Unexpected EOF on client connection with an open transaction

Question

I want to using threading to connect postgresql but postgresql log show：

unexpected EOF on client connection with an open transaction

here is my code：

conn = []
for i in range(10):
    conn.append(psycopg2.connect("dbname=test user=higis password=dbrgdbrg host=10.1.1.215 port=5432"))
print conn
def test_query(a,b,c,d,name,i):
    try:
        #conn = psycopg2.connect("dbname=test user=higis password=dbrgdbrg host=10.1.1.215 port=5432")
        cur = conn[i].cursor()
        sql_query = "SELECT count(*) FROM " + str(name) + " WHERE ST_MAKEENVELOPE" + str(
            (a, b, c, d, 4326)) + "&& wkb_geometry"
        start = time.time()
        cur.execute(sql_query)
        #conn.commit()
        end = time.time()
        results_time = end - start
        results = cur.fetchall()
        cur.close()
        conn[i].close()
        #print results
        #print  results[0][0]
        suit_f = open("/home/pj/Desktop/test/log/replicate_query_time.txt", 'a')
        print >> suit_f, (
            'range query table:,%s,(%s %s %s %s),%s,%s' % (name, a, b, c, d, results[0][0], results_time))
    except Exception, e:
        print e

a_all = [1，2，3，4，5，6，7，8，9，10]
b_all = [1，2，3，4，5，6，7，8，9，10]
c_all = [1，2，3，4，5，6，7，8，9，10]
d_all = [1，2，3，4，5，6，7，8，9，10]
threads = []
for i in range(10):
    a = a_all[i]
    b = b_all[i]
    c = c_all[i]
    d = d_all[i]
    t = threading.Thread(target=test_query,args=(a,b,c,d,"replicate_table1",i))
    threads.append(t)

if __name__ == '__main__':
    i = 0
    for t in threads:
        print "Thread:" + str(i) + " t and the time = %s" %(ctime())
        t.setDaemon(True)
        t.start()
        i = i+1
    t.join()
    #conn.commit()

Answer 1

At some point the server received a client connection which presented the appropriate credentials (and thus a session was established).

This log message is informing you that the client disconnected the session "it just walked away!" without shutting down cleanly. Maybe the code is throwing an exception before it gets to the cur.close() statement.