ID: 31533
User updated by: martin dot pala at oskar dot cz
Reported By: martin dot pala at oskar dot cz
Status: Assigned
Bug Type: OCI8 related
Operating System: Solaris + Linux
PHP Version: 5.0.x
Assigned To: tony2001
New Comment:
... finaly we've found the problem :)
We were using the same tnsname to create two connections (to two
different schemes on the same DB) - the second initialization damaged
the oci session context (the physical connection is only one and is
shared).
Maybe php oci module should not allow to rewrite the existing oci
session context ...
Possible workaround is:
- either use different tnsname (alias) for each connection - it will
create several physical connections (one per tnsname)
- or consolidate the connections (don't use multiple connections to the
same tnsname)
Previous Comments:
------------------------------------------------------------------------
[2005-04-06 10:36:46] martin dot pala at oskar dot cz
We have moved our application to linux (Redhat EL3), it is more stable
then on solaris, however the problem persist.
Current configuration is PHP-5.0.4 + Apache-2.0.46 + OCI instant client
10.1.0.3.
We now see the same crashes in OCI as on solaris. It happens when the
child wants to gracefuly exit in _oci_close_session:
--8<--
(gdb) bt
#0 0x015898f0 in kpufhndl0 () from
/usr/lib/oracle/10.1.0.3/client/lib/libclntsh.so.10.1
#0 0x015898f0 in kpufhndl0 () from
/usr/lib/oracle/10.1.0.3/client/lib/libclntsh.so.10.1
#1 0x015898a8 in kpufhndl () from
/usr/lib/oracle/10.1.0.3/client/lib/libclntsh.so.10.1
#2 0x015fa043 in OCIHandleFree () from
/usr/lib/oracle/10.1.0.3/client/lib/libclntsh.so.10.1
#3 0x0111c83a in _oci_close_session (session=0x1f78510) at
/usr/src/redhat/BUILD/php-5.0.4/ext/oci8/oci8.c:3007
#4 0x011f54ff in list_entry_destructor (ptr=0xb6a0bc24) at
/usr/src/redhat/BUILD/php-5.0.4/Zend/zend_list.c:178
#5 0x011f4248 in zend_hash_apply_deleter (ht=0xb69fe404,
p=0xb69fe434)
at /usr/src/redhat/BUILD/php-5.0.4/Zend/zend_hash.c:574
#6 0x011f42ec in zend_hash_graceful_reverse_destroy (ht=0x1407754) at
/usr/src/redhat/BUILD/php-5.0.4/Zend/zend_hash.c:640
#7 0x011e3fd6 in shutdown_executor () at
/usr/src/redhat/BUILD/php-5.0.4/Zend/zend_execute_API.c:283
#8 0x011edaf4 in zend_deactivate () at
/usr/src/redhat/BUILD/php-5.0.4/Zend/zend.c:817
#9 0x011b8b66 in php_request_shutdown (dummy=0x0) at
/usr/src/redhat/BUILD/php-5.0.4/main/main.c:1216
#10 0x01216fc7 in php_handler (r=0xb72eb030) at
/usr/src/redhat/BUILD/php-5.0.4/sapi/apache2handler/sapi_apache2.c:590
#11 0x080685c5 in ap_run_handler ()
#12 0x08068bdf in ap_invoke_handler ()
#13 0x08065266 in ap_process_request ()
#14 0x080608bc in _start ()
#15 0xb72eb030 in ?? ()
#16 0x00000004 in ?? ()
#17 0xb72eb030 in ?? ()
#18 0x080722dc in ap_run_pre_connection ()
#19 0x08072195 in ap_run_process_connection ()
#20 0x08066ae1 in ap_graceful_stop_signalled ()
#21 0x08066c34 in ap_graceful_stop_signalled ()
#22 0x08066ed9 in ap_graceful_stop_signalled ()
#23 0x08067570 in ap_mpm_run ()
#24 0x0806da4f in main ()
--8<--
It seems that the session context was damaged:
--8<--
(gdb) frame 3
#3 0x0111c83a in _oci_close_session (session=0x1f78510) at
/usr/src/redhat/BUILD/php-5.0.4/ext/oci8/oci8.c:3007
3007 );
(gdb) print session
$14 = (oci_session *) 0x1f78510
(gdb) print *session
$15 = {num = 11990016, persistent = 0 '\0', is_open = 0 '\0', exclusive
= 0 '\0', thread = 0 '\0', sessions_list = 0x0,
server = 0x1a6eac6, pSession = 0x1882cae, pEnv = 0x1d40c08, charsetId
= 51142}
(gdb) print *session->server
$16 = {num = -2081649835, persistent = 2106149100, is_open =
-864712248,
dbname = 0x8b08458b <Address 0x8b08458b out of bounds>, pServer =
0x4d8b0c55}
--8<--
=> it seems that the problem affects all systems, the session context
gets somehow corrupted.
