Provided by: ovn-host_22.03.3-0ubuntu0.22.04.5_amd64 
NAME
ovn-controller - Open Virtual Network local controller
SYNOPSIS
ovn-controller [options] [ovs-database]
DESCRIPTION
ovn-controller is the local controller daemon for OVN, the Open Virtual Network. It connects up to the
OVN Southbound database (see ovn-sb(5)) over the OVSDB protocol, and down to the Open vSwitch database
(see ovs-vswitchd.conf.db(5)) over the OVSDB protocol and to ovs-vswitchd(8) via OpenFlow. Each
hypervisor and software gateway in an OVN deployment runs its own independent copy of ovn-controller;
thus, ovn-controller’s downward connections are machine-local and do not run over a physical network.
ACL LOGGING
ACL log messages are logged through ovn-controller’s logging mechanism. ACL log entries have the module
acl_log at log level info. Configuring logging is described below in the Logging Options section.
OPTIONS
Daemon Options
--pidfile[=pidfile]
Causes a file (by default, program.pid) to be created indicating the PID of the running process.
If the pidfile argument is not specified, or if it does not begin with /, then it is created in .
If --pidfile is not specified, no pidfile is created.
--overwrite-pidfile
By default, when --pidfile is specified and the specified pidfile already exists and is locked by
a running process, the daemon refuses to start. Specify --overwrite-pidfile to cause it to instead
overwrite the pidfile.
When --pidfile is not specified, this option has no effect.
--detach
Runs this program as a background process. The process forks, and in the child it starts a new
session, closes the standard file descriptors (which has the side effect of disabling logging to
the console), and changes its current directory to the root (unless --no-chdir is specified).
After the child completes its initialization, the parent exits.
--monitor
Creates an additional process to monitor this program. If it dies due to a signal that indicates a
programming error (SIGABRT, SIGALRM, SIGBUS, SIGFPE, SIGILL, SIGPIPE, SIGSEGV, SIGXCPU, or
SIGXFSZ) then the monitor process starts a new copy of it. If the daemon dies or exits for another
reason, the monitor process exits.
This option is normally used with --detach, but it also functions without it.
--no-chdir
By default, when --detach is specified, the daemon changes its current working directory to the
root directory after it detaches. Otherwise, invoking the daemon from a carelessly chosen
directory would prevent the administrator from unmounting the file system that holds that
directory.
Specifying --no-chdir suppresses this behavior, preventing the daemon from changing its current
working directory. This may be useful for collecting core files, since it is common behavior to
write core dumps into the current working directory and the root directory is not a good directory
to use.
This option has no effect when --detach is not specified.
--no-self-confinement
By default this daemon will try to self-confine itself to work with files under well-known
directories determined at build time. It is better to stick with this default behavior and not to
use this flag unless some other Access Control is used to confine daemon. Note that in contrast to
other access control implementations that are typically enforced from kernel-space (e.g. DAC or
MAC), self-confinement is imposed from the user-space daemon itself and hence should not be
considered as a full confinement strategy, but instead should be viewed as an additional layer of
security.
--user=user:group
Causes this program to run as a different user specified in user:group, thus dropping most of the
root privileges. Short forms user and :group are also allowed, with current user or group assumed,
respectively. Only daemons started by the root user accepts this argument.
On Linux, daemons will be granted CAP_IPC_LOCK and CAP_NET_BIND_SERVICES before dropping root
privileges. Daemons that interact with a datapath, such as ovs-vswitchd, will be granted three
additional capabilities, namely CAP_NET_ADMIN, CAP_NET_BROADCAST and CAP_NET_RAW. The capability
change will apply even if the new user is root.
On Windows, this option is not currently supported. For security reasons, specifying this option
will cause the daemon process not to start.
Logging Options
-v[spec]
--verbose=[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 ovs-appctl(8), limits the log
level change to the specified module.
• syslog, console, or file, to limit the log level change to only to the system log, to the
console, or to a file, respectively. (If --detach is specified, the daemon closes its
standard file descriptors, so logging to the console will have no effect.)
