Provided by: ovn-common_23.03.0-1_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. Note that
the chassis name can also be provided via the system-id-override file in the
local OVN "etc" directory or via the -n command-line option. The following
precedence is used: first, the command-line option is read; if not present,
the system-id-override file is read; if not present, then the name
configured in the database is used.
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). When more than one controllers are running on the same
host, external_ids:ovn-bridge-CHASSIS_NAME should be set for each of them,
pointing to a unique bridge. This is required to avoid controllers stepping
on each others’ feet.
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 optimal to set it to true in use cases when the chassis would
anyway need to monitor most of the records in ovs-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 are geneve and stt.
Gateways may use geneve, vxlan, or stt.
Due to the limited amount of metadata in vxlan, the capabilities and
performance of connected gateways 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-encap-df_default
indicates the DF flag handling of the encapulation. Set to true to set the
DF flag for new data paths or false to clear the DF flag.
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.
Most of configuration options listed above can also be set for a particular chassis name
(see external_ids:system-id for more information). This can be achieved by setting
external_ids:option-[chassis] instead of external_ids:option. For example, set
external_ids:ovn-encap-ip-otherhv to use a particular IP address for the controller
instance named otherhv. Name specific configuration options always override any global
options set in the database.
Chassis-specific configuration options in the database plus the ability to configure the
chassis name to use via the system-id-override file or command line allows to run multiple
ovn-controller instances with unique chassis names on the same host using the same
vswitchd instance. This may be useful when running a hybrid setup with more than one CMS
managing ports on the host, or to use different datapath types on the same host. Note that
this ability is highly experimental and has known limitations (for example, stateful ACLs
are not supported). Use at your own risk.
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
particular 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/show-stats engine_node_name counter_name
Display the ovn-controller engine counter(s) for the specified
engine_node_name. counter_name is optional and can be one of recompute,
compute or abort.
inc-engine/clear-stats
Reset ovn-controller engine counters.