This program summarizes ovs-dpctl flow content by aggregating the
number of packets, total bytes and occurrence of the following
fields:
- Datapath in_port
- Ethernet type
- Source and destination MAC addresses
- IP protocol
- Source and destination IPv4 addresses
- Source and destination IPv6 addresses
- UDP and TCP destination port
- Tunnel source and destination addresses
Output shows four values:
- FIELDS: the flow fields for example in_port(1).
- COUNT: the number of lines in the dump-flow output
contain the flow field.
- PACKETS: the total number of packets containing the flow
field.
- BYTES: the total number of bytes containing the flow
field. If units are not present then values are in bytes.
- AVERAGE: the average packets size (BYTES/PACKET).
Top Behavior
While in top mode, the default behavior, the following single
character commands are supported:
a - toggles top in accumulate and live mode. Accumulate
mode is described below.
s - toggles which column is used to sort content in
decreasing order. A DESC title is placed over the column.
_ - a space indicating to collect dump-flow content again
h - halt output. Any character will restart sampling
f - cycle through flow fields
q - q for quit.
Accumulate Mode
There are two supported modes: live and accumulate. The default
is live. The parameter --accumulate or the 'a' character in top
mode enables the latter. In live mode, recent dump-flow content
is presented. Where as accumulate mode keeps track of the prior
historical information until the flow is reset not when the flow
is purged. Reset flows are determined when the packet count for
a flow has decreased from its previous sample. There is one
caveat, eventually the system will run out of memory if, after
the accumulate-decay period any flows that have not been
refreshed are purged. The goal here is to free memory of flows
that are not active. Statistics are not decremented. Their
purpose is to reflect the overall history of the flow fields.
Debugging Errors
Parsing errors are counted and displayed in the status line at
the beginning of the output. Use the --verbose option with
--script to see what output was not parsed, like this:
$ ovs-dpctl dump-flows | ovs-dpctl-top --script --verbose
Error messages will identify content that failed to parse.
Access Remote Hosts
The --host must follow the format user@hostname. This script
simply calls 'ssh user@Hostname' without checking for login
credentials therefore public keys should be installed on the
system identified by hostname, such as:
$ ssh-copy-id user@hostname
Consult ssh-copy-id man pages for more details.
Expected usage
$ ovs-dpctl-top
or to run as a script:
$ ovs-dpctl dump-flows > dump-flows.log
$ ovs-dpctl-top --script --flow-file dump-flows.log
OPTIONS
-h, --help
show this help message and exit.
-v, --version
show program's version number and exit.
-f FLOWFILES, --flow-file FLOWFILES
file containing flows from ovs-dpctl dump-flow.
-V, --verbose
enable debug level verbosity.
-s, --script
Run from a script (no user interface).
--host HOST
Specify a user@host for retrieving flows see Accessing
Remote Hosts for more information.
-a, --accumulate
Accumulate dump-flow content.
--accumulate-decay ACCUMULATEDECAY
Decay old accumulated flows. The default is 5 minutes. A
value of 0 disables decay.
-d DELAY, --delay DELAY
Delay in milliseconds to collect dump-flow content (sample
rate).
