I'm having a bit of difficulty interperting the act/fe/be/srv
connection numbers in my option tcplog (definitions from manual
appended below.)
Sample entry from my logs:
Jan 20 14:33:49 lbtest1 haproxy[25582]: AAAA:34456
[20/Jan/2010:14:33:47.826] LDAPFarm LDAPFarm/dp2 0/0/1227 202 --
29/29/29/13/0 0/0
haproxy is usually only one process at a time, unless I use the
unrecommended nbproc at more than 1, or I'm in the middle of a -sf/-st
and there's a second process that started running and the first is
still waiting to close out existing connections. actconn mentions
process.
Is actconn across all pools (eg: all listen stanzas)? So it's equal
to the number of connections across LDAP, LDAPS, WWW, services that
I'm serving, as well as incoming requests from clients for all those
services? Shouldn't it be equal to feconn+srvconn? So feconn for
LDAP + srvconn for LDAP + feconn for LDAPS + srvconn for LDAPS....?
Is feconn only for that particular listen? So it's only for just the
LDAP, or only just the LDAPS, etc service I'm serving? If I had 10
requests each of LDAP, LDAPS, and WWW, the actconn would be 60 (30
total incoming requests and 30 total server connections serving those
requests) but feconn would be 10?
Is beconn total across all backends for a particular listen? I'm not
sure, because the docs say "the backend" implying just one specific
backend server (in my example log entry "dp2"). But the docs later
state "includes the total number of concurrent connections active on
servers", implying it's across all the backend servers for a specific
listen statement. beconn includes both the number of active
connections to all (or one) backend server(s) plus all the requests
"backed-up" in haproxy that haven't yet been sent to the backend
servers, right?
srvconn is only the number of actual active connections for a single
specific backend server (again in this case "dp2")?
Thank you,
PH
- "actconn" is the total number of concurrent connections on the process when
the session was logged. It it useful to detect when some per-process system
limits have been reached. For instance, if actconn is close to 512 when
multiple connection errors occur, chances are high that the system limits
the process to use a maximum of 1024 file descriptors and that all of them
are used. See section 3 "Global parameters" to find how to tune the system.
- "feconn" is the total number of concurrent connections on the frontend when
the session was logged. It is useful to estimate the amount of resource
required to sustain high loads, and to detect when the frontend's "maxconn"
has been reached. Most often when this value increases by huge jumps, it is
because there is congestion on the backend servers, but sometimes it can be
caused by a denial of service attack.
- "beconn" is the total number of concurrent connections handled by the
backend when the session was logged. It includes the total number of
concurrent connections active on servers as well as the number of
connections pending in queues. It is useful to estimate the amount of
additional servers needed to support high loads for a given application.
Most often when this value increases by huge jumps, it is because there is
congestion on the backend servers, but sometimes it can be caused by a
denial of service attack.
- "srv_conn" is the total number of concurrent connections still active on
the server when the session was logged. It can never exceed the server's
configured "maxconn" parameter. If this value is very often close or equal
to the server's "maxconn", it means that traffic regulation is involved a
lot, meaning that either the server's maxconn value is too low, or that
there aren't enough servers to process the load with an optimal response
time. When only one of the server's "srv_conn" is high, it usually means
that this server has some trouble causing the connections to take longer to
be processed than on other servers.
