show sess

Display all clients that have ongoing active streams (formerly called sessions) connected to the load balancer.

Description Jump to heading #

Display all clients that have ongoing active streams connected to the load balancer. This information is useful for the HAProxy Technologies development and support teams. The output may change from version to version.

When a client connects to the load balancer, the load balancer maintains the stream with the client until their connection with the backend server has finished. To use the show sess command, the level parameter on the stats socket line must be operator or admin. It displays all active streams that are currently connected to the load balancer.

Examples Jump to heading #

All streams Jump to heading #

Dumping multiple streams can produce an excessive amount of output and consume an excessive amount of time and CPU resources. It is recommended that you dump the minimum required stream information.

In the example below, there are two active streams. The first is a TCP connection and the second is a UNIX socket stream (the Runtime API connection itself):

nix
# Show all by default:
echo "show sess" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999
# Show all by specifying all parameter (version 2.9r1 only):
echo "show sess all" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

nix
# Show all by default:
echo "show sess" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999
# Show all by specifying all parameter (version 2.9r1 only):
echo "show sess all" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

output
text
0x7fa44c02a470: proto=tcpv4 src=192.168.50.1:62423 fe=fe_main be=websocket srv=server1 ts=00 age=16s calls=5 rate=0 cpu=0 lat=0 rq[f=8848000h,i=0,an=00h,rx=59m55s,wx=,ax=] rp[f=88048202h,i=0,an=00h,rx=59m55s,wx=,ax=] s0=[8,200008h,fd=19,ex=] s1=[8,200118h,fd=20,ex=] exp=59m50s
0x55e4db986ba0: proto=unix_stream src=unix:1 fe=GLOBAL be=<NONE> srv=<none> ts=00 age=0s calls=2 rate=2 cpu=0 lat=0 rq[f=c4c220h,i=0,an=00h,rx=,wx=,ax=] rp[f=80008002h,i=0,an=00h,rx=,wx=,ax=] s0=[8,280008h,fd=23,ex=] s1=[8,204018h,fd=-1,ex=] exp=10m

output
text
0x7fa44c02a470: proto=tcpv4 src=192.168.50.1:62423 fe=fe_main be=websocket srv=server1 ts=00 age=16s calls=5 rate=0 cpu=0 lat=0 rq[f=8848000h,i=0,an=00h,rx=59m55s,wx=,ax=] rp[f=88048202h,i=0,an=00h,rx=59m55s,wx=,ax=] s0=[8,200008h,fd=19,ex=] s1=[8,200118h,fd=20,ex=] exp=59m50s
0x55e4db986ba0: proto=unix_stream src=unix:1 fe=GLOBAL be=<NONE> srv=<none> ts=00 age=0s calls=2 rate=2 cpu=0 lat=0 rq[f=c4c220h,i=0,an=00h,rx=,wx=,ax=] rp[f=80008002h,i=0,an=00h,rx=,wx=,ax=] s0=[8,280008h,fd=23,ex=] s1=[8,204018h,fd=-1,ex=] exp=10m

Single stream Jump to heading #

Display details for a single stream by specifying the stream identifier:

nix
# show sess <ID>
echo "show sess 0x7f42a0048050" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

nix
# show sess <ID>
echo "show sess 0x7f42a0048050" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

output
text
0x7f42a0048050: [14/Jun/2023:17:15:04.943049] id=4478 proto=unix_stream source=unix:1 flags=0x8, conn_retries=0, conn_exp=<NEVER> conn_et=0x000 srv_conn=(nil), pend_pos=(nil) waiting=0 epoch=0x21 frontend=GLOBAL (id=0 mode=tcp), listener=? (id=1) addr=unix:1

output
text
0x7f42a0048050: [14/Jun/2023:17:15:04.943049] id=4478 proto=unix_stream source=unix:1 flags=0x8, conn_retries=0, conn_exp=<NEVER> conn_et=0x000 srv_conn=(nil), pend_pos=(nil) waiting=0 epoch=0x21 frontend=GLOBAL (id=0 mode=tcp), listener=? (id=1) addr=unix:1

Streams by age Jump to heading #

Display only streams older than <age> (in seconds by default):

nix
# show sess older <age>
echo "show sess older 2" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

nix
# show sess older <age>
echo "show sess older 2" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

output
text
0x7f42a0048050: [14/Jun/2023:17:15:04.943049] id=4478 proto=unix_stream source=unix:1 flags=0x8, conn_retries=0, conn_exp=<NEVER> conn_et=0x000 srv_conn=(nil), pend_pos=(nil) waiting=0 epoch=0x21 frontend=GLOBAL (id=0 mode=tcp), listener=? (id=1) addr=unix:1

output
text
0x7f42a0048050: [14/Jun/2023:17:15:04.943049] id=4478 proto=unix_stream source=unix:1 flags=0x8, conn_retries=0, conn_exp=<NEVER> conn_et=0x000 srv_conn=(nil), pend_pos=(nil) waiting=0 epoch=0x21 frontend=GLOBAL (id=0 mode=tcp), listener=? (id=1) addr=unix:1

