PgBouncer changelog
===================

PgBouncer 1.25.x
----------------

**2025-12-03  -  PgBouncer 1.25.1  -  "Fixing a bunch of bugs before Christmas"**

- Security
  * Fix CVE-2025-12819: Before this release it was possible for an unauthenticated attacker to execute arbitrary SQL during authentication by providing a malicious search_path parameter in the StartupMessage. Systems that have ALL the following configurations are vulnerable:

    1. `track_extra_parameters` includes search_path (non-default configuration, probably only configured in setups involving Citus or PostgreSQL 18)
    2. `auth_user` is set to a non-empty string (non-default configuration)
    3. `auth_query` is configured without fully-qualified object names (default configuration, the < operator is not schema qualified)

- Fixes
    - Fix errors with ad-hoc SCRAM auth after reconnect to server ([#1432], introduced in 1.25.0)
    - Add missing typedefs for exotic architectures without SIMD support ([#1414], introduced in 1.25.0)
    - Remove noisy warning log when client closes the connection before sending any data ([#1420], introduced in 1.25.0)
    - Prevent potential NULL pointer dereference ([#1423], introduced in 1.25.0)
    - Fix potential memory leak ([#1422], introduced in 1.25.0)
    - Fix SCRAM parsing of server messages ([#1431], introduced in 1.25.0)

[#1414]: https://github.com/pgbouncer/pgbouncer/pull/1414
[#1420]: https://github.com/pgbouncer/pgbouncer/pull/1420
[#1422]: https://github.com/pgbouncer/pgbouncer/pull/1422
[#1423]: https://github.com/pgbouncer/pgbouncer/pull/1423
[#1431]: https://github.com/pgbouncer/pgbouncer/pull/1431
[#1432]: https://github.com/pgbouncer/pgbouncer/pull/1432

**2025-11-09  -  PgBouncer 1.25.0  -  "The one with LDAP support"**

- Features
    * Add LDAP authentication! You can configure it using an HBA file or using `auth_ldap_options`. ([#731])
    * Add support for client-side direct TLS connections. This allows clients to using the faster TLS connection setup that was introduced in PostgreSQL 17. PgBouncer cannot (yet) connect to PostgreSQL servers using this faster connection setup. ([#1359])
    * Add idle state to `SHOW CLIENTS`. ([#1191])
    * Add `transaction_timeout` setting, both globally and at the user level. ([#1242])
    * Send a NOTICE message to the client if it is queued without receiving a connection for more than 5 seconds. This duration can be changed/disabled using `query_wait_notify`. ([#1264])
    * Add `scram_iterations` setting to allow operators to trade security for authentication speed ([#1339])
    * Add `client_tls13_ciphers` and `server_tls13_ciphers` to choose which TLSv1.3 cipher suites to enable. ([#1352])
- Changes
    * Greatly improve performance of ad hoc SCRAM authentication. ([#1338])
    * Allow `KILL` to not take any database, which now means to `KILL` all databases. ([#1317])
    * Health check query defaults to sending empty query instead of `SELECT 1`. ([#1233])
    * Log full PAM queue as a warning. This makes it easier to find the cause of slow queries caused by this. ([#1297])
    * The `RELOAD` command now reports any errors that happened during the reload. ([#1231])
    * Enable access to the PgBouncer UNIX socket during shutdown for admin connections. This makes it easier for an operator to find out why a PgBouncer process is not shutting down and/or manually run `KILL_CLIENT` for stuck connections. ([#1305])
    * Change `mkauth.py` to not add an obsolete third field anymore ([#1365])
    * Improve `FATAL` messages in `disconnect_client` and `disconnect_server` functions. ([#1382])
    * Stop using deprecated OpenSSL function `EVP_PKEY_get0_EC_KEY`. This could cause issues with certain FIPS implementatinos. ([#1384])
- Fixes
    * Fix crash involving long passwords (1024 characters or more). ([#1215])
    * Fix multi-host connections when using `server_tls_sslmode=verify-full`. ([#1303])
    * Fix rare `FATAL` error when forwarding cancel requests. ([#1383])
    * Fix sorting of parameters in `SHOW CONFIG`. ([#1403])
    * Harden parsing of the startup packet. ([#1407])

[#731]: https://github.com/pgbouncer/pgbouncer/pull/731
[#1191]: https://github.com/pgbouncer/pgbouncer/pull/1191
[#1215]: https://github.com/pgbouncer/pgbouncer/pull/1215
[#1231]: https://github.com/pgbouncer/pgbouncer/pull/1231
[#1233]: https://github.com/pgbouncer/pgbouncer/pull/1233
[#1242]: https://github.com/pgbouncer/pgbouncer/pull/1242
[#1264]: https://github.com/pgbouncer/pgbouncer/pull/1264
[#1297]: https://github.com/pgbouncer/pgbouncer/pull/1297
[#1303]: https://github.com/pgbouncer/pgbouncer/pull/1303
[#1305]: https://github.com/pgbouncer/pgbouncer/pull/1305
[#1317]: https://github.com/pgbouncer/pgbouncer/pull/1317
[#1338]: https://github.com/pgbouncer/pgbouncer/pull/1338
[#1339]: https://github.com/pgbouncer/pgbouncer/pull/1339
[#1352]: https://github.com/pgbouncer/pgbouncer/pull/1352
[#1359]: https://github.com/pgbouncer/pgbouncer/pull/1359
[#1365]: https://github.com/pgbouncer/pgbouncer/pull/1365
[#1382]: https://github.com/pgbouncer/pgbouncer/pull/1382
[#1383]: https://github.com/pgbouncer/pgbouncer/pull/1383
[#1384]: https://github.com/pgbouncer/pgbouncer/pull/1384
[#1403]: https://github.com/pgbouncer/pgbouncer/pull/1403
[#1407]: https://github.com/pgbouncer/pgbouncer/pull/1407

PgBouncer 1.24.x
----------------

**2025-04-16  -  PgBouncer 1.24.1  -  "CVE-2025-2291 VALID UNTIL yesterday"**

- Security
  * Fix CVE-2025-2291: Previously PgBouncer did not take into account the VALID
    UNTIL of a user password when querying for password hashes using its
    auth_query. So if PgBouncer is used as a transparent proxy in front of
    Postgres it could allow passwords that had already expired. To solve this
    issue the default auth_query and the examples of custom auth_query functions
    in the documentation have been changed to take VALID UNTIL into account. If
    you are using a custom auth_query you should update that accordingly. If
    you are using the default auth_query, you can either update to PgBouncer
    1.24.1 or change your config to use the new default auth_query on a
    previous release of PgBouncer.

- Fixes
  * Fix PAM support by reverting `pam` authentication support in HBA file. ([#1291]) (bug introduced in 1.24.0)
  * Fix bug when decrementing user connection count. This was included in the tag of 1.24.0 on GitHub, but the release tarball did not contain this fix.  ([#1238]) (bug introduced in 1.24.0)
  * Add `test_load_balance_hosts.py` to the tarball. ([#1282])
  * Fix issues with tests to allow them to be run by Debian packagers. ([#1266], [#1250])

- Docs
  * Update `auth_query` example to set a safe `search_path`. ([#1245])

[#1238]: https://github.com/pgbouncer/pgbouncer/pull/1238
[#1291]: https://github.com/pgbouncer/pgbouncer/pull/1291
[#1282]: https://github.com/pgbouncer/pgbouncer/pull/1282
[#1266]: https://github.com/pgbouncer/pgbouncer/pull/1266
[#1250]: https://github.com/pgbouncer/pgbouncer/pull/1250
[#1245]: https://github.com/pgbouncer/pgbouncer/pull/1245

**2025-01-10  -  PgBouncer 1.24.0  -  "New year, new bouncer"**

- Features
  * Add support for `Type=notify-reload` for systemd. This requires systemd
    version 253 or later. ([#1148])
  * Add `KILL_CLIENT` command to the admin console. This allows terminating a
    client connection by force. ([#1147])
  * Add `max_user_client_connections` setting, both globally and at the user level. ([#1137])
  * Add `max_db_client_connections` setting, both globally and at the database level. ([#1138])
  * Add `current_client_connections` counter to `SHOW USERS` and `SHOW DATABASES` output. ([#1137], [#1138])
  * Add `load_balance_hosts` parameter, to support **not** load balancing between hosts. ([#736])
  * Expose prepared statement usage counters in `SHOW STATS`. ([#1192])
  * Add `client_idle_timeout` setting. ([#1189])
  * Add user level `query_timeout` and `reserve_pool_size`. ([#1180], [#1228])
  * Enable `pam` authentication support in HBA file. ([#326])

- Changes
  * Don't recycle connections on RELOAD if TLS config is unchanged. Previously
    if you had TLS connections they would all be recycled on RELOAD, which could
    cause a temporary but serious performance degradation. Now this only
    happens when the TLS settings are actually changed. ([#1157])
  * Enable prepared statement support by default, `max_prepared_statements` is
    now set to 200 by default. This change in defaultls should only impact
    clients that actually use prepared statements. If you do use prepared
    statements it's recommended to read about the limitations of the prepared
    statement support in [our documentation][prepared-docs] ([#1144])
  * Sockets/clients/servers can now be identified by a unique ID in the admin
    output. Previously they could be identified by their pointer, but these
    would often be reused by new clients after disconnect. ([#1172])
  * Clearer error for empty pidfile. ([#1195])
  * Return original error to client in case of `server_login_retry` failure. ([#1152])
  * Log original server error in case of error from `auth_query`. ([#1187])
  * Setting `default_pool_size` to 0 means unlimited size. ([#1227])
  * Change the name of the `reserve_pool` setting for databases, to
    `reserve_pool_size`. The previous name is still an alias for the new name.
    ([#1232])

- Fixes
  * Handle various unlikely error cases better, such as OOM errors. These could
    previously cause crashes or memory leaks. ([#1108], [#1101], [#1099], [#1169], [#1202])
  * Correct default value for `server_tls_sslmode` in sample config file. ([#1133])
  * Remove mention in docs of invalid alias for `server_tls_protocols`. ([#1155])
  * Fix bug when using `auth_query` and replication connections together. This
    bug would cause connection failures in such setups. ([#1166])
  * Ignore client cancel requests while PgBouncer is configuring server setting. ([#298])

