phplib-users

[Phplib-users] Sessions in text files

[Hristo O. <od...@gm...>]

Hi everybody,
I have trouble with phplib because it is writing its sessions in a
mysql DB. It happens quite often that my active_sessions table is
corrupted or inconsistent in some way. I would like to use PHP's
session mechanism and even prefer its default setting of writing
sessions in txt files somewhere. Did anyone make such a conversion and
if yes could you give me some hints. An example will be greatly
appreciated.

As to the DB corruption, I can only say that my application is heavily
used and my session data is quite big sometimes. The active_session
table is usually 500+MB.
May be the smoothest way would be to wrap PHP's functionality using
PHPLIB's function so that such a conversion is less painful.

Thanks,
Christo

Re: [Phplib-users] Sessions in text files

[Layne W. <la...@dr...>]

> I have trouble with phplib because it is writing its sessions in a
> mysql DB. It happens quite often that my active_sessions table is
> corrupted or inconsistent in some way. I would like to use PHP's
> session mechanism and even prefer its default setting of writing
> sessions in txt files somewhere. Did anyone make such a conversion and
> if yes could you give me some hints. An example will be greatly
> appreciated.

A PHPLib-style wrapper for native PHP4 sessions has been in place for some
time. There are actually two variations: session4.inc and
session4_custom.inc. For documentation on using these classes, check
<http://sanisoft.com/phplib/> (the server seems to be down at the moment).


> As to the DB corruption, I can only say that my application is heavily
> used and my session data is quite big sometimes. The active_session
> table is usually 500+MB.

With a heavily used application, you are most likely going to see a slowdow=
n
in using native PHP4 sessions due to the disk I/O. How often are you seeing
a corrupted active_sessions table? (In the last 6 years, I've only seen a
corrupted active_sessions table once.) You could set a cron job to check th=
e
table and repair it if there are problems, or if you have a short period of
no activity (early Sunday morning almost always works for me) you could dro=
p
and rebuild the table daily or weekly.

--=20

Layne Weathers

Re: [Phplib-users] Sessions in text files

[Nathaniel P. <np...@te...>]

Hristo Odiseev wrote:

>Hi everybody,
>I have trouble with phplib because it is writing its sessions in a
>mysql DB. It happens quite often that my active_sessions table is
>corrupted or inconsistent in some way. I would like to use PHP's
>session mechanism and even prefer its default setting of writing
>sessions in txt files somewhere. Did anyone make such a conversion and
>if yes could you give me some hints. An example will be greatly
>appreciated.
>
>As to the DB corruption, I can only say that my application is heavily
>used and my session data is quite big sometimes. The active_session
>table is usually 500+MB.
>May be the smoothest way would be to wrap PHP's functionality using
>PHPLIB's function so that such a conversion is less painful.
>  
>
This has been part of PHPlib for some time. Make sure you have the 
latest distribution of PHPlib and use prepend.php to include PHPlib 
instead of prepend.php3. The prepend.php file includes classes designed 
to work with PHP4 sessions (namely local4.inc, page4.inc, session4.inc, 
auth4.inc, and user4.inc). Their default configuration uses native PHP 
sessions, though it provides some hooks to make sessions work like 
PHPlib sessions, so you should have few problems porting an application 
over from one to another. Also, if you have customized your local.inc or 
prepend.php3, make sure you port those customizations over to local4.inc 
and prepend.php. Be aware, however, that you will lose any existing 
session data. (User data, if you use it, should be unaffected; it will 
still use the active_sessions table for that.)

I'd point you to the relevant documentation, but the website appears to 
be down at the moment.

-- 
___________________________
Nathaniel Price
http://www.tesserportal.net
Webmaster

Re: [Phplib-users] Sessions in text files

[Hristo O. <od...@gm...>]

Hi guys,
First thanks for the competent replies.

>With a heavily used application, you are most likely going to see a slowdown
>in using native PHP4 sessions due to the disk I/O. How often are you seeing
>a corrupted active_sessions table? (In the last 6 years, I've only seen a
>corrupted active_sessions table once.) You could set a cron job to check the
>table and repair it if there are problems, or if you have a short period of
>no activity (early Sunday morning almost always works for me) you could drop
>and rebuild the table daily or weekly.

If I say that the table is constantly in some inconsistent state, I
will not lie you.
When I run a repair, I stop the webserver and mysql. Then run a
myisamchk -r. The table is ok although a lot of the sessions are lost
due to the repair. After starting the mysql and the apache and waiting
for 5 min., the table is again reported "corrupted but usable". I gave
up using myisamchk -c as it is reported unsafe while running mysql. So
the table seems to get corrupted immediately after starting to write
in it. I guess size dosn't play a role here. My last experience was
that the last time I did a repair I got a 11MB table (before repair -
233MB). As you see that is really a problem. And if I don't do
anything the table grows to 2Gb which is really an overkill for mysql.
But that was just some background info. Why do you think that the I/O
will become a problem? Could you give me some reasoning? I guess that
the size of the sessions will not be so big as it is in the DB. At
current its extreme size is mostly due to the corrupted data.


On Fri, 03 Dec 2004 09:12:41 -0700, Nathaniel Price
<np...@te...> wrote:
> Hristo Odiseev wrote:
> 
> 
> 
> >Hi everybody,
> >I have trouble with phplib because it is writing its sessions in a
> >mysql DB. It happens quite often that my active_sessions table is
> >corrupted or inconsistent in some way. I would like to use PHP's
> >session mechanism and even prefer its default setting of writing
> >sessions in txt files somewhere. Did anyone make such a conversion and
> >if yes could you give me some hints. An example will be greatly
> >appreciated.
> >
> >As to the DB corruption, I can only say that my application is heavily
> >used and my session data is quite big sometimes. The active_session
> >table is usually 500+MB.
> >May be the smoothest way would be to wrap PHP's functionality using
> >PHPLIB's function so that such a conversion is less painful.
> >
> >
> This has been part of PHPlib for some time. Make sure you have the
> latest distribution of PHPlib and use prepend.php to include PHPlib
> instead of prepend.php3. The prepend.php file includes classes designed
> to work with PHP4 sessions (namely local4.inc, page4.inc, session4.inc,
> auth4.inc, and user4.inc). Their default configuration uses native PHP
> sessions, though it provides some hooks to make sessions work like
> PHPlib sessions, so you should have few problems porting an application
> over from one to another. Also, if you have customized your local.inc or
> prepend.php3, make sure you port those customizations over to local4.inc
> and prepend.php. Be aware, however, that you will lose any existing
> session data. (User data, if you use it, should be unaffected; it will
> still use the active_sessions table for that.)

Thanks for that! I should say that my phplib version is not the latest
one (found 2001/01/19 in the files that were obviously not changed). 
These changes won't be easy because the programming practices were not
always the best ones.
> 
> I'd point you to the relevant documentation, but the website appears to
> be down at the moment.
> 
> --
> ___________________________
> Nathaniel Price
> http://www.tesserportal.net
> Webmaster
> 
>

Re: [Phplib-users] Sessions in text files

[Layne W. <la...@dr...>]

Hristo Odiseev wrote:

> My last experience was that the last time I did a repair I got a 11MB
> table (before repair - 233MB). As you see that is really a problem.
> And if I don't do anything the table grows to 2Gb which is really an
> overkill for mysql. But that was just some background info.

That sounds like a serious problem. If you haven't spent money on
professional MySQL support yet, you probably should try to find