openldap/man/lloadd.8

.lf 1 stdin
.TH LLOADD 8C "2025/05/22" "OpenLDAP 2.6.10"
.\" Copyright 2017-2024 The OpenLDAP Foundation All Rights Reserved.
.\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
.\" $OpenLDAP$
.SH NAME
lloadd \- LDAP Load Balancer Daemon
.SH SYNOPSIS
.B /usr/libexec/lloadd
[\c
.BR \-4 | \-6 ]
[\c
.BI \-d \ debug-level\fR]
[\c
.BI \-f \ lloadd-config-file\fR]
[\c
.BI \-h \ URLs\fR]
[\c
.BI \-n \ service-name\fR]
[\c
.BI \-s \ syslog-level\fR]
[\c
.BI \-l \ syslog-local-user\fR]
[\c
.BI \-o \ option\fR[ = value\fR]]
[\c
.BI \-r \ directory\fR]
[\c
.BI \-u \ user\fR]
[\c
.BI \-g \ group\fR]
.SH DESCRIPTION
.LP
.B Lloadd
is the stand-alone LDAP daemon. It listens for LDAP connections on
any number of ports (default \fB389\fP), forwarding the LDAP operations
it receives over these connections to be handled by the configured
backends.
.B lloadd
is typically invoked at boot time, usually out of
.BR  /etc/rc.local .
Upon startup,
.B lloadd
normally forks and disassociates itself from the invoking tty.
If configured in the config file, the
.B lloadd
process will print its process ID (see
.BR getpid (2))
to a
.B .pid
file, as well as the command line options during invocation to an
.B .args
file (see
.BR lloadd.conf (5)).
If the
.B \-d
flag is given, even with a zero argument,
.B lloadd
will not fork and disassociate from the invoking tty.
.LP
See the "OpenLDAP Administrator's Guide" for more details on
.BR lloadd .
.SH OPTIONS
.TP
.B \-4
Listen on IPv4 addresses only.
.TP
.B \-6
Listen on IPv6 addresses only.
.TP
.BI \-d \ debug-level
Turn on debugging as defined by
.IR debug-level .
If this option is specified, even with a zero argument,
.B lloadd
will not fork or disassociate from the invoking terminal.  Some general
operation and status messages are printed for any value of \fIdebug-level\fP.
\fIdebug-level\fP is taken as a bit string, with each bit corresponding to a
different kind of debugging information.  See <ldap_log.h> for details.
Comma-separated arrays of friendly names can be specified to select
debugging output of the corresponding debugging information.
All the names recognized by the \fIloglevel\fP directive
described in \fBlloadd.conf\fP(5) are supported.
If \fIdebug-level\fP is \fB?\fP, a list of installed debug-levels is printed,
and lloadd exits.

Remember that if you turn on packet logging, packets containing bind passwords
will be output, so if you redirect the log to a logfile, that file should
be read-protected.
.TP
.BI \-s \ syslog-level
This option tells
.B lloadd
at what debug-level debugging statements should be logged to the
.BR syslog (8)
facility.
The value \fIsyslog-level\fP can be set to any value or combination
allowed by the \fB\-d\fP switch.
Lloadd logs all messages selected by \fIsyslog-level\fP
at the
.BR syslog (3)
severity debug-level \fBDEBUG\fP,
on the unit specified with \fB\-l\fP.
.TP
.BI \-n \ service-name
Specifies the service name for logging and other purposes.  Defaults
to basename of argv[0], i.e.: "lloadd".
.TP
.BI \-l \ syslog-local-user
Selects the local user of the
.BR syslog (8)
facility. Value can be
.BR LOCAL0 ,
through
.BR LOCAL7 ,
as well as
.B USER
and
.BR DAEMON .
The default is
.BR LOCAL4 .
However, this option is only permitted on systems that support
local users with the
.BR syslog (8)
facility.
Logging to syslog(8) occurs at the "DEBUG" severity debug-level.
.TP
.BI \-f \ lloadd-config-file
Specifies the lloadd configuration file. The default is
.BR /etc/openldap/lloadd.conf .
.TP
.BI \-h \ URLlist
.B lloadd
will by default serve
.B ldap:///
(LDAP over TCP on all interfaces on default LDAP port).  That is,
it will bind using INADDR_ANY and port \fB389\fP.
The
.B \-h
option may be used to specify LDAP (and other scheme) URLs to serve.
For example, if lloadd is given
.BR "\-h \(dqldap://127.0.0.1:9009/ ldaps:/// ldapi:///\(dq" ,
it will listen on 127.0.0.1:9009 for LDAP, 0.0.0.0:636 for LDAP over TLS,
and LDAP over IPC (Unix domain sockets).  Host 0.0.0.0 represents
INADDR_ANY (any interface).
A space separated list of URLs is expected.  The URLs should be of the LDAP,
PLDAP, LDAPS, PLDAPS, or LDAPI schemes, and generally without a DN or other
optional parameters (excepting as discussed below).  Support for the latter
three schemes depends on selected configuration options. Hosts may be specified
by name or IPv4 and IPv6 address formats.  Ports, if specified, must be
numeric.  The default ldap:// port is \fB389\fP and the default ldaps:// port
is \fB636\fP, same for the proxy enabled variants.

The PLDAP and PLDAPS URL schemes provide support for the HAProxy proxy protocol
version 2, which allows a load balancer or proxy server to provide the remote
client IP address to slapd to be used for access control or logging. Ports
configured for PLDAP or PLDAPS will only accept connections that include the
necessary proxy protocol header. Connections to these ports should be
restricted at the network level to only trusted load balancers or proxies to
avoid spoofing of client IP addresses by third parties.

At the moment, the load balancer does not act on the recorded address in any
way.

For LDAP over IPC,
.B name
is the name of the socket, and no
.B port
is required, nor allowed; note that directory separators must be
URL-encoded, like any other characters that are special to URLs;
so the socket

        /usr/local/var/ldapi

must be specified as

        ldapi://%2Fusr%2Flocal%2Fvar%2Fldapi

The default location for the IPC socket is /var/openldap/run/ldapi
.TP
.BI \-r \ directory
Specifies a directory to become the root directory.  lloadd will
change the current working directory to this directory and
then
.BR chroot (2)
to this directory.  This is done after opening listeners but before
reading any configuration file or initializing any backend.  When
used as a security mechanism, it should be used in conjunction with
.B \-u
and
.B \-g
options.
.TP
.BI \-u \ user
.B lloadd
will run lloadd with the specified user name or id, and that user's
supplementary group access list as set with initgroups(3).  The group ID
is also changed to this user's gid, unless the \fB\-g\fP option is used to
override.  Note when used with
.BR \-r ,
lloadd will use the user database in the change root environment.
.TP
.BI \-g \ group
.B lloadd
will run with the specified group name or id.  Note when used with
.BR \-r ,
lloadd will use the group database in the change root environment.
.TP
.BI \-o \ option\fR[ = value\fR]
This option provides a generic means to specify options without the need to reserve
a separate letter for them.

It supports the following options:
.RS
.TP
.BR slp= { on \||\| off \||\| \fIslp-attrs\fP }
When SLP support is compiled into lloadd, disable it (\fBoff\fP),
 enable it by registering at SLP DAs without specific SLP attributes (\fBon\fP),
or with specific SLP attributes
.I slp-attrs
that must be an SLP attribute list definition according to the SLP standard.

For example, \fB"slp=(tree=production),(server-type=OpenLDAP),(server\-version=2.4.15)"\fP
registers at SLP DAs with the three SLP attributes tree, server-type and server-version
that have the values given above.
This allows one to specifically query the SLP DAs for LDAP servers holding the
.I production
tree in case multiple trees are available.
.RE

.SH RELATION TO SLAPD(8)
.B Lloadd
can be compiled as a
.B slapd
loadable module. In that case, it can be loaded as such:
.LP
.nf
.ft tt
    moduleload path/to/lloadd.la
    backend lload
    listen "listening URLs"
.ft
.fi

This enables
.B lloadd
to provide additional features through the host slapd process like access to
run-time statistics in
.B cn=monitor
and dynamic configuration from
.BR cn=config .

The listening sockets specified will be under direct control of
.B lloadd
and need to be different from the sockets slapd is configured to listen on.
Clients connecting to these are completely separate from regular LDAP clients
connecting to the usual
.B slapd
sockets -
.B lloadd
clients have no access to slapd databases, similarly,
.B slapd
client traffic does not propagate to the
.B lloadd
backend servers in any way.

.SH CN=MONITOR INTERFACE
As part of
.BR lloadd 's
.B cn=monitor
interface it is possible to close a client connection it manages by writing to
the corresponding entry,
.B replacing
the
.B olmConnectionState
attribute with the value
.BR closing .
This is subject to ACLs configured on the monitor database. The server will
send a
.B Notice of Disconnection
to the client, refuse any new operations and once all pending operations have
finished, close the connection.

For example, to close connection number 42:

.LP
.nf
.ft tt
    dn: cn=connection 42,cn=incoming connections,cn=load balancer,cn=backends,cn=monitor
    changetype: modify
    replace: olmConnectionState
    olmConnectionState: closing
.ft
.fi

.SH EXAMPLES
To start
.I lloadd
and have it fork and detach from the terminal and start load-balancing
the LDAP servers defined in the default config file, just type:
.LP
.nf
.ft tt
	/usr/libexec/lloadd
.ft
.fi
.LP
To start
.B lloadd
with an alternate configuration file, and turn
on voluminous debugging which will be printed on standard error, type:
.LP
.nf
.ft tt
	/usr/libexec/lloadd \-f /var/tmp/lloadd.conf \-d 255
.ft
.fi
.LP
To start
.B lloadd
as a module inside a slapd process listening on ldap://:1389 and ldaps://,
put the following in your slapd.conf (or its equivalent in cn=config):
.LP
.nf
.ft tt
    moduleload lloadd.la
    backend lload
    listen "ldap://:1389 ldaps://"
.ft
.fi
.SH "SEE ALSO"
.BR ldap (3),
.BR lloadd.conf (5),
.BR slapd-config (5),
.BR slapd-monitor (5),
.BR slapd (8).
.LP
"OpenLDAP Administrator's Guide" (http://www.OpenLDAP.org/doc/admin/)
.SH BUGS
See http://www.openldap.org/its/
.SH ACKNOWLEDGEMENTS
.lf 1 ./../Project
.\" Shared Project Acknowledgement Text
.B "OpenLDAP Software"
is developed and maintained by The OpenLDAP Project <http://www.openldap.org/>.
.B "OpenLDAP Software"
is derived from the University of Michigan LDAP 3.3 Release.
.lf 342 stdin