Provided by: pgbouncer_1.18.0-1_amd64 bug

NAME

       pgbouncer.ini - configuration file for pgbouncer

DESCRIPTION

       The  configuration file is in “ini” format.  Section names are between “[” and ”]”.  Lines
       starting with “;” or “#” are taken as comments and ignored.  The characters  “;”  and  “#”
       are not recognized as special when they appear later in the line.

GENERIC SETTINGS

   logfile
       Specifies the log file.  For daemonization (-d), either this or syslog need to be set.

       The  log  file  is kept open, so after rotation, kill -HUP or on console RELOAD; should be
       done.  On Windows, the service must be stopped and started.

       Note that setting logfile does not by itself turn off logging to stderr.  Use the command-
       line option -q or -d for that.

       Default: not set

   pidfile
       Specifies the PID file.  Without pidfile set, daemonization (-d) is not allowed.

       Default: not set

   listen_addr
       Specifies  a list (comma-separated) of addresses where to listen for TCP connections.  You
       may also use * meaning “listen  on  all  addresses”.   When  not  set,  only  Unix  socket
       connections are accepted.

       Addresses can be specified numerically (IPv4/IPv6) or by name.

       Default: not set

   listen_port
       Which port to listen on.  Applies to both TCP and Unix sockets.

       Default: 6432

   unix_socket_dir
       Specifies  the  location  for  Unix  sockets.  Applies to both the listening socket and to
       server connections.  If set to an empty string, Unix sockets are disabled.  A  value  that
       starts  with  @  specifies  that a Unix socket in the abstract namespace should be created
       (currently supported on Linux and Windows).

       For online reboot (-R) to work, a Unix socket needs to be configured, and it needs  to  be
       in the file-system namespace.

       Default: /tmp (empty on Windows)

   unix_socket_mode
       File  system  mode  for  Unix socket.  Ignored for sockets in the abstract namespace.  Not
       supported on Windows.

       Default: 0777

   unix_socket_group
       Group name to use for Unix socket.  Ignored for sockets in the  abstract  namespace.   Not
       supported on Windows.

       Default: not set

   user
       If  set,  specifies  the Unix user to change to after startup.  Works only if PgBouncer is
       started as root or if it’s already running as the given user.  Not supported on Windows.

       Default: not set

   pool_mode
       Specifies when a server connection can be reused by other clients.

       session
              Server is released back to pool after client disconnects.  Default.

       transaction
              Server is released back to pool after transaction finishes.

       statement
              Server is released back  to  pool  after  query  finishes.   Transactions  spanning
              multiple statements are disallowed in this mode.

   max_client_conn
       Maximum number of client connections allowed.

       When  this  setting  is increased, then the file descriptor limits in the operating system
       might also have to be increased.  Note that the number  of  file  descriptors  potentially
       used  is  more than max_client_conn.  If each user connects under its own user name to the
       server, the theoretical maximum used is:

              max_client_conn + (max pool_size * total databases * total users)

       If a database user is specified in the connection string (all users connect under the same
       user name), the theoretical maximum is:

              max_client_conn + (max pool_size * total databases)

       The  theoretical  maximum  should  never be reached, unless somebody deliberately crafts a
       special load for it.  Still, it means you should set the number of file descriptors  to  a
       safely high number.

       Search  for  ulimit  in  your  favorite  shell man page.  Note: ulimit does not apply in a
       Windows environment.

       Default: 100

   default_pool_size
       How many server connections to allow per user/database pair.  Can  be  overridden  in  the
       per-database configuration.

       Default: 20

   min_pool_size
       Add  more  server  connections  to  pool if below this number.  Improves behavior when the
       normal load suddently comes back after  a  period  of  total  inactivity.   The  value  is
       effectively capped at the pool size.

       Default: 0 (disabled)

   reserve_pool_size
       How  many  additional  connections  to  allow  to  a  pool  (see reserve_pool_timeout).  0
       disables.

       Default: 0 (disabled)

   reserve_pool_timeout
       If a client has not been serviced in  this  time,  use  additional  connections  from  the
       reserve pool.  0 disables.  [seconds]

       Default: 5.0

   max_db_connections
       Do  not  allow  more  than this many server connections per database (regardless of user).
       This considers the PgBouncer database that the client has connected to, not the PostgreSQL
       database of the outgoing connection.