Martin
------------------------------------------------------------------------
[2005-01-26 16:09:19] martin dot pala at oskar dot cz
We did extensive testing - here is result and possible workarounds:
I. the crash in _oci_close_session is solaris-related only and it
happens only if persistent connections are used.
---
We did following tests:
1.) solaris9 + apache-1.3.31 + php5-STABLE snapshot (5.0.4-devel) + OCI
8.1.7
[result: CRASH]
2.) solaris9 + apache-1.3.31 + php5-STABLE snapshot (5.0.4-devel) + OCI
9.2.0.1
[result: CRASH]
3.) solaris9 + apache-1.3.31 + php5-STABLE snapshot (5.0.4-devel) + OCI
10.1.0.3
[result: CRASH]
4.) solaris9 + apache-2.0.52 + php-5.0.[23] + OCI 9.2.0.1
[result: CRASH]
5.) linux (redhat 7.3) + apache-1.3.27 + php5-STABLE snapshot
(5.0.4-devel) + OCI 10.1.0.3
[result: STABLE]
There is also PHP Bug #24531 reported which describes the same error on
Solaris8 and PHP-4.x.
The core backtrace shows the crash in _oci_close_session ->
OCIHandleAlloc() -> kpughndl0() or kpusattr() functions (both
libclntsh.so library):
core '/usr/apache/core' of 13559: /usr/apache/bin/httpd
fc99b9a8 kpughndl0 (3, 0, 3, 0, f8e9d800, 2) + 78
fd8c035c _oci_close_session (ac7520, 15, ffbff094, fdcc2240, fdcc222c,
ac7520) + 6c
fd9d7900 list_entry_destructor (6b2ac8, 75c00, 10, 512310, 0, 252a0) +
74
fd9d657c zend_hash_apply_deleter (fdcc65d0, 43d5c0, 10, 5ad1cba6,
5122e0, 3181d0) + 194
fd9d6604 zend_hash_graceful_reverse_destroy (fdcc65d0, fd9c0540, 0, 0,
0, 0) + 14
fd9c14ec shutdown_executor (0, fd9ce650, 0, 0, 0, 0) + 2b8
fd9ce6a0 zend_deactivate (fdcc6c34, fd990e30, 0, ffbff5f8, 0, 0) + bc
fd990ed4 php_request_shutdown (0, fda0e308, 0, ffbff5f8, 0, 0) + 258
fda0e39c apache_php_module_main (ffffffff, 0, 0, ffbff6d8, 0, 0) +
158
fda0ee7c send_php (ffffffff, 0, 0, 0, 0, 0) + 334
fda0f0f8 send_parsed_php (3384d8, fdbb1aa7, ffffffff, 0, 70, 70) + 18
0001c090 ap_invoke_handler (3384d8, 25, 1, 6fc00, 33b2c8, 5) + f8
0002fd6c ???????? (3384d8, fe2f0b88, 1, ffbff964, 4, 1)
0002fdbc ap_process_request (3384d8, 4, 3384d8, ffbff9e4, ffbff9d4,
12) + 28
00027be8 ???????? (77c00, 77c00, 77c00, 10, 6fc00, 26000)
00027df8 ???????? (7aa28, 12, 41ee7f47, 12, 51, 76d68)
000286a8 ???????? (77c00, 77c00, 77c00, 8, 0, 6fc00)
00028dd8 main (1, ffbffbdc, ffbffbe4, 6fc00, 0, 0) + 34c
00017a70 _start (0, 0, 0, 0, 0, 0) + 108
core '/usr/apache/core' of 12472: /usr/apache/bin/httpd
fc978480 kpusattr (0, 3, 74de78, 0, 6, 168f6c) + 9c
fd8c039c _oci_close_session (702268, 15, ffbfefac, fdcc2240, fdcc222c,
702268) + ac
fd9d7900 list_entry_destructor (6d61c8, 75c00, 10, 266d10, 0, 252a0) +
74
fd9d657c zend_hash_apply_deleter (fdcc65d0, 6d5e80, 10, 5ad1cba6,
266ce0, 239ed0) + 194
fd9d6604 zend_hash_graceful_reverse_destroy (fdcc65d0, fd9c0540, 0, 0,
0, 0) + 14
fd9c14ec shutdown_executor (0, fd9ce650, 0, 0, 0, 0) + 2b8
fd9ce6a0 zend_deactivate (fdcc6c34, fd990e30, 0, ffbff510, 0, 0) + bc
fd990ed4 php_request_shutdown (0, fda0e308, 0, ffbff510, 0, 0) + 258
fda0e39c apache_php_module_main (ffffffff, 0, 0, ffbff5f0, 0, 0) +
158
fda0ee7c send_php (ffffffff, 0, 0, 0, 0, 0) + 334
fda0f0f8 send_parsed_php (259bc8, fdbb1aa7, ffffffff, 0, 70, 70) + 18
0001c090 ap_invoke_handler (259bc8, 25, 1, 6fc00, 25c9e8, 6) + f8
0002fd6c ???????? (259bc8, fe2f03d8, 1, ffbff87c, 4, 1)
0002fdbc ap_process_request (259bc8, 4, 259bc8, ffbff8fc, ffbff8ec, 6)
+ 28
00027be8 ???????? (77c00, 77c00, 77c00, 10, 6fc00, 26000)
00027df8 ???????? (7aa28, 6, 41ee7c91, 0, ffbffa60, 1)
