[Q][LONG] using IPC::Shareable to cache data, Apache doesnt start
Hello everyone,
I am trying to use a IPC::Shareable tied hash to cache some data at the
start of apache from my startup.pl script.
this is my startup.pl
-
$ENV{GATEWAY_INTERFACE} =~ /^CGI-Perl/ or
die GATEWAY_INTERFACE not Perl!;
use Apache::Registry;
use Apache::DBI;
use IPC::Shareable;
use GXV::Abonados;
use strict;
my %GLOBALDATA;
my %options = (
create= 1,
exclusive = 0,
mode = 0666,
destroy = 1,
);
tie %GLOBALDATA, 'IPC::Shareable', 'GLUE', { %options } ||
die tie failed\n;
my $gxv = GXV::Abonados-new ||
die not able to connect to GXV\n;
eval {
%GLOBALDATA = $gxv-paquetes_shared;
};
die Global data is not accessible: $ if ($);
1;
--
The method GXV::Abonados::paquetes_shared() works, I have tried many
forms of recieving (and returning of course) the data (a flat scalar,
arrays, hashes).
If I asign to *GLOBALDATA a short string or number it works, I checked
IPC::Shareable::SHM_BUFSIZ(); and it's more than enough to hold the
return value of $gxv-paquetes_shared;
The worst of all is that Apache simply doesnt start, and I get no error
message at all.
Can someone please give me some insight?
TIA,
Best Regards,
Juan Jose Natera
Re: [Q][LONG] using IPC::Shareable to cache data, Apache doesnt start
Juan Natera wrote: The worst of all is that Apache simply doesnt start, and I get no error message at all. The error might be on the console, or you could try capturing it and writing it to a file. However, I suggest you ditch IPC::Shareable since it's dog slow. Use MLDBM::Sync, Cache::FileCache, IPC::MM, or Cache::Mmap. - Perrin
IPC::Shareable
Pardon the off topic thread,
I am trying to make IPC::Shareable work with my script, however I get
this error:
IPC::Shareable::SharedMem: shmget: Permission denied
at /usr/local/lib/perl5/site_perl/5.005/IPC/Shareable.pm line 456
[Tue Oct 16 14:44:15 2001] [error] Could not create shared memory
segment: Permission denied
Does any one know what's up?
Here is how I am using it to set:
unless (defined(%WEBACCESS) tied(%WEBACCESS))
{
die Could not bind shared memory: $! unless
tie %WEBACCESS, 'IPC::Shareable', 'randh_webaccess', {create =1, mode
= 0666}; }
tied(%WEBACCESS)-shlock;
my $user= $WEBACCESS{$code};
unless ($user)
{
$WEBACCESS{$code} = {access_level = $status, access =
$entities, time =$time};
}
tied(%WEBACCESS)-shunlock;
And to read it:
tie %WEBACCESS, 'IPC::Shareable', 'randh_webaccess' unless
(defined(%WEBACCESS) tied(%WEBACCESS));
tied(%WEBACCESS)-shlock;
my $info= $WEBACCESS{$user};
tied(%WEBACCESS)-shunlock;
Any help will be greatly appreciated.
Thanks
-r
[OT] Re: IPC::Shareable
Hi, The shared memory segment was already created by another user, and it was created without permissions for you to write to it. Try the ipcs command to view existing shared memory segments. Try the ipcrm command to remove an old one. Stephen At 03:02 PM 10/16/2001 -0700, Rasoul Hajikhani wrote: Pardon the off topic thread, I am trying to make IPC::Shareable work with my script, however I get this error: IPC::Shareable::SharedMem: shmget: Permission denied at /usr/local/lib/perl5/site_perl/5.005/IPC/Shareable.pm line 456 [Tue Oct 16 14:44:15 2001] [error] Could not create shared memory segment: Permission denied Does any one know what's up?