       This can also be set per database in the [databases] section.

       Note  that  when  you  hit  the  limit,  closing  a client connection to one pool will not
       immediately allow a server connection to be established  for  another  pool,  because  the
       server  connection  for  the  first pool is still open.  Once the server connection closes
       (due to idle timeout), a new server connection will immediately be opened for the  waiting
       pool.

       Default: 0 (unlimited)

   max_user_connections
       Do  not  allow  more  than this many server connections per user (regardless of database).
       This considers the PgBouncer user that is associated with a pool, which is either the user
       specified  for  the  server  connection  or  in  absence  of  that the user the client has
       connected as.

       This can also be set per user in the [users] section.

       Note that when you hit the limit, closing  a  client  connection  to  one  pool  will  not
       immediately  allow  a  server  connection  to be established for another pool, because the
       server connection for the first pool is still open.  Once  the  server  connection  closes
       (due  to idle timeout), a new server connection will immediately be opened for the waiting
       pool.

       Default: 0 (unlimited)

   server_round_robin
       By default, PgBouncer reuses server connections in LIFO (last-in,  first-out)  manner,  so
       that  few connections get the most load.  This gives best performance if you have a single
       server serving a database.  But if there is a round-robin system behind a database address
       (TCP,  DNS,  or  host  list), then it is better if PgBouncer also uses connections in that
       manner, thus achieving uniform load.

       Default: 0

   ignore_startup_parameters
       By default, PgBouncer allows only parameters it can keep  track  of  in  startup  packets:
       client_encoding,   datestyle,   timezone   and  standard_conforming_strings.   All  others
       parameters will raise an error.  To allow others parameters, they can be  specified  here,
       so that PgBouncer knows that they are handled by the admin and it can ignore them.

       If   you   need   to   specify   multiple   values,   use  a  comma-separated  list  (e.g.
       options,extra_float_digits)

       Default: empty

   disable_pqexec
       Disable the Simple Query protocol (PQexec).  Unlike the Extended  Query  protocol,  Simple
       Query  allows  multiple  queries in one packet, which allows some classes of SQL-injection
       attacks.  Disabling it can improve security.  Obviously,  this  means  only  clients  that
       exclusively use the Extended Query protocol will stay working.

       Default: 0

   application_name_add_host
       Add  the  client  host  address and port to the application name setting set on connection
       start.  This helps in identifying the source of bad queries etc.  This logic applies  only
       at  the  start  of a connection.  If application_name is later changed with SET, PgBouncer
       does not change it again.

       Default: 0

   conffile
       Show location of current config file.  Changing it will make PgBouncer use another  config
       file for next RELOAD / SIGHUP.

       Default: file from command line

   service_name
       Used on win32 service registration.

       Default: pgbouncer

   job_name
       Alias for service_name.

   stats_period
       Sets  how  often  the  averages  shown  in various SHOW commands are updated and how often
       aggregated statistics are written to the log (but see log_stats).  [seconds]

       Default: 60

AUTHENTICATION SETTINGS

       PgBouncer handles its own client authentication and has its own database of users.   These
       settings control this.

   auth_type
       How to authenticate users.

       cert   Client  must connect over TLS connection with a valid client certificate.  The user
              name is then taken from the CommonName field from the certificate.

       md5    Use  MD5-based  password  check.   This  is  the  default  authentication   method.
              auth_file  may  contain  both  MD5-encrypted  and  plain-text passwords.  If md5 is
              configured and a user has  a  SCRAM  secret,  then  SCRAM  authentication  is  used
              automatically instead.

       scram-sha-256
              Use  password  check with SCRAM-SHA-256.  auth_file has to contain SCRAM secrets or
              plain-text passwords.

       plain  The clear-text password is sent over the wire.  Deprecated.

       trust  No authentication is done.  The user name must still exist in auth_file.

       any    Like the trust method, but the user name  given  is  ignored.   Requires  that  all
              databases  are  configured to log in as a specific user.  Additionally, the console
              database allows any user to log in as admin.

       hba    The actual authentication type is loaded from auth_hba_file.  This allows different
              authentication  methods  for  different access paths, for example: connections over
              Unix socket use the peer auth method, connections over TCP must use TLS.

       pam    PAM is used to authenticate users,  auth_file  is  ignored.   This  method  is  not
              compatible with databases using the auth_user option.  The service name reported to
              PAM is “pgbouncer”.  pam is not supported in the HBA configuration file.

   auth_hba_file
       HBA configuration file to use when auth_type is hba.