[prepared-docs]: https://www.pgbouncer.org/config.html#max_prepared_statements

[#1148]: https://github.com/pgbouncer/pgbouncer/pull/1148
[#1147]: https://github.com/pgbouncer/pgbouncer/pull/1147
[#1137]: https://github.com/pgbouncer/pgbouncer/pull/1137
[#1138]: https://github.com/pgbouncer/pgbouncer/pull/1138
[#736]: https://github.com/pgbouncer/pgbouncer/pull/736
[#1192]: https://github.com/pgbouncer/pgbouncer/pull/1192
[#1189]: https://github.com/pgbouncer/pgbouncer/pull/1189
[#1180]: https://github.com/pgbouncer/pgbouncer/pull/1180
[#1228]: https://github.com/pgbouncer/pgbouncer/pull/1228
[#326]: https://github.com/pgbouncer/pgbouncer/pull/326
[#1157]: https://github.com/pgbouncer/pgbouncer/pull/1157
[#1144]: https://github.com/pgbouncer/pgbouncer/pull/1144
[#1172]: https://github.com/pgbouncer/pgbouncer/pull/1172
[#1195]: https://github.com/pgbouncer/pgbouncer/pull/1195
[#1152]: https://github.com/pgbouncer/pgbouncer/pull/1152
[#1187]: https://github.com/pgbouncer/pgbouncer/pull/1187
[#1227]: https://github.com/pgbouncer/pgbouncer/pull/1227
[#1232]: https://github.com/pgbouncer/pgbouncer/pull/1232
[#1108]: https://github.com/pgbouncer/pgbouncer/pull/1108
[#1101]: https://github.com/pgbouncer/pgbouncer/pull/1101
[#1099]: https://github.com/pgbouncer/pgbouncer/pull/1099
[#1169]: https://github.com/pgbouncer/pgbouncer/pull/1169
[#1202]: https://github.com/pgbouncer/pgbouncer/pull/1202
[#1133]: https://github.com/pgbouncer/pgbouncer/pull/1133
[#1155]: https://github.com/pgbouncer/pgbouncer/pull/1155
[#1166]: https://github.com/pgbouncer/pgbouncer/pull/1166
[#298]: https://github.com/pgbouncer/pgbouncer/pull/298


PgBouncer 1.23.x
----------------

**2024-08-02  -  PgBouncer 1.23.1  -  "Everything is put back in order"**

- Fixes
  * Fix a possible segmentation fault after PgBouncer reloads its
    configuration. ([#1105]) (bug introduced in 1.23.0)
  * Fix all known put_in_order crashes. ([#1120])
    (new crashes were introduced in 1.23.0)
  * Add missing files to release tarball that are required for testing.
    ([#1124]) (missing files were introduced in 1.23.0)

[#1120]: https://github.com/pgbouncer/pgbouncer/pull/1120
[#1105]: https://github.com/pgbouncer/pgbouncer/pull/1105
[#1124]: https://github.com/pgbouncer/pgbouncer/pull/1124

**2024-07-03  -  PgBouncer 1.23.0  -  "Into the new beginnings"**

- Features
  * Add support for rolling restarts. SIGTERM doesn't cause immediate shutdown
    of the PgBouncer process anymore. It now does a "super safe shutdown":
    waiting for all clients to disconnect before shutting down. The new SIGTERM
    behaviour allows rolling restarts of multiple PgBouncer processes behind a
    load balancer, or listening on the same port using `so_reuseport`.
    This is a **minor breaking change**. If you relied on the old behaviour of
    SIGTERM in your Dockerfile or Systemd service file you should now use SIGQUIT.
    ([#902])
  * Add support for user name maps for `cert` and `peer` authentication
    methods. This feature provides the flexibility that the user initiating
    the connection does not have to be the database user. PgBouncer support
    for user name maps works very similar to the postgres with the exceptions
    listed in the docs. ([#996])
  * Add support for replication connections through PgBouncer. ([#876])

- Changes
  * Improve `SHOW USERS` output listing the connections. ([#1040])
  * Allow `pool_size` configuration per user. ([#1049])
  * Allow `server_lifetime` configuration per database. ([#1057])
  * Add support for listing dynamically created users in the output of `SHOW USERS`. ([#1052])
  * Add support for `all` address type in hba configuration. ([#1078])
  * Add support for automatically restarting when using systemd. ([#1080])
  * Increase c-ares minimum version requirement to 1.9.0 ([#1076])

- Fixes
  * Fix issues handling large and partial startup packets. ([#1058])
  * Add support for `--config=value` format in options startup parameter. ([#1064])
  * Fix `avg_wait_time` metric calculation. ([#727])
  * Add support for negotiating the postgres protocol version with the client. ([#1007])
  * Add outstanding request for `auth_query`. ([#1034])
  * Multiple documentation and CI improvements.

[#996]: https://github.com/pgbouncer/pgbouncer/pull/996
[#1040]: https://github.com/pgbouncer/pgbouncer/pull/1040
[#1049]: https://github.com/pgbouncer/pgbouncer/pull/1049
[#1057]: https://github.com/pgbouncer/pgbouncer/pull/1057
[#1052]: https://github.com/pgbouncer/pgbouncer/pull/1052
[#1058]: https://github.com/pgbouncer/pgbouncer/pull/1058
[#1007]: https://github.com/pgbouncer/pgbouncer/pull/1007
[#876]: https://github.com/pgbouncer/pgbouncer/pull/876
[#902]: https://github.com/pgbouncer/pgbouncer/pull/902
[#1064]: https://github.com/pgbouncer/pgbouncer/pull/1064
[#1078]: https://github.com/pgbouncer/pgbouncer/pull/1078
[#1080]: https://github.com/pgbouncer/pgbouncer/pull/1080
[#727]: https://github.com/pgbouncer/pgbouncer/pull/727
[#1076]: https://github.com/pgbouncer/pgbouncer/pull/1076
[#1034]: https://github.com/pgbouncer/pgbouncer/pull/1034


PgBouncer 1.22.x
----------------

**2024-03-04  -  PgBouncer 1.22.1  -  "It's summer in Bangalore"**

- Fixes
  * Fix issues caused by some clients using `COPY FROM STDIN` queries. Such
    queries could introduce memory leaks, performance regressions and prepared
    statement misbehavior. ([#1025])
    (bug introduced in 1.21.0)
  * Add missing tests to release tarball ([#1026])
    (missing tests were introduced in 1.19.0 & 1.21.0)

[#1025]: https://github.com/pgbouncer/pgbouncer/pull/1025
[#1026]: https://github.com/pgbouncer/pgbouncer/pull/1026

**2024-01-31  -  PgBouncer 1.22.0  -  "DEALLOCATE ALL"**

- Features
  * Adds support for `DEALLOCATE ALL` and `DISCARD ALL` when
    `max_prepared_statements` is set to a non-zero value (normal `DEALLOCATE`
    is still unsupported) ([#972])
  * Support configuring `auth_query` per database ([#979])

- Changes
  * Improve settings in the recommended systemd unit file ([#983])
  * Make fail fast logic handle all scenarios where no working connections to
    the database exist anymore and none can be established ([#998])
  * Multiple documentation improvements

- Fixes
  * Fix issue in PG14+ where PgBouncer would send `SET DateStyle='ISO'` for
    every transaction ([#879])
  * Fix handling of empty `application_name` ([#999])
  * Fix building on Windows with OpenSSL 3.2.0 ([#1009])

[#972]: https://github.com/pgbouncer/pgbouncer/pull/972
[#979]: https://github.com/pgbouncer/pgbouncer/pull/979
[#983]: https://github.com/pgbouncer/pgbouncer/pull/983
[#998]: https://github.com/pgbouncer/pgbouncer/pull/998
[#879]: https://github.com/pgbouncer/pgbouncer/pull/879
[#999]: https://github.com/pgbouncer/pgbouncer/pull/999
[#1009]: https://github.com/pgbouncer/pgbouncer/pull/1009


PgBouncer 1.21.x
----------------

**2023-10-16  -  PgBouncer 1.21.0  -  "The one with prepared statements"**

- Features
  * Add support for protocol-level named prepared statements! This is probably
    one of the most requested features for PgBouncer. Using prepared statements
    together with PgBouncer can reduce the CPU load on your system a lot (both
    at the PgBouncer side and the PostgreSQL side). In synthetic benchmarks
    this feature was able to increase query throughput anywhere from 15% to
    250%, depending on the workload. To benefit from this new feature you need
    to change the new `max_prepared_statements` setting to a non-zero value
    (the exact value depends on your workload, but 100 is probably reasonable).
    See [the docs on
    `max_prepared_statements`](https://pgbouncer.org/config.html#max_prepared_statements)
    for details on how the feature works, its limitations, and how to tune the
    value. After doing that you need to make sure your client library
    actually uses prepared statements. How to do that differs for each client,
    so you should look at the docs for the client you're using. This feature
    has been tested very well before releasing, but performance issues or
    bugs might very well exist due to the complexity of the feature. If you
    find those, please report them. ([#845])

- Changes
  * Improve security of OpenSSL settings, the defaults used were VERY outdated.
    With this release the defaults are now the same as the OpenSSL defaults of the
    system that runs PgBouncer. ([#948] & [libusual/#41])
  * PgBouncer now uses OpenSSL to calculate MD5 hashes when possible. This is
    necessary to use PgBouncer in a FIPS compliant way. ([#949])
  * Maintain `min_pool_size` for pools with a forced user even if no clients
    are connected to PgBouncer ([#947])
  * The way a `peer_id` is encoded in the cancellation token by PgBouncer has
    changed, this means that peering between different PgBouncer versions will
    not work if not all of them are on the same side of the v1.21.0 version
    boundary. ([#945])

- Fixes
  * Fix crash with error message: "FATAL in function client\_proto(): bad
    client state: 6/7" ([#928]) (bug introduced in 1.18.0)
  * Fix crash with error message: "FATAL in function server\_proto(): server in
    bad state: 11" ([#927]) (bug introduced in 1.18.0)
  * Reduce cancellation sending log level ([#903])
  * Fix slog log prefix for peers ([#922])
  * Fix typos in docs ([#932])
  * Fix errors pointed out by static analyzer ([#943])
  * Don't kill all waiting clients on temporary FATAL errors during login ([#946])
  * Use auto-database when database in `auth_dbname` is not explicitly configured
    ([#921])

- Cleanup
  * Remove support for udns ([#938])