Re: IPC::Shareable
Make sure that you're not creating a too big shared memory segment and that you're (apache) running with an uid that is allowed to create shared memory segments. From the apache configuration file: # . On HPUX you may not be able to use shared memory as nobody, and the #suggested workaround is to create a user www and use that user. # NOTE that some kernels refuse to setgid(Group) or semctl(IPC_SET) # when the value of (unsigned)Group is above 6; hugs Luciano Rocha -- Luciano Rocha, [EMAIL PROTECTED] The trouble with computers is that they do what you tell them, not what you want. -- D. Cohen
Re: IPC::Shareable
I am trying to make IPC::Shareable work with my script, however I get this error: IPC::Shareable::SharedMem: shmget: Permission denied at /usr/local/lib/perl5/site_perl/5.005/IPC/Shareable.pm line 456 [Tue Oct 16 14:44:15 2001] [error] Could not create shared memory segment: Permission denied Does any one know what's up? In the time it takes you to debug it, you could switch your code to MLDBM::Sync and forget about all these annoying shared memory issues. It would probably be faster too. - Perrin
Re: IPC::Shareable
Perrin Harkins wrote: I am trying to make IPC::Shareable work with my script, however I get this error: IPC::Shareable::SharedMem: shmget: Permission denied at /usr/local/lib/perl5/site_perl/5.005/IPC/Shareable.pm line 456 [Tue Oct 16 14:44:15 2001] [error] Could not create shared memory segment: Permission denied Does any one know what's up? In the time it takes you to debug it, you could switch your code to MLDBM::Sync and forget about all these annoying shared memory issues. It would probably be faster too. - Perrin Cool, it is really fast... and very easy to implement... Curious though, is there a delete method/operation any where? Could not find anything in the perldoc docs indicating a method like that! Any ideas?? Thanks in advance. -r
Re: IPC::Shareable
is there a delete method/operation any where? Could not find anything in the perldoc docs indicating a method like that! It supports the same interface as normal hashes, so you can delete keys in the same way. You may also want to read the MLDBM documentation if you haven't already. - Perrin
Shared cache with IPC::Shareable
Hi all, I'm sharing memory between httpd processes using IPC::Shareable. It is working but seems to behave inconsistently (memory is often not being freed etc..). I'm using it for creating common cached areas for file and database contents shared between httpd children. Is there a better way to do this i.e. Am I stuck with IPC::Shareable? I'm running mod_perl and the whole application is running as a single content handler. It also isn't as fast as I thought it would be - sure it takes a long time to do the initial load of all caches on the first request, but I just thought it would be a little faster than it is. Are there any performance issues I should be aware of with IPC::Shareable or shared mem in general? Thanks! ~mark
Re: Shared cache with IPC::Shareable
You should try Apache::Cache, it's under developpement but seem to be stable. For a real documentation look at the CVS version, the actual release is poorelly documented. http://www.rhapsodyk.net/cgi-bin/cvsweb/Apache-Cache/ -- ___ O l i v i e rP o i t r e y USA disaster support http://www.osdn.com/911.shtml - Original Message - From: Mark Maunder [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Wednesday, September 19, 2001 5:21 PM Subject: Shared cache with IPC::Shareable Hi all, I'm sharing memory between httpd processes using IPC::Shareable. It is working but seems to behave inconsistently (memory is often not being freed etc..). I'm using it for creating common cached areas for file and database contents shared between httpd children. Is there a better way to do this i.e. Am I stuck with IPC::Shareable? I'm running mod_perl and the whole application is running as a single content handler. It also isn't as fast as I thought it would be - sure it takes a long time to do the initial load of all caches on the first request, but I just thought it would be a little faster than it is. Are there any performance issues I should be aware of with IPC::Shareable or shared mem in general? Thanks! ~mark
Re: Shared cache with IPC::Shareable
I'm sharing memory between httpd processes using IPC::Shareable. It is working but seems to behave inconsistently (memory is often not being freed etc..). I'm using it for creating common cached areas for file and database contents shared between httpd children. Is there a better way to do this i.e. Am I stuck with IPC::Shareable? I'm running mod_perl and the whole application is running as a single content handler. It also isn't as fast as I thought it would be - sure it takes a long time to do the initial load of all caches on the first request, but I just thought it would be a little faster than it is. Are there any performance issues I should be aware of with IPC::Shareable or shared mem in general? Yes, shared memory can be pretty slow. You should look at Cache::Cache (specifically the file cache) or MLDBM::Sync. - Perrin
Re: IPC::Shareable, or, it's supposed to SHARE it, not make more!
Rob Bloodgood [EMAIL PROTECTED] writes:
The code in expire_old_accounts is creating a new tied ARRAYREF instead of
replacing the value of the hash key on this line:
$ACCOUNTS{'QUEUE'} = [@accounts]; #also tried \@accounts;
This didn't happen w/ IPC::Shareable 0.52. But 0.6 is apparently very
different, and I can't make the code look like it wants, so the new
reference is a replacement, not an autovivication.