       Default: not set

   auth_file
       The name of the file to load user names and passwords from.   See  section  Authentication
       file format below about details.

       Most  authentication  types (see above) require that either auth_file or auth_user be set;
       otherwise there would be no users defined.

       Default: not set

   auth_user
       If auth_user is set, then any user not specified in auth_file will be queried through  the
       auth_query  query  from  pg_shadow  in  the  database,  using  auth_user.  The password of
       auth_user will be taken from auth_file.  (If the auth_user does  not  require  a  password
       then it does not need to be defined in auth_file.)

       Direct  access to pg_shadow requires admin rights.  It’s preferable to use a non-superuser
       that calls a SECURITY DEFINER function instead.

       Default: not set

   auth_query
       Query to load user’s password from database.

       Direct access to pg_shadow requires admin rights.  It’s preferable to use a  non-superuser
       that calls a SECURITY DEFINER function instead.

       Note that the query is run inside the target database.  So if a function is used, it needs
       to be installed into each database.

       Default: SELECT usename, passwd FROM pg_shadow WHERE usename=$1

LOG SETTINGS

   syslog
       Toggles syslog on/off.  On Windows, the event log is used instead.

       Default: 0

   syslog_ident
       Under what name to send logs to syslog.

       Default: pgbouncer (program name)

   syslog_facility
       Under what facility to send logs to syslog.  Possibilities: auth, authpriv, daemon,  user,
       local0-7.

       Default: daemon

   log_connections
       Log successful logins.

       Default: 1

   log_disconnections
       Log disconnections with reasons.

       Default: 1

   log_pooler_errors
       Log error messages the pooler sends to clients.

       Default: 1

   log_stats
       Write  aggregated  statistics  into  the log, every stats_period.  This can be disabled if
       external monitoring tools are used to grab the same data from SHOW commands.

       Default: 1

   verbose
       Increase verbosity.  Mirrors the “-v” switch on the command line.  For example, using  “-v
       -v” on the command line is the same as verbose=2.

       Default: 0

CONSOLE ACCESS CONTROL

   admin_users
       Comma-separated list of database users that are allowed to connect and run all commands on
       the console.  Ignored when auth_type is any, in which case any user name is allowed in  as
       admin.

       Default: empty

   stats_users
       Comma-separated  list  of  database  users  that  are allowed to connect and run read-only
       queries on the console.  That means all SHOW commands except SHOW FDS.

       Default: empty

CONNECTION SANITY CHECKS, TIMEOUTS

   server_reset_query
       Query sent to server on connection release, before making it available to  other  clients.
       At  that  moment  no  transaction is in progress, so the value should not include ABORT or
       ROLLBACK.

       The query is supposed to clean any changes made to the database session so that  the  next
       client  gets  the  connection  in a well-defined state.  The default is DISCARD ALL, which
       cleans everything, but that leaves the next client no pre-cached state.  It  can  be  made
       lighter, e.g. DEALLOCATE ALL to just drop prepared statements, if the application does not
       break when some state is kept around.

       When transaction pooling is used, the server_reset_query is  not  used,  because  in  that
       mode, clients must not use any session-based features, since each transaction ends up in a
       different connection and thus gets a different session state.

       Default: DISCARD ALL

   server_reset_query_always
       Whether server_reset_query should be run in all pooling modes.  When this setting  is  off
       (default),  the  server_reset_query will be run only in pools that are in sessions-pooling
       mode.  Connections in transaction-pooling mode should not have any need for a reset query.

       This setting is for working around broken setups that run applications  that  use  session
       features  over  a  transaction-pooled PgBouncer.  It changes non-deterministic breakage to
       deterministic breakage: Clients always lose their state after each transaction.

       Default: 0

   server_check_delay
       How long to keep released connections available  for  immediate  re-use,  without  running
       server_check_query on it.  If 0 then the check is always run.

       Default: 30.0

   server_check_query
       Simple do-nothing query to check if the server connection is alive.

       If an empty string, then sanity checking is disabled.