[#845]: https://github.com/pgbouncer/pgbouncer/pull/845
[#948]: https://github.com/pgbouncer/pgbouncer/pull/948
[#949]: https://github.com/pgbouncer/pgbouncer/pull/949
[#947]: https://github.com/pgbouncer/pgbouncer/pull/947
[#945]: https://github.com/pgbouncer/pgbouncer/pull/945
[#903]: https://github.com/pgbouncer/pgbouncer/pull/903
[#922]: https://github.com/pgbouncer/pgbouncer/pull/922
[#932]: https://github.com/pgbouncer/pgbouncer/pull/932
[#928]: https://github.com/pgbouncer/pgbouncer/pull/928
[#927]: https://github.com/pgbouncer/pgbouncer/pull/927
[#943]: https://github.com/pgbouncer/pgbouncer/pull/943
[#946]: https://github.com/pgbouncer/pgbouncer/pull/946
[#921]: https://github.com/pgbouncer/pgbouncer/pull/921
[#938]: https://github.com/pgbouncer/pgbouncer/pull/938
[libusual/#41]: https://github.com/libusual/libusual/pull/41


PgBouncer 1.20.x
----------------

**2023-08-09  -  PgBouncer 1.20.1  -  "Optional options"**

- Fixes
  * Fix regression where putting `options` inside `ignore_startup_parameters`
    would not ignore unknown parameters inside the `options` startup parameter
    anymore. ([#908]) (regression was introduced in 1.20.0)
  * Fix confusing typo in the docs ([#917])

[#908]: https://github.com/pgbouncer/pgbouncer/pull/908
[#917]: https://github.com/pgbouncer/pgbouncer/pull/917

**2023-07-20  -  PgBouncer 1.20.0  -  "A funny name goes here"**

- Deprecations
  * Online restart option is now considered deprecated. The feature has
    received very little love in recent years. There are multiple known issues
    with it and newly added features often don't support it. The recommended
    method to do online restarts these days is using the `so_reuseport` and
    `peers` feature. That way you can have multiple different PgBouncer
    processes running on the same port. Then by restarting those processes
    one-by-one, you can make sure there's always a PgBouncer process listening
    on the desired port. ([#894])

- Features
  * Introduce the `track_extra_parameters` which allows tracking of more
    parameters in transaction pooling mode. Previously, PgBouncer only tracked
    `application_name`, `DateStyle`, `TimeZone` and
    `standard_conforming_strings`. Now PgBouncer also tracks `IntervalStyle` by
    default. And by changing `track_extra_parameters` you can track even more
    settings, but only [ones that PostgreSQL reports back to the
    client][guc_report]. If you're using Citus 12.0+, then Citus will make sure
    that PostgreSQL also reports `search_path` back to the client. So if you use
    Citus you can add `search_path` to the `track_extra_parameters` setting.
    ([#867])
  * Forward SQLSTATE in authentication phase. This allows the detection of
    database not existing, which is done by Npgsql (a .NET data provider for
    PostgreSQL). ([#814])
  * Change default `server_tls_sslmode` to `prefer`. ([#866])
  * Add support for the `options` startup parameter. This allows usage of [the
    `PGOPTIONS` environment variable that `psql` and `libpq` know
    about][pgoptions]. Using this variable you can set any PostgreSQL parameter at
    startup. This only works for PostgreSQL parameters that PgBouncer tracks
    through `track_extra_parameters`. ([#878])

- Fixes
  * Don't crash when the `pgbouncer` admin database is used as auth_dbname. It's
    still not supported, but this now gives a clear error instead of crashing.
    ([#817])
  * Fix name of `peer_cache` in `SHOW MEM`. It was incorrectly showing up as
    `db_cache` before. ([#864])
  * Fix src/dst confusion in log. PgBouncer was logging a source IP when it
    meant to log the destination IP. ([#880])
  * Only log admin connections over unix sockets when `log_connections` is set
    to `1`. ([#883])

[guc_report]: https://www.postgresql.org/docs/15/protocol-flow.html#PROTOCOL-ASYNC
[pgoptions]: https://www.postgresql.org/docs/current/config-setting.html#id-1.6.7.4.5
[#867]: https://github.com/pgbouncer/pgbouncer/pull/867
[#814]: https://github.com/pgbouncer/pgbouncer/pull/814
[#866]: https://github.com/pgbouncer/pgbouncer/pull/866
[#878]: https://github.com/pgbouncer/pgbouncer/pull/878
[#817]: https://github.com/pgbouncer/pgbouncer/pull/817
[#864]: https://github.com/pgbouncer/pgbouncer/pull/864
[#880]: https://github.com/pgbouncer/pgbouncer/pull/880
[#883]: https://github.com/pgbouncer/pgbouncer/pull/883
[#894]: https://github.com/pgbouncer/pgbouncer/pull/894

PgBouncer 1.19.x
----------------

**2023-05-31  -  PgBouncer 1.19.1  -  "Sunny Spring"**

This is a minor release that fixes a few recently introduced bugs:

- Fixes
  * Fix: FATAL in function disconnect_client(): bad client state: 0 ([#846])
    (bug introduced in 1.18.0)
  * Fix: FATAL in function server_proto(): server in bad state: 14 ([#849])
    (bug introduced in 1.18.0)
  * Add files required to run python based tests to release tarball ([#852])
    (new tests introduced in 1.19.0)

[#846]: https://github.com/pgbouncer/pgbouncer/pull/846
[#849]: https://github.com/pgbouncer/pgbouncer/pull/849
[#852]: https://github.com/pgbouncer/pgbouncer/pull/852

**2023-05-04  -  PgBouncer 1.19.0  -  "The old-fashioned, human-generated kind"**

- Features
  * Add `auth_dbname` option, which specifies against which database
    to run the `auth_query`. ([#764])
  * Add the `SHOW STATE` command, which shows if PgBouncer is active,
    paused or suspended. ([#528])
  * Add support for peering between PgBouncer processes.  This allows
    configuring PgBouncer such that cancellation requests continue to
    work when multiple different PgBouncer processes are behind a
    single load balancer. ([#666])
  * Add a dedicated `cancel_wait_timeout` setting, which determines
    after how long to give up on forwarding a cancel request.  Default
    is 10 seconds. ([#833])
  * New testing framework ([#792])

- Fixes
  * Fix possible memory leak on TLS handshake failure. ([#796])
  * Give more accurate error messages for unsupported command-line
    options on Windows. ([#620])
  * Fix calling `disconnect_server` on a server in `BEING_CANCELED`
    state. ([#815]) (introduced in 1.18.0)
  * Don't exit with a non-zero status when a `SIGTERM` is
    received. ([#834])
  * Fail hard during startup when a socket could not be created in
    `unix_socket_dir`. ([#830])
  * Fail hard during startup when none of the addresses in
    `listen_addr` could be listened on. ([#838])
  * Give more warning messages with more information when
    `sbuf_connect` fails.  This is especially useful when failing to
    create Unix sockets. ([#837])

- Cleanups
  * Various CI updates for better performance
  * Removed AppVeyor

[#528]: https://github.com/pgbouncer/pgbouncer/issues/528
[#620]: https://github.com/pgbouncer/pgbouncer/pull/620
[#666]: https://github.com/pgbouncer/pgbouncer/pull/666
[#764]: https://github.com/pgbouncer/pgbouncer/pull/764
[#792]: https://github.com/pgbouncer/pgbouncer/pull/792
[#796]: https://github.com/pgbouncer/pgbouncer/pull/796
[#815]: https://github.com/pgbouncer/pgbouncer/pull/815
[#830]: https://github.com/pgbouncer/pgbouncer/pull/830
[#833]: https://github.com/pgbouncer/pgbouncer/pull/833
[#834]: https://github.com/pgbouncer/pgbouncer/pull/834
[#837]: https://github.com/pgbouncer/pgbouncer/pull/837
[#838]: https://github.com/pgbouncer/pgbouncer/pull/838

PgBouncer 1.18.x
----------------

**2022-12-12  -  PgBouncer 1.18.0  -  "No real mystery"**

- Features
  * Add `application_name` to `SHOW CLIENTS`/`SERVERS`/`SOCKETS`
    output ([#449](https://github.com/pgbouncer/pgbouncer/pull/449))
  * Add information about cancel requests to `SHOW
    CLIENTS`/`SERVERS`/`POOLS` output
    ([#782](https://github.com/pgbouncer/pgbouncer/pull/782))

- Fixes
  * Fail `sbuf_send_pending` operation if destination socket is closed
    ([#652](https://github.com/pgbouncer/pgbouncer/pull/652))
  * Fix a few possible crashes
    ([#700](https://github.com/pgbouncer/pgbouncer/pull/700),
    [#730](https://github.com/pgbouncer/pgbouncer/pull/730))
  * Fix for overflow bug in comma-separated host list feature, causing
    connection to get re-routed to Unix socket
    ([#747](https://github.com/pgbouncer/pgbouncer/pull/747))
  * Don't evict connections to achieve `min_pool_size`
    ([#648](https://github.com/pgbouncer/pgbouncer/pull/648))
  * Fix `SHOW HELP` with PostgreSQL 15
    ([#769](https://github.com/pgbouncer/pgbouncer/issues/769))
  * Fix race condition in query cancellation handling.  It was possible
    that a query cancellation for one client canceled a query for
    another one.  This could happen when a cancel request was received
    by PgBouncer when the query it was meant to cancel already
    completed by itself.
    ([#717](https://github.com/pgbouncer/pgbouncer/pull/717))

- Cleanups
  * Various CI updates

PgBouncer 1.17.x
----------------

**2022-03-23  -  PgBouncer 1.17.0  -  "A line has been drawn"**

- Features
  * A database definition can specify a comma-separated host list.
    The hosts will be connected to in a round-robin manner.
  * When connecting to a non-existing database, the error ("no such
    database") is now reported after authentication.  This prevents
    unauthenticated clients from probing what databases exist.  (This
    is similar to the change in version 1.15.0 to report missing users
    after authentication.)
  * Don't send server disconnect errors to the client before login.
    This could reveal not-quite-public information, such as
    configuration details, to a client that is not logged in yet.
  * Increase maximum password length again.  Apparently, the last
    increase wasn't enough for long enough.
  * Remove automatic `auth_file` reload.  The `auth_file` is now
    reread only on configuration file reload, no longer automatically
    as soon as it is changed.
  * The Windows build now includes a version-information resource
    file.
  * The Windows builds created on CI are now statically linked, so
    they can be used directly without requiring any dependencies.

