[collectd] 5.4 tcp write_graphite gets stuck in closed_wait

[ryanL]

heya. i've compiled 5.4 for linux (centos) at commit 0a161fcfd, and
seem to be having a problem that does not exist at 5.1.

my collectd is pretty barebones, just doing snmp polling against
network devices every 60s. when first starting it up, i get an
established TCP connection to my graphite collector and values get
written. then, we get stuck. i can see in tcpdump that collectd is
polling the network and getting values, but can't write to graphite.

i see this:

# while sleep 1; do pgrep collectd | xargs sudo /usr/sbin/lsof -Pnp |
grep TCP; done
collectd 7996 produser   10u  IPv4           36198298      0t0
TCP 10.1.12.2:53798->10.101.3.213:2003 (CLOSE_WAIT)
collectd 7996 produser   10u  IPv4           36198298      0t0
TCP 10.1.12.2:53798->10.101.3.213:2003 (CLOSE_WAIT)
collectd 7996 produser   10u  IPv4           36198298      0t0
TCP 10.1.12.2:53798->10.101.3.213:2003 (CLOSE_WAIT)
collectd 7996 produser   10u  IPv4           36198298      0t0
TCP 10.1.12.2:53798->10.101.3.213:2003 (CLOSE_WAIT)
collectd 7996 produser   10u  IPv4           36198298      0t0
TCP 10.1.12.2:53798->10.101.3.213:2003 (CLOSE_WAIT)

it stays in this state forever until i restart collectd. upon doing so
i'll get one initial blast of collected data, and then we're jammed
again.

my relevant collectd config:

<Plugin write_graphite>
  <Carbon>
    Host "graphite-collector"
    Port "2003"
    Protocol "tcp"
    Prefix "collectd."
    StoreRates false
    AlwaysAppendDS false
    Postfix ""
    EscapeCharacter "_"
  </Carbon>
</Plugin>

on the collectd 5.1 box, it remains like this:

$ while sleep 1; do pgrep collectd | xargs sudo /usr/sbin/lsof -Pnp |
grep TCP; done
collectd 5638 root    9u  IPv4          561435650      0t0       TCP
10.101.3.9:51249->10.101.3.213:2003 (ESTABLISHED)
collectd 5638 root    9u  IPv4          561435650      0t0       TCP
10.101.3.9:51249->10.101.3.213:2003 (ESTABLISHED)
collectd 5638 root    9u  IPv4          561435650      0t0       TCP
10.101.3.9:51249->10.101.3.213:2003 (ESTABLISHED)
collectd 5638 root    9u  IPv4          561435650      0t0       TCP
10.101.3.9:51249->10.101.3.213:2003 (ESTABLISHED)
collectd 5638 root    9u  IPv4          561435650      0t0       TCP
10.101.3.9:51249->10.101.3.213:2003 (ESTABLISHED)
collectd 5638 root    9u  IPv4          561435650      0t0       TCP
10.101.3.9:51249->10.101.3.213:2003 (ESTABLISHED)
collectd 5638 root    9u  IPv4          561435650      0t0       TCP
10.101.3.9:51249->10.101.3.213:2003 (ESTABLISHED)
collectd 5638 root    9u  IPv4          561435650      0t0       TCP
10.101.3.9:51249->10.101.3.213:2003 (ESTABLISHED)

any ideas, or further info i can give you guys?

thanks!

ryan