       Default: select 1

   server_fast_close
       Disconnect  a  server  in session pooling mode immediately or after the end of the current
       transaction if it is in  “close_needed”  mode  (set  by  RECONNECT,  RELOAD  that  changes
       connection  settings,  or  DNS  change),  rather  than  waiting  for  the session end.  In
       statement or transaction pooling mode, this has  no  effect  since  that  is  the  default
       behavior there.

       If  because  of  this  setting  a server connection is closed before the end of the client
       session, the client connection is also closed.  This ensures that the client notices  that
       the session has been interrupted.

       This  setting makes connection configuration changes take effect sooner if session pooling
       and long-running sessions are used.  The downside is that client sessions are liable to be
       interrupted by a configuration change, so client applications will need logic to reconnect
       and reestablish session state.  But note  that  no  transactions  will  be  lost,  because
       running transactions are not interrupted, only idle sessions.

       Default: 0

   server_lifetime
       The  pooler  will  close  an unused (not currently linked to any client connection) server
       connection that has been connected longer than this.  Setting it to 0 means the connection
       is to be used only once, then closed.  [seconds]

       Default: 3600.0

   server_idle_timeout
       If  a server connection has been idle more than this many seconds it will be closed.  If 0
       then this timeout is disabled.  [seconds]

       Default: 600.0

   server_connect_timeout
       If connection and login don’t finish in this  amount  of  time,  the  connection  will  be
       closed.  [seconds]

       Default: 15.0

   server_login_retry
       If  login  to the server failed, because of failure to connect or from authentication, the
       pooler waits this much before retrying to  connect.   During  the  waiting  interval,  new
       clients  trying  to  connect  to  the failing server will get an error immediately without
       another connection attempt.  [seconds]

       The purpose of this behavior is that clients don’t unnecessarily queue up  waiting  for  a
       server  connection  to  become  available  if the server is not working.  However, it also
       means that if a server is momentarily failing, for example during  a  restart  or  if  the
       configuration  was  erroneous,  then it will take at least this long until the pooler will
       consider connecting to it again.  Planned events  such  as  restarts  should  normally  be
       managed using the PAUSE command to avoid this.

       Default: 15.0

   client_login_timeout
       If  a  client  connects  but  does not manage to log in in this amount of time, it will be
       disconnected.  Mainly needed to avoid dead connections stalling SUSPEND  and  thus  online
       restart.  [seconds]

       Default: 60.0

   autodb_idle_timeout
       If  the automatically created (via “*“) database pools have been unused this many seconds,
       they are freed.  The negative aspect of that is that their statistics are also  forgotten.
       [seconds]

       Default: 3600.0

   dns_max_ttl
       How long DNS lookups can be cached.  The actual DNS TTL is ignored.  [seconds]

       Default: 15.0

   dns_nxdomain_ttl
       How long DNS errors and NXDOMAIN DNS lookups can be cached.  [seconds]

       Default: 15.0

   dns_zone_check_period
       Period to check if a zone serial has changed.

       PgBouncer  can  collect  DNS  zones  from host names (everything after first dot) and then
       periodically check if the zone serial changes.  If it  notices  changes,  all  host  names
       under  that  zone  are  looked  up  again.   If  any  host IP changes, its connections are
       invalidated.

       Works only with UDNS and c-ares backends (configure option --with-udns or --with-cares).

       Default: 0.0 (disabled)

   resolv_conf
       The location of a custom resolv.conf file.  This is to allow specifying custom DNS servers
       and  perhaps  other  name  resolution  options, independent of the global operating system
       configuration.

       Requires evdns (>= 2.0.3) or c-ares (>= 1.15.0) backend.

       The parsing of the file is done by the DNS backend library,  not  PgBouncer,  so  see  the
       library’s documentation for details on allowed syntax and directives.

       Default: empty (use operating system defaults)

TLS SETTINGS

   client_tls_sslmode
       TLS  mode  to  use for connections from clients.  TLS connections are disabled by default.
       When enabled, client_tls_key_file and client_tls_cert_file must be also configured to  set
       up the key and certificate PgBouncer uses to accept client connections.

       disable
              Plain TCP.  If client requests TLS, it’s ignored.  Default.

       allow  If  client  requests  TLS,  it  is used.  If not, plain TCP is used.  If the client
              presents a client certificate, it is not validated.

       prefer Same as allow.

       require
              Client must use TLS.  If not, the client connection is  rejected.   If  the  client
              presents a client certificate, it is not validated.

       verify-ca
              Client must use TLS with valid client certificate.

       verify-full
              Same as verify-ca.

   client_tls_key_file
       Private key for PgBouncer to accept client connections.