On Windows platform, syslog is accepted as a word and is only useful along 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. See ovs-appctl(8) for a definition of each log level.
Case is not significant within spec.
Regardless of the log levels set for file, logging to a file will not take place unless --log-file
is also specified (see below).
For compatibility with older versions of OVS, any is accepted as a word but has no effect.
-v
--verbose
Sets the maximum logging verbosity level, equivalent to --verbose=dbg.
-vPATTERN:destination:pattern
--verbose=PATTERN:destination:pattern
Sets the log pattern for destination to pattern. Refer to ovs-appctl(8) for a description of the
valid syntax for pattern.
-vFACILITY:facility
--verbose=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. If this option is not specified, daemon is used as the default for
the local system syslog and local0 is used while sending a message to the target provided via the
--syslog-target option.
--log-file[=file]
Enables logging to a file. If file is specified, then it is used as the exact name for the log file.
The default log file name used if file is omitted is /var/log/ovn/program.log.
--syslog-target=host:port
Send syslog messages to UDP port on host, in addition to the system syslog. The host must be a
numerical IP address, not a hostname.
--syslog-method=method
Specify method as how syslog messages should be sent to syslog daemon. The following forms are
supported:
• libc, to use the libc syslog() function. Downside of using this options is that libc adds
fixed prefix to every message before it is actually sent to the syslog daemon over /dev/log
UNIX domain socket.
• unix:file, to use a UNIX domain socket directly. It is possible to specify arbitrary message
format with this option. However, rsyslogd 8.9 and older versions use hard coded parser
function anyway that limits UNIX domain socket use. If you want to use arbitrary message
format with older rsyslogd versions, then use UDP socket to localhost IP address instead.
• udp:ip:port, to use a UDP socket. With this method it is possible to use arbitrary message
format also with older rsyslogd. When sending syslog messages over UDP socket extra
precaution needs to be taken into account, for example, syslog daemon needs to be configured
to listen on the specified UDP port, accidental iptables rules could be interfering with
local syslog traffic and there are some security considerations that apply to UDP sockets,
but do not apply to UNIX domain sockets.
• null, to discard all messages logged to syslog.
The default is taken from the OVS_SYSLOG_METHOD environment variable; if it is unset, the default is
libc.
PKI Options
PKI configuration is required in order to use SSL for the connections to the Northbound and Southbound
databases.
-p privkey.pem
--private-key=privkey.pem
Specifies a PEM file containing the private key used as identity for outgoing SSL
connections.
-c cert.pem
--certificate=cert.pem
Specifies a PEM file containing a certificate that certifies the private key specified on -p
or --private-key to be trustworthy. The certificate must be signed by the certificate
authority (CA) that the peer in SSL connections will use to verify it.
-C cacert.pem
--ca-cert=cacert.pem
Specifies a PEM file containing the CA certificate for verifying certificates presented to
this program by SSL peers. (This may be the same certificate that SSL peers use to verify the
certificate specified on -c or --certificate, or it may be a different one, depending on the
PKI design in use.)
-C none
--ca-cert=none
Disables verification of certificates presented by SSL peers. This introduces a security
risk, because it means that certificates cannot be verified to be those of known trusted
hosts.
--bootstrap-ca-cert=cacert.pem
When cacert.pem exists, this option has the same effect as -C or --ca-cert. If it does not
exist, then the executable will attempt to obtain the CA certificate from the SSL peer on
its first SSL connection and save it to the named PEM file. If it is successful, it will
immediately drop the connection and reconnect, and from then on all SSL connections must be
authenticated by a certificate signed by the CA certificate thus obtained.
This option exposes the SSL connection to a man-in-the-middle attack obtaining the initial
CA certificate, but it may be useful for bootstrapping.
This option is only useful if the SSL peer sends its CA certificate as part of the SSL
certificate chain. The SSL protocol does not require the server to send the CA certificate.