- Fixes
  * OpenSSL 3 support has been fixed.  Previous releases would crash.
  * Don't apply fast-fail at connect time.  This is part of the
    above-mentioned change to not report server errors before
    authentication.  It also fixes a particular situation with SCRAM
    pass-through authentication, where we need to allow the
    client-side authentication exchange in order to be able to fix the
    server-side connection by re-authenticating.  The fast-fail
    mechanism still applies right after authentication, so the
    effective observed behavior will be the same in most situations.
  * Change `auth_type` in sample `pgbouncer.ini` to `md5` to match the
    built-in default.  Some deploy this file as the default
    configuration file, so check if this changed configuration still
    makes sense for you.
  * Fix crash at exit in assert-enabled builds.
  * Improve `tcp_defer_accept` documentation and behavior.  The
    documentation was incorrect and misleading about the default.  In
    some cases the wrong value was showing in "show config".  Also, if
    it's set but not supported, give an error instead of ignoring,
    similar to how other platform-specific socket options are handled.
  * Fix build with c-ares on Windows.  c-ares >=1.18.0 is now required
    on Windows.

- Cleanups
  * Most deprecation warnings from Autoconf >=2.70 have been cleaned
    up.  Older Autoconf versions are still supported.
  * Cirrus CI use has been expanded to more platforms.
  * Travis CI support has been removed.
  * Update locations to search for default root CA file, to cover more
    platforms, such as Fedora/RHEL/CentOS.
  * Python scripts now all use `python3` by default.  Python 2
    compatibility is no longer maintained.
  * The test suite scripts use `command -v` instead of `which`, which
    is deprecated.
  * Several error messages have been reworded to make it clearer which
    command or configuration setting they relate to.
  * The test suite scripts no longer require GNU sed.
  * `make check` now works on Windows (but not the SSL test suite
    yet).
  * Document that the admin console only supports the simple query
    protocol, and give better error messages about this.

PgBouncer 1.16.x
----------------

**2021-11-11  -  PgBouncer 1.16.1  -  "Test of depth against quiet efficiency"**

This is a minor release with a security fix.

* Make PgBouncer acting as a server reject extraneous data after an
  SSL or GSS encryption handshake.

  A man-in-the-middle with the ability to inject data into the TCP
  connection could stuff some cleartext data into the start of a
  supposedly encryption-protected database session.  This could be
  abused to send faked SQL commands to the server, although that would
  only work if PgBouncer did not demand any authentication data.
  (However, a PgBouncer setup relying on SSL certificate
  authentication might well not do so.)  (CVE-2021-3935)

**2021-08-09  -  PgBouncer 1.16.0  -  "Fended off a jaguar"**

- Features
  * Support hot reloading of TLS settings.  When the configuration
    file is reloaded, changed TLS settings automatically take effect.
  * Add support for abstract Unix-domain sockets.  Prefix a
    Unix-domain socket path with `@` to use a socket in the abstract
    namespace.  This matches the corresponding PostgreSQL 14 feature.
  * The maximum lengths of passwords and user names have been
    increased to 996 and 128, respectively.  Various cloud services
    require this.
  * The minimum pool size can now be set per database, similar to the
    regular pool size and the reserve pool size.
  * The number of pending query cancellations is shown in `SHOW
    POOLS`.

- Fixes
  * Configuration parsing now has tighter error handling in many
    places.  Where previously it might have logged an error and
    proceeded, those configuration errors would now result in startup
    failures.  This is what always should have happened, but some code
    didn't do this right.  Some users might discover that their
    configurations have been faulty all along and will not work
    anymore.
  * Query cancel handling has been fixed.  Under some circumstances,
    cancel requests would seemingly get stuck for a long time.  This
    should no longer happen.  In fact, cancel requests can now exceed
    the pool size by a factor of two, so they really shouldn't get
    stuck
    anymore. ([#542](https://github.com/pgbouncer/pgbouncer/pull/542),
    [#543](https://github.com/pgbouncer/pgbouncer/pull/543))
  * Mixed use of md5 and scram via hba has been fixed.
  * The build with c-ares on Windows has been fixed.
  * The dreaded "FIXME: query end, but query_start == 0" messages have
    been fixed.  We now know why they happen, and you shouldn't see
    them anymore. ([#565](https://github.com/pgbouncer/pgbouncer/pull/565))
  * Fix reloading of `default_pool_size`, `min_pool_size`, and
    `res_pool_size`.  Reloading these settings previously didn't work.

- Cleanups
  * Cirrus CI is now
    [used](https://cirrus-ci.com/github/pgbouncer/pgbouncer) instead
    of Travis CI.
  * As usual, many tests have been added.
  * The "unclean server" log message has been clarified a bit.  It now
    says "client disconnect while server was not ready" or "client
    disconnect before everything was sent to the server".  The former
    can happen if the client connection is closed when the server has
    a transaction block open, which confused some users.
  * You can no longer use "pgbouncer" as a database name.  This name
    is reserved for the admin console, and using it as a normal
    database name never really worked right.  This is now explicitly
    prohibited.
  * Errors sent to clients before the connection is closed are now
    labeled as FATAL instead of just ERROR.  Some clients were
    confused
    otherwise. ([#564](https://github.com/pgbouncer/pgbouncer/pull/564))
  * Fix compiler warnings with GCC 11.
    ([#623](https://github.com/pgbouncer/pgbouncer/issues/623))

PgBouncer 1.15.x
----------------

**2020-11-19  -  PgBouncer 1.15.0  -  "Ich hab noch einen Koffer in Berlin"**

- Features
  * Improve authentication failure reporting.  The authentication
    failure messages sent to the client now only state that
    authentication failed but give no further details.  Details are
    available in the PgBouncer log.  Also, if the requested user does
    not exist, the authentication is still processed to the end and
    will result in the same generic failure message.  All this
    prevents clients from probing the PgBouncer instance for user
    names and other authentication-related insights.  This is similar
    to how PostgreSQL behaves.
  * Don't log anything if client disconnects immediately.  This avoids
    log spam when monitoring systems just open a TCP/IP connection but
    don't send anything before disconnecting.
  * Use systemd journal for logging when in use.  When we detect that
    stderr is going to the systemd journal, we use systemd native
    functions for log output.  This avoids printing duplicate
    timestamp and pid, thus making the log a bit cleaner.  Also, this
    adds metadata such as the severity to the logs, so that if the
    journal gets sent on to syslog, the messages have useful metadata
    attached.
  * A subset of the test suite can now be run under Windows.
  * `SHOW CONFIG` now also shows the default values of the settings.

- Fixes
  * Fix the `so_reuseport` option on FreeBSD.  The original code in
    PgBouncer 1.12.0 didn't actually work on FreeBSD.
    ([#504](https://github.com/pgbouncer/pgbouncer/pull/504))
  * Repair compilation on systems with older systemd versions.  This
    was broken in 1.14.0.
    ([#505](https://github.com/pgbouncer/pgbouncer/issues/505))
  * The makefile target to build Windows binary zip packages has been
    repaired.
  * Long command-line options now also work on Windows.
  * Fix the behavior of the global `auth_user` setting.  The old
    behavior was confusing and fragile as it depended on the order in
    the configuration file.  This is no longer the
    case. ([#391](https://github.com/pgbouncer/pgbouncer/issues/391),
    [#393](https://github.com/pgbouncer/pgbouncer/issues/393))

- Cleanups
  * Improve test stability and portability.
  * Modernize Autoconf-related code.
  * Disable deprecation compiler warnings from OpenSSL 3.0.0.

PgBouncer 1.14.x
----------------

**2020-06-11  -  PgBouncer 1.14.0  -  "La ritrovata magia"**

- Features
  * Add SCRAM authentication pass-through.  This allows using
    encrypted SCRAM secrets in PgBouncer (either in `userlist.txt` or
    from `auth_query`) for logging into servers.
  * Add support for systemd socket activation.  This is especially
    useful to let systemd handle the creation of the Unix-domain
    sockets on systems where access to `/var/run/postgresql` is
    restricted.
  * Add support for Unix-domain sockets on Windows.

- Cleanups
  * Add an alternative smaller sample configuration file
    `pgbouncer-minimal.ini` for testing or deployment.

PgBouncer 1.13.x
----------------

**2020-04-27  -  PgBouncer 1.13.0  -  "My favourite game"**

- Features
  * Add configuration setting `tcp_user_timeout`, to set the
    corresponding socket option.
  * `client_tls_protocols` and `server_tls_protocols` now default to
    `secure`, which means only TLS 1.2 and TLS 1.3 are enabled.  Older
    versions are still supported, they are just not turned on by
    default.
  * Add support for systemd service notifications.  Right now, this
    allows using `Type=notify` service units.  More integration is
    planned for future versions.

- Fixes
  * Fix multiline log messages
    ([libusual #24](https://github.com/libusual/libusual/pull/24))
  * Handle null user names returned from `auth_query` properly
    ([#340](https://github.com/pgbouncer/pgbouncer/pull/340))

- Cleanups
  * The Debian packaging files under `debian` have been removed.  It
    is recommended to use the packages from https://apt.postgresql.org/.
  * Numerous fixes and improvements in the test suite
  * The tests no longer try to use sudo by default.  This can now be
    activated explicitly by setting the environment variable
    `USE_SUDO`.
  * The libevent API use was updated to use version 2 style interfaces
    and to no longer use deprecated interfaces from version 1.

PgBouncer 1.12.x
----------------

**2019-10-17  -  PgBouncer 1.12.0  -  "It's about learning and getting better"**

This release contains a variety of minor enhancements and fixes.

- Features
  * Add a setting to turn on the `SO_REUSEPORT` socket option.  On
    some operating systems, this allows running multiple PgBouncer
    instances on the same host listening on the same port and having
    the kernel distribute the connections automatically.
  * Add a setting to use a `resolv.conf` file separate from the
    operating system.  This allows setting custom DNS servers and
    perhaps other DNS options.
  * Send the output of `SHOW VERSION` as a normal result row instead
    of a NOTICE message.  This makes it easier to consume and is
    consistent with other `SHOW` commands.

- Fixes
  * Send statistics columns as `numeric` instead of `bigint`.  This
    avoids some client libraries failing on values that overflow the
    `bigint`
    range. ([#360](https://github.com/pgbouncer/pgbouncer/pull/360),
    [#401](https://github.com/pgbouncer/pgbouncer/pull/401))
  * Fix issue with PAM users losing their
    password. ([#285](https://github.com/pgbouncer/pgbouncer/issues/285))
  * Accept SCRAM channel binding enabled clients.  Previously, a
    client supporting channel binding (that is, PostgreSQL 11+) would
    get a connection failure when connecting to PgBouncer in certain
    situations.  (PgBouncer does not support channel binding.  This
    change just fixes support for clients that offer it.)
  * Fix compilation with newer versions of musl-libc (used by Alpine
    Linux).

