# TigerBeetle Changelog

## 2024-03-19

- Bump version to 0.15.x
- Starting with 0.15.x, TigerBeetle is ready for production use, preserves durability and
  provides a forward upgrade path through storage stability.

### Safety And Performance
- [#1755](https://github.com/tigerbeetle/tigerbeetle/pull/1755)

  Set TigerBeetle's block size to 512KB.

  Previously, we used to have a block size of 1MB to help with approximate pacing. Now that pacing
  can be tuned independently of block size, reduce this value (but not too much - make the roads
  wider than you think) to help with read amplification on queries.

### TigerTracks 🎧

- [Immigrant Song - Live 1972](https://open.spotify.com/track/2aH2dcPnwoQwhLsXFezU2r?si=eead2c0cd17c429e)

## 2024-03-18

### Safety And Performance

- [#1660](https://github.com/tigerbeetle/tigerbeetle/pull/1660)

  Implement compaction pacing: traditionally LSM databases run compaction on a background thread.
  In contrast compaction in tigerbeetle is deterministically interleaved with normal execution
  process, to get predictable latencies and to guarantee that ingress can never outrun compaction.

  In this PR, this "deterministic scheduling" is greatly improved, slicing compaction work into
  smaller bites which are more evenly distributed across a bar of batched requests.

- [#1722](https://github.com/tigerbeetle/tigerbeetle/pull/1722)

  Include information about tigerbeetle version into the VSR protocol and the data file.

- [#1732](https://github.com/tigerbeetle/tigerbeetle/pull/1732),
  [#1743](https://github.com/tigerbeetle/tigerbeetle/pull/1743),
  [#1742](https://github.com/tigerbeetle/tigerbeetle/pull/1742),
  [#1720](https://github.com/tigerbeetle/tigerbeetle/pull/1720),
  [#1719](https://github.com/tigerbeetle/tigerbeetle/pull/1719),
  [#1705](https://github.com/tigerbeetle/tigerbeetle/pull/1705),
  [#1708](https://github.com/tigerbeetle/tigerbeetle/pull/1708),
  [#1707](https://github.com/tigerbeetle/tigerbeetle/pull/1707),
  [#1723](https://github.com/tigerbeetle/tigerbeetle/pull/1723),
  [#1706](https://github.com/tigerbeetle/tigerbeetle/pull/1706),
  [#1700](https://github.com/tigerbeetle/tigerbeetle/pull/1700),
  [#1696](https://github.com/tigerbeetle/tigerbeetle/pull/1696),
  [#1686](https://github.com/tigerbeetle/tigerbeetle/pull/1686).

  Many availability issues found by the simulator fixed!

- [#1734](https://github.com/tigerbeetle/tigerbeetle/pull/1734)

  Fix a buffer leak when `get_account_balances` is called on an invalid account.


### Features

- [#1671](https://github.com/tigerbeetle/tigerbeetle/pull/1671),
  [#1713](https://github.com/tigerbeetle/tigerbeetle/pull/1713),
  [#1709](https://github.com/tigerbeetle/tigerbeetle/pull/1709),
  [#1688](https://github.com/tigerbeetle/tigerbeetle/pull/1688),
  [#1691](https://github.com/tigerbeetle/tigerbeetle/pull/1691),
  [#1690](https://github.com/tigerbeetle/tigerbeetle/pull/1690).

  Many improvements to the documentation!

- [#1733](https://github.com/tigerbeetle/tigerbeetle/pull/1733)

  Rename `get_account_history` to `get_account_balances`.

- [#1657](https://github.com/tigerbeetle/tigerbeetle/pull/1657)

  Automatically expire pending transfers.

- [#1682](https://github.com/tigerbeetle/tigerbeetle/pull/1682)

  Implement in-place upgrades, so that the version of tigerbeetle binary can be updated without
  recreating the data file from scratch.

- [#1674](https://github.com/tigerbeetle/tigerbeetle/pull/1674)

  Consistently use `MiB` rather than `MB` in the CLI interface.

- [#1678](https://github.com/tigerbeetle/tigerbeetle/pull/1678)

  Mark `--standby` and `benchmark` CLI arguments as experimental.

### Internals

- [#1726](https://github.com/tigerbeetle/tigerbeetle/pull/1726)

  Unify PostedGroove and the index pending_status.

- [#1681](https://github.com/tigerbeetle/tigerbeetle/pull/1681)

  Include an entire header into checkpoint state to ease recovery after state sync.


### TigerTracks 🎧

- [Are You Gonna Go My Way](https://open.spotify.com/track/4LQOa4kXu0QAD88nMpr4fA?si=f7faf501919942b5)

## 2024-03-11

### Safety And Performance

- [#1663](https://github.com/tigerbeetle/tigerbeetle/pull/1663)

  Fetching account history and transfers now has unit tests, helping detect and fix a reported bug
  with posting and voiding transfers.

### Internals

- [#1648](https://github.com/tigerbeetle/tigerbeetle/pull/1648),
  [#1665](https://github.com/tigerbeetle/tigerbeetle/pull/1665),
  [#1654](https://github.com/tigerbeetle/tigerbeetle/pull/1654),
  [#1651](https://github.com/tigerbeetle/tigerbeetle/pull/1651)

  Testing and Timer logic was subject to some spring cleaning.

### Features

- [#1656](https://github.com/tigerbeetle/tigerbeetle/pull/1656),
  [#1659](https://github.com/tigerbeetle/tigerbeetle/pull/1659),
  [#1666](https://github.com/tigerbeetle/tigerbeetle/pull/1666),
  [#1667](https://github.com/tigerbeetle/tigerbeetle/pull/1667),
  [#1667](https://github.com/tigerbeetle/tigerbeetle/pull/1670)

  Preparation for in-place upgrade support.

- [#1633](https://github.com/tigerbeetle/tigerbeetle/pull/1633),
  [#1661](https://github.com/tigerbeetle/tigerbeetle/pull/1661),
  [#1652](https://github.com/tigerbeetle/tigerbeetle/pull/1652),
  [#1647](https://github.com/tigerbeetle/tigerbeetle/pull/1647),
  [#1637](https://github.com/tigerbeetle/tigerbeetle/pull/1637),
  [#1638](https://github.com/tigerbeetle/tigerbeetle/pull/1638),
  [#1655](https://github.com/tigerbeetle/tigerbeetle/pull/1655)

  [Documentation](https://docs.tigerbeetle.com/) has received some very welcome organizational
  and clarity changes. Go check them out!

### TigerTracks 🎧

- [Você Chegou](https://open.spotify.com/track/5Ns9a6JKX4sdUlaAh4SSGy)

## 2024-03-04

### Safety And Performance

- [#1584](https://github.com/tigerbeetle/tigerbeetle/pull/1584)
  Lower our memory usage by removing a redundant stash and not requiring a non-zero object cache
  size for Grooves.

  The object cache is designed to help things like Account lookups, where the positive case can
  skip all the prefetch machinery, but it doesn't make as much sense for other Grooves.

- [#1581](https://github.com/tigerbeetle/tigerbeetle/pull/1581)
  [#1611](https://github.com/tigerbeetle/tigerbeetle/pull/1611)

  Hook [nyrkiö](https://nyrkio.com/) up to our CI! You can find our dashboard
  [here](https://nyrkio.com/public/https%3A%2F%2Fgithub.com%2Ftigerbeetle%2Ftigerbeetle/main/devhub)
  in addition to our [devhub](https://tigerbeetle.github.io/tigerbeetle/).

- [#1635](https://github.com/tigerbeetle/tigerbeetle/pull/1635)
  [#1634](https://github.com/tigerbeetle/tigerbeetle/pull/1634)
  [#1623](https://github.com/tigerbeetle/tigerbeetle/pull/1623)
  [#1619](https://github.com/tigerbeetle/tigerbeetle/pull/1619)
  [#1609](https://github.com/tigerbeetle/tigerbeetle/pull/1609)
  [#1608](https://github.com/tigerbeetle/tigerbeetle/pull/1608)
  [#1595](https://github.com/tigerbeetle/tigerbeetle/pull/1595)

  Lots of small VSR changes, including a VOPR crash fix.

- [#1598](https://github.com/tigerbeetle/tigerbeetle/pull/1598)

  Fix a VOPR failure where state sync would cause a break in the hash chain.

### Internals

- [#1599](https://github.com/tigerbeetle/tigerbeetle/pull/1599)
  [#1597](https://github.com/tigerbeetle/tigerbeetle/pull/1597)

  Use Expand-Archive over unzip in PowerShell - thanks @felipevalerio for reporting!

- [#1607](https://github.com/tigerbeetle/tigerbeetle/pull/1607)
  [#1620](https://github.com/tigerbeetle/tigerbeetle/pull/1620)

  Implement [explicit coverage marks](https://ferrous-systems.com/blog/coverage-marks/).

- [#1621](https://github.com/tigerbeetle/tigerbeetle/pull/1621)
  [#1625](https://github.com/tigerbeetle/tigerbeetle/pull/1625)
  [#1622](https://github.com/tigerbeetle/tigerbeetle/pull/1622)
  [#1600](https://github.com/tigerbeetle/tigerbeetle/pull/1600)
  [#1605](https://github.com/tigerbeetle/tigerbeetle/pull/1605)
  [#1618](https://github.com/tigerbeetle/tigerbeetle/pull/1618)
  [#1606](https://github.com/tigerbeetle/tigerbeetle/pull/1606)

  Minor doc fixups.

- [#1636](https://github.com/tigerbeetle/tigerbeetle/pull/1636)
  [#1626](https://github.com/tigerbeetle/tigerbeetle/pull/1626)

  Default the VOPR to short log, and fix a false assertion in the liveness checker.

- [#1596](https://github.com/tigerbeetle/tigerbeetle/pull/1596)

  Fix a memory leak in our Java tests.

### TigerTracks 🎧

- [Auffe aufn Berg](https://www.youtube.com/watch?v=eRbkRNaqy9Y)

## 2024-02-26

### Safety And Performance

- [#1591](https://github.com/tigerbeetle/tigerbeetle/pull/1591)
  [#1589](https://github.com/tigerbeetle/tigerbeetle/pull/1589)
  [#1579](https://github.com/tigerbeetle/tigerbeetle/pull/1579)
  [#1576](https://github.com/tigerbeetle/tigerbeetle/pull/1576)

  Rework the log repair logic to never repair beyond a "confirmed" checkpoint, fixing a
  [liveness issue](https://github.com/tigerbeetle/tigerbeetle/issues/1378) where it was impossible
  for the primary to repair its entire log, even with a quorum of replicas at a recent checkpoint.

- [#1572](https://github.com/tigerbeetle/tigerbeetle/pull/1572)

  Some Java unit tests created native client instances without the proper deinitialization,
  causing an `OutOfMemoryError` during CI.

- [#1569](https://github.com/tigerbeetle/tigerbeetle/pull/1569)
  [#1570](https://github.com/tigerbeetle/tigerbeetle/pull/1570)

  Fix Vopr's false alarms.

### Internals

- [#1585](https://github.com/tigerbeetle/tigerbeetle/pull/1585)

  Document how assertions should be used, especially those with complexity _O(n)_ under
  the `constants.verify` conditional.

- [#1580](https://github.com/tigerbeetle/tigerbeetle/pull/1580)

  Harmonize and automate the logging pattern by using the `@src` built-in to retrieve the
  function name.

- [#1568](https://github.com/tigerbeetle/tigerbeetle/pull/1568)

  Include the benchmark smoke as part of the `zig build test` command rather than a special case
  during CI.

- [#1574](https://github.com/tigerbeetle/tigerbeetle/pull/1574)

  Remove unused code coverage metrics from the CI.

- [#1575](https://github.com/tigerbeetle/tigerbeetle/pull/1575)
  [#1573](https://github.com/tigerbeetle/tigerbeetle/pull/1573)
  [#1582](https://github.com/tigerbeetle/tigerbeetle/pull/1582)

  Re-enable Windows CI 🎉.

### TigerTracks 🎧

- [Dos Margaritas](https://www.youtube.com/watch?v=Ts_7BYubYws)

  [(_versión en español_)](https://www.youtube.com/watch?v=B_VLegyguoI)

## 2024-02-19

### Safety And Performance

- [#1533](https://github.com/tigerbeetle/tigerbeetle/pull/1533)

  DVCs implicitly nack missing prepares from old log-views.

  (This partially addresses a liveness issue in the view change.)

- [#1552](https://github.com/tigerbeetle/tigerbeetle/pull/1552)

  When a replica joins a view by receiving an SV message, some of the SV's headers may be too far
  ahead to insert into the journal. (That is, they are beyond the replica's checkpoint trigger.)

  During a view change, those headers are now eligible to be DVC headers.

  (This partially addresses a liveness issue in the view change.)

- [#1560](https://github.com/tigerbeetle/tigerbeetle/pull/1560)

  Fixes a bug in the C client that wasn't handling `error.TooManyOutstanding` correctly.

### Internals

- [#1482](https://github.com/tigerbeetle/tigerbeetle/pull/1482)

  Bring back Windows tests for .Net client in CI.

- [#1540](https://github.com/tigerbeetle/tigerbeetle/pull/1540)

  Add script to scaffold changelog updates.

- [#1542](https://github.com/tigerbeetle/tigerbeetle/pull/1542),
  [#1553](https://github.com/tigerbeetle/tigerbeetle/pull/1553),
  [#1559](https://github.com/tigerbeetle/tigerbeetle/pull/1559),
  [#1561](https://github.com/tigerbeetle/tigerbeetle/pull/1561)

  Improve CI/test error reporting.

- [#1551](https://github.com/tigerbeetle/tigerbeetle/pull/1551)

  Draw devhub graph as line graph.

- [#1554](https://github.com/tigerbeetle/tigerbeetle/pull/1554)

  Simplify command to run a single test.

- [#1555](https://github.com/tigerbeetle/tigerbeetle/pull/1555)

  Add client batching integration tests.

- [#1557](https://github.com/tigerbeetle/tigerbeetle/pull/1557)

  Format default values into the CLI help message.

- [#1558](https://github.com/tigerbeetle/tigerbeetle/pull/1558)

  Track commit timestamp to enable retrospective benchmarking in the devhub.

- [#1562](https://github.com/tigerbeetle/tigerbeetle/pull/1562),
  [#1563](https://github.com/tigerbeetle/tigerbeetle/pull/1563)

  Improve CI/test performance.

- [#1567](https://github.com/tigerbeetle/tigerbeetle/pull/1567)

  Guarantee that the test runner correctly reports "zero tests run" when run with a filter that
  matches no tests.

### TigerTracks 🎧

- [Eye Of The Tiger](https://www.youtube.com/watch?v=btPJPFnesV4)

  (Hat tip to [iofthetiger](https://ziggit.dev/t/iofthetiger/3065)!)

## 2024-02-12

### Safety And Performance

- [#1519](https://github.com/tigerbeetle/tigerbeetle/pull/1519)

  Reduce checkpoint latency by checkpointing the grid concurrently with other trailers.

- [#1515](https://github.com/tigerbeetle/tigerbeetle/pull/1515)

  Fix a logical race condition (which was caught by an assert) when reading and writing client
  replies concurrently.


- [#1522](https://github.com/tigerbeetle/tigerbeetle/pull/1522)

  Double check that both checksum and request number match between a request and the corresponding
  reply.

- [#1520](https://github.com/tigerbeetle/tigerbeetle/pull/1520)

  Optimize fields with zero value by not adding them to an index.

### Features

- [#1526](https://github.com/tigerbeetle/tigerbeetle/pull/1526),
  [#1531](https://github.com/tigerbeetle/tigerbeetle/pull/1531).

  Introduce `get_account_history` operation for querying the historical balances of a given account.

- [#1523](https://github.com/tigerbeetle/tigerbeetle/pull/1523)

  Add helper function for generating approximately monotonic IDs to various language clients.

### TigerTracks 🎧

- [Musique à Grande Vitesse](https://open.spotify.com/album/0pmrBIfqDn65p4FX9ubqXn?si=aLliiV5dSOeeId57jtaHhw)

## 2024-02-05

### Safety And Performance

- [#1489](https://github.com/tigerbeetle/tigerbeetle/pull/1489),
  [#1496](https://github.com/tigerbeetle/tigerbeetle/pull/1496),
  [#1501](https://github.com/tigerbeetle/tigerbeetle/pull/1501).

  Harden VSR against edge cases.

- [#1508](https://github.com/tigerbeetle/tigerbeetle/pull/1508),
  [#1509](https://github.com/tigerbeetle/tigerbeetle/pull/1509).

  Allows VSR to perform checkpoint steps concurrently to reduce latency spikes.

- [#1505](https://github.com/tigerbeetle/tigerbeetle/pull/1505)

  Removed unused indexes on account balances for a nice bump in throughput and lower memory usage.

- [#1512](https://github.com/tigerbeetle/tigerbeetle/pull/1512)

  Only zero-out the parts necessary for correctness of fresh storage buffers. "Defense in Depth"
  without sacrificing performance!

### Features

- [#1491](https://github.com/tigerbeetle/tigerbeetle/pull/1491),
  [#1503](https://github.com/tigerbeetle/tigerbeetle/pull/1503).

  TigerBeetle's [dev workbench](https://tigerbeetle.github.io/tigerbeetle/) now also tracks
  memory usage (RSS), throughput, and latency benchmarks over time!

### Internals

- [#1481](https://github.com/tigerbeetle/tigerbeetle/pull/1481),
  [#1493](https://github.com/tigerbeetle/tigerbeetle/pull/1493),
  [#1495](https://github.com/tigerbeetle/tigerbeetle/pull/1495),
  [#1498](https://github.com/tigerbeetle/tigerbeetle/pull/1498).

  Simplify assertions and tests for VSR and Replica.

- [#1497](https://github.com/tigerbeetle/tigerbeetle/pull/1497),
  [#1502](https://github.com/tigerbeetle/tigerbeetle/pull/1502),
  [#1504](https://github.com/tigerbeetle/tigerbeetle/pull/1504).

  .NET CI fixups

- [#1485](https://github.com/tigerbeetle/tigerbeetle/pull/1485),
  [#1499](https://github.com/tigerbeetle/tigerbeetle/pull/1499),
  [#1504](https://github.com/tigerbeetle/tigerbeetle/pull/1504).

  Spring Cleaning

### TigerTracks 🎧

- [Bone Dry](https://open.spotify.com/track/0adZjn5WV3b0BcZbvSi0y9)

## 2024-01-29

### Safety And Performance

- [#1446](https://github.com/tigerbeetle/tigerbeetle/pull/1446)

  Panic on checkpoint divergence. Previously, if a replica's state on disk diverged, we'd
  use state sync to bring it in line. Now, we don't allow any storage engine nondeterminism
  (mixed version clusters are forbidden) and panic if we encounter any.

- [#1476](https://github.com/tigerbeetle/tigerbeetle/pull/1476)

  Fix a liveness issues when starting a view across checkpoints in an idle cluster.

- [#1460](https://github.com/tigerbeetle/tigerbeetle/pull/1460)

  Stop an isolated replica from locking a standby out of a cluster.

### Features

- [#1470](https://github.com/tigerbeetle/tigerbeetle/pull/1470)

  Change `get_account_transfers` to use `timestamp_min` and `timestamp_max` to allow filtering by
  timestamp ranges.

- [#1463](https://github.com/tigerbeetle/tigerbeetle/pull/1463)

  Allow setting `--addresses=0` when starting TigerBeetle to enable a mode helpful for integration
  tests:
  * A free port will be picked automatically.
  * The port, and only the port, will be printed to stdout which will then be closed.
  * TigerBeetle will [exit when its stdin is closed](https://matklad.github.io/2023/10/11/unix-structured-concurrency.html).

- [#1402](https://github.com/tigerbeetle/tigerbeetle/pull/1402)

  TigerBeetle now has a [dev workbench](https://tigerbeetle.github.io/tigerbeetle/)! Currently we
  track our build times and executable size over time.

- [#1461](https://github.com/tigerbeetle/tigerbeetle/pull/1461)

  `tigerbeetle client ...` is now `tigerbeetle repl ...`.

### Internals

- [#1480](https://github.com/tigerbeetle/tigerbeetle/pull/1480)

  Deprecate support and testing for Node 16, which is EOL.

- [#1477](https://github.com/tigerbeetle/tigerbeetle/pull/1477),
  [#1469](https://github.com/tigerbeetle/tigerbeetle/pull/1469),
  [#1475](https://github.com/tigerbeetle/tigerbeetle/pull/1475),
  [#1457](https://github.com/tigerbeetle/tigerbeetle/pull/1457),
  [#1452](https://github.com/tigerbeetle/tigerbeetle/pull/1452).

  Improve VOPR & VSR logging, docs, assertions and tests.

- [#1474](https://github.com/tigerbeetle/tigerbeetle/pull/1474)

  Improve integration tests around Node and `pending_transfer_expired` - thanks to our friends at
  Rafiki for reporting!

### TigerTracks 🎧

- [Paint It, Black](https://www.youtube.com/watch?v=170sceOWWXc)

## 2024-01-22

### Safety And Performance

- [#1438](https://github.com/tigerbeetle/tigerbeetle/pull/1438)

  Avoid an extra copy of data when encoding the superblock during checkpoint.

- [#1429](https://github.com/tigerbeetle/tigerbeetle/pull/1429)

  Use more precise upper bounds for static memory allocation, reducing memory usage by about 200MiB.

- [#1439](https://github.com/tigerbeetle/tigerbeetle/pull/1439)

  When reading data past the end of the file, defensively zero-out the result buffer.

### Features

- [#1443](https://github.com/tigerbeetle/tigerbeetle/pull/1443)

  Upgrade C# client API to use `Span<T>`.

- [#1347](https://github.com/tigerbeetle/tigerbeetle/pull/1347)

  Add ID generation function to the Java client. TigerBeetle doesn't assign any meaning to IDs and
  can use anything as long as it is unique. However, for optimal performance it is best if these
  client-generated IDs are approximately monotonic. This can be achieved by, for example, using
  client's current timestamp for high order bits of an ID. The new helper does just that.

### Internals

- [#1437](https://github.com/tigerbeetle/tigerbeetle/pull/1437),
  [#1435](https://github.com/tigerbeetle/tigerbeetle/pull/1435),
  [d7c3f46](https://github.com/tigerbeetle/tigerbeetle/commit/d7c3f4654ea7c65b6d141be33dadd29e869c3984).

  Rewrite git history to remove large files accidentally added to the repository during early quick
  prototyping phase. To make this durable, add CI checks for unwanted files. The original history
  is available at:

  <https://github.com/tigerbeetle/tigerbeetle-history-archive>

- [#1421](https://github.com/tigerbeetle/tigerbeetle/pull/1421),
  [#1401](https://github.com/tigerbeetle/tigerbeetle/pull/1401).

  New tips for the style guide:

  - [write code top-down](https://www.teamten.com/lawrence/programming/write-code-top-down.html)
  - [pair up assertions](https://tigerbeetle.com/blog/2023-12-27-it-takes-two-to-contract/)

### TigerTracks 🎧

- [Don't Take No For An Answer](https://youtu.be/BUDe0bJAHjY?si=_rdqeGRgRoA9HQnV)

## 2024-01-15

Welcome to 2024!

### Safety And Performance

- [#1425](https://github.com/tigerbeetle/tigerbeetle/pull/1425),
  [#1412](https://github.com/tigerbeetle/tigerbeetle/pull/1412),
  [#1410](https://github.com/tigerbeetle/tigerbeetle/pull/1410),
  [#1408](https://github.com/tigerbeetle/tigerbeetle/pull/1408),
  [#1395](https://github.com/tigerbeetle/tigerbeetle/pull/1395).

  Run more fuzzers directly in CI as a part of not rocket science package.

- [#1413](https://github.com/tigerbeetle/tigerbeetle/pull/1413)

   Formalize some ad-hoc testing practices as proper integration tests (that is, tests that interact
   with a `tigerbeetle` binary through IPC).

- [#1404](https://github.com/tigerbeetle/tigerbeetle/pull/1404)

   Add a lint check for unused Zig files.

- [#1390](https://github.com/tigerbeetle/tigerbeetle/pull/1390)

  Improve cluster availability by including conservative information about the current view into
  ping-pong messages. In particular, prevent the cluster from getting stuck when all replicas become
  primaries for different views.

- [#1365](https://github.com/tigerbeetle/tigerbeetle/pull/1365)

  Test both the latest and the oldest supported Java version on CI.

- [#1389](https://github.com/tigerbeetle/tigerbeetle/pull/1389)

  Fix a data race on close in the Java client.

### Features

- [#1403](https://github.com/tigerbeetle/tigerbeetle/pull/1403)

  Make binaries on Linux about six times smaller (12MiB -> 2MiB). Turns `tigerbeetle` was
  accidentally including 10 megabytes worth of debug info! Note that unfortunately stripping _all_
  debug info also prevents getting a nice stack trace in case of a crash. We are working on finding
  the minimum amount of debug information required to get _just_ the stack traces.

- [#1423](https://github.com/tigerbeetle/tigerbeetle/pull/1423),
  [#1426](https://github.com/tigerbeetle/tigerbeetle/pull/1426).

  Cleanup error handling API for Java client to never surface internal errors as checked exceptions.

- [#1405](https://github.com/tigerbeetle/tigerbeetle/pull/1405)

  Add example for setting up TigerBeetle as a systemd service.

- [#1400 ](https://github.com/tigerbeetle/tigerbeetle/pull/1400)

  Drop support for .Net Standard 2.1.

- [#1397](https://github.com/tigerbeetle/tigerbeetle/pull/1397)

  Don't exit repl on `help` command.

### Internals

- [#1422](https://github.com/tigerbeetle/tigerbeetle/pull/1422),
  [#1420](https://github.com/tigerbeetle/tigerbeetle/pull/1420),
  [#1417](https://github.com/tigerbeetle/tigerbeetle/pull/1417)

  Overhaul documentation-testing infrastructure to reduce code duplication.

- [#1398](https://github.com/tigerbeetle/tigerbeetle/pull/1398)

  Don't test NodeJS client on platforms for which there are no simple upstream installation scripts.

- [#1388](https://github.com/tigerbeetle/tigerbeetle/pull/1388)

  Use histogram in the benchmark script to reduce memory usage.

### TigerTracks 🎧

- [Stripped](https://open.spotify.com/track/20BDMQu40KIUxUeFusq6eq)

## 2023-12-20

_“The exception confirms the rule in cases not excepted."_ ― Cicero.

Due to significant commits we had this last week, we decided to make an exception
in our release schedule and cut one more release in 2023!

Still, **the TigerBeetle team wishes everyone happy holidays!** 🎁

### Internals

- [#1362](https://github.com/tigerbeetle/tigerbeetle/pull/1362),
  [#1367](https://github.com/tigerbeetle/tigerbeetle/pull/1367),
  [#1374](https://github.com/tigerbeetle/tigerbeetle/pull/1374),
  [#1375](https://github.com/tigerbeetle/tigerbeetle/pull/1375)

  Some CI-related stuff plus the `-Drelease` flag, which will bring back the joy of
  using the compiler from the command line 🤓.

- [#1373](https://github.com/tigerbeetle/tigerbeetle/pull/1373)

  Added value count to `TableInfo`, allowing future optimizations for paced compaction.

### Safety And Performance

- [#1346](https://github.com/tigerbeetle/tigerbeetle/pull/1346)

  The simulator found a failure when the WAL gets corrupted near a checkpoint boundary, leading us
  to also consider scenarios where corrupted blocks in the grid end up "intersecting" with
  corruption in the WAL, making the state unrecoverable where it should be. We fixed it by
  extending the durability of "prepares", evicting them from the WAL only when there's a quorum of
  checkpoints covering this "prepare".

- [#1366](https://github.com/tigerbeetle/tigerbeetle/pull/1366)

  Fix a unit test that regressed after we changed an undesirable behavior that allowed `prefetch`
  to invoke its callback synchronously.

- [#1381](https://github.com/tigerbeetle/tigerbeetle/pull/1381)

  Relaxed a simulator's verification, allowing replicas of the core cluster to be missing some
  prepares, as long as they are from a past checkpoint.

### Features

- [#1054](https://github.com/tigerbeetle/tigerbeetle/pull/1054)

  A highly anticipated feature lands on TigerBeetle: it's now possible to retrieve the transfers
  involved with a given account by using the new operation `get_account_transfers`.

  Note that this feature itself is an ad-hoc API intended to be replaced once we have a proper
  Querying API. The real improvement of this PR is the implementation of range queries, enabling
  us to land exciting new features on the next releases.

- [#1368](https://github.com/tigerbeetle/tigerbeetle/pull/1368)

  Bump the client's maximum limit and the default value of `concurrency_max` to fully take
  advantage of the batching logic.

### TigerTracks 🎧

- [Everybody needs somebody](https://www.youtube.com/watch?v=m1M5Tc7eLCo)

## 2023-12-18

*As the last release of the year 2023, the TigerBeetle team wishes everyone happy holidays!* 🎁

### Internals

- [#1359](https://github.com/tigerbeetle/tigerbeetle/pull/1359)

  We've established a rotation between the team for handling releases. As the one writing these
  release notes, I am now quite aware.

- [#1357](https://github.com/tigerbeetle/tigerbeetle/pull/1357)

  Fix panic in JVM unit test on Java 21. We test JNI functions even if they're not used by the Java
  client and the semantics have changed a bit since Java 11.

- [#1351](https://github.com/tigerbeetle/tigerbeetle/pull/1351),
  [#1356](https://github.com/tigerbeetle/tigerbeetle/pull/1356),
  [#1360](https://github.com/tigerbeetle/tigerbeetle/pull/1360)

  Move client sessions from the Superblock (database metadata) into the Grid (general storage). This
  simplifies control flow for various sub-components like Superblock checkpointing and Replica state
  sync.

### Safety And Performance

- [#1352](https://github.com/tigerbeetle/tigerbeetle/pull/1352)

  An optimization for removes on secondary indexes makes a return. Now tombstone values in the LSM
  can avoid being compacted all the way down to the lowest level if they can be cancelled out by
  inserts.

- [#1257](https://github.com/tigerbeetle/tigerbeetle/pull/1257)

  Clients automatically batch pending similar requests 🎉! If a tigerbeetle client submits a
  request, and one with the same operation is currently in-flight, they will be grouped and
  processed together where possible (currently, only for `CreateAccount` and `CreateTransfers`).
  This should [greatly improve the performance](https://github.com/tigerbeetle/tigerbeetle/pull/1257#issuecomment-1812648270)
  of workloads which submit a single operation at a time.

### TigerTracks 🎧

- [Carouselambra](https://open.spotify.com/track/0YZKbKo9i91i7LD0m1KASq)

## 2023-12-11

### Safety And Performance

- [#1339](https://github.com/tigerbeetle/tigerbeetle/pull/1339)

  Defense in depth: add checkpoint ID to prepare messages. Checkpoint ID is a hash that covers, via
  hash chaining, the entire state stored in the data file. Verifying that checkpoint IDs match
  provides a direct strong cryptographic guarantee that the state is the same across replicas, on
  top of existing guarantee that the sequence of events leading to the state is identical.

### Internals

- [#1343](https://github.com/tigerbeetle/tigerbeetle/pull/1343),
  [#1341](https://github.com/tigerbeetle/tigerbeetle/pull/1341),
  [#1340](https://github.com/tigerbeetle/tigerbeetle/pull/1340)

  Gate the main branch on more checks: unit-tests for NodeJS and even more fuzzers.

- [#1332](https://github.com/tigerbeetle/tigerbeetle/pull/1332),
  [#1348](https://github.com/tigerbeetle/tigerbeetle/pull/1348)

  Code cleanups after removal of storage size limit.

### TigerTracks 🎧

- [Concrete Reservation](https://open.spotify.com/track/1Li9HBLXG2LJSeD4fEhtcd?si=64611215922a4436)

## 2023-12-04

### Safety And Performance

- [#1330](https://github.com/tigerbeetle/tigerbeetle/pull/1330),
  [#1319](https://github.com/tigerbeetle/tigerbeetle/pull/1319)

  Fix free set index. The free set is a bitset of free blocks in the grid. To speed up block
  allocation, the free set also maintains an index --- a coarser-grained bitset where a single bit
  corresponds to 1024 blocks. Maintaining consistency between a data structure and its index is
  hard, and thorough assertions are crucial. When moving free set to the grid, we discovered that,
  in fact, we don't have enough assertions in this area and, as a result, even have a bug!
  Assertions added, bug removed!

- [#1323](https://github.com/tigerbeetle/tigerbeetle/pull/1323),
  [#1336](https://github.com/tigerbeetle/tigerbeetle/pull/1336),
  [#1324](https://github.com/tigerbeetle/tigerbeetle/pull/1324)

  LSM tree fuzzer found a couple of bugs in its own code.

### Features

- [#1331](https://github.com/tigerbeetle/tigerbeetle/pull/1331),
  [#1322](https://github.com/tigerbeetle/tigerbeetle/pull/1322),
  [#1328](https://github.com/tigerbeetle/tigerbeetle/pull/1328)

  Remove format-time limit on the size of the data file. Before, the maximum size of the data file
  affected the layout of the superblock, and there wasn't any good way to increase this limit, short
  of recreating the cluster from scratch. Now, this limit only applies to the in-memory data
  structures: when a data files grows large, it is sufficient to just restart its replica with a
  larger amount of RAM.

- [#1321](https://github.com/tigerbeetle/tigerbeetle/pull/1321).

  We finally have the "installation" page in our docs!

### Internals

- [#1334](https://github.com/tigerbeetle/tigerbeetle/pull/1334)

  Use Zig's new `if (@inComptime())` builtin to compute checksum of an empty byte slice at compile
  time.

- [#1315](https://github.com/tigerbeetle/tigerbeetle/pull/1315)

  Fix unit tests for the Go client and add them to
  [not rocket science](https://graydon2.dreamwidth.org/1597.html)
  set of checks.

### TigerTracks 🎧

- [Times Like These](https://www.youtube.com/watch?v=cvCUXXsP5WE)

## 2023-11-27

### Internals

- [#1306](https://github.com/tigerbeetle/tigerbeetle/pull/1306),
  [#1308](https://github.com/tigerbeetle/tigerbeetle/pull/1308)

  When validating our releases, use the `release` branch instead of `main` to ensure everything is
  in sync, and give the Java validation some retry logic to allow for delays in publishing to
  Central.

- [#1310](https://github.com/tigerbeetle/tigerbeetle/pull/1310)

  Pad storage checksums from 128-bit to 256-bit. These are currently unused, but we're reserving
  the space for AEAD tags in future.

- [#1312](https://github.com/tigerbeetle/tigerbeetle/pull/1312)

  Remove a trailing comma in our Java client sample code.

- [#1313](https://github.com/tigerbeetle/tigerbeetle/pull/1313)

  Switch `bootstrap.sh` to use spaces only for indentation and ensure it's checked by our
  shellcheck lint.

- [#1314](https://github.com/tigerbeetle/tigerbeetle/pull/1314)

  Update our `DESIGN.md` to better reflect storage fault probabilities and add in a reference.

- [#1316](https://github.com/tigerbeetle/tigerbeetle/pull/1316)

  Add `CHANGELOG.md` validation to our tidy lint script. We now check line length limits and
  trailing whitespace.

- [#1317](https://github.com/tigerbeetle/tigerbeetle/pull/1317)

  In keeping with
  [TigerStyle](https://github.com/tigerbeetle/tigerbeetle/blob/main/docs/TIGER_STYLE.md#naming-things),
  rename `reserved_nonce` to `nonce_reserved`.

- [#1318](https://github.com/tigerbeetle/tigerbeetle/pull/1318)

  Note in TigerStyle that callbacks go last in the list of parameters.

- [#1325](https://github.com/tigerbeetle/tigerbeetle/pull/1325)

  Add an exception for line length limits if there's a link in said line.

### TigerTracks 🎧

- [Space Trash](https://www.youtube.com/watch?v=tmcVAJd87Wk)

## 2023-11-20

### Safety And Performance

- [#1300](https://github.com/tigerbeetle/tigerbeetle/pull/1300)

  Recursively check for padding in structs used for data serialization, ensuring that no
  uninitialized bytes can be stored or transmitted over the network. Previously, we checked only
  if the struct had no padding, but not its fields.

### Internals

- [#1299](https://github.com/tigerbeetle/tigerbeetle/pull/1299)

  Minor adjustments in the release process, making it easier to track updates in the documentation
  website when a new version is released, even if there are no changes in the documentation itself.

- [#1301](https://github.com/tigerbeetle/tigerbeetle/pull/1301)

  Fix outdated documentation regarding 128-bit balances.

- [#1302](https://github.com/tigerbeetle/tigerbeetle/pull/1302)

  Fix a [bug](https://github.com/tigerbeetle/tigerbeetle/issues/1290) discovered and reported
  during the [Hackathon 2023](https://github.com/tigerbeetle/hackathon-2023), where the Node.js
  client's error messages were truncated due to an incorrect string concatenation adding a null
  byte `0x00` in the middle of the string.

- [#1291](https://github.com/tigerbeetle/tigerbeetle/pull/1291)

  Update the Node.js samples instructions, guiding the user to install all dependencies before
  the sample project.

- [#1295](https://github.com/tigerbeetle/tigerbeetle/pull/1295)

  We've doubled the `Header`s size to 256 bytes, paving the way for future improvements that will
  require extra space. Concurrently, this change also refactors a great deal of code.
  Some of the `Header`'s fields are shared by all messages, however, each `Command` also requires
  specific pieces of information that are only used by its kind of message, and it was necessary to
  repurpose and reinterpret fields so that the same header could hold different data depending on
  the context. Now, commands have their own specialized data type containing the fields that are
  only pertinent to the context, making the API much safer and intent-clear.

- [#1304](https://github.com/tigerbeetle/tigerbeetle/pull/1304)

  With larger headers (see #1295) we have enough room to make the cluster ID a 128-bit integer,
  allowing operators to generate random cluster IDs without the cost of having a centralized ID
  coordinator. Also updates the documentation and sample programs to reflect the new maximum batch
  size, which was reduced from 8191 to 8190 items after we doubled the header.

### TigerTracks 🎧

- [She smiled sweetly](https://www.youtube.com/watch?v=fB1EpEFz6Lg)

## 2023-11-13

### Safety And Performance

- [#1264](https://github.com/tigerbeetle/tigerbeetle/pull/1264)

  Implement last-mile release artifact verification in CI.

- [#1268](https://github.com/tigerbeetle/tigerbeetle/pull/1268)

  Bump the simulator's safety phase max-ticks to avoid false positives from the liveness check.

- [#1270](https://github.com/tigerbeetle/tigerbeetle/pull/1270)

  Fix a crash caused by a race between a commit and a repair acquiring a client-reply `Write`.

- [#1278](https://github.com/tigerbeetle/tigerbeetle/pull/1278)

  Fix a crash caused by a race between state (table) sync and a move-table compaction.

  Both bugs didn't stand a chance in the [Line of Fire](https://www.youtube.com/watch?v=pq-G3EWO9XM)
  of our deterministic simulator!

### Internals

- [#1244](https://github.com/tigerbeetle/tigerbeetle/pull/1244)

  Specify which CPU features are supported in builds.

- [#1275](https://github.com/tigerbeetle/tigerbeetle/pull/1275)

  Improve `shell.zig`'s directory handling, to guard against mistakes with respect to the current
  working directory.

- [#1277](https://github.com/tigerbeetle/tigerbeetle/pull/1277)

  Interpret a git hash as a VOPR seed, to enable reproducible simulator smoke tests in CI.

- [#1288](https://github.com/tigerbeetle/tigerbeetle/pull/1288)

  Explicitly target glibc 2.7 when building client libraries, to make sure TigerBeetle clients are
  compatible with older distributions.

## 2023-11-06

### Safety And Performance

- [#1263](https://github.com/tigerbeetle/tigerbeetle/pull/1263)

  Revive the TigerBeetle [VOPRHub](https://github.com/tigerbeetle-vopr)! Some previous changes left
  it on it's [Last Stand](https://open.spotify.com/track/1ibHApXtb0pgplmNDRLHrJ), but the bot is
  back in business finding liveness bugs:
  [#1266](https://github.com/tigerbeetle/tigerbeetle/issues/1266)

### Features

- [#1260](https://github.com/tigerbeetle/tigerbeetle/pull/1260)

  Set the latest Docker image to track the latest release. Avoids language clients going out of sync
  with your default docker replica installations.

### Internals

- [#1261](https://github.com/tigerbeetle/tigerbeetle/pull/1261)

  Move website doc generation for https://docs.tigerbeetle.com/ into the main repo.

- [#1265](https://github.com/tigerbeetle/tigerbeetle/pull/1265),
  [#1243](https://github.com/tigerbeetle/tigerbeetle/pull/1243)

  Addressed some release quirks with the .NET and Go client builds.

## 2023-10-30

### Safety And Performance

- [#1251](https://github.com/tigerbeetle/tigerbeetle/pull/1251)

  Prove a tighter upper bound for the size of manifest log. With this new bound, manifest log is
  guaranteed to fit in allocated memory and is smaller. Additionally, manifest log compaction is
  paced depending on the current length of the log, balancing throughput and time-to-recovery.

- [#1198](https://github.com/tigerbeetle/tigerbeetle/pull/1198)

  Recommend using [ULID](https://github.com/ulid/spec) for event IDs. ULIDs are approximately
  sorted, which significantly improves common-case performance.

### Internals

- [#1218](https://github.com/tigerbeetle/tigerbeetle/pull/1218)

  Rewrite Node.js client implementation to use the common C client underneath. While clients for
  other languages already use the underlying C library, the Node.js client duplicated some code for
  historical reasons, but now we can leave that duplication in the past. [This Is A
  Photograph](https://www.youtube.com/watch?v=X0i7whWLW8M).

## 2023-10-25

### Safety And Performance

- [#1240](https://github.com/tigerbeetle/tigerbeetle/pull/1240)

  Increase block size to reduce latencies due to compaction work. Today, we use a simplistic
  schedule for compaction, which causes latency spikes at the end of the bar. While the future
  solution will implement a smarter compaction pacing to distribute the work more evenly, we can
  get a quick win by tweaking the block and the bar size, which naturally evens out latency spikes.

- [#1246](https://github.com/tigerbeetle/tigerbeetle/pull/1246)

  The new release process changed the names of the published artifacts (the version is no longer
  included in the name). This broke our quick start scripts, which we have fixed. Note that we are
  in the process of rolling out the new release process, so some unexpected breakage is expected.

- [#1239](https://github.com/tigerbeetle/tigerbeetle/pull/1239),
  [#1243](https://github.com/tigerbeetle/tigerbeetle/pull/1243)

  Speed up secondary index maintenance by statically distinguishing between insertions and
  updates. [Faster than the speed of night!](https://open.spotify.com/track/30oZqbcUROFLSru3WcN3bx)

### Features

- [#1245](https://github.com/tigerbeetle/tigerbeetle/pull/1245)

  Include Docker images in the release.

### Internals

- [#1234](https://github.com/tigerbeetle/tigerbeetle/pull/1234)

  Simplify superblock layout by using a linked list of blocks for manifest log, so that the
  superblock needs to store only two block references.

  P.S. Note the PR number!

## 2023-10-23

This is the start of the changelog. A lot happened before this point and is lost in the mist of git
history, but any notable change from this point on shall be captured by this document.

### Safety And Performance

- [#1225](https://github.com/tigerbeetle/tigerbeetle/pull/1225)

  Remove bloom filters. TigerBeetle implements more targeted optimizations for
  both positive and negative lookups, making bloom filters a net loss.

### Features

- [#1228](https://github.com/tigerbeetle/tigerbeetle/pull/1228)

  Increase alignment of data blocks to 128KiB (from 512 bytes). Larger alignment gives operators
  better control over physical layout of data on disk.

### Internals

- [#1201](https://github.com/tigerbeetle/tigerbeetle/pull/1201),
  [#1232](https://github.com/tigerbeetle/tigerbeetle/pull/1232)

  Overhaul of CI and release infrastructure. CI and releases are now driven by Zig code. The main
  branch is gated on integration tests for all clients.

  This is done in preparation for the first TigerBeetle release.

## Prehistory

For archeological inquiries, check out the state of the repository at the time of the first
changelog:

[https://github.com/tigerbeetle/tigerbeetle/](
https://github.com/tigerbeetle/tigerbeetle/tree/d2d6484188ecc57680e8bde446b5d09b6f2d83ca)