This option is mutually exclusive with -C and --ca-cert.
--peer-ca-cert=peer-cacert.pem
Specifies a PEM file that contains one or more additional certificates to send to SSL
peers. peer-cacert.pem should be the CA certificate used to sign the program’s own
certificate, that is, the certificate specified on -c or --certificate. If the program’s
certificate is self-signed, then --certificate and --peer-ca-cert should specify the same
file.
This option is not useful in normal operation, because the SSL peer must already have the
CA certificate for the peer to have any confidence in the program’s identity. However, this
offers a way for a new installation to bootstrap the CA certificate on its first SSL
connection.
Other Options
-h
--help
Prints a brief help message to the console.
-V
--version
Prints version information to the console.
CONFIGURATION
ovn-controller retrieves most of its configuration information from the local Open vSwitch’s ovsdb-server
instance. The default location is db.sock in the local Open vSwitch’s "run" directory. It may be
overridden by specifying the ovs-database argument as an OVSDB active or passive connection method, as
described in ovsdb(7).
ovn-controller assumes it gets configuration information from the following keys in the Open_vSwitch
table of the local OVS instance:
external_ids:system-id
The chassis name to use in the Chassis table. Changing the system-id while ovn-controller
is running is not directly supported. Users have two options: either first gracefully stop
ovn-controller or manually delete the stale Chassis and Chassis_Private records after
changing the system-id.
external_ids:hostname
The hostname to use in the Chassis table.
external_ids:ovn-bridge
The integration bridge to which logical ports are attached. The default is br-int. If this
bridge does not exist when ovn-controller starts, it will be created automatically with the
default configuration suggested in ovn-architecture(7).
external_ids:ovn-bridge-datapath-type
This configuration is optional. If set, then the datapath type of the integration bridge
will be set to the configured value. If this option is not set, then ovn-controller will
not modify the existing datapath-type of the integration bridge.
external_ids:ovn-remote
The OVN database that this system should connect to for its configuration, in one of the
same forms documented above for the ovs-database.
external_ids:ovn-monitor-all
A boolean value that tells if ovn-controller should monitor all records of tables in ovs-
database. If set to false, it will conditionally monitor the records that is needed in the
current chassis.
It is more efficient to set it to true in use cases where the chassis would anyway need to
monitor most of the records in OVN Southbound database, which would save the overhead of
conditions processing, especially for server side. Typically, set it to true for
environments that all workloads need to be reachable from each other.
Default value is false.
external_ids:ovn-remote-probe-interval
The inactivity probe interval of the connection to the OVN database, in milliseconds. If
the value is zero, it disables the connection keepalive feature.
If the value is nonzero, then it will be forced to a value of at least 1000 ms.
external_ids:ovn-openflow-probe-interval
The inactivity probe interval of the OpenFlow connection to the OpenvSwitch integration
bridge, in seconds. If the value is zero, it disables the connection keepalive feature.
If the value is nonzero, then it will be forced to a value of at least 5s.
external_ids:ovn-encap-type
The encapsulation type that a chassis should use to connect to this node. Multiple
encapsulation types may be specified with a comma-separated list. Each listed encapsulation
type will be paired with ovn-encap-ip.
Supported tunnel types for connecting hypervisors and gateways are geneve, vxlan, and stt.
Due to the limited amount of metadata in vxlan, the capabilities and performance of
connected gateways and hypervisors will be reduced versus other tunnel formats.
external_ids:ovn-encap-ip
The IP address that a chassis should use to connect to this node using encapsulation types
specified by external_ids:ovn-encap-type.
external_ids:ovn-bridge-mappings
A list of key-value pairs that map a physical network name to a local ovs bridge that
provides connectivity to that network. An example value mapping two physical network names
to two ovs bridges would be: physnet1:br-eth0,physnet2:br-eth1.
external_ids:ovn-encap-csum
ovn-encap-csum indicates that encapsulation checksums can be transmitted and received with
reasonable performance. It is a hint to senders transmitting data to this chassis that they
should use checksums to protect OVN metadata. Set to true to enable or false to disable.
