.TH MAGLEVD 8 "April 2026" "vpp\-maglev" "System Administration"
.SH NAME
maglevd \- Maglev health\-checker daemon
.SH SYNOPSIS
.B maglevd
[\fB\-config\fR \fIfile\fR]
[\fB\-grpc\-addr\fR \fIaddr\fR]
[\fB\-log\-level\fR \fIlevel\fR]
[\fB\-version\fR]
.SH DESCRIPTION
.B maglevd
is a health\-checker daemon that monitors backends (HTTP, TCP, ICMP) and
exposes their aggregated state via a gRPC API.
Configuration is loaded from a YAML file.
A running daemon reloads its configuration when it receives
.BR SIGHUP .
.PP
Backends are tracked with a rise/fall counter model.
Each backend cycles through the states
.BR unknown ,
.BR up ,
.BR down ,
and
.B paused
(operator\-set).
Health\-check intervals adapt automatically: a faster interval is used when
a backend is not fully healthy, and a slower interval when it has been
continuously down.
.SH OPTIONS
Each flag may also be supplied via an environment variable (shown in
parentheses); the flag takes precedence.
.TP
.BI \-config " file"
Path to the YAML configuration file.
.RI "(default: " /etc/maglev/maglev.conf "; env: " MAGLEV_CONFIG )
.TP
.BI \-grpc\-addr " addr"
TCP address on which the gRPC server listens.
.RI "(default: " :9090 "; env: " MAGLEV_GRPC_ADDR )
.TP
.BI \-log\-level " level"
Structured\-log verbosity:
.BR debug ,
.BR info ,
.BR warn ,
or
.BR error .
.RI "(default: " info "; env: " MAGLEV_LOG_LEVEL )
.TP
.B \-version
Print version, commit hash, and build date, then exit.
.SH SIGNALS
.TP
.B SIGHUP
Reload the configuration file without restarting.
New backends are added, removed backends are stopped, and unchanged
backend workers are left running.
.TP
.BR SIGTERM ", " SIGINT
Gracefully shut down: drain active gRPC streams, then exit.
.SH FILES
.TP
.I /etc/maglev/maglev.conf
Default configuration file (YAML).
.TP
.I /etc/default/maglev
Environment file sourced by the systemd unit before starting
.BR maglevd .
.SH CONFIGURATION
The configuration file uses YAML and has four top\-level sections under the
.B maglev
key:
.BR healthchecker ,
.BR healthchecks ,
.BR backends ,
and
.BR frontends .
.PP
See the example at
.I /etc/maglev/maglev.conf
and the full reference in the project documentation.
.SH SEE ALSO
.BR maglevc (1)
.SH AUTHOR
Pim van Pelt <pim@ipng.ch>