- Cleanups
  * Add `make check` target.  This allows running all the tests from a
    single command.
  * Remove references to the PostgreSQL wiki.  All information is now
    either in the PgBouncer documentation or on the web site.
  * Remove support for Libevent version 1.x.  Libevent 2.x is now
    required.  Libevent is now detected using pkg-config.
  * Fix compiler warnings on macOS and Windows.  The build on these
    platforms should now be free of warnings.
  * Fix some warnings from LLVM scan-build.

PgBouncer 1.11.x
----------------

**2019-08-27  -  PgBouncer 1.11.0  -  "Instinct for Greatness"**

- Features
  * Add support for SCRAM authentication for clients and servers.  A
    new authentication type `scram-sha-256` is added.
  * Handle `auth_type=password` when the stored password is md5, like
    a PostgreSQL server
    would. ([#129](https://github.com/pgbouncer/pgbouncer/pull/129))
  * Add option `log_stats` to disable printing stats to
    log. ([#287](https://github.com/pgbouncer/pgbouncer/pull/287))
  * Add time zone to log timestamps.
  * Put PID into [brackets] in log prefix.
- Fixes
  * Fix OpenSSL configure test when running against newer OpenSSL with
    `-Werror`.
  * Fix wait time computation with `auth_user`.  This would either
    crash or report garbage values for wait
    time. ([#393](https://github.com/pgbouncer/pgbouncer/pull/393))
  * Handle GSSENCRequest packet, added in PostgreSQL 12.  It doesn't
    do anything right now, but it avoids confusing error messages
    about "bad packet header".
- Cleanups
  * Many improvements in the test suite and several new tests
  * Fix several compiler warnings on Windows.
  * Expand documentation of the `[users]` section and add to example
    config
    file. ([#330](https://github.com/pgbouncer/pgbouncer/pull/330))

PgBouncer 1.10.x
----------------

**2019-07-01  -  PgBouncer 1.10.0  -  "Afraid of the World"**

- Features
  * Add support for enabling and disabling TLS 1.3.  (TLS 1.3 was
    already supported, depending on the OpenSSL library, but now the
    configuration settings to pick the TLS protocol versions also
    support it.)
- Fixes
  * Fix TLS 1.3 support.  This was broken with OpenSSL 1.1.1 and
    1.1.1a (but not before or after).
  * Fix a rare crash in `SHOW FDS`
    ([#311](https://github.com/pgbouncer/pgbouncer/issues/311)).
  * Fix an issue that could lead to prolonged downtime if many cancel
    requests arrive
    ([#329](https://github.com/pgbouncer/pgbouncer/issues/329)).
  * Avoid "unexpected response from login query" after a postgres
    reload
    ([#220](https://github.com/pgbouncer/pgbouncer/issues/220)).
  * Fix `idle_transaction_timeout` calculation
    ([#125](https://github.com/pgbouncer/pgbouncer/issues/125)).  The
    bug would lead to premature timeouts in specific situations.
- Cleanups
  * Make various log and error messages more precise.
  * Fix issues found by Coverity (none had a significant impact in
    practice).
  * Improve and document all test scripts.
  * Add additional SHOW commands to the documentation.
  * Convert the documentation from rst to Markdown.
  * Python scripts in the source tree are all compatible with Python 3
    now.

PgBouncer 1.9.x
---------------

**2018-08-13  -  PgBouncer 1.9.0  -  "Chaos Survival"**

- Features
  * RECONNECT command
  * WAIT_CLOSE command
  * Fast close - Disconnect a server in session pool mode immediately if
    it is in "close_needed" (reconnect) mode.
  * Add close_needed column to SHOW SERVERS
- Fixes
  * Avoid double-free in parse_filename
  * Avoid NULL pointer deref in parse_line
- Cleanups
  * Port mkauth.py to Python 3
  * Improve signals documentation
  * Improve quick start documentation
  * Document SET command
  * Correct list of required software
  * Fix -Wimplicit-fallthrough warnings
  * Add missing documentation for various SHOW fields
  * Document reconnect behavior on reload and DNS change
  * Document that KILL requires RESUME afterwards
  * Clarify documentation of server_lifetime
  * Typos and capitalization fixes in messages and docs
  * Fix psql invocation in tests
  * Various other test setup improvements

PgBouncer 1.8.x
---------------

**2017-12-20  -  PgBouncer 1.8.1  -  "Ground-and-pound Mentality"**

- Fixes
  * Include file `include/pam.h` into distribution tarball.  This
    prevented the 1.8 tarball from building at all.

**2017-12-19  -  PgBouncer 1.8  -  "Confident at the Helm"**

- Features
  * Support PAM authentication.  (Enable with `--with-pam`.)
  * Add `paused` and `disabled` fields to `SHOW DATABASES` output.
  * Add `maxwait_us` field to `SHOW POOLS` output.
  * Add `wait` and `wait_us` fields to `SHOW` commands output.
  * Add new commands `SHOW STATS_TOTALS` and `SHOW STATS_AVERAGES`.
  * Track queries and transactions separately in `SHOW STATS`.  The
    fields `total_requests`, `avg_req`, and
    `avg_query` have been replaced by new fields.
  * Add `wait_time` to `SHOW STATS`.
- Fixes
  * Updated libusual supports OpenSSL 1.1.
  * Do not attempt to use TLS on Unix sockets.
  * When parsing `pg_hba.conf`, keep parsing after erroneous lines instead of rejecting the whole file.
    ([#118](https://github.com/pgbouncer/pgbouncer/issues/118))
  * Several other hba parsing fixes.
  * Fix race condition when canceling query.
    ([#141](https://github.com/pgbouncer/pgbouncer/issues/141))
- Cleanups
  * `auth_user` setting is now also allowed globally, not only per database.
    ([#142](https://github.com/pgbouncer/pgbouncer/issues/142))
  * Set console client and server encoding to `UTF8`.

PgBouncer 1.7.x
---------------

**2016-02-26  -  PgBouncer 1.7.2  -  "Finally Airborne"**

- Fixes
  * Fix crash on stale pidfile removal.  Problem introduced in 1.7.1.
  * Disable cleanup - it breaks takeover and is not useful
    for production loads.  Problem introduced in 1.7.1.
  * After takeover, wait until pidfile is gone before booting.
    Slow shutdown due to memory cleanup exposed existing race.
    ([#113](https://github.com/pgbouncer/pgbouncer/issues/113))
- Cleanups
  * Make build reproducible by dropping DBGVER handling.
    ([#112](https://github.com/pgbouncer/pgbouncer/issues/112))
  * Antimake: Sort file list from $(wildcard), newer gmake does not
    sort it anymore.
    ([#111](https://github.com/pgbouncer/pgbouncer/issues/111))
  * Show libssl version in log.
  * deb: Turn on full hardening.

**2016-02-18  -  PgBouncer 1.7.1  -  "Forward To Five Friends Or Else"**

WARNING: Since version 1.7, `server_reset_query` is not executed when
database is in transaction-pooling mode.  Seems this was not highlighted
enough in 1.7 announcement.  If your apps depend on that happening, use
`server_reset_query_always` to restore previous behaviour.

Otherwise main work of this release was to track down TLS-related memory
leak, which turned out to not exist.  Instead there is libssl build in
Debian/wheezy which has 600k overhead per connection (without leaking)
instead expected 20-30k.  Something to keep an eye on when using TLS.

- Fixes
  * TLS: Rename sslmode "disabled" to "disable" as that is what
    PostgreSQL uses.
  * TLS: `client_tls_sslmode=verify-ca/-full` now reject
    connections without client certificate.
    ([#104](https://github.com/pgbouncer/pgbouncer/issues/104))
  * TLS: `client_tls_sslmode=allow/require` do validate client
    certificate if sent.  Previously they left cert validation
    unconfigured so connections with client cert failed.
    ([#105](https://github.com/pgbouncer/pgbouncer/issues/105))
  * Fix memleak when freeing database.
  * Fix potential memleak in tls_handshake().
  * Fix EOF handling in tls_handshake().
  * Fix too small memset in asn1_time_parse compat.
  * Fix non-TLS (`--without-openssl`) build.
    ([#101](https://github.com/pgbouncer/pgbouncer/issues/101))
  * Fix various issues with Windows build.
    ([#100](https://github.com/pgbouncer/pgbouncer/issues/100))
- Cleanups
  * TLS: Use SSL_MODE_RELEASE_BUFFERS to decrease memory usage
    of inactive connections.
  * Clean allocated memory on exit.  Helps to run memory-leak checkers.
  * Improve `server_reset_query` documentation.
    ([#110](https://github.com/pgbouncer/pgbouncer/issues/110))
  * Add TLS options to sample config.

**2015-12-18  -  PgBouncer 1.7  -  "Colors Vary After Resurrection"**

- Features
  * Support TLS connections.  OpenSSL/LibreSSL is used
    as backend implementation.
  * Support authentication via TLS client certificate.
  * Support "peer" authentication on Unix sockets.
  * Support Host Based Access control file, like
    [pg_hba.conf](http://www.postgresql.org/docs/9.4/static/auth-pg-hba-conf.html)
    in Postgres.  This allows to configure TLS for network connections and "peer"
    authentication for local connections.
- Cleanups
  * Set `query_wait_timeout` to 120s by default.  Current default
    (0) causes infinite queueing, which is not useful.  That
    means if client has pending query and has not been
    assigned to server connection, the client connection will
    be dropped.
  * Disable `server_reset_query_always` by default.  Now reset
    query is used only in pools that are in session mode.
  * Increase pkt_buf to 4096 bytes.  Improves performance with TLS.
    The behaviour is probably load-specific, but it should be
    safe to do as since v1.2 the packet buffers are split
    from connections and used lazily from pool.
  * Support pipelining count expected ReadyForQuery packets.
    This avoids releasing server too early.  Fixes
    [#52](https://github.com/pgbouncer/pgbouncer/issues/52).
  * Improved sbuf_loopcnt logic - socket is guarateed to be
    reprocessed even if there are no event from socket.
    Required for TLS as it has it's own buffering.
  * Adapt system tests to work with modern BSD and MacOS.
    (Eric Radman)
  * Remove **crypt** auth.  It's obsolete and not supported
    by PostgreSQL since 8.4.
  * Fix plain "--with-cares" configure option - without argument
    it was broken.

