HAProxy reload – old processes never terminated

I have HAProxy setup in TCP mode, with client/server/connect timeout of 120s.

When I reload the configuration too fast, I sometime end up with multiple processes.
By design, this is expected, so all established connections are drained.

My issue is that they not never terminated, even though all connections are closed.

ps aux | haproxy

    haproxy  12483  0.0  0.1 103748  1084 ?        Ss   20:45   0:00 /usr/sbin/haproxy -D -f /etc/haproxy/haproxy.cfg -p /var/run/haproxy.pid -sf 12405
    haproxy  12485  0.0  0.1 103748  1088 ?        Ss   20:45   0:00 /usr/sbin/haproxy -D -f /etc/haproxy/haproxy.cfg -p /var/run/haproxy.pid -sf 12405
    haproxy  12487  0.0  0.1 103748  1084 ?        Ss   20:45   0:00 /usr/sbin/haproxy -D -f /etc/haproxy/haproxy.cfg -p /var/run/haproxy.pid -sf 12405
    haproxy  25115  0.0  0.1 103748  1084 ?        Ss   21:26   0:00 /usr/sbin/haproxy -D -f /etc/haproxy/haproxy.cfg -p /var/run/haproxy.pid -sf 12488

netstat -pant | grep haproxy

tcp        0      0 0.0.0.0:443                 0.0.0.0:*                   LISTEN      25115/haproxy
    tcp        0      0 0.0.0.0:1936                0.0.0.0:*                   LISTEN      25115/haproxy
    tcp        0      0 0.0.0.0:80                  0.0.0.0:*                   LISTEN      25115/haproxy

I waited longer than the timeout of 120s. I don't understand what is holding them.

The following lsof for one of those old process show that there are still some FD for TCP LISTEN

# lsof -p 12483
COMMAND   PID    USER   FD   TYPE  DEVICE SIZE/OFF   NODE NAME
haproxy 12483 haproxy  cwd    DIR   202,1     4096      2 /
haproxy 12483 haproxy  rtd    DIR   202,1     4096      2 /
haproxy 12483 haproxy  txt    REG   202,1  4381869 412355 /usr/local/sbin/haproxy
haproxy 12483 haproxy  mem    REG   202,1    62864 396140 /lib64/libnss_files-2.17.so
haproxy 12483 haproxy  mem    REG   202,1   126288 396526 /usr/lib64/libselinux.so.1
haproxy 12483 haproxy  mem    REG   202,1   141760 396148 /lib64/libpthread-2.17.so
haproxy 12483 haproxy  mem    REG   202,1    89312 396076 /lib64/libgcc_s-4.8.2-20140120.so.1
haproxy 12483 haproxy  mem    REG   202,1    98720 396150 /lib64/libresolv-2.17.so
haproxy 12483 haproxy  mem    REG   202,1    13224 396957 /lib64/libkeyutils.so.1.5
haproxy 12483 haproxy  mem    REG   202,1    43768 396966 /lib64/libkrb5support.so.0.1
haproxy 12483 haproxy  mem    REG   202,1    19512 396128 /lib64/libdl-2.17.so
haproxy 12483 haproxy  mem    REG   202,1   170784 396962 /lib64/libk5crypto.so.3.1
haproxy 12483 haproxy  mem    REG   202,1    12744 396594 /usr/lib64/libcom_err.so.2.1
haproxy 12483 haproxy  mem    REG   202,1   937952 396964 /lib64/libkrb5.so.3.3
haproxy 12483 haproxy  mem    REG   202,1   273672 396958 /lib64/libgssapi_krb5.so.2.2
haproxy 12483 haproxy  mem    REG   202,1   486512 396073 /lib64/libfreebl3.so
haproxy 12483 haproxy  mem    REG   202,1  2000552 396122 /lib64/libc-2.17.so
haproxy 12483 haproxy  mem    REG   202,1  1967496 400756 /lib64/libcrypto.so.1.0.1j
haproxy 12483 haproxy  mem    REG   202,1   445424 400761 /usr/lib64/libssl.so.1.0.1j
haproxy 12483 haproxy  mem    REG   202,1    88568 396529 /lib64/libz.so.1.2.7
haproxy 12483 haproxy  mem    REG   202,1    36856 396126 /lib64/libcrypt-2.17.so
haproxy 12483 haproxy  mem    REG   202,1   152376 396115 /lib64/ld-2.17.so
haproxy 12483 haproxy    0u  0000     0,9        0   5420 anon_inode
haproxy 12483 haproxy    4u  IPv4 1435667      0t0    TCP *:http (LISTEN)
haproxy 12483 haproxy    5u  IPv4 1435668      0t0    TCP *:https (LISTEN)
haproxy 12483 haproxy    6u  IPv4 1435673      0t0    TCP *:jetcmeserver (LISTEN)