       Default: not set

   client_tls_cert_file
       Certificate for private key.  Clients can validate it.

       Default: not set

   client_tls_ca_file
       Root certificate file to validate client certificates.

       Default: not set

   client_tls_protocols
       Which  TLS  protocol  versions  are  allowed.   Allowed values: tlsv1.0, tlsv1.1, tlsv1.2,
       tlsv1.3.   Shortcuts:  all  (tlsv1.0,tlsv1.1,tlsv1.2,tlsv1.3),  secure  (tlsv1.2,tlsv1.3),
       legacy (all).

       Default: secure

   client_tls_ciphers
       Allowed  TLS  ciphers,  in  OpenSSL  syntax.   Shortcuts:  default/secure,  compat/legacy,
       insecure/all, normal, fast.

       Only connections using TLS version 1.2 and lower are  affected.   There  is  currently  no
       setting that controls the cipher choices used by TLS version 1.3 connections.

       Default: fast

   client_tls_ecdhcurve
       Elliptic Curve name to use for ECDH key exchanges.

       Allowed values: none (DH is disabled), auto (256-bit ECDH), curve name

       Default: auto

   client_tls_dheparams
       DHE key exchange type.

       Allowed values: none (DH is disabled), auto (2048-bit DH), legacy (1024-bit DH)

       Default: auto

   server_tls_sslmode
       TLS  mode  to  use for connections to PostgreSQL servers.  TLS connections are disabled by
       default.

       disable
              Plain TCP.  TCP is not even requested from the server.  Default.

       allow  FIXME: if server rejects plain, try TLS?

       prefer TLS connection  is  always  requested  first  from  PostgreSQL.   If  refused,  the
              connection  will  be  established  over  plain  TCP.   Server  certificate  is  not
              validated.

       require
              Connection must go over TLS.  If server rejects it, plain  TCP  is  not  attempted.
              Server certificate is not validated.

       verify-ca
              Connection  must  go  over  TLS  and  server certificate must be valid according to
              server_tls_ca_file.  Server host name is not checked against certificate.

       verify-full
              Connection must go over TLS and server  certificate  must  be  valid  according  to
              server_tls_ca_file.  Server host name must match certificate information.

   server_tls_ca_file
       Root certificate file to validate PostgreSQL server certificates.

       Default: not set

   server_tls_key_file
       Private key for PgBouncer to authenticate against PostgreSQL server.

       Default: not set

   server_tls_cert_file
       Certificate for private key.  PostgreSQL server can validate it.

       Default: not set

   server_tls_protocols
       Which  TLS  protocol  versions  are  allowed.   Allowed values: tlsv1.0, tlsv1.1, tlsv1.2,
       tlsv1.3.   Shortcuts:  all  (tlsv1.0,tlsv1.1,tlsv1.2,tlsv1.3),  secure  (tlsv1.2,tlsv1.3),
       legacy (all).

       Default: secure

   server_tls_ciphers
       Allowed  TLS  ciphers,  in  OpenSSL  syntax.   Shortcuts:  default/secure,  compat/legacy,
       insecure/all, normal, fast.

       Only connections using TLS version 1.2 and lower are  affected.   There  is  currently  no
       setting that controls the cipher choices used by TLS version 1.3 connections.

       Default: fast

DANGEROUS TIMEOUTS

       Setting the following timeouts can cause unexpected errors.

   query_timeout
       Queries  running  longer than that are canceled.  This should be used only with a slightly
       smaller server-side statement_timeout, to apply only for network problems.  [seconds]

       Default: 0.0 (disabled)

   query_wait_timeout
       Maximum time queries are allowed to spend waiting for execution.   If  the  query  is  not
       assigned  to  a server during that time, the client is disconnected.  0 disables.  If this
       is disabled, clients will be queued indefinitely.  [seconds]

       This setting is used to prevent unresponsive servers from  grabbing  up  connections.   It
       also helps when the server is down or rejects connections for any reason.

