description
We ran into a situation where electrs was stuck in its mempool update loop, trying to retrieve a tx (or txes) from bitcoin core.
This occurred on signet chain. The bitcoin core node serving electrs is not provisioned differently than mainnet or other nodes.
The only logs from electrs were from https://github.com/Blockstream/electrs/blob/new-index/src/new_index/mempool.rs#L590, example:
2025-09-22 18:29:50.739warn2025-09-22T18:29:50.738+00:00 - WARN failed to fetch 2 mempool txs, retrying...
2025-09-22 18:29:50.419warn2025-09-22T18:29:50.418+00:00 - WARN failed to fetch 2 mempool txs, retrying...
2025-09-22 18:29:50.099warn2025-09-22T18:29:50.098+00:00 - WARN failed to fetch 2 mempool txs, retrying...
2025-09-22 18:29:49.778warn2025-09-22T18:29:49.778+00:00 - WARN failed to fetch 2 mempool txs, retrying...
2025-09-22 18:29:49.458warn2025-09-22T18:29:49.458+00:00 - WARN failed to fetch 2 mempool txs, retrying...
2025-09-22 18:29:49.138warn2025-09-22T18:29:49.138+00:00 - WARN failed to fetch 2 mempool txs, retrying...
2025-09-22 18:29:48.818warn2025-09-22T18:29:48.817+00:00 - WARN failed to fetch 2 mempool txs, retrying...
2025-09-22 18:29:48.498warn2025-09-22T18:29:48.497+00:00 - WARN failed to fetch 2 mempool txs, retrying...
2025-09-22 18:29:48.178warn2025-09-22T18:29:48.178+00:00 - WARN failed to fetch 3 mempool txs, retrying...
2025-09-22 18:29:47.858warn2025-09-22T18:29:47.857+00:00 - WARN failed to fetch 2 mempool txs, retrying...
2025-09-22 18:29:47.538warn2025-09-22T18:29:47.538+00:00 - WARN failed to fetch 2 mempool txs, retrying...
2025-09-22 18:29:47.218warn2025-09-22T18:29:47.218+00:00 - WARN failed to fetch 2 mempool txs, retrying...
2025-09-22 18:29:46.897warn2025-09-22T18:29:46.897+00:00 - WARN failed to fetch 1 mempool txs, retrying...
2025-09-22 18:29:46.577warn2025-09-22T18:29:46.577+00:00 - WARN failed to fetch 1 mempool txs, retrying...
2025-09-22 18:29:46.258warn2025-09-22T18:29:46.258+00:00 - WARN failed to fetch 1 mempool txs, retrying...
2025-09-22 18:29:45.939warn2025-09-22T18:29:45.939+00:00 - WARN failed to fetch 1 mempool txs, retrying...
2025-09-22 18:29:45.620warn2025-09-22T18:29:45.619+00:00 - WARN failed to fetch 1 mempool txs, retrying...
2025-09-22 18:29:45.300warn2025-09-22T18:29:45.300+00:00 - WARN failed to fetch 1 mempool txs, retrying...
2025-09-22 18:29:44.981warn2025-09-22T18:29:44.981+00:00 - WARN failed to fetch 1 mempool txs, retrying...
Graph showing stats from the metrics. Note that "tx" line remained constant:
