[Glossary](https://blnkfinance.com/glossary) Hot balance # What is a hot balance? Hot balance A hot balance is a ledger balance that takes so many concurrent posts that it becomes a bottleneck. The row is locked, queued work piles up, and latency rises. Engineers often call this a hot row. The balance is the thing that overheats. ## How does a hot balance show up? One balance sits on the path of many transfers. A settlement pool, a fee sink, or a single omnibus account are common. Each post has to read, lock, and write that row. When arrivals outrun the lock, the queue grows and every other flow that touches the same balance waits. ## Hot balance vs hot row Hot row is the database name for the same problem. The ledger name is hot balance because the contention is on a balance record, not on an arbitrary table. The fix is the same idea: fewer writes to that one record, or more records to write to. ## How do you cool a hot balance? Two patterns show up in production. Coalescing batches queued posts that share a source, destination, and currency, then applies them in one commit. Sharding splits one logical balance into many, and your app routes each transfer to a shard. Coalescing helps when the same pair of balances trades over and over. Sharding helps when one account is a funnel for the whole book. Do not shard a customer wallet unless that wallet is the funnel. In Blnk, queued transactions and inflight holds both write the same balance row. If a pool or @ account is the bottleneck, coalesce or shard it. See [handling hot balances](https://docs.blnkfinance.com/guides/hot-balances). Related terms - [Balance](https://blnkfinance.com/glossary/balance) - [Historical balance](https://blnkfinance.com/glossary/historical-balance) - [Transaction](https://blnkfinance.com/glossary/transaction) - [Ledger](https://blnkfinance.com/glossary/ledger)