       Default: 120

   client_idle_timeout
       Client connections idling longer than this many seconds are closed.  This should be larger
       than the client-side connection lifetime settings, and only  used  for  network  problems.
       [seconds]

       Default: 0.0 (disabled)

   idle_transaction_timeout
       If  a  client  has  been  in  “idle in transaction” state longer, it will be disconnected.
       [seconds]

       Default: 0.0 (disabled)

   suspend_timeout
       How long to wait for buffer flush during SUSPEND or reboot (-R).  A connection is  dropped
       if the flush does not succeed.  [seconds]

       Default: 10

LOW-LEVEL NETWORK SETTINGS

   pkt_buf
       Internal  buffer  size  for  packets.  Affects size of TCP packets sent and general memory
       usage.  Actual libpq packets can be larger than this, so no need to set it large.

       Default: 4096

   max_packet_size
       Maximum size for PostgreSQL packets that PgBouncer allows through.  One packet  is  either
       one query or one result set row.  The full result set can be larger.

       Default: 2147483647

   listen_backlog
       Backlog  argument  for  listen(2).  Determines how many new unanswered connection attempts
       are kept in the queue.  When the queue is full, further new connections are dropped.

       Default: 128

   sbuf_loopcnt
       How many times to process data on one connection, before proceeding.  Without this  limit,
       one  connection  with  a  big  result  set  can stall PgBouncer for a long time.  One loop
       processes one pkt_buf amount of data.  0 means no limit.

       Default: 5

   so_reuseport
       Specifies whether to set the socket option SO_REUSEPORT on TCP listening sockets.  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.
       This  option  is  a  way  to  get  PgBouncer to use more CPU cores.  (PgBouncer is single-
       threaded and uses one CPU core per instance.)

       The behavior in detail depends on the operating system kernel.  As of this  writing,  this
       setting  has  the desired effect on (sufficiently recent versions of) Linux, DragonFlyBSD,
       and FreeBSD.  (On FreeBSD, it applies the socket option  SO_REUSEPORT_LB  instead.)   Some
       other operating systems support the socket option but it won’t have the desired effect: It
       will allow multiple processes to bind to the same port but only one of them will  get  the
       connections.  See your operating system’s setsockopt() documentation for details.

       On  systems  that  don’t  support  the  socket option at all, turning this setting on will
       result in an error.

       Each  PgBouncer  instance  on  the  same  host  needs  different  settings  for  at  least
       unix_socket_dir  and  pidfile,  as well as logfile if that is used.  Also note that if you
       make use of this option, you can no longer connect to a specific  PgBouncer  instance  via
       TCP/IP, which might have implications for monitoring and metrics collection.

       Default: 0

   tcp_defer_accept
       Sets  the  TCP_DEFER_ACCEPT  socket option; see man 7 tcp for details.  (This is a Boolean
       option: 1 means enabled.  The actual value set if enabled is  currently  hardcoded  to  45
       seconds.)

       This is currently only supported on Linux.

       Default: 1 on Linux, otherwise 0

   tcp_socket_buffer
       Default: not set

   tcp_keepalive
       Turns on basic keepalive with OS defaults.

       On  Linux,  the  system  defaults  are tcp_keepidle=7200, tcp_keepintvl=75, tcp_keepcnt=9.
       They are probably similar on other operating systems.

       Default: 1

   tcp_keepcnt
       Default: not set

   tcp_keepidle
       Default: not set

   tcp_keepintvl
       Default: not set

   tcp_user_timeout
       Sets the TCP_USER_TIMEOUT socket option.  This specifies the maximum  amount  of  time  in
       milliseconds  that transmitted data may remain unacknowledged before the TCP connection is
       forcibly closed.  If set to 0, then operating system’s default is used.

       This is currently only supported on Linux.

       Default: 0

SECTION [DATABASES]

       The section [databases] defines the names of the databases that clients of  PgBouncer  can
       connect  to  and  specifies  where those connections will be routed.  The section contains
       key=value lines like

              dbname = connection string

       where the key will be taken as a database name and  the  value  as  a  connection  string,
       consisting of key=value pairs of connection parameters, described below (similar to libpq,
       but the actual libpq is not  used  and  the  set  of  available  features  is  different).
       Example:

              foodb = host=host1.example.com port=5432
              bardb = host=localhost dbname=bazdb

       The  database  name can contain characters _0-9A-Za-z without quoting.  Names that contain
       other characters need to be quoted with standard SQL identifier  quoting:  double  quotes,
       with “” for a single instance of a double quote.

       The  database  name  “pgbouncer” is reserved for the admin console and cannot be used as a
       key here.