Depending on the capabilities of the network interface card, enabling encapsulation
checksum may incur performance loss. In such cases, encapsulation checksums can be
disabled.
external_ids:ovn-encap-tos
ovn-encap-tos indicates the value to be applied to OVN tunnel interface’s option:tos as
specified in the Open_vSwitch database Interface table. Please refer to Open VSwitch Manual
for details.
external_ids:ovn-cms-options
A list of options that will be consumed by the CMS Plugin and which specific to this
particular chassis. An example would be: cms_option1,cms_option2:foo.
external_ids:ovn-transport-zones
The transport zone(s) that this chassis belongs to. Transport zones is a way to group
different chassis so that tunnels are only formed between members of the same group(s).
Multiple transport zones may be specified with a comma-separated list. For example:
tz1,tz2,tz3.
If not set, the Chassis will be considered part of a default transport zone.
external_ids:ovn-chassis-mac-mappings
A list of key-value pairs that map a chassis specific mac to a physical network name. An
example value mapping two chassis macs to two physical network names would be:
physnet1:aa:bb:cc:dd:ee:ff,physnet2:a1:b2:c3:d4:e5:f6. These are the macs that ovn-
controller will replace a router port mac with, if packet is going from a distributed
router port on vlan type logical switch.
external_ids:ovn-is-interconn
The boolean flag indicates if the chassis is used as an interconnection gateway.
external_ids:ovn-match-northd-version
The boolean flag indicates if ovn-controller needs to check ovn-northd version. If this
flag is set to true and the ovn-northd’s version (reported in the Southbound database)
doesn’t match with the ovn-controller’s internal version, then it will stop processing the
southbound and local Open vSwitch database changes. The default value is considered false
if this option is not defined.
external_ids:ovn-ofctrl-wait-before-clear
The time, in milliseconds, to wait before clearing flows in OVS after OpenFlow
connection/reconnection during ovn-controller initialization. The purpose of this wait is
to give time for ovn-controller to compute the new flows before clearing existing ones, to
avoid data plane down time during ovn-controller restart/upgrade at large scale
environments where recomputing the flows takes more than a few seconds or even longer. It
is difficult for ovn-controller to determine when the new flows computing is completed,
because of the dynamics in the cloud environments, which is why this configuration is
provided for users to adjust based on the scale of the environment. By default, it is 0,
which means clearing existing flows without waiting. Not setting the value, or setting it
too small, may result in data plane down time during upgrade/restart, while setting it too
big may result in unnecessary extra control plane latency of applying new changes of CMS
during upgrade/restart. In most cases, a slightly bigger value is not harmful, because the
extra control plane latency happens only once during the OpenFlow connection. To get a
reasonable range of the value setting, it is recommended to run the below commands on a
node in the target environment and then set this configuration to twice the value of
Maximum shown in the output of the second command.
• ovn-appctl -t ovn-controller inc-engine/recompute
• ovn-appctl -t ovn-controller stopwatch/show flow-generation
external_ids:ovn-enable-lflow-cache
The boolean flag indicates if ovn-controller should enable/disable the logical flow in-
memory cache it uses when processing Southbound database logical flow changes. By default
caching is enabled.
external_ids:ovn-limit-lflow-cache
When used, this configuration value determines the maximum number of logical flow cache
entries ovn-controller may create when the logical flow cache is enabled. By default the
size of the cache is unlimited.
external_ids:ovn-memlimit-lflow-cache-kb
When used, this configuration value determines the maximum size of the logical flow cache
(in KB) ovn-controller may create when the logical flow cache is enabled. By default the
size of the cache is unlimited.
external_ids:ovn-trim-limit-lflow-cache
When used, this configuration value sets the minimum number of entries in the logical flow
cache starting with which automatic memory trimming is performed. By default this is set to
10000 entries.
