2023-10-16 - PgBouncer 1.21.0 - “The one with prepared statements”
- 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
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- Improve security of OpenSSL settings, the defaults used were VERY outdated.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)
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
- 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
- Remove support for udns (#938)
2023-08-09 - PgBouncer 1.20.1 - “Optional options”
- Fix regression where putting
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)
2023-07-20 - PgBouncer 1.20.0 - “A funny name goes here”
- 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
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
standard_conforming_strings. Now PgBouncer also tracks
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
- Forward SQLSTATE in authentication phase. This allows the detection of
database not existing, which is done by Npgsql (a .NET data provider for
- Change default
- Add support for the
options startup parameter. This allows usage of the
PGOPTIONS environment variable that
about. Using this variable you can set any PostgreSQL parameter at
startup. This only works for PostgreSQL parameters that PgBouncer tracks
- 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.
- Fix name of
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
2023-05-31 - PgBouncer 1.19.1 - “Sunny Spring”
This is a minor release that fixes a few recently introduced bugs:
- 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)
2023-05-04 - PgBouncer 1.19.0 - “The old-fashioned, human-generated kind”
auth_dbname option, which specifies against which database
to run the
- 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
state. (#815) (introduced in 1.18.0)
- Don’t exit with a non-zero status when a
- Fail hard during startup when a socket could not be created in
- 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
2022-12-12 - PgBouncer 1.18.0 - “No real mystery”
- Add information about cancel requests to
sbuf_send_pending operation if destination socket is closed
- Fix a few possible crashes
- Fix for overflow bug in comma-separated host list feature, causing
connection to get re-routed to Unix socket
- Don’t evict connections to achieve
SHOW HELP with PostgreSQL 15
- 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.
2022-03-23 - PgBouncer 1.17.0 - “A line has been drawn”
- 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
- 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
- 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.
auth_type in sample
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.
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
- 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
- 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
- Document that the admin console only supports the simple query
protocol, and give better error messages about this.
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”
- 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
- 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
- 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
- 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
- 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
res_pool_size. Reloading these settings previously didn’t work.
- Cirrus CI is now
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
- Errors sent to clients before the connection is closed are now
labeled as FATAL instead of just ERROR. Some clients were
- Fix compiler warnings with GCC 11.
2020-11-19 - PgBouncer 1.15.0 - “Ich hab noch einen Koffer in Berlin”
- 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
- 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.
- Repair compilation on systems with older systemd versions. This
was broken in 1.14.0.
- The makefile target to build Windows binary zip packages has been
- 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
- Improve test stability and portability.
- Modernize Autoconf-related code.
- Disable deprecation compiler warnings from OpenSSL 3.0.0.
2020-06-11 - PgBouncer 1.14.0 - “La ritrovata magia”
- Add SCRAM authentication pass-through. This allows using
encrypted SCRAM secrets in PgBouncer (either in
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
- Add support for Unix-domain sockets on Windows.
- Add an alternative smaller sample configuration file
pgbouncer-minimal.ini for testing or deployment.
2020-04-27 - PgBouncer 1.13.0 - “My favourite game”
- Add configuration setting
tcp_user_timeout, to set the
corresponding socket option.
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
- Add support for systemd service notifications. Right now, this
Type=notify service units. More integration is
planned for future versions.
- Fix multiline log messages
- Handle null user names returned from
- 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
- The libevent API use was updated to use version 2 style interfaces
and to no longer use deprecated interfaces from version 1.
2019-10-17 - PgBouncer 1.12.0 - “It’s about learning and getting better”
This release contains a variety of minor enhancements and fixes.
- 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
- Send statistics columns as
numeric instead of
avoids some client libraries failing on values that overflow the
- Fix issue with PAM users losing their
- 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
make check target. This allows running all the tests from a
- 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.
2019-08-27 - PgBouncer 1.11.0 - “Instinct for Greatness”
- Add support for SCRAM authentication for clients and servers. A
new authentication type
scram-sha-256 is added.
auth_type=password when the stored password is md5, like
a PostgreSQL server
- Add option
log_stats to disable printing stats to
- Add time zone to log timestamps.
- Put PID into [brackets] in log prefix.
- Fix OpenSSL configure test when running against newer OpenSSL with
- Fix wait time computation with
auth_user. This would either
crash or report garbage values for wait
- 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
2019-07-01 - PgBouncer 1.10.0 - “Afraid of the World”
- 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
- 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
- Fix an issue that could lead to prolonged downtime if many cancel
- Avoid “unexpected response from login query” after a postgres
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
- 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
2018-08-13 - PgBouncer 1.9.0 - “Chaos Survival”
- 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
2017-12-20 - PgBouncer 1.8.1 - “Ground-and-pound Mentality”
- 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”
- Support PAM authentication. (Enable with
disabled fields to
SHOW DATABASES output.
maxwait_us field to
SHOW POOLS output.
wait_us fields to
SHOW commands output.