Sorry, but I think you're SOL with IPC::Shareable. Use something else
instead- I like BerkeleyDB for things like this, but you'll have to
serialize/stringify your hash values first.
--
Joe Schaefer
IPC::Shareable, or, it's supposed to SHARE it, not make more!
So, once upon a time, I bought the Eagle and realized I had purchased a
small slice of heaven.
One of the shiny golden nuggets I received from said slice was a shared
memory cache. It was simple, it was elegant, it was perfect. It was also
based on IPC::Shareable. GREAT idea. BAD juju.
The code in expire_old_accounts is creating a new tied ARRAYREF instead of
replacing the value of the hash key on this line:
$ACCOUNTS{'QUEUE'} = [@accounts]; #also tried \@accounts;
This didn't happen w/ IPC::Shareable 0.52. But 0.6 is apparently very
different, and I can't make the code look like it wants, so the new
reference is a replacement, not an autovivication.
HELP!
My code follows:
use vars qw/%ACCOUNTS/;
sub handler {
...
# bind accounts structure to shared memory
bind_accounts() unless defined(%ACCOUNTS) tied(%ACCOUNTS);
my $accountinfo = lookup_account($account)
or $r-log_reason(no such account: $account), return
HTTP_NO_CONTENT;
}
# Bind the account variables to shared memory using IPC::Shareable
sub bind_accounts {
warn bind_accounts: Binding shared memory if $debug;
unless (tied(%ACCOUNTS)) {
tie (%ACCOUNTS,
'IPC::Shareable',
SIGNATURE,
{ create = 1,
destroy = 0,
mode = 0666,
}
) or die Couldn't bind shared memory: $!\n;
}
warn bind_accounts: done if $debug;
}
# bring the current session to the front and
# get rid of any that haven't been used recently
sub expire_old_accounts {
my $id = shift;
warn expire_old_accounts: entered\n if $debug;
tied(%ACCOUNTS)-shlock;
my @accounts = grep($id ne $_, @{$ACCOUNTS{'QUEUE'}});
unshift @accounts, $id;
if (@accounts MAX_ACCOUNTS) {
my $to_delete = pop @accounts;
delete $ACCOUNTS{$to_delete};
}
$ACCOUNTS{'QUEUE'} = [@accounts]; #also tried \@accounts;
tied(%ACCOUNTS)-shunlock;
warn expire_old_accounts: done\n if $debug;
}
sub lookup_account {
my $id = shift;
warn lookup_account: begin if $debug;
expire_old_accounts($id);
warn lookup_account: Accessing \$ACCOUNTS{$id} if $debug;
my $s = $ACCOUNTS{$id};
if ($s and @{$s-{cat}}) {
# SUCCESSFUL CACHE HIT
warn lookup_account: Retrieved accountinfo from Cache (bypassing
SQL) if $debug;
warn Data::Dumper-Dump([$s],[qw/s/]) if $debug;
return $s;
}
## NOT IN CACHE... refreshing.
warn lookup_account: preparing SQL if $debug;
# ... look up some data here. store in $s
warn lookup_account: locking shared mem if $debug;
tied(%ACCOUNTS)-shlock;
warn lookup_account: assigning \$s to shared mem if $debug;
$ACCOUNTS{$id} = $s;
warn Just stored a value, Data::Dumper-Dump([$ACCOUNTS{$id}],[qw/s/])
if $debug;
warn lookup_account: unlocking shared mem if $debug;
tied(%ACCOUNTS)-shunlock;
return $s;
}
TIA!
L8r,
Rob
Re: IPC::Shareable, or, it's supposed to SHARE it, not make more!
One of the shiny golden nuggets I received from said slice was a shared memory cache. It was simple, it was elegant, it was perfect. It was also based on IPC::Shareable. GREAT idea. BAD juju. Just use Cache::Cache. It's faster and easier. - Perrin
Re: IPC::Shareable (was Re: Perl module - LWP)
On Sun, 22 Oct 2000, Steven Cotton wrote:
What version of Perl are you using? I had some problems with make test,
one of the tests doesn't return and I got a few munged shared memory
segment errors, I was attempting to install under Solaris 7 and Perl
5.6.0.