       “*” acts as a fallback database: If the exact name does not exist, its value is  taken  as
       connection  string  for the requested database.  For example, if there is an entry (and no
       other overriding entries)

              * = host=foo

       then a connection to PgBouncer specifying a database “bar” will effectively behave  as  if
       an entry

              bar = host=foo dbname=bar

       exists  (taking  advantage  of the default for dbname being the client-side database name;
       see below).

       Such automatically created database entries are cleaned up if they stay idle  longer  than
       the time specified by the autodb_idle_timeout parameter.

   dbname
       Destination database name.

       Default: same as client-side database name

   host
       Host  name  or  IP address to connect to.  Host names are resolved at connection time, the
       result is cached per dns_max_ttl  parameter.   When  a  host  name’s  resolution  changes,
       existing  server connections are automatically closed when they are released (according to
       the pooling mode), and new server connections immediately use the new resolution.  If  DNS
       returns several results, they are used in a round-robin manner.

       If  the  value begins with /, then a Unix socket in the file-system namespace is used.  If
       the value begins with @, then a Unix socket in the abstract namespace is used.

       A comma-separated list of host names  or  addresses  can  be  specified.   In  that  case,
       connections are made in a round-robin manner.  (If a host list contains host names that in
       turn resolve via DNS to multiple addresses, the round-robin systems operate independently.
       This is an implementation dependency that is subject to change.)  Note that in a list, all
       hosts must be available at all times: There are no mechanisms to skip unreachable hosts or
       to  select  only  available  hosts from a list or similar.  (This is different from what a
       host list in libpq means.)  Also note that this only affects how the destinations  of  new
       connections  are  chosen.   See  also  the  setting server_round_robin for how clients are
       assigned to already established server connections.

       Examples:

              host=localhost
              host=127.0.0.1
              host=2001:0db8:85a3:0000:0000:8a2e:0370:7334
              host=/var/run/postgresql
              host=192.168.0.1,192.168.0.2,192.168.0.3

       Default: not set, meaning to use a Unix socket

   port
       Default: 5432

   user
       If user= is set, all connections to  the  destination  database  will  be  done  with  the
       specified user, meaning that there will be only one pool for this database.

       Otherwise, PgBouncer logs into the destination database with the client user name, meaning
       that there will be one pool per user.

   password
       If no password is specified here, the password from the auth_file or  auth_query  will  be
       used.

   auth_user
       Override of the global auth_user setting, if specified.

   pool_size
       Set  the  maximum  size  of pools for this database.  If not set, the default_pool_size is
       used.

   min_pool_size
       Set the minimum pool size for this database.  If not  set,  the  global  min_pool_size  is
       used.

   reserve_pool
       Set additional connections for this database.  If not set, reserve_pool_size is used.

   connect_query
       Query to be executed after a connection is established, but before allowing the connection
       to be used by any clients.  If the query  raises  errors,  they  are  logged  but  ignored
       otherwise.

   pool_mode
       Set the pool mode specific to this database.  If not set, the default pool_mode is used.

   max_db_connections
       Configure  a  database-wide maximum (i.e. all pools within the database will not have more
       than this many server connections).

   client_encoding
       Ask specific client_encoding from server.

   datestyle
       Ask specific datestyle from server.

   timezone
       Ask specific timezone from server.

SECTION [USERS]

       This section contains key=value lines like

              user1 = settings

       where the key will be taken as a user name and the value as a list of key=value  pairs  of
       configuration settings specific for this user.  Example:

              user1 = pool_mode=session

       Only a few settings are available here.

   pool_mode
       Set the pool mode to be used for all connections from this user.  If not set, the database
       or default pool_mode is used.

   max_user_connections
       Configure a maximum for the user (i.e. all pools with the user will  not  have  more  than
       this many server connections).

INCLUDE DIRECTIVE

       The  PgBouncer  configuration  file  can contain include directives, which specify another
       configuration file to read and process.  This allows splitting the configuration file into
       physically separate parts.  The include directives look like this:

              %include filename

       If  the  file name is not an absolute path, it is taken as relative to the current working
       directory.