00028148 ???????? (7, 7, 75fc0, 6fc00, 75c00, 6fc00)
00028728 ???????? (77c00, 77c00, 77c00, 8, 0, 6fc00)
00028dd8 main (1, ffbffbdc, ffbffbe4, 6fc00, 0, 0) + 34c
00017a70 _start (0, 0, 0, 0, 0, 0) + 108
II. possible workarounds:
---
1.) to decrease the crash count it helped to initalize the OCI using
OCI_THREADED flag (which is not used in PHP by default).
When was apache running as single process (using -X) it was stable in
one PHP script which can
we used to 100% replicate the crash. When was apache running normaly
with preforked child worker processes (not threads), it crashed.
With bellow patch (OCI_THREADED flag) it worked without problems this
script. However, we found later another script which caused
crash in _oci_close_session again => this patch doesn't solve the
problem (though the crash ratio descreased significantly).
--8<--
diff -Naur php-5.0.3/ext/oci8/oci8.c php-5.0.3-mp/ext/oci8/oci8.c
--- php-5.0.3/ext/oci8/oci8.c 2004-11-22 22:46:49.000000000 +0100
+++ php-5.0.3-mp/ext/oci8/oci8.c 2005-01-11 14:20:56.802128000
+0100
@@ -622,11 +622,7 @@
#endif
-#ifdef ZTS
#define PHP_OCI_INIT_MODE PHP_OCI_INIT_MODE_TMP | OCI_THREADED
-#else
-#define PHP_OCI_INIT_MODE PHP_OCI_INIT_MODE_TMP
-#endif
mutex_alloc(mx_lock);
--8<--
2.) It works better with lot of preforked childs with unlimited life.
We compared following apache test configurations:
MinSpareServers 25
MaxSpareServers 50
StartServers 75
MaxClients 150
MaxRequestsPerChild 0
and
MinSpareServers 5
MaxSpareServers 10
StartServers 5
MaxClients 150
MaxRequestsPerChild 5
Using the same requests count, the first configuration achieved ca. 10x
less crashes then the second one (where childs are restarted very
often).
3.) Final and "best" workaround: don't use persistent connections at
all
When we switched the scripts to not use persistent connections, PHP was
stable (this solution was confirmed in PHP Bug #24531 too).
III. Summary:
---
The PHP module OCI persistent connections on solaris are very
unstable.
It is question where the problem is (solaris libraries? / solaris
version of OCI library? / PHP?) ... it works on linux like a charm.
------------------------------------------------------------------------
[2005-01-18 11:32:28] [EMAIL PROTECTED]
Ok, marking the report as waiting for feedback then.
------------------------------------------------------------------------
[2005-01-18 10:19:59] martin dot pala at oskar dot cz
I'm little bit busy, i'll try to trace the root cause later this week.
As i wrote in the report, in the case that apache is running as single
process (using -X option) it works well, if it runs in preforked childs
mode, PHP fails until OCI_THREADED flag is set ...
------------------------------------------------------------------------
[2005-01-14 21:27:34] [EMAIL PROTECTED]
Before making any changes I'd like to know why there are necessary.
As far as I know, OCI_THREADED is necessary only if you're using OCI in
threaded environment and is not necessary when you're using
Apache1/Apache2-prefork.
Could you plz give me more info about why Solaris requires this flag?
I'm sure it's Solaris-specific problem, as I do use OCI8 at Linux
without any problems for a long time.
------------------------------------------------------------------------
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the rest of the comments, please view the bug report online at
http://bugs.php.net/31533
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