Edit report at http://bugs.php.net/bug.php?id=52948edit=1
ID: 52948
User updated by:gilles dot rayrat at continuent dot com
Reported by:gilles dot rayrat at continuent dot com
Summary:Improper connection closing logic leads to TIME_WAIT
sockets on server
Status: Open
Type: Bug
Package:MySQLi related
Operating System: Any
PHP Version:5.2.14
Block user comment: N
New Comment:
Re-reading my previous comment, I realized that the 1st paragraph can be
misunderstood. No offense, I just need you to tell me how to provide
more accurate
info
Cheers,
Gilles.
Previous Comments:
[2010-10-01 17:18:55] gilles dot rayrat at continuent dot com
I'm not sure what I'm using, I am not a php user. I run ubuntu 9.10 and
got the
package php5-mysql. If you need further info, please advise on how to
collect
it.
I also encountered the case of double time_wait, I guess that the
behavior is
not fully predictable, and depends on whom between server and client
starts the
connection closing first.
Using, on client, shutdown(sock, SHUT_RD) before sending the quit
command, then
running shutdown(sock, SHUT_WR) will give more predictable (and, at
least to me,
appropriate) results
[2010-10-01 03:10:15] cataphr...@php.net
I can't reproduce this. Are you using mysqlnd?
With the mysql client (package for Ubuntu 10.4), I sometimes get a
simultaneous shutdown (which means TIME_WAIT on both sides):
(look only at the source, 192.168.1.102 is the client and 192.168.1.2 is
the server; the varying destination is because of DNAT)
02:20:31.109223 IP (tos 0x8, ttl 64, id 30843, offset 0, flags [DF],
proto TCP (6), length 57) 192.168.1.102.50375 79.168.249.157.3306: P
451:456(5) ack 5105 win 23584 nop,nop,timestamp 549252121 211008142
02:20:31.109535 IP (tos 0x8, ttl 64, id 30844, offset 0, flags [DF],
proto TCP (6), length 52) 192.168.1.102.50375 79.168.249.157.3306: F,
cksum 0xe3b8 (correct), 456:456(0) ack 5105 win 23584 nop,nop,timestamp
549252121 211008142
02:20:31.109766 IP (tos 0x0, ttl 128, id 7011, offset 0, flags [DF],
proto TCP (6), length 52) 192.168.1.2.3306 192.168.1.1.50375: F, cksum
0xc83d (correct), 5105:5105(0) ack 456 win 64705 nop,nop,timestamp
211008872 549252121
02:20:31.110026 IP (tos 0x0, ttl 128, id 7012, offset 0, flags [DF],
proto TCP (6), length 52) 192.168.1.2.3306 192.168.1.1.50375: ., cksum
0xc83c (correct), ack 457 win 64705 nop,nop,timestamp 211008872
549252121
02:20:31.112839 IP (tos 0x8, ttl 64, id 30845, offset 0, flags [DF],
proto TCP (6), length 52) 192.168.1.102.50375 79.168.249.157.3306: .,
cksum 0xe0dd (correct), ack 5106 win 23584 nop,nop,timestamp 549252121
211008872
Other times I get the same I get with your example script, a client
initiated shutdown, with TIME_WAIT only on the client):
02:24:51.798486 IP (tos 0x0, ttl 64, id 18397, offset 0, flags [DF],
proto TCP (6), length 57) 192.168.1.102.55529 79.168.249.157.3306: P
70:75(5) ack 79 win 5840 nop,nop,timestamp 549278188 211034639
02:24:51.798790 IP (tos 0x0, ttl 64, id 18398, offset 0, flags [DF],
proto TCP (6), length 52) 192.168.1.102.55529 79.168.249.157.3306: F,
cksum 0x3dd4 (correct), 75:75(0) ack 79 win 5840 nop,nop,timestamp
549278188 211034639
02:24:51.800286 IP (tos 0x0, ttl 128, id 8297, offset 0, flags [DF],
proto TCP (6), length 52) 192.168.1.2.3306 192.168.1.1.55529: ., cksum
0xdd38 (correct), ack 76 win 65086 nop,nop,timestamp 211034940
549278188
02:24:51.800583 IP (tos 0x0, ttl 128, id 8298, offset 0, flags [DF],
proto TCP (6), length 52) 192.168.1.2.3306 192.168.1.1.55529: F, cksum
0xdd37 (correct), 79:79(0) ack 76 win 65086 nop,nop,timestamp 211034940
549278188
02:24:51.802275 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto
TCP (6), length 52) 192.168.1.102.55529 79.168.249.157.3306: ., cksum
0x3ca6 (correct), ack 80 win 5840 nop,nop,timestamp 549278188
211034940
Looking at the source code for mysqlnd, it just calls the PHP stream
closing function, which, on Linux, is just a call to close(). I'm by no
means a socket expert, but from what I read, unless someone messed with
the linger options, close() will send the FIN as soon as it's emptied
the send buffer. I don't see how calling shutdown explicitly could
possibly help.
[2010-09-30 09:03:39] gilles dot rayrat at continuent dot com
php:
No. TimeSourceDestination Protocol
Info
1 0.00192.168.50.129192.168.50.128TCP
57338
mysql [SYN] Seq=0 Win=5840 Len=0 MSS=1460 TSV=88257291 TSER=0 WS=5
2 0.000550192.168.50.128192.168.50.129TCP
mysql
57338 [SYN, ACK] Seq=0 Ack=1 Win=5792
