php.net |  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login

go to bug id or search bugs for

Bug #59151 session_redundancy + 2 servers + 1 offline = segfault
Submitted: 2010-04-09 09:51 UTC Modified: 2010-04-10 08:58 UTC
From: abodera at gmail dot com Assigned:
Status: Duplicate Package: memcache (PECL)
PHP Version: 5.3.2 OS: Fedora 10
Private report: No CVE-ID: None
View Developer Edit
Welcome back! If you're the original bug submitter, here's where you can edit the bug or add additional notes.
If you forgot your password, you can retrieve your password here.
Password:
Status:
Package:
Bug Type:
Summary:
From: abodera at gmail dot com
New email:
PHP Version: OS:

 

 [2010-04-09 09:51 UTC] abodera at gmail dot com 
Description:
------------
When using latest SVN of NON_BLOCKING_IO with session_redundancy and one of the servers fails, a segfault occurs.

Note that session_redundancy of 2 makes session handler NOT write to both servers (another bug), even if both are alive. Setting session_redundancy to 3 makes it work as expected -  session handler writes a copy of session data to both servers.

Unfortunatelly, just after one of the servers is not available, a warning + segfault is thrown.

Reproduce code:
---------------
---~----~----~- memcache.ini ---~----~----~-
extension=memcache.so
memcache.session_redundancy=3
session.save_handler="memcache"
session.save_path="tcp://127.0.0.1:11302,tcp://127.0.0.1:11211"

---~----~----~- php code ---~----~----~----~----
php -r 'session_start();'



Expected result:
----------------
Working with one server.

Actual result:
--------------
PHP Warning:  Unknown: Failed to write session data (memcache). Please verify that the current setting of session.save_path is correct (tcp://127.0.0.1:11305,tcp://127.0.0.1:11211) in Unknown on line 0
Segmentation fault

Patches

Pull Requests

History

AllCommentsChangesGit/SVN commitsRelated reports
 [2010-04-09 10:14 UTC] tony at daylessday dot org 
Thank you for this bug report. To properly diagnose the problem, we
need a backtrace to see what is happening behind the scenes. To
find out how to generate a backtrace, please read
http://bugs.php.net/bugs-generating-backtrace.php for *NIX and
http://bugs.php.net/bugs-generating-backtrace-win32.php for Win32

Once you have generated a backtrace, please submit it to this bug
report and change the status back to "Open". Thank you for helping
us make PHP better.
 [2010-04-09 10:18 UTC] pierre dot php at gmail dot com 
Duplicate of #13623
 [2010-04-09 11:08 UTC] abodera at gmail dot com 
Same happens under 5.3.2 - Debugged there:

Starting program: /usr/bin/php -r 'session_start();'
[Thread debugging using libthread_db enabled]

Program received signal SIGSEGV, Segmentation fault.
zend_mm_add_to_free_list (heap=<value optimized out>, mm_block=0xb14e70) at /usr/src/debug/php-5.3.2/Zend/zend_alloc.c:767
767                                             prev->next_free_block = next->prev_free_block = mm_block;
Missing separate debuginfos, use: debuginfo-install cyrus-sasl-lib-2.1.23-8.fc12.x86_64 keyutils-libs-1.2-6.fc12.x86_64 libcurl-7.19.7-7.fc12.x86_64 libidn-1.9-5.x86_64 libselinux-2.0.90-5.fc12.x86_64 libssh2-1.2.4-1.fc12.x86_64 mysql-libs-5.1.44-1.fc12.x86_64 nspr-4.8.4-2.fc12.x86_64 nss-3.12.6-1.2.fc12.x86_64 nss-softokn-3.12.4-15.fc12.x86_64 nss-softokn-freebl-3.12.4-15.fc12.x86_64 nss-util-3.12.6-1.fc12.x86_64 openldap-2.4.19-3.fc12.x86_64 php-pecl-apc-3.1.3p1-1.fc12.x86_64 sqlite-3.6.20-1.fc12.x86_64
(gdb) bt
#0  zend_mm_add_to_free_list (heap=<value optimized out>, mm_block=0xb14e70) at /usr/src/debug/php-5.3.2/Zend/zend_alloc.c:767
#1  0x0000000000584730 in _zend_mm_free_int (heap=0x9232b0, p=0xb14e80) at /usr/src/debug/php-5.3.2/Zend/zend_alloc.c:2032
#2  0x00007ffff014b0ca in mmc_pool_free (pool=0xb148f8) at /root/NON_BLOCKING_IO/memcache_pool.c:925
#3  0x00007ffff0152201 in ps_close_memcache (mod_data=0x91df00) at /root/NON_BLOCKING_IO/memcache_session.c:185
#4  0x00000000004b1065 in php_session_save_current_state () at /usr/src/debug/php-5.3.2/ext/session/session.c:601
#5  php_session_flush () at /usr/src/debug/php-5.3.2/ext/session/session.c:1489
#6  0x00000000004b134b in zm_deactivate_session (type=<value optimized out>, module_number=<value optimized out>) at /usr/src/debug/php-5.3.2/ext/session/session.c:2143
#7  0x00000000005a2ffc in module_registry_cleanup (module=<value optimized out>) at /usr/src/debug/php-5.3.2/Zend/zend_API.c:2150
#8  0x00000000005ad3a4 in zend_hash_reverse_apply (ht=0x922840, apply_func=0x5a2fe0 <module_registry_cleanup>) at /usr/src/debug/php-5.3.2/Zend/zend_hash.c:755
#9  0x00000000005a1a6d in zend_deactivate_modules () at /usr/src/debug/php-5.3.2/Zend/zend.c:866
#10 0x00000000005502ad in php_request_shutdown (dummy=<value optimized out>) at /usr/src/debug/php-5.3.2/main/main.c:1607
#11 0x0000000000629ba4 in main (argc=<value optimized out>, argv=<value optimized out>) at /usr/src/debug/php-5.3.2/sapi/cli/php_cli.c:1373
 [2010-04-09 11:14 UTC] abodera at gmail dot com 
Same happens on pecl ver 3.0.4

http://pecl.php.net/package/memcache/3.0.4
 [2010-04-09 12:13 UTC] pierre dot php at gmail dot com 
Please do not reopen this bug. There is no need to have two reports about the same issue.
 [2010-04-10 08:58 UTC] abodera at gmail dot com 
http://pecl.php.net/bugs/bug.php?id=13623
 
PHP Copyright © 2001-2025 The PHP Group
All rights reserved. 		Last updated: Wed Jan 15 10:01:29 2025 UTC