- Add new commands
SHOW STATS_TOTALS and
- Track queries and transactions separately in
SHOW STATS. The
avg_query have been replaced by new fields.
- 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.
- Several other hba parsing fixes.
- Fix race condition when canceling query.
auth_user setting is now also allowed globally, not only per database.
- Set console client and server encoding to
2016-02-26 - PgBouncer 1.7.2 - “Finally Airborne”
- 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.
- Make build reproducible by dropping DBGVER handling.
- Antimake: Sort file list from $(wildcard), newer gmake does not
sort it anymore.
- 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.
- TLS: Rename sslmode “disabled” to “disable” as that is what
client_tls_sslmode=verify-ca/-full now reject
connections without client certificate.
client_tls_sslmode=allow/require do validate client
certificate if sent. Previously they left cert validation
unconfigured so connections with client cert failed.
- 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 (
- Fix various issues with Windows build.
- TLS: Use SSL_MODE_RELEASE_BUFFERS to decrease memory usage
of inactive connections.
- Clean allocated memory on exit. Helps to run memory-leak checkers.
- Add TLS options to sample config.
2015-12-18 - PgBouncer 1.7 - “Colors Vary After Resurrection”
- 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
in Postgres. This allows to configure TLS for network connections and “peer”
authentication for local connections.
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
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
- 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.
- 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.
2015-09-03 - PgBouncer 1.6.1 - “Studio Audience Approves”
server_reset_query_always. When set,
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.
[SECURITY] Remove invalid assignment of
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.
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”
Load user password hash from postgres database.
user to use for connecting same db and fetching user info.
Can be set per-database too.
SQL query to run under auth_user.
Default: “SELECT usename, passwd FROM pg_shadow WHERE usename=$1”
Pooling mode can be configured both per-database and per-user.
Per-database and per-user connection limits: max_db_connections and
(Cody Cutrer / Pavel Stehule)
Add DISABLE/ENABLE commands to prevent new connections.
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.
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’.
Config files have ‘%include FILENAME’ directive to allow configuration
to be split into several files.
- 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
- Allow comments (with ‘;’) in auth files.
- Fix spelling mistakes in log messages and comments.
- fix launching new connections during maintenance
- don’t load auth file twice at boot
- 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.
- Small bug fix, must check calloc result
- Add newline at the end of the PID file
- Don’t allow new server connections when PAUSE was issued.
- Fix ‘bad packet’ during login when header is delayed.
(Michał Trojnara, Marko Kreen)
- Fix errors detected by Coverty.
- Disable server_idle_timeout when server count gets below min_pool (#60)
2015-04-09 - PgBouncer 1.5.5 - “Play Dead To Win”
- 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”
- 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”
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.
- 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
- 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.
2012-05-29 - PgBouncer 1.5.2 - “Don’t Chew, Just Swallow”
- 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?”
- Parameters to tune permissions on unix socket:
- 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
- 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 Satisified 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.
- Detect DNS reply changes and invalidate connections to IPs no longer
present in latest reply.
- 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.
- 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.
- 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.
- 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.
- Create auto databases as needed when doing PAUSE.
- Fix wrong log message issued by RESUME command.
- 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.
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
- 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”
- Support listening/connect for IPv6 addresses.
- 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.
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.
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
- 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.
- win32: fix auth file on DOS line endings - load_file() did not take
account of file shringage when loading.
- <usual/endian.h>: add autoconf detection for enc/dec functions
so it would not create conflicts on BSD.
- Don’t crash when config file does not exist.
- 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.
- Use ‘awk’ instead of ‘sed’ in find_modules.sh to make it more portable.
- 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”
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.
- 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.
2010-09-09 - PgBouncer 1.3.4 - “Bouncer is always right”
- 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=
- 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”
- 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.
2010-03-15 - PgBouncer 1.3.2 - “Boomerang Bullet”
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”
- 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
- 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”
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:
Afterwards you can set “syslog = 1” in config.
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.
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.
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…
2008-08-08 - PgBouncer 1.2.3 - “Carefully Selected Bytes”
- 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”
- 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”
- 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.
- 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.
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
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:
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.
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.
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.
- 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)
2007-12-10 - PgBouncer 1.1.2 - “The Hammer”
- 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:
- 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
- reorder struct SBuf fields to get better alignment for buffer.
2007-10-26 - PgBouncer 1.1.1 - “Breakdancing Bee”
- 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”
- 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.
2007-06-18 - PgBouncer 1.0.8 - “Undead Shovel Jutsu”
- Fix crash in cancel packet handling. (^C from psql)
- PAUSE ; RESUME ; works now.
- Cleanup of console command parsing.
- Disable expensive in-list assert check.
2007-04-19 - PgBouncer 1.0.7 - “With Vitamin A-Z”
- 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”
- 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”
- 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”
- 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”
- 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”
- 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.
2007-03-15 - PgBouncer 1.0.1 - “Alien technology”
- 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.
2007-03-13 - PgBouncer 1.0 - “Tuunitud bemm”