add tcplife (iovisor#773)

README.md

@@ -121,6 +121,7 @@ Examples:
 - tools/[tcpaccept](tools/tcpaccept.py): Trace TCP passive connections (accept()). [Examples](tools/tcpaccept_example.txt).
 - tools/[tcpconnect](tools/tcpconnect.py): Trace TCP active connections (connect()). [Examples](tools/tcpconnect_example.txt).
 - tools/[tcpconnlat](tools/tcpconnlat.py): Trace TCP active connection latency (connect()). [Examples](tools/tcpconnlat_example.txt).
+- tools/[tcplife](tools/tcplife.py): Trace TCP sessions and summarize lifespan. [Examples](tools/tcplife_example.txt).
 - tools/[tcpretrans](tools/tcpretrans.py): Trace TCP retransmits and TLPs. [Examples](tools/tcpretrans_example.txt).
 - tools/[tcptop](tools/tcptop.py): Summarize TCP send/recv throughput by host. Top for TCP. [Examples](tools/tcptop_example.txt).
 - tools/[tplist](tools/tplist.py): Display kernel tracepoints or USDT probes and their formats. [Examples](tools/tplist_example.txt).

man/man8/tcplife.8

@@ -0,0 +1,130 @@
+.TH tcplife 8  "2016-10-19" "USER COMMANDS"
+.SH NAME
+tcplife \- Trace TCP sessions and summarize lifespan. Uses Linux eBPF/bcc.
+.SH SYNOPSIS
+.B tcplife [\-h] [\-T] [\-t] [\-w] [\-s] [\-p PID] [\-D PORTS] [\-L PORTS]
+.SH DESCRIPTION
+This tool traces TCP sessions that open and close while tracing, and prints
+a line of output to summarize each one. This includes the IP addresses, ports,
+duration, and throughput for the session. This is useful for workload
+characterisation and flow accounting: identifying what connections are
+happening, with the bytes transferred.
+
+This tool works by using kernel dynamic tracing, and will need to be updated
+if the kernel implementation changes. Only TCP state changes are traced, so
+it is expected that the overhead of this tool is much lower than typical
+send/receive tracing.
+
+Since this uses BPF, only the root user can use this tool.
+.SH REQUIREMENTS
+CONFIG_BPF and bcc.
+.SH OPTIONS
+.TP
+\-h
+Print usage message.
+.TP
+\-s
+Comma separated values output (parseable).
+.TP
+\-t
+Include a timestamp column (seconds).
+.TP
+\-T
+Include a time column (HH:MM:SS).
+.TP
+\-w
+Wide column output (fits IPv6 addresses).
+.TP
+\-p PID
+Trace this process ID only (filtered in-kernel).
+.TP
+\-L PORTS
+Comma-separated list of local ports to trace (filtered in-kernel).
+.TP
+\-D PORTS
+Comma-separated list of destination ports to trace (filtered in-kernel).
+.SH EXAMPLES
+.TP
+Trace all TCP sessions, and summarize lifespan and throughput:
+#
+.B tcplife
+.TP
+Include a timestamp column, and wide column output:
+#
+.B tcplife \-tw
+.TP
+Trace PID 181 only:
+#
+.B tcplife \-p 181
+.TP
+Trace connections to local ports 80 and 81 only:
+#
+.B tcplife \-L 80,81
+.TP
+Trace connections to remote port 80 only:
+#
+.B tcplife \-D 80
+.SH FIELDS
+.TP
+TIME
+Time of the call, in HH:MM:SS format.
+.TP
+TIME(s)
+Time of the call, in seconds.
+.TP
+PID
+Process ID
+.TP
+COMM
+Process name
+.TP
+IP
+IP address family (4 or 6)
+.TP
+LADDR
+Local IP address.
+.TP
+DADDR
+Remote IP address.
+.TP
+LPORT
+Local port.
+.TP
+DPORT
+Destination port.
+.TP
+TX_KB
+Total transmitted Kbytes.
+.TP
+RX_KB
+Total received Kbytes.
+.TP
+MS
+Lifespan of the session, in milliseconds.
+.SH OVERHEAD
+This traces the kernel TCP set state function, which should be called much
+less often than send/receive tracing, and therefore have lower overhead. The
+overhead of the tool is relative to the rate of new TCP sessions: if this is
+high, over 10,000 per second, then there may be noticable overhead just to
+print out 10k lines of formatted output per second.
+
+You can find out the rate of new TCP sessions using "sar \-n TCP 1", and
+adding the active/s and passive/s columns.
+
+As always, test and understand this tools overhead for your types of
+workloads before production use.
+.SH SOURCE
+This is from bcc.
+.IP
+https://github.com/iovisor/bcc
+.PP
+Also look in the bcc distribution for a companion _examples.txt file containing
+example usage, output, and commentary for this tool.
+.SH OS
+Linux
+.SH STABILITY
+Unstable - in development.
+.SH AUTHOR
+Brendan Gregg
+.SH SEE ALSO
+tcpaccept(8), tcpconnect(8), tcptop(8)