AUTHENTICATION FILE FORMAT

       This section describes the format of the file specified by the auth_file setting.  It is a
       text file in the following format:

              "username1" "password" ...
              "username2" "md5abcdef012342345" ...
              "username2" "SCRAM-SHA-256$<iterations>:<salt>$<storedkey>:<serverkey>"

       There  should  be  at least 2 fields, surrounded by double quotes.  The first field is the
       user name and the second is either a plain-text, a MD5-hashed password, or a SCRAM secret.
       PgBouncer  ignores the rest of the line.  Double quotes in a field value can be escaped by
       writing two double quotes.

       PostgreSQL MD5-hashed password format:

              "md5" + md5(password + username)

       So    user    admin    with    password    1234    will    have    MD5-hashed     password
       md545f2603610af569b6155c45067268c6b.

       PostgreSQL SCRAM secret format:

              SCRAM-SHA-256$<iterations>:<salt>$<storedkey>:<serverkey>

       See the PostgreSQL documentation and RFC 5803 for details on this.

       The  passwords  or  secrets  stored in the authentication file serve two purposes.  First,
       they are used to verify the passwords of incoming client connections, if a  password-based
       authentication  method is configured.  Second, they are used as the passwords for outgoing
       connections  to  the  backend  server,  if  the  backend  server  requires  password-based
       authentication  (unless  the  password  is specified directly in the database’s connection
       string).  The latter works if the password is stored in plain text or  MD5-hashed.   SCRAM
       secrets  can only be used for logging into a server if the client authentication also uses
       SCRAM, the PgBouncer database definition does not specify  a  user  name,  and  the  SCRAM
       secrets  are  identical  in PgBouncer and the PostgreSQL server (same salt and iterations,
       not merely the same password).  This is due to an inherent security property of SCRAM: The
       stored SCRAM secret cannot by itself be used for deriving login credentials.

       The  authentication  file can be written by hand, but it’s also useful to generate it from
       some other list of users and passwords.   See  ./etc/mkauth.py  for  a  sample  script  to
       generate  the  authentication  file  from  the pg_shadow system table.  Alternatively, use
       auth_query instead of auth_file to avoid having  to  maintain  a  separate  authentication
       file.

HBA FILE FORMAT

       The  location  of the HBA file is specified by the setting auth_hba_file.  It is only used
       if auth_type is set to hba.

       The   file   follows   the   format   of   the   PostgreSQL    pg_hba.conf    file    (see
       <https://www.postgresql.org/docs/current/auth-pg-hba-conf.html>).

       • Supported record types: local, host, hostssl, hostnossl.

       • Database   field:  Supports  all,  sameuser,  @file,  multiple  names.   Not  supported:
         replication, samerole, samegroup.

       • User name field: Supports all, @file, multiple names.  Not supported: +groupname.

       • Address field: Supports IPv4, IPv6.  Not supported: DNS names, domain prefixes.

       • Auth-method field: Only methods supported by PgBouncer’s auth_type are  supported,  plus
         peer and reject, but except any and pam, which only work globally.  User name map (map=)
         parameter is not supported.

EXAMPLES

       Small example configuration:

              [databases]
              template1 = host=localhost dbname=template1 auth_user=someuser

              [pgbouncer]
              pool_mode = session
              listen_port = 6432
              listen_addr = localhost
              auth_type = md5
              auth_file = users.txt
              logfile = pgbouncer.log
              pidfile = pgbouncer.pid
              admin_users = someuser
              stats_users = stat_collector

       Database examples:

              [databases]

              ; foodb over Unix socket
              foodb =

              ; redirect bardb to bazdb on localhost
              bardb = host=localhost dbname=bazdb

              ; access to destination database will go with single user
              forcedb = host=localhost port=300 user=baz password=foo client_encoding=UNICODE datestyle=ISO

       Example of a secure function for auth_query:

              CREATE OR REPLACE FUNCTION pgbouncer.user_lookup(in i_username text, out uname text, out phash text)
              RETURNS record AS $$
              BEGIN
                  SELECT usename, passwd FROM pg_catalog.pg_shadow
                  WHERE usename = i_username INTO uname, phash;
                  RETURN;
              END;
              $$ LANGUAGE plpgsql SECURITY DEFINER;
              REVOKE ALL ON FUNCTION pgbouncer.user_lookup(text) FROM public, pgbouncer;
              GRANT EXECUTE ON FUNCTION pgbouncer.user_lookup(text) TO pgbouncer;

SEE ALSO

       pgbouncer(1) - man page for general usage, console commands

       <https://www.pgbouncer.org/>