PgBouncer 1.6.x
---------------

**2015-09-03  -  PgBouncer 1.6.1  -  "Studio Audience Approves"**

- Features
  * New setting: `server_reset_query_always`.  When set,
    disables `server_reset_query` use on non-session pools.
    PgBouncer introduces per-pool pool_mode, but session-pooling
    and transaction-pooling should not use same reset query.
    In fact, transaction-pooling should not use any reset query.

    It is set in 1.6.x, but will be disabled in 1.7.

- Fixes
  * [SECURITY]  Remove invalid assignment of `auth_user`. (#69)
    When `auth_user` is set and client asks non-existing username,
    client will log in as `auth_user`.  Not good.

    [CVE-2015-6817](https://access.redhat.com/security/cve/cve-2015-6817)

  * Skip NoticeResponse in handle_auth_response.  Otherwise verbose
    log levels on server cause login failures.

  * console: Fill `auth_user` when auth_type=any.  Otherwise
    logging can crash (#67).

  * Various portability fixes (OpenBSD, Solaris, OSX).

**2015-08-01  -  PgBouncer 1.6  -  "Zombies of the future"**

- Features

  * Load user password hash from postgres database.
    New parameters:

    auth_user
        user to use for connecting same db and fetching user info.
        Can be set per-database too.

    auth_query
        SQL query to run under auth_user.
        Default: "SELECT usename, passwd FROM pg_shadow WHERE usename=$1"

    (Cody Cutrer)

  * Pooling mode can be configured both per-database and per-user.
    (Cody Cutrer)

  * Per-database and per-user connection limits: max_db_connections and
    max_user_connections.
    (Cody Cutrer / Pavel Stehule)

  * Add DISABLE/ENABLE commands to prevent new connections.
    (William Grant)

  * New DNS backend: c-ares.  Only DNS backend that supports all
    interesting features:  /etc/hosts with refresh, SOA lookup,
    large replies (via TCP/EDNS+UDP), IPv6.  It is the preferred
    backend now, and probably will be **only** backend in the future,
    as it's pointless to support zoo of inadequate libraries.

    SNAFU: c-ares versions <= 1.10 have bug which breaks CNAME-s support
    when IPv6 has been enabled.  (Fixed upstream.)  As a workaround,
    c-ares <= 1.10 is used IPv4-only.  So PgBouncer will drop other backends
    only when c-ares >1.10 (still unreleased) has been out some time...

  * Show remote_pid in SHOW CLIENTS/SERVERS.  Available for clients that
    connect over unix sockets and both tcp and unix socket server.
    In case of tcp-server, the pid is taken from cancel key.

  * Add separate config param (dns_nxdomain_ttl) for controlling
    negative dns caching.
    (Cody Cutrer)

  * Add the client host IP address and port to application_name.
    This is enabled by a config parameter application_name_add_host
    which defaults to 'off'.
    (Andrew Dunstan)

  * Config files have '%include FILENAME' directive to allow configuration
    to be split into several files.
    (Andrew Dunstan)

- Cleanups

  * log: wrap ipv6 address with []
  * log: On connect to server, show local ip and port
  * win32: use gnu-style for long args: --foo
  * Allow numbers in hostname, always try to parse with inet_pton
  * Fix deallocate_all() in FAQ
  * Fix incorrect keyword in example config file
    (Magnus Hagander)
  * Allow comments (with ';') in auth files.
    (Guillaume Aubert)
  * Fix spelling mistakes in log messages and comments.
    (Dmitriy Olshevskiy)

- Fixes

  * fix launching new connections during maintenance
    (Cody Cutrer)
  * don't load auth file twice at boot
    (Cody Cutrer)
  * Proper invalidation for autodbs
  * ipv6: Set IPV6_V6ONLY on listen socket.
  * win32: Don't set SO_REUSEADDR on listen socket.
  * Fix IPv6 address memcpy
  * Fix cancellation of of waiting clients.
    (Mathieu Fenniak)
  * Small bug fix, must check calloc result
    (Heikki Linnakangas)
  * Add newline at the end of the PID file
    (Peter Eisentraut)
  * Don't allow new server connections when PAUSE <db> was issued.
    (Petr Jelinek)
  * Fix 'bad packet' during login when header is delayed.
    (Michał Trojnara, Marko Kreen)
  * Fix errors detected by Coverty.
    (Euler Taveira)
  * Disable server_idle_timeout when server count gets below min_pool (#60)
    (Marko Kreen)

PgBouncer 1.5.x
---------------

**2015-04-09  -  PgBouncer 1.5.5  -  "Play Dead To Win"**

- Fixes
  * Fix remote crash - invalid packet order causes lookup of NULL
    pointer.  Not exploitable, just DoS.

**2012-11-28  -  PgBouncer 1.5.4  -  "No Leaks, Potty-Training Successful"**

- Fixes
  * DNS: Fix memory leak in getaddrinfo_a() backend.
  * DNS: Fix memory leak in udns backend.
  * DNS: Fix stats calculation.
  * DNS: Improve error message handling for getaddrinfo_a().
  * Fix win32 compile.
  * Fix compiler dependency support check in configure.
  * Few documentation fixes.

**2012-09-12  -  PgBouncer 1.5.3  -  "Quantum Toaster"**

- Critical fix

  * Too long database names can lead to crash, which
    is remotely triggerable if autodbs are enabled.

    The original checks assumed all names come from config files,
    thus using fatal() was fine, but when autodbs are enabled
    - by '*' in [databases] section - the database name can come
    from network thus making remote shutdown possible.

    [CVE-2012-4575](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2012-4575)

- Minor Features

  * max_packet_size - config parameter to tune maximum packet size
    that is allowed through.  Default is kept same: (2G-1), but now
    it can be made smaller.
  * In case of unparsable packet header, show it in hex in log and
    error message.

- Fixes

  * AntiMake: it used $(relpath) and $(abspath) to manipulate pathnames,
    but the result was build failure when source tree path contained
    symlinks.  The code is now changed to work on plain strings only.
  * console: now SET can be used to set empty string values.
  * config.txt: show that all timeouts can be set in floats.
    This is well-hidden feature introduced in 1.4.

**2012-05-29  -  PgBouncer 1.5.2  -  "Don't Chew, Just Swallow"**

- Fixes
  * Due to mistake, reserve_pool_timeout was taken in microseconds,
    not seconds, effectively activating reserve pool immediately
    when pool got full.  Now use it as seconds, as was intended.
    (Noticed by Keyur Govande)

**2012-04-17  -  PgBouncer 1.5.1  -  "Abort, Retry, Ignore?"**

- Features
  * Parameters to tune permissions on unix socket:
    unix_socket_mode=0777, unix_socket_group=''.
- Fixes
  * Allow empty string for server-side variable - this is
    needed to get "application_name" properly working, as it's
    the only parameter that does not have server-side default.
  * If connect string changes, require refresh of server parameters.
    Previously PgBouncer continued with old parameters,
    which breaks in case of Postgres upgrade.
  * If autodb connect string changes, drop old connections.
  * cf_setint: Use strtol() instead atoi() to parse integer config
    parameters.  It allows hex, octal and better error detection.
  * Use sigqueue() to detect union sigval existence - fixes
    compilation on HPUX.
  * Remove 'git' command from Makefile, it throws random errors
    in case of plain-tarball build.
  * Document stats_period parameter.  This tunes the period for
    stats output.
  * Require Asciidoc >= 8.4, seems docs are not compatible with
    earlier versions anymore.
  * Stop trying to retry on EINTR from close().

**2012-01-05  -  PgBouncer 1.5  -  "Bouncing Satisfied Clients Since 2007"**

If you use more than 8 IPs behind one DNS name, you now need to
use EDNS0 protocol to query.  Only getaddrinfo_a()/getaddrinfo()
and UDNS backends support it, libevent 1.x/2.x does not.
To enable it for libc, add 'options edns0' to /etc/resolv.conf.

GNU Make 3.81+ is required for building.

- Features
  * Detect DNS reply changes and invalidate connections to IPs no longer
    present in latest reply.
    (Petr Jelinek)
  * DNS zone serial based hostname invalidation.  When option
    dns_zone_check_period is set, all DNS zones will be queried
    for SOA, and when serial has changed, all hostnames
    will be queried.  This is needed to get deterministic
    connection invalidation, because invalidation on lookup
    is useless when no lookups are performed.
    Works only with new UDNS backend.
  * New SHOW DNS_HOSTS, SHOW DNS_ZONES commands to examine DNS cache.
  * New param: min_pool_size - avoids dropping all connections
    when there is no load.
    (Filip Rembiałkowski)
  * idle_in_transaction_timeout - kill transaction if idle too long.
    Not set by default.
  * New libudns backend for DNS lookups.  More featureful than evdns.
    Use --with-udns to activate.  Does not work with IPv6 yet.
  * KILL command, to immediately kill all connections for one database.
    (Michael Tharp)
  * Move to Antimake build system to have better looking Makefiles.
    Now GNU Make 3.81+ is required for building.
- Fixes
  * DNS now works with IPv6 hostnames.
  * Don't change connection state when NOTIFY arrives from server.
  * Various documentation fixes.
    (Dan McGee)
  * Console: Support ident quoting with "".  Originally we did not
    have any commands that took database names, so no quoting was needed.
  * Console: allow numbers at the start of word regex.  Trying
    to use strict parser makes things too complex here.
  * Don't expire auto DBs that are paused.
    (Michael Tharp)
  * Create auto databases as needed when doing PAUSE.
    (Michael Tharp)
  * Fix wrong log message issued by RESUME command.
    (Peter Eisentraut)
  * When user= without password= is in database connect string,
    password will be taken from userlist.
  * Parse '*' properly in takeover code.
  * autogen.sh: work with older autoconf/automake.
  * Fix run-as-service crash on win32 due to bad basename() from
    mingw/msvc runtime.  Now compat basename() is always used.

PgBouncer 1.4.x
---------------

**2011-06-16  -  PgBouncer 1.4.2  -  "Strike-First Algorithm"**

Affected OS-es: \*BSD, Solaris, Win32.

- Portability Fixes
  * Give CFLAGS to linker.  Needed when using pthread-based
    getaddrinfo_a() fallback.
  * lib/find_modules.sh: Replace split() with index()+substr().
    This should make it work with older AWKs.
  * <usual/endian.h>: Ignore system htoX/Xtoh defines.  There
    may be only subset of macros defined.
  * <usual/signal.h>: Separate compat sigval from compat sigevent
  * <usual/socket.h>: Include <sys/uio.h> to get iovec
  * <usual/time.h>: Better function autodetection on win32
  * <usual/base_win32.h>: Remove duplicate sigval/sigevent declaration

**2011-04-01  -  PgBouncer 1.4.1  -  "It Was All An Act"**

- Features

  * Support listening/connect for IPv6 addresses.
    (Hannu Krosing)
  * Multiple listen addresses in 'listen_addr'.  For each getaddrinfo()
    is called, so names can also be used.
  * console: Send PgBouncer version as 'server_version' to client.

