1berry/haproxy
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

DOC: management: precise some of the fields of "show servers conn"

Browse Source 
As reported in issue #2970, the output of "show servers conn" is not
clear. It was essentially meant as a debugging tool during some changes
to idle connections management, but if some users want to monitor or
graph them, more info is needed. The doc mentions the currently known
list of fields, and reminds that this output is not meant to be stable
over time, but as long as it does not change, it can provide some useful
metrics to some users.
This commit is contained in:
Willy Tarreau 2025-05-21 10:45:07 +02:00
parent 4b52d5e406
commit 5c628d4e09
1 changed files with 23 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
doc/management.txt
View File

@ -3293,7 +3293,29 @@ show servers conn [<backend>]
The output consists in a header line showing the fields titles, then one
server per line with for each, the backend name and ID, server name and ID,
the address, port and a series or values. The number of fields varies
depending on thread count.
depending on thread count. The exact format of the output may vary slightly
across versions and depending on the number of threads. One needs to pay
attention to the header line to match columns when extracting output values,
and to the number of threads as the last columns are per-thread:
bkname/svname Backend name '/' server name
bkid/svid Backend ID '/' server ID
addr Server's IP address
port Server's port (or zero if none)
- Unused field, serves as a visual delimiter
purge_delay Interval between connection purges, in milliseconds
used_cur Number of connections currently in use
used_max Highest value of used_cur since the process started
need_est Floating estimate of total needed connections
unsafe_nb Number of idle connections considered as "unsafe"
safe_nb Number of idle connections considered as "safe"
idle_lim Configured maximum number of idle connections
idle_cur Total of the per-thread currently idle connections
idle_per_thr[NB] Idle conns per thread for each one of the NB threads
HAProxy will kill a portion of <idle_cur> every <purge_delay> when the total
of <idle_cur> + <used_cur> exceeds the estimate <need_est>. This estimate
varies based on connection activity.
Given the threaded nature of idle connections, it's important to understand
that some values may change once read, and that as such, consistency within a