#33994 [WFx]: DB unavailable after forked child exits
| From: | greatwhitepine at bigfoot dot com | Date: | Fri, 05 Aug 2005 02:27:23 +0000 |
| Subject: | #33994 [WFx]: DB unavailable after forked child exits | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-82995@lists.php.net to get a copy of this message | ||
ID: 33994
User updated by: greatwhitepine at bigfoot dot com
Reported By: greatwhitepine at bigfoot dot com
Status: Wont fix
Bug Type: Ingres II related
Operating System: Tru64 UNIX V5.1B (Rev. 2650)
PHP Version: 5.0.4
New Comment:
The workaround is not required if the parent db connections are
properly closed before spawning children. Sorry about that Sniper.
Previous Comments:
------------------------------------------------------------------------
[2005-08-05 00:15:23] greatwhitepine at bigfoot dot com
Just in case anyone might care I have a workaround... the parent must
not open a db connection until all children have completed. Thus if
the parent needs to use the db before forking child processes it should
fork a db_child process to do so.
This code works as expected...
print 'parent before parent query'."\n\n";
$int_pid = pcntl_fork();
if(!$int_pid) {
ingres_connect($str_database, $str_username, $str_password);
if (ingres_query('select count(*) from auto_ldg_run')) {
print 'db ok for for parent query'."\n\n";
}
exit();
}
pcntl_waitpid($int_pid, $int_returnCode, WUNTRACED);
print 'parent before child process is spawned'."\n\n";
$arr_pids = FALSE;
for ($i=0; $i < 3; $i++) {
$arr_pids[] = pcntl_fork();
if(!$arr_pids[$i]) {
ingres_connect($str_database, $str_username, $str_password);
if (ingres_query('select count(*) from auto_ldg_run')) {
print 'db ok for child '.$i." \n\n";
}
exit();
}
}
for ($i=0; $i < 3; $i++) {
pcntl_waitpid($arr_pids[$i], $int_returnCode, WUNTRACED);
}
print 'parent after children have completed'."\n\n";
ingres_connect($str_database, $str_username, $str_password);
if (ingres_query('select count(*) from auto_ldg_run')) {
print 'db ok for parent after children have completed'."\n\n";
}
Output...
parent before parent query
db ok for for parent query
parent before child process is spawned
db ok for child 0
db ok for child 1
db ok for child 2
parent after children have completed
db ok for parent after children have completed
------------------------------------------------------------------------
[2005-08-04 18:39:52] greatwhitepine at bigfoot dot com
Seperate connections does not work (as per the example)!
------------------------------------------------------------------------
[2005-08-04 08:45:38] sniper@php.net
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to
report
a bug at http://bugs.php.net/how-to-report.php
Use separate connections or something else than ingres (moved to PECL,
report bugs on it to pecl.php.net/bugs..)
------------------------------------------------------------------------
[2005-08-04 08:14:13] greatwhitepine at bigfoot dot com
Sorry, forgot the pcntl_waitpid during my 1st edit (see below).
ingres_connect($str_database, $str_username, $str_password);
if (ingres_query('select count(*) from auto_ldg_run')) {
print 'db ok during fork'."\n\n";
}
$int_pid = pcntl_fork();
if(!$int_pid) {
ingres_connect($str_database, $str_username, $str_password);
if (ingres_query('select count(*) from auto_ldg_run')) {
print 'db ok for child'."\n\n";
}
exit();
}
pcntl_waitpid ($int_pid, $str_status);
ingres_connect($str_database, $str_username, $str_password);
if (!ingres_query('select count(*) from auto_ldg_run')) {
print 'db not ok after fork'."\n\n";
}
exit(1);
------------------------------------------------------------------------
[2005-08-04 08:03:06] greatwhitepine at bigfoot dot com
Description:
------------
As per the manual ingres_connect connections are terminated when the
process exits. When a forked child exits the connection is terminated
permanently until the parent process is restarted.
Reproduce code:
---------------
ingres_connect($str_database, $str_username, $str_password);
if (ingres_query('select count(*) from table')) {
print 'db ok during fork'."\n\n";
}
$int_pid = pcntl_fork();
if(!$int_pid) {
ingres_connect($str_database, $str_username, $str_password);
if (ingres_query('select count(*) from table')) {
print 'db ok for child'."\n\n";
}
exit();
}
ingres_connect($str_database, $str_username, $str_password);
if (!ingres_query('select count(*) from table')) {
print 'db not ok after fork'."\n\n";
}
Expected result:
----------------
db ok during fork
db ok for child
Actual result:
--------------
db ok during fork
db ok for child
Warning: ingres_query(): Ingres II: Server or API error : Read from
peer process failed; it may have exited. in
/home/its/autoldg/lib/php/local/lib_autoldg_daemon.php on line 228
Warning: ingres_query(): Ingres II: SQLSTATE : 08004 in
/home/its/autoldg/lib/php/local/lib_autoldg_daemon.php on line 228
db not ok after fork
Warning: Unknown: Ingres II: Server or API error : API function cannot
be called in the current state. in Unknown on line 0
Warning: Unknown: Ingres II: SQLSTATE : 5000R in Unknown on line 0
Warning: Unknown: Ingres II: Unable to close statement !! in Unknown
on line 0
Warning: Unknown: Ingres II: Unable to rollback transaction !! in
Unknown on line 0
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=33994&edit=1