- Important Fixes

  * Disable getaddrinfo_a() on glibc < 2.9 as it crashes on older versions.

    Notable affected OS'es: RHEL/CentOS 5.x (glibc 2.5), Ubuntu 8.04 (glibc 2.7).
    Also Debian/lenny (glibc 2.7) which has non-crashing getaddrinfo_a()
    but we have no good way to detect it.

    Please use libevent 2.x on such OS'es, fallback getaddrinfo_a() is not
    meant for production systems.  And read new 'DNS lookup support' section
    in README to see how DNS backend is picked.

    (Hubert Depesz Lubaczewski, Dominique Hermsdorff, David Sommerseth)

  * Default to --enable-evdns if libevent 2.x is used.

  * Turn on tcp_keepalive by default, as that's what Postgres also does.
    (Hubert Depesz Lubaczewski)

  * Set default server_reset_query to DISCARD ALL to be compatible
    with Postgres by default.

  * win32: Fix crashes with NULL unix socket addr.
    (Hiroshi Saito)

  * Fix autodb cleanup: old cleanup code was mixing up databases and pools:
    as soon as one empty pool was found, the database was tagged as 'idle',
    potentially later killing database with active users.

    Reported-By: Hubert Depesz Lubaczewski

- Fixes

  * Make compat getaddrinfo_a() non-blocking, by using single parallel
    thread to do lookups.
  * Enable pthread compilation if compat getaddrinfo_a is used.
  * release_server missed setting ->last_lifetime_disconnect on lifetime disconnect.
    (Emmanuel Courreges)
  * win32: fix auth file on DOS line endings - load_file() did not take
    account of file shringage when loading.
    (Rich Schaaf)
  * <usual/endian.h>: add autoconf detection for enc/dec functions
    so it would not create conflicts on BSD.
    (James Pye)
  * Don't crash when config file does not exist.
    (Lou Picciano)
  * Don't crash on DNS lookup failure when logging on noise level (-v -v).
    (Hubert Depesz Lubaczewski, Dominique Hermsdorff)
  * Use backticks instead of $(cmd) in find_modules.sh to make it more portable.
    (Lou Picciano)
  * Use 'awk' instead of 'sed' in find_modules.sh to make it more portable.
    (Giorgio Valoti)
  * Log active async DNS backend info on startup.
  * Fix --disable-evdns to mean 'no' instead 'yes'.
  * Mention in docs that -R requires unix_socket_dir.
  * Discuss server_reset_query in faq.txt.
  * Restore lost memset in slab allocator
  * Various minor portability fixes in libusual.

**2011-01-11  -  PgBouncer 1.4  -  "Gore Code"**

- Features

  * Async DNS lookup - instead of resolving hostnames at reload time,
    the names are now resolved at connect time, with configurable caching.
    (See dns_max_ttl parameter.)

    By default it uses getaddrinfo_a() (glibc) as backend, if it does not
    exist, then getaddrinfo_a() is emulated via blocking(!) getaddrinfo().

    When --enable-evdns argument to configure, libevent's evdns is used
    as backend.  It is not used by default, because libevent 1.3/1.4
    contain buggy implementation.  Only evdns in libevent 2.0 seems OK.

  * New config var: syslog_ident, to tune syslog name.

  * Proper support for `application_name` startup parameter.

  * Command line long options (Guillaume Lelarge)

  * Solaris portability fixes (Hubert Depesz Lubaczewski)

  * New config var: disable_pqexec.  Highly-paranoid environments
    can disable Simple Query Protocol with that.  Requires apps
    that use only Extended Query Protocol.

  * Postgres compat: if database name is empty in startup packet,
    use user name as database.

- Fixes

  * DateStyle and TimeZone server params need to use exact case.
  * Console: send datetime, timezone and stdstr server params to client.

- Internal cleanups

  * Use libusual library for low-level utility functions.
  * Remove fixed-length limit from server params.

PgBouncer 1.3.x
---------------

**2010-09-09  -  PgBouncer 1.3.4  -  "Bouncer is always right"**

- Fixes
  * Apply fast-fail logic at connect time.  So if server is failing,
    the clients get error when connecting.
  * Don't tag automatically generated databases for checking on reload time,
    otherwise they get killed, because they don't exist in config.
  * Ignore application_name parameter by default.  This avoids the need
    for all Postgres 9.0 users to add it into ignore_startup_parameters=
    themselves.
  * Correct pg_auth quoting.  '\' is not used there.
  * Better error reporting on console, show incoming query to user.
  * Support OS'es (OpenBSD) where tv_sec is not time_t.
  * Avoid too noisy warnings on gcc 4.5.

**2010-05-10  -  PgBouncer 1.3.3  -  "NSFW"**

- Improvements
  * Make listen(2) argument configurable: listen_backlog.  This is
    useful on OS'es, where system max allowed is configurable.
  * Improve disconnect messages to show what username or dbname caused
    login to fail.
- Fixes
  * Move fast-fail relaunch logic around.  Old one was annoying in case of
    permanently broken databases or users, by trying to retry even if
    there is no clients who want to login.
  * Make logging functions keep old errno, otherwise pgbouncer may act funny
    on higher loglevels and logging problems.
  * Increase the size of various startup-related buffers to handle
    EDB more noisy startup.
  * Detect V2 protocol startup request and give clear reason for disconnect.

**2010-03-15  -  PgBouncer 1.3.2  -  "Boomerang Bullet"**

- Fixes

  * New config var 'query_wait_timeout'.  If client does not get
    server connection in this many seconds, it will be killed.

  * If no server connection in pool and last connect failed, then
    don't put client connections on hold but send error immediately.

    This together with previous fix avoids unnecessary stalls if
    a database has gone down.

  * Track libevent state in sbuf.c to avoid double event_del().  Although
    it usually is safe, it does not seem to work 100%.  Now we should always
    know whether it has been called or not.

  * Disable maintenance during SUSPEND.  Otherwise with short timeouts
    the old bouncer could close few connections after sending them over.

  * Apply client_login_timeout to clients waiting for welcome packet
    (first server connection).  Otherwise they can stay waiting
    infinitely, unless there is query_timeout set.

  * win32: Add switch -U/-P to -regservice to let user pick account
    to run service under.  Old automatic choice between Local Service and
    Local System was not reliable enough.

  * console: Remove \0 from end of text columns.  It was hard to notice,
    as C clients were fine with it.

  * Documentation improvements.  (Greg Sabino Mullane)

  * Clarify few login-related log messages.

  * Change logging level for pooler-sent errors (usually on disconnect) from INFO
    to WARNING, as they signify problems.

  * Change log message for query_timeout to "query timeout".

**2009-07-06  -  PgBouncer 1.3.1  -  "Now fully conforming to NSA monitoring requirements"**

- Fixes
  * Fix problem with sbuf_loopcnt which could make connections hang.
    If query or result length is nearby of multiple of (pktlen*sbuf_loopcnt)
    [10k by default], it could stay waiting for more data which will not
    appear.
  * Make database reconfigure immediate.  Currently old connections
    could be reused after SIGHUP.
  * Fix SHOW DATABASES which was broken due to column addition.
  * Console access was disabled when "auth_type=any" as pgbouncer dropped username.
    Fix: if "auth_type=any", allow any user to console as admin.
  * Fix bad CUSTOM_ALIGN macro.  Luckily it's unused if OS already
    defines ALIGN macro thus seems the bug has not happened in wild.
  * win32: call WSAStartup() always, not only in daemon mode
    as config parsing wants to resolve hosts.
  * win32: put quotes around config filename in service
    cmdline to allow spaces in paths.  Executable path
    does not seem to need it due to some win32 magic.
  * Add STATS to SHOW HELP text.
  * doc/usage.txt: the time units in console results are in
    microseconds, not milliseconds.

**2009-02-18  -  PgBouncer 1.3 -  "New Ki-Smash Finishing Move"**

- Features

  * IANA has assigned port 6432 to be official port for PgBouncer.
    Thus the default port number has changed to 6432.  Existing
    individual users do not need to change, but if you distribute
    packages of PgBouncer, please change the package default
    to official port.

  * Dynamic database creation (David Galoyan)

    Now you can define database with name "*".  If defined, it's connect
    string will be used for all undefined databases.  Useful mostly
    for test / dev environments.

  * Windows support (Hiroshi Saito)

    PgBouncer runs on Windows 2000+ now.  Command line usage stays same,
    except it cannot run as daemon and cannot do online reboot.
    To run as service, define parameter service_name in config. Then:

        > pgbouncer.exe config.ini -regservice
        > net start SERVICE_NAME

    To stop and unregister:

        > net stop SERVICE_NAME
        > pgbouncer.exe config.ini -unregservice

    To use Windows Event Log, event DLL needs to be registered first:

        > regsrv32 pgbevent.dll

    Afterwards you can set "syslog = 1" in config.

- Minor features

  * Database names in config file can now be quoted with standard SQL
    ident quoting, to allow non-standard characters in db names.

  * New tunables: 'reserve_pool_size' and 'reserve_pool_timeout'.
    In case there are clients in pool that have waited more that
    'reserve_pool_timeout' seconds, 'reserve_pool_size' specifies
    the number of connections that can be added to pool.  It can also
    set per-pool with 'reserve_pool' connection variable.

  * New tunable 'sbuf_loopcnt' to limit time spent on one socket.

    In some situations - eg SMP server, local Postgres and fast network -
    pgbouncer can run recv()->send() loop many times without blocking
    on either side.  But that means other connections will stall for
    a long time.  To make processing more fair, limit the times
    of doing recv()->send() one socket.  If count reaches limit,
    just proceed processing other sockets.  The processing for
    that socket will resume on next event loop.

    Thanks to Alexander Schöcke for report and testing.

  * crypt() authentication is now optional, as it was removed from Postgres.
    If OS does not provide it, pgbouncer works fine without it.

  * Add milliseconds to log timestamps.

  * Replace old MD5 implementation with more compact one.

  * Update ISC licence with the FSF clarification.