The messages about "munged shared memory" seem to be going if you change
my($tag, $ice) = unpack 'A14 A*' = $stuff;
in the file lib/IPC/Shareable.pm, sub _thaw to the:
my($tag, $ice) = unpack 'A13 A*' = $stuff;
(since the sub _freeze calls
my $stuff = 'IPC::Shareable' . $ice;
- i.e. 13 chars). But there are further problems ("make test" hangs)...
Re: IPC::Shareable (was Re: Perl module - LWP)
my $stuff = 'IPC::Shareable' . $ice; - i.e. 13 chars) Oops, sorry - I can't count on mondays!
Re: IPC::Shareable (was Re: Perl module - LWP)
On Sat, 21 Oct 2000, Alexander Farber (EED) wrote: Is anybody successfully using it under Solaris or OpenBSD? "make test" hangs for me on these platforms and the module author is unreachable :-( What version of Perl are you using? I had some problems with make test, one of the tests doesn't return and I got a few munged shared memory segment errors, I was attempting to install under Solaris 7 and Perl 5.6.0. If not IPC::Shareable, what module do you use for fast communication between Apache-children? I started with IPC::SharedCache since it did most of what I wanted, but took Sam Tregars advice and went with IPC::ShareLite (and serialised all data myself with Storables freeze thaw methods) and it works a dream. One thing I couldn't seem to do was delete() tied IPC::Shareable hash elements without getting the aforementioned "munged shared memory segment" errors, which I can do with IPC::ShareLite. -- steven
IPC::Shareable (was Re: Perl module - LWP)
"David M. Davisson" wrote: Yes, it works fine. No mods. From: "David Jourard" [EMAIL PROTECTED] Has anyone worked with the LWP module under mod_perl and have they found that it works with no modification. I would like to ask the same question about IPC::Shareable. Is anybody successfully using it under Solaris or OpenBSD? "make test" hangs for me on these platforms and the module author is unreachable :-( http://vorpal.mcs.drexel.edu/bsd-ports/helix/shared-memory.html doesn't seem to help on OpenBSD (increasing SHMMAXPGS up to 4096) If not IPC::Shareable, what module do you use for fast communication between Apache-children?
Re: IPC::Shareable (was Re: Perl module - LWP)
"Alexander Farber (EED)" wrote: "David M. Davisson" wrote: Yes, it works fine. No mods. From: "David Jourard" [EMAIL PROTECTED] Has anyone worked with the LWP module under mod_perl and have they found that it works with no modification. I would like to ask the same question about IPC::Shareable. Is anybody successfully using it under Solaris or OpenBSD? "make test" hangs for me on these platforms and the module author is unreachable :-( http://vorpal.mcs.drexel.edu/bsd-ports/helix/shared-memory.html doesn't seem to help on OpenBSD (increasing SHMMAXPGS up to 4096) If not IPC::Shareable, what module do you use for fast communication between Apache-children? IPC::ShareLite is writen in C (and hence faster (arguably)), but it does not serial data structures, so either Freeze / Thaw or DataDumper are you friends here. I've seen IPC::Sharable working ok on Solaris 2.6 but cannot offer any guideance as to why it may not work. Greg
Amount of memory available to IPC::Shareable?
I would like to write a small web chat using IPC::Shareable. How do I find out, how much shared memory is available on some host, esp. under Solaris and OpenBSD? I have looked at "perldoc IPC::Shareable" and the outputs of "dmesg", "ipcs -a" and "ulimit -a" but don't see it yet. Also, does anyone care to share his/her sources for a mod_perl based web-chat (modertion option would be great)? Thank you!
RE: Amount of memory available to IPC::Shareable?
Hi there, this may be of some interest to you: http://perlchat.sourceforge.net/ --Original Message-- From: "Alexander Farber (EED)" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: October 12, 2000 9:21:58 AM GMT Subject: Amount of memory available to IPC::Shareable? I would like to write a small web chat using IPC::Shareable. How do I find out, how much shared memory is available on some host, esp. under Solaris and OpenBSD? I have looked at "perldoc IPC::Shareable" and the outputs of "dmesg", "ipcs -a" and "ulimit -a" but don't see it yet. Also, does anyone care to share his/her sources for a mod_perl based web-chat (modertion option would be great)? Thank you! -- ./ricarDo oliveiRa __ FREE Personalized Email at Mail.com Sign up at http://www.mail.com/?sr=signup
Re: Amount of memory available to IPC::Shareable?