Suspicious streams Jump to heading #

Specify the susp parameter to report streams that are considered suspicious by developers. The criteria for this consideration may change from version to version.

nix
echo "show sess susp" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

nix
echo "show sess susp" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

output
text
0x7f42a0048050: [14/Jun/2023:17:15:04.943049] id=4478 proto=unix_stream source=unix:1 flags=0x8, conn_retries=0, conn_exp=<NEVER> conn_et=0x000 srv_conn=(nil), pend_pos=(nil) waiting=0 epoch=0x21 frontend=GLOBAL (id=0 mode=tcp), listener=? (id=1) addr=unix:1

output
text
0x7f42a0048050: [14/Jun/2023:17:15:04.943049] id=4478 proto=unix_stream source=unix:1 flags=0x8, conn_retries=0, conn_exp=<NEVER> conn_et=0x000 srv_conn=(nil), pend_pos=(nil) waiting=0 epoch=0x21 frontend=GLOBAL (id=0 mode=tcp), listener=? (id=1) addr=unix:1

Show the URI Jump to heading #

Add the show-uri argument to include the URI requested in an active stream. In the example below, the output includes uri="GET /example/ HTTP/1.1".

nix
echo "show sess show-uri" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

nix
echo "show sess show-uri" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

output
text
0x7fd3240553b0: proto=tcpv4 src=172.16.0.1:58606 fe=mysite be=webservers srv=<none> ts=00 epoch=0x41 age=0s calls=1 rate=0 cpu=0 lat=0 rq[f=1800000h,i=16294,an=8000h,ax=] rp[f=80000000h,i=0,an=00h,ax=] scf=[8,482h,fd=215,rex=,wex=] scb=[2,1811h,fd=-1,rex=,wex=] exp=9m59s rc=0 c_exp=9m59s uri="GET /example/ HTTP/1.1"

output
text
0x7fd3240553b0: proto=tcpv4 src=172.16.0.1:58606 fe=mysite be=webservers srv=<none> ts=00 epoch=0x41 age=0s calls=1 rate=0 cpu=0 lat=0 rq[f=1800000h,i=16294,an=8000h,ax=] rp[f=80000000h,i=0,an=00h,ax=] scf=[8,482h,fd=215,rex=,wex=] scb=[2,1811h,fd=-1,rex=,wex=] exp=9m59s rc=0 c_exp=9m59s uri="GET /example/ HTTP/1.1"

Filter streams Jump to heading #

You can filter the list of streams to list only streams attached to a specific backend, frontend, or combination of backend and server.

In the example below, we filter the streams to show only those attached to the backend be_app and server app1:

nix
echo "show sess server be_app/app1" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

nix
echo "show sess server be_app/app1" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

output
text
0x7aa854058ce0: proto=tcpv4 src=127.0.0.1:33686 fe=fe_main be=be_app srv=app1 ts=00 epoch=0x60 age=1s calls=2 rate=0 cpu=0 lat=0 rq[f=1840000h,i=0,an=8000h,ax=] rp[f=80000000h,i=0,an=1400000h,ax=] scf=[8,482h,fd=14,rex=,wex=] scb=[8,1411h,fd=15,rex=4m58s,wex=] exp=8s rc=0 c_exp=

output
text
0x7aa854058ce0: proto=tcpv4 src=127.0.0.1:33686 fe=fe_main be=be_app srv=app1 ts=00 epoch=0x60 age=1s calls=2 rate=0 cpu=0 lat=0 rq[f=1840000h,i=0,an=8000h,ax=] rp[f=80000000h,i=0,an=1400000h,ax=] scf=[8,482h,fd=14,rex=,wex=] scb=[8,1411h,fd=15,rex=4m58s,wex=] exp=8s rc=0 c_exp=

Display help Jump to heading #

To show the available options for the show sess command, use the option help.

nix
echo "show sess help" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

nix
echo "show sess help" | \
  sudo socat stdio tcp4-connect:127.0.0.1:9999

output
text
Usage: show sess [<id> | all | help] [<options>*]
Dumps active streams (formerly called 'sessions'). Available selectors:
   <id>         dump only this stream identifier (0x...)
   all          dump all matching streams in large format
   help         show this message
   susp         report streams considered suspicious
Available options: 
   show-uri     also display the transaction URI, if available
   older <age>  only display streams older than <age> seconds
   server <b/s> only show streams attached to this backend+server
   backend <b>  only show streams attached to this backend
   frontend <f> only show streams attached to this frontend
Without any argument, all streams are dumped in a shorter format.

output
text
Usage: show sess [<id> | all | help] [<options>*]
Dumps active streams (formerly called 'sessions'). Available selectors:
   <id>         dump only this stream identifier (0x...)
   all          dump all matching streams in large format
   help         show this message
   susp         report streams considered suspicious
Available options: 
   show-uri     also display the transaction URI, if available
   older <age>  only display streams older than <age> seconds
   server <b/s> only show streams attached to this backend+server
   backend <b>  only show streams attached to this backend
   frontend <f> only show streams attached to this frontend
Without any argument, all streams are dumped in a shorter format.

See also Jump to heading #

• shutdown session
• shutdown sessions server