ovn-appctl(8) — Linux manual page


ovn-appctl(8)                  OVN Manual                  ovn-appctl(8)

NAME         top

       ovn-appctl - utility for configuring running OVN daemons

SYNOPSIS         top

        ovn-appctl [-target=target | -t target] [-T secs |
       -timeout=secs] command [arg...]

       ovn-appctl -help

       ovn-appctl -version

DESCRIPTION         top

       OVN daemons accept certain commands at runtime to control their
       behavior and query their settings. Every daemon accepts a common
       set of commands documented under COMMON COMMANDS below. Some
       daemons support additional commands documented in their own

       The ovn-appctl program provides a simple way to invoke these
       commands. The command to be sent is specified on ovn-appctl’s
       command line as non-option arguments. ovn-appctl sends the
       command and prints the daemon’s response on standard output.

       ovn-ctl is exactly similar to Open vSwitch ovs-appctl utility.


       Every OVN daemon supports a common set of commands, which are
       documented in this section.

   General Commands
       These commands display daemon-specific commands and the running
       version. Note that these commands are different from the -help
       and -version options that return information about the ovn-appctl
       utility itself.

                     Lists the commands supported by the target.

                     Displays the version and compilation date of the

   Logging Commands
       OVN has several log levels. The highest-severity log level is:

              off    No message is ever logged at this level, so setting
                     a logging destination’s log level to off disables
                     logging to that destination.

       The following log levels, in order of descending severity, are

              emer   A major failure forced a process to hard stop.

              err    A high-level operation or a subsystem failed.
                     Attention is warranted.

              warn   A low-level operation failed, but higher-level
                     subsystems may be able to recover.

              info   Information that may be useful in retrospect when
                     investigating a problem.

              dbg    Information useful only to someone with intricate
                     knowledge of the system, or that would commonly
                     cause too-voluminous log output. Log messages at
                     this level are not logged by default.

       Every OVN daemon supports the following commands for examining
       and adjusting log levels.

                     Lists the known logging modules and their current

                     Lists logging pattern used for each destination.

              vlog/set [spec]
                     Sets logging levels. Without any spec, sets the log
                     level for every module and destination to dbg.
                     Otherwise, spec is a list of words separated by
                     spaces or commas or colons, up to one from each
                     category below:

                     •      A valid module name, as displayed by the
                            vlog/list command on ovn-appctl(8), limits
                            the log level change to the specified

                     •      syslog, console, or file, to limit the log
                            level change to only to the system log, to
                            the console, or to a file, respectively.

                            On Windows platform, syslog is accepted as a
                            word and is only useful if the target was
                            started with the --syslog-target option (the
                            word has no effect otherwise).

                     •      off, emer, err, warn, info, or dbg, to
                            control the log level. Messages of the given
                            severity or higher will be logged, and
                            messages of lower severity will be filtered
                            out. off filters out all messages.

                     Case is not significant within spec.

              vlog/set PATTERN:destination: pattern
                     Sets the log pattern for destination to pattern.
                     Each time a message is logged to destination,
                     pattern determines the message’s formatting. Most
                     characters in pattern are copied literally to the
                     log, but special escapes beginning with % are
                     expanded as follows:

                     •      %A : The name of the application logging the
                            message, e.g. ovn-controller.

                     •      %B : The RFC5424 syslog PRI of the message.

                     •      %c : The name of the module (as shown by
                            ovn-appctl -list) logging the message.

                     •      %d : The current date and time in ISO 8601
                            format (YYYY-MM-DD HH:MM:SS).

                     •      %d{format} : The current date and time in
                            the specified format, which takes the same
                            format as the template argument to
                            strftime(3). As an extension, any #
                            characters in format will be replaced by
                            fractional seconds, e.g. use %H:%M:%S.###
                            for the time to the nearest millisecond.
                            Sub-second times are only approximate and
                            currently decimal places after the third
                            will always be reported as zero.

                     •      %D : The current UTC date and time in ISO
                            8601 format (YYYY-MM-DD HH:MM:SS).

                     •      %D{format} : The current UTC date and time
                            in the specified format, which takes the
                            same format as the template argument to
                            strftime(3). Supports the same extension for
                            sub-second resolution as %d{...}.

                     •      %E : The hostname of the node running the

                     •      %m : The message being logged.

                     •      %N : A serial number for this message within
                            this run of the program, as a decimal
                            number. The first message a program logs has
                            serial number 1, the second one has serial
                            number 2, and so on.

                     •      %n : A new-line.

                     •      %p : The level at which the message is
                            logged, e.g. DBG.

                     •      %P : The program’s process ID (pid), as a
                            decimal number.

                     •      %r : The number of milliseconds elapsed from
                            the start of the application to the time the
                            message was logged.

                     •      %t : The subprogram name, that is, an
                            identifying name for the process or thread
                            that emitted the log message, such as
                            monitor for the process used for -monitor or
                            main for the primary process or thread in a

                     •      %T : The subprogram name enclosed in
                            parentheses, e.g. (monitor), or the empty
                            string for the primary process or thread in
                            a program.

                     •      %% : A literal %.

                     A few options may appear between the % and the
                     format specifier character, in this order:

                     •      - : Left justify the escape’s expansion
                            within its field width. Right justification
                            is the default.

                     •      - : Pad the field to the field width with
                            0s. Padding with spaces is the default.

                     width A number specifies the minimum field width.
                     If the escape expands to fewer characters than
                     width then it is padded to fill the field width. (A
                     field wider than width is not truncated to fit.)

                     The default pattern for console and file output is
                     %D{%Y-%m-%dT %H:%M:%SZ}|%05N|%c|%p|%m; for syslog
                     output, %05N|%c|%p|%m.

              vlog/set FACILITY:facility
                     Sets the RFC5424 facility of the log message.
                     facility can be one of kern, user, mail, daemon,
                     auth, syslog, lpr, news, uucp, clock, ftp, ntp,
                     audit, alert, clock2, local0, local1, local2,
                     local3, local4, local5, local6 or local7.

                     Causes the daemon to close its log file, if it is
                     open. (Use vlog/reopen to reopen it later.)

                     Causes the daemon to close its log file, if it is
                     open, and then reopen it. (This is useful after
                     rotating log files, to cause a new log file to be

                     This has no effect if the target application was
                     not invoked with the --log-file option.

OPTIONS         top

            Prints a brief help message to the console.

            Prints version information to the console.

COLOPHON         top

       This page is part of the Open Virtual Network (Daemons for Open
       vSwitch that translate virtual network configurations into
       OpenFlow) project.  Information about the project can be found at
       ⟨https://www.ovn.org/⟩.  If you have a bug report for this manual
       page, send it to bugs@openvswitch.org.  This page was obtained
       from the project's upstream Git repository
       ⟨https://github.com/ovn-org/ovn⟩ on 2024-06-14.  (At that time,
       the date of the most recent commit that was found in the
       repository was 2024-06-12.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

OVN 24.03.90                   ovn-appctl                  ovn-appctl(8)

Pages that refer to this page: ovn-nbctl(8)ovn-sbctl(8)