- Fixes

  * In case event_del() reports failure, just proceed with cleanup.
    Previously pgbouncer retried it, in case the failure was due ENOMEM.
    But this has caused log floods with infinite repeats, so it seems
    libevent does not like it.

    Why event_del() report failure first time is still mystery.

  * --enable-debug now just toggles whether debug info is stripped from binary.
    It no longer plays with -fomit-frame-pointer as it's dangerous.

  * Fix include order, as otherwise system includes could come before
    internal ones.  Was problem for new md5.h include file.

  * Include COPYRIGHT file in .tgz...

PgBouncer 1.2.x
---------------

**2008-08-08  -  PgBouncer 1.2.3  -  "Carefully Selected Bytes"**

- Fixes
  * Disable SO_ACCEPTFILTER code for BSDs which did not work.
  * Include example etc/userlist.txt in tgz.
  * Use '$(MAKE)' instead 'make' for recursion (Jørgen Austvik)
  * Define _GNU_SOURCE as glibc is useless otherwise.
  * Let the libevent 1.1 pass link test so we can later report "1.3b+ needed"
  * Detect stale pidfile and remove it.

Thanks to Devrim GÜNDÜZ and Bjoern Metzdorf for problem reports and testing.

**2008-08-06  -  PgBouncer 1.2.2  -  "Barf-bag Included"**

- Fixes
  * Remove 'drop_on_error', it was a bad idea.  It was added as workaround
    for broken plan cache behaviour in Postgres, but can cause damage
    in common case when some queries always return error.

**2008-08-04  -  PgBouncer 1.2.1  -  "Waterproof"**

- Features
  * New parameter 'drop_on_error' - if server throws error the connection
    will not be reused but dropped after client finished with it.  This is
    needed to refresh plan cache.  Automatic refresh does not work even in 8.3.
    Defaults to 1.
- Fixes
  * SHOW SOCKETS/CLIENTS/SERVERS: Don't crash if socket has no buffer.
  * Fix infinite loop on SUSPEND if suspend_timeout triggers.
- Minor cleanups
  * Use <sys/uio.h> for 'struct iovec'.
  * Cancel shutdown (from SIGINT) on RESUME/SIGUSR2,
    otherwise it will trigger on next PAUSE.
  * Proper log message if console operation is canceled.

**2008-07-29  -  PgBouncer 1.2  -  "Ordinary Magic Flute"**

PgBouncer 1.2 now requires libevent version 1.3b or newer.
Older libevent versions crash with new restart code.

- Features

  * Command line option (-u) and config parameter (user=) to support user
    switching at startup.  Also now pgbouncer refuses to run as root.

    (Jacob Coby)

  * More descriptive usage text (-h).  (Jacob Coby)

  * New database option: connect_query to allow run a query on new
    connections before they are taken into use.

    (Teodor Sigaev)

  * New config var 'ignore_startup_parameters' to allow and ignore
    extra parameters in startup packet.  By default only 'database'
    and 'user' are allowed, all others raise error.  This is needed
    to tolerate overenthusiastic JDBC wanting to unconditionally
    set 'extra_float_digits=2' in startup packet.

  * Logging to syslog: new parameters syslog=0/1 and
    syslog_facility=daemon/user/local0.

  * Less scary online restart (-R)

    - Move FD loading before fork, so it logs to console and can be canceled by ^C

    - Keep SHUTDOWN after fork, so ^C would be safe

    - A connect() is attempted to unix socket to see if anyone is listening.
      Now -R can be used even when no previous process was running.  If there
      is previous process, but -R is not used, startup fails.

  * New console commands:

    - SHOW TOTALS that shows stats summary (as goes to log) plus mem usage.

    - SHOW ACTIVE_SOCKETS - like show sockets; but filter only active ones.

- Less visible features

  * suspend_timeout - drop stalled conns and long logins. This brings
    additional safety to reboot.

  * When remote database throws error on logging in, notify clients.

  * Removing a database from config and reloading works - all connections
    are killed and the database is removed.

  * Fake some parameters on console SHOW/SET commands to be more Postgres-like.
    That was needed to allow psycopg to connect to console.
    (client_encoding/default_transaction_isolation/datestyle/timezone)

  * Make server_lifetime=0 disconnect server connection immediately
    after first use.  Previously "0" made PgBouncer ignore server age.
    As this behavior was undocumented, there should not be any users
    depending on it.

  * Internal improvements:

    - Packet buffers are allocated lazily and reused.  This should bring
      huge decrease in memory usage.  This also makes realistic to use
      big pktbuf with lot of connections.

    - Lot's of error handling improvements, PgBouncer should now
      survive OOM situations gracefully.

    - Use slab allocator for memory management.

    - Lots of code cleanups.

- Fixes

  * Only single accept() was issued per event loop which could
    cause connection backlog when having high amount of connection
    attempts.  Now the listening socket is always drained fully,
    which should fix this.
  * Handle EINTR from connect().
  * Make configure.ac compatible with autoconf 2.59.
  * Solaris compatibility fixes (Magne Mæhre)

PgBouncer 1.1.x
---------------

**2007-12-10  -  PgBouncer 1.1.2  -  "The Hammer"**

- Features
  * Disconnects because of server_lifetime are now separated by
    (server_lifetime / pool_size) seconds.  This avoids pgbouncer
    causing reconnect floods.
- Fixes
  * Online upgrade 1.0 -> 1.1 problems:
    - 1.0 does not track server parameters, so they stay NULL
      but 1.1 did not expect it and crashed.
    - If server params are unknown, but client ones are set,
      then issue a SET for them, instead complaining.
  * Remove temp debug statements that were accidentally left
    in code on INFO level, so they polluted logs.
  * Unbroke debian/changelog
- Cleanup
  * reorder struct SBuf fields to get better alignment for buffer.

**2007-10-26  -  PgBouncer 1.1.1  -  "Breakdancing Bee"**

- Fixes
  * Server parameter cache could stay uninitialized, which caused
    unnecessary SET of them.  This caused problem on 8.1 which
    does not allow touching standard_conforming_strings.
    (Thanks to Dimitri Fontaine for report & testing.)
  * Some doc fixes.
  * Include doc/fixman.py in .tgz.

**2007-10-09  -  PgBouncer 1.1  -  "Mad-Hat Toolbox"**

- Features

  * Keep track of following server parameters:

        client_encoding  datestyle, timezone, standard_conforming_strings

  * Database connect string enhancements:

    - Accept hostname in host=
    - Accept custom unix socket location in host=
    - Accept quoted values: password=' asd''foo'

  * New config var: server_reset_query, to be sent immediately after release
  * New config var: server_round_robin, to switch between LIFO and RR.
  * Cancel pkt sent for idle connection does not drop it anymore.
  * Cancel with ^C from psql works for SUSPEND / PAUSE.
  * Print FD limits on startup.
  * When suspending, try to hit packet boundary ASAP.
  * Add 'timezone' to database parameters.
  * Use longlived logfile fd.  Reopened on SIGHUP / RELOAD;
  * Local connection endpoint info in SHOW SERVERS/CLIENTS/SOCKETS.

- Code cleanup

  * More debug log messages include socket info.
  * Magic number removal and error message cleanup. (David Fetter)
  * Wrapper struct for current pkt info.  Removes lot of compexity.

- Fixes

  * Detect invalid pkt headers better.
  * auth_file modification check was broken, which made pgbouncer
    reload it too often.

PgBouncer 1.0.x
---------------

**2007-06-18  -  PgBouncer 1.0.8  -  "Undead Shovel Jutsu"**

- Fixes
  * Fix crash in cancel packet handling. (^C from psql)
- Features
  * PAUSE <db>; RESUME <db>; works now.
  * Cleanup of console command parsing.
  * Disable expensive in-list assert check.

**2007-04-19  -  PgBouncer 1.0.7  -  "With Vitamin A-Z"**

- Fixes
  * Several error/notice packets with send() blocking between
    triggered assert.  Fix it by removing flushing logic altogether.
    As pgbouncer does not actively buffer anything, its not needed.
    It was a remnant from the time when buffering was pushed to
    kernel with MSG_MORE.
  * Additionally avoid calling recv() logic when sending unblocks.
  * List search code for admin_users and stats_users
    mishandled partial finds.  Fix it.
  * Standardise UNIX socket peer UID finding to getpeereid().

**2007-04-12  -  PgBouncer 1.0.6  -  "Daily Dose"**

- Fixes
  * The "Disable maintenance during the takeover" fix could
    disable maintenance altogether.  Fix it.
  * Compilation fix for FreeBSD, <sys/ucred.h> requires <sys/param.h> there.
    Thanks go to Robert Gogolok for report.

**2007-04-11  -  PgBouncer 1.0.5  -  "Enough for today"**

- Fixes
  * Fix online-restart bugs:
    - Set ->ready for idle servers.
    - Remove obsolete code from use_client_socket()
    - Disable maintenance during the takeover.

**2007-04-11  -  PgBouncer 1.0.4  -  "Last 'last' bug"**

- Fixes
  * Notice from idle server tagged server dirty.
    release_server() did not expect it.  Fix it
    by dropping them.

**2007-04-11  -  PgBouncer 1.0.3  -  "Fearless Fork"**

- Fixes
  * Some error handling was missing in login path, so dying
    connection there could trigger asserts.
  * Cleanup of asserts in sbuf.c to catch problems earlier.
  * Create core when Assert() triggers.

- New stuff
  * New config vars: log_connections, log_disconnections,
    log_pooler_errors to turn on/off noise.
  * Config var: client_login_timeout to kill dead connections
    in login phase that could stall SUSPEND and thus online restart.

**2007-03-28  -  PgBouncer 1.0.2  -  "Supersonic Spoon"**

- Fixes
  * libevent may report a deleted event inside same loop.
    Avoid socket reuse for one loop.
  * release_server() from disconnect_client() didn't look
    it the packet was actually sent.

**2007-03-15  -  PgBouncer 1.0.1  -  "Alien technology"**

- Fixes
  * Mixed usage of cached and non-cached time, plus unsigned usec_t typedef
    created spurious query_timeout errors.
  * Fix rare case when socket woken up from send-wait could stay stalling.
  * More fair queueing of server connections.  Before, a new query could
    get a server connections before older one.
  * Delay server release until everything is guaranteed to be sent.

- Features
  * SHOW SOCKETS command to have detailed info about state state.
  * Put PgSocket ptr to log, to help tracking one connection.
  * In console, allow SELECT in place of SHOW.
  * Various code cleanups.

**2007-03-13  -  PgBouncer 1.0  -  "Tuunitud bemm"**

- First public release.