ricarDo oliveiRa [EMAIL PROTECTED] writes: Hi there, this may be of some interest to you: http://perlchat.sourceforge.net/ --Original Message-- From: "Alexander Farber (EED)" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: October 12, 2000 9:21:58 AM GMT Subject: Amount of memory available to IPC::Shareable? I would like to write a small web chat using IPC::Shareable. How do I find out, how much shared memory is available on some host, esp. under Solaris and OpenBSD? I have looked at "perldoc IPC::Shareable" and the outputs of "dmesg", "ipcs -a" and "ulimit -a" but don't see it yet. On Linux, you get the interesting stuff by doing $ ipcs -lm -- -- Eivind Trondsenhttp://www.allycards.com -- UberGeekgsm://+4797044324
IPC::Shareable problems
Hi, I've been having some problems delete()'ing elements from a tied IPC::Shareable hash. The example from the pod works fine (but that's not running under mod_perl) so I'm wondering if there are any lifetime/scope issues with using IPC::Shareable 0.51 under mod_perl 1.24. Has anyone had any "Munged shared memory segment (size exceeded?)" errors when trying to access (I'm using `exists()') a previously deleted hash element? I see no examples in the Eagle of deleting tied and shared hash elements (only under Apache::Registry), and Deja and various newsgroups and web searches haven't turned up anything. I'm running Apache 1.3.12 and Perl 5.6.0. Thanks, -- Steven Cotton [EMAIL PROTECTED]
Re: IPC::Shareable problems
Steven Cotton wrote: Hi, I've been having some problems delete()'ing elements from a tied IPC::Shareable hash. The example from the pod works fine (but that's not running under mod_perl) so I'm wondering if there are any lifetime/scope issues with using IPC::Shareable 0.51 under mod_perl 1.24. Has anyone had any "Munged shared memory segment (size exceeded?)" errors when trying to access (I'm using `exists()') a previously deleted hash element? I see no examples in the Eagle of deleting tied and shared hash elements (only under Apache::Registry), and Deja and various newsgroups and web searches haven't turned up anything. I'm running Apache 1.3.12 and Perl 5.6.0. Thanks, -- Steven Cotton [EMAIL PROTECTED] hi, you should try with IPC::ShareLite which provide the same things but seems better maintained...
Apache::SpeedLimit and problems with IPC::Shareable
I inserted Apache::SpeedLimit into one of our servers the other day. It works as advertised, but I'm now seeing errors in the error_log that are coming from Apache::SpeedLimit/IPC::Shareable. I wonder if anyone else has had this problem. From the error_log: [Wed Nov 10 13:28:55 1999] [notice] Apache/1.3.9 (Unix) mod_perl/1.21 mod_ssl/2.4.2 OpenSSL/0.9.4 configured -- resuming normal operations [Wed Nov 10 13:28:55 1999] [notice] suEXEC mechanism enabled (wrapper: /www/www/apache/bin/suexec) panic: restartop panic: POPSTACK Callback called exit. panic: restartop panic: POPSTACK Callback called exit. panic: restartop panic: POPSTACK Callback called exit. panic: restartop panic: POPSTACK Callback called exit. panic: restartop panic: POPSTACK Callback called exit. [Wed Nov 10 13:29:14 1999] [notice] caught SIGTERM, shutting down My software/hardware setup: IRIX64 akalice 6.5 11051732 IP25 mod_perl-1.21 apache-1.3.9 Apache::SpeedLimit direct from the "Apache Modules" book My apache configuration: Location / PerlAccessHandler Apache::SpeedLimit PerlSetVar SpeedLimit 61 PerlSetVar SpeedSamples20 PerlSetVar SpeedForgive10 /Location Output from ipcs: [akalice:www] /_ ipcs -mbcopt IPC status from /dev/kmem as of Wed Nov 10 13:42:19 1999 T ID KEYMODE OWNERGROUP CREATOR CGROUP NATTCH SEGSZ CPID LPID ATIMEDTIMECTIME Shared Memory: m 0 0x53637444 --rw-r--r-- root root root root 1 200382 382 9:40:42 no-entry 9:40:42 m140 0x53504c4d --rw-r--r-- www-nobo www-nobo www-nobo www-nobo 0 65536 73426277621049 13:29:07 13:29:07 16:13:46 Any help on this would be appreciated. Regards, Christian - Christian Gilmore Senior Technical Staff Member ATT Labs IP Technology, Florham Park [EMAIL PROTECTED] http://www.research.att.com/info/cgilmore
