PgBouncer

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 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)

Improve security of OpenSSL settings, the defaults used were VERY outdated.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)

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)

Remove support for udns (#938)

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)

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)

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. 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. 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)

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)

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)

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)

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)

Various CI updates for better performance

Removed AppVeyor

Add application_name to SHOW CLIENTS/SERVERS/SOCKETS output (#449)

Add information about cancel requests to SHOW CLIENTS/SERVERS/POOLS output (#782)

Fail sbuf_send_pending operation if destination socket is closed (#652)

Fix a few possible crashes (#700, #730)

Fix for overflow bug in comma-separated host list feature, causing connection to get re-routed to Unix socket (#747)

Don’t evict connections to achieve min_pool_size (#648)

Fix SHOW HELP with PostgreSQL 15 (#769)

Fix race condition in query cancelation 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)

Various CI updates

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.

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.

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.

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.

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, #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)

Fix reloading of default_pool_size, min_pool_size, and res_pool_size. Reloading these settings previously didn’t work.

Cirrus CI is now used 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)

Fix compiler warnings with GCC 11. (#623)

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.

Fix the so_reuseport option on FreeBSD. The original code in PgBouncer 1.12.0 didn’t actually work on FreeBSD. (#504)

Repair compilation on systems with older systemd versions. This was broken in 1.14.0. (#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, #393)

Improve test stability and portability.

Modernize Autoconf-related code.

Disable deprecation compiler warnings from OpenSSL 3.0.0.

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.

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

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.

Fix multiline log messages (libusual #24)

Handle null user names returned from auth_query properly (#340)

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.

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.

Send statistics columns as numeric instead of bigint. This avoids some client libraries failing on values that overflow the bigint range. (#360, #401)

Fix issue with PAM users losing their password. (#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).

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.

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)

Add option log_stats to disable printing stats to log. (#287)

Add time zone to log timestamps.

Put PID into [brackets] in log prefix.

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)

Handle GSSENCRequest packet, added in PostgreSQL 12. It doesn’t do anything right now, but it avoids confusing error messages about “bad packet header”.

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)

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.)

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).

Fix an issue that could lead to prolonged downtime if many cancel requests arrive (#329).

Avoid “unexpected response from login query” after a postgres reload (#220).

Fix idle_transaction_timeout calculation (#125). The bug would lead to premature timeouts in specific situations.

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.

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

Avoid double-free in parse_filename

Avoid NULL pointer deref in parse_line

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

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

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.

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)

Several other hba parsing fixes.

Fix race condition when canceling query. (#141)

auth_user setting is now also allowed globally, not only per database. (#142)

Set console client and server encoding to UTF8.

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)

Make build reproducible by dropping DBGVER handling. (#112)

Antimake: Sort file list from $(wildcard), newer gmake does not sort it anymore. (#111)

Show libssl version in log.

deb: Turn on full hardening.

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)

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)

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)

Fix various issues with Windows build. (#100)

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)

Add TLS options to sample config.

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 in Postgres. This allows to configure TLS for network connections and “peer” authentication for local connections.

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.

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.

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.

[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.

Skip NoticeResponce 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).

Load user password hash from postgres database. New parameters:

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.

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)

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)

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 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)

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

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.

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

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 unparseable packet header, show it in hex in log and error message.

AntiMake: it used $(relpath) and $(abspath) to manupulate 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.

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)

Parameters to tune permissions on unix socket: unix_socket_mode=0777, unix_socket_group=’’.

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().

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.

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 stard 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.

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

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.

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

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.

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.

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.)

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.

DateStyle and TimeZone server params need to use exact case.

Console: send datetime, timezone and stdstr server params to client.

Use libusual library for low-level utility functions.

Remove fixed-length limit from server params.

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.

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.

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.

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.

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 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”.

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.

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)

Windows support (Hiroshi Saito)

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

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

> regsrv32 pgbevent.dll

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.

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.

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 inifinite repeats, so it seems libevent does not like it.

–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…

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.

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.

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.

SHOW SOCKETS/CLIENTS/SERVERS: Don’t crash if socket has no buffer.

Fix infinite loop on SUSPEND if suspend_timeout triggers.

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.

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

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.

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)

New console commands:

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:

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)

Disconnects because of server_lifetime are now separated by (server_lifetime / pool_size) seconds. This avoids pgbouncer causing reconnect floods.

Online upgrade 1.0 → 1.1 problems:

Remove temp debug statements that were accidentally left in code on INFO level, so they polluted logs.

Unbroke debian/changelog

reorder struct SBuf fields to get better alignment for buffer.

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.

Keep track of following server parameters:

client_encoding  datestyle, timezone, standard_conforming_strings

Database connect string enhancements:

New config var: server_reset_query, to be sent immidiately 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.

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.

Detect invalid pkt headers better.

auth_file modification check was broken, which made pgbouncer reload it too often.

Fix crash in cancel packet handling. (^C from psql)

PAUSE ; RESUME ; works now.

Cleanup of console command parsing.

Disable expensive in-list assert check.

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().

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.

Fix online-restart bugs:

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

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 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.

libevent may report a deleted event inside same loop. Avoid socket reuse for one loop.

release_server() from disconnect_client() didnt look it the packet was actually sent.

Mixed usage of cached and non-cached time, plus unsiged 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.

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.