external_ids:ovn-trim-wmark-perc-lflow-cache
When used, this configuration value sets the percentage from the high watermark number of
entries in the logical flow cache under which automatic memory trimming is performed. E.g.,
if the trim watermark percentage is set to 50%, automatic memory trimming happens only when
the number of entries in the logical flow cache gets reduced to less than half of the last
measured high watermark. By default this is set to 50.
external_ids:ovn-trim-timeout-ms
When used, this configuration value specifies the time, in milliseconds, since the last
logical flow cache operation after which ovn-controller performs memory trimming regardless
of how many entries there are in the cache. By default this is set to 30000 (30 seconds).
external_ids:ovn-set-local-ip
The boolean flag indicates if ovn-controller when create tunnel ports should set local_ip
parameter. Can be heplful to pin source outer IP for the tunnel when multiple interfaces
are used on the host for overlay traffic.
ovn-controller reads the following values from the Open_vSwitch database of the local OVS instance:
datapath-type from Bridge table
This value is read from local OVS integration bridge row of Bridge table and populated in
other_config:datapath-type of the Chassis table in the OVN_Southbound database.
iface-types from Open_vSwitch table
This value is populated in external_ids:iface-types of the Chassis table in the
OVN_Southbound database.
private_key, certificate, ca_cert, and bootstrap_ca_cert from SSL table
These values provide the SSL configuration used for connecting to the OVN southbound
database server when an SSL connection type is configured via external_ids:ovn-remote. Note
that this SSL configuration can also be provided via command-line options, the
configuration in the database takes precedence if both are present.
OPEN VSWITCH DATABASE USAGE
ovn-controller uses a number of external_ids keys in the Open vSwitch database to keep track of ports and
interfaces. For proper operation, users should not change or clear these keys:
external_ids:ovn-chassis-id in the Port table
The presence of this key identifies a tunnel port within the integration bridge as one
created by ovn-controller to reach a remote chassis. Its value is the chassis ID of the
remote chassis.
external_ids:ct-zone-* in the Bridge table
Logical ports and gateway routers are assigned a connection tracking zone by ovn-controller
for stateful services. To keep state across restarts of ovn-controller, these keys are
stored in the integration bridge’s Bridge table. The name contains a prefix of ct-zone-
followed by the name of the logical port or gateway router’s zone key. The value for this
key identifies the zone used for this port.
external_ids:ovn-localnet-port in the Port table
The presence of this key identifies a patch port as one created by ovn-controller to
connect the integration bridge and another bridge to implement a localnet logical port. Its
value is the name of the logical port with type set to localnet that the port implements.
See external_ids:ovn-bridge-mappings, above, for more information.
Each localnet logical port is implemented as a pair of patch ports, one in the integration
bridge, one in a different bridge, with the same external_ids:ovn-localnet-port value.
external_ids:ovn-l2gateway-port in the Port table
The presence of this key identifies a patch port as one created by ovn-controller to
connect the integration bridge and another bridge to implement a l2gateway logical port.
Its value is the name of the logical port with type set to l2gateway that the port
implements. See external_ids:ovn-bridge-mappings, above, for more information.
Each l2gateway logical port is implemented as a pair of patch ports, one in the integration
bridge, one in a different bridge, with the same external_ids:ovn-l2gateway-port value.
external-ids:ovn-l3gateway-port in the Port table
This key identifies a patch port as one created by ovn-controller to implement a l3gateway
logical port. Its value is the name of the logical port with type set to l3gateway. This
patch port is similar to the OVN logical patch port, except that l3gateway port can only be
bound to a paticular chassis.
external-ids:ovn-logical-patch-port in the Port table
This key identifies a patch port as one created by ovn-controller to implement an OVN
logical patch port within the integration bridge. Its value is the name of the OVN logical
patch port that it implements.
external-ids:ovn-startup-ts in the Bridge table
This key represents the timestamp (in milliseconds) at which ovn-controller process was
started.
external-ids:ovn-nb-cfg in the Bridge table
This key represents the last known OVN_Southbound.SB_Global.nb_cfg value for which all
flows have been successfully installed in OVS.
external-ids:ovn-nb-cfg-ts in the Bridge table
This key represents the timestamp (in milliseconds) of the last known
OVN_Southbound.SB_Global.nb_cfg value for which all flows have been successfully installed
in OVS.
external_ids:ovn-installed and external_ids:ovn-installed-ts in the Interface table
This key is set after all openflow operations corresponding to the OVS interface have been
processed by ovs-vswitchd. At the same time a timestamp, in milliseconds since the epoch,
is stored in external_ids:ovn-installed-ts.
