FreeNAS

It might also that the async loop is throwing some exception here:

github_src/freenas/gui/tools/freenas-snmpd.py: unmodified, readonly:
line 195 of 35

class Loop_Sockserver(threading.Thread):
    def __init__(self):
        super(Loop_Sockserver, self).__init__()
        self.daemon = True
        self.obj = SockSelect()

    def run(self):
        try:
            asyncore.loop()
        except Exception as e:
            syslog(LOG_ALERT, str(e)) <---- another possible leak to syslog 
        finally:

This blows up the logs with this sort of output:

Jun  1 13:43:52 TNC2 snmpd[3217]: params 1017/1024  -n 
#pragma D option quiet
 inline int OPT_time = 0;
 inline int OPT_txg = 0;
 inline int OPT_pool = 0;
 inline int OPT_mega = 0;
 inline int INTERVAL = 1;
 inline int LINES = -1;
 inline int COUNTER = 1;
 inline int FILTER = 0;
 inline string POOL = "";
 dtrace:::BEGIN
 {
    /* starting values */
    MEGA = 1000000;
    counts = COUNTER;
    secs = INTERVAL;
    interval = INTERVAL;
    interval == 0 ? interval++ : 1;
    line = 0;
    last_event[""] = 0;
    nused=0;
    nused_max_per_sec=0;
    nused_per_sec=0;
    size=0;
    size_max_per_sec=0;
    size_per_sec=0;
    syncops=0;
    size_4k=0;
    size_4k_32k=0;
    size_32k=0;
    OPT_txg ? printf("waiting for txg commit...\n") : 1;
 }

 /*
  * collect info when zil_lwb_write_start fires
  */
fbt::zil_lwb_write_start:entry
/OPT_pool == 0 || POOL == args[0]->zl_dmu_pool->dp_spa->spa_name/
{
     nused += args[1]->lwb_nused;
     nused_per_sec += args[1]->lwb_nused;
     size += args[1]->lwb_sz;
     size_per_sec += args[1]->lwb_sz;
     syncops+
 ....
....