OVN SOUTHBOUND DATABASE USAGE
ovn-controller reads from much of the OVN_Southbound database to guide its operation. ovn-controller also
writes to the following tables:
Chassis
Upon startup, ovn-controller creates a row in this table to represent its own chassis. Upon
graceful termination, e.g. with ovs-appctl -t ovn-controller exit (but not SIGTERM),
ovn-controller removes its row.
Encap Upon startup, ovn-controller creates a row or rows in this table that represent the tunnel
encapsulations by which its chassis can be reached, and points its Chassis row to them.
Upon graceful termination, ovn-controller removes these rows.
Port_Binding
At runtime, ovn-controller sets the chassis columns of ports that are resident on its
chassis to point to its Chassis row, and, conversely, clears the chassis column of ports
that point to its Chassis row but are no longer resident on its chassis. The chassis column
has a weak reference type, so when ovn-controller gracefully exits and removes its Chassis
row, the database server automatically clears any remaining references to that row.
MAC_Binding
At runtime, ovn-controller updates the MAC_Binding table as instructed by put_arp and
put_nd logical actions. These changes persist beyond the lifetime of ovn-controller.
RUNTIME MANAGEMENT COMMANDS
ovs-appctl can send commands to a running ovn-controller process. The currently supported commands are
described below.
exit Causes ovn-controller to gracefully terminate.
ct-zone-list
Lists each local logical port and its connection tracking zone.
meter-table-list
Lists each meter table entry and its local meter id.
group-table-list
Lists each group table entry and its local group id.
inject-pkt microflow
Injects microflow into the connected Open vSwitch instance. microflow must contain an
ingress logical port (inport argument) that is present on the Open vSwitch instance.
The microflow argument describes the packet whose forwarding is to be simulated, in the
syntax of an OVN logical expression, as described in ovn-sb(5), to express constraints. The
parser understands prerequisites; for example, if the expression refers to ip4.src, there
is no need to explicitly state ip4 or eth.type == 0x800.
connection-status
Show OVN SBDB connection status for the chassis.
recompute
Trigger a full compute iteration in ovn-controller based on the contents of the Southbound
database and local OVS database.
This command is intended to use only in the event of a bug in the incremental processing
engine in ovn-controller to avoid inconsistent states. It should therefore be used with
care as full recomputes are cpu intensive.
sb-cluster-state-reset
Reset southbound database cluster status when databases are destroyed and rebuilt.
If all databases in a clustered southbound database are removed from disk, then the stored
index of all databases will be reset to zero. This will cause ovn-controller to be unable
to read or write to the southbound database, because it will always detect the data as
stale. In such a case, run this command so that ovn-controller will reset its local index
so that it can interact with the southbound database again.
debug/delay-nb-cfg-report seconds
This command is used to delay ovn-controller updating the nb_cfg back to OVN_Southbound
database. This is useful when ovn-nbctl --wait=hv is used to measure end-to-end latency in
a large scale environment. See ovn-nbctl(8) for more details.
lflow-cache/flush
Flushes the ovn-controller logical flow cache.
lflow-cache/show-stats
Displays logical flow cache statistics: enabled/disabled, per cache type entry counts.
inc-engine/show-stats
Display ovn-controller engine counters. For each engine node the following counters have
been added:
• recompute
• compute
• abort
inc-engine/clear-stats
Reset ovn-controller engine counters.
OVN 22.03.3 ovn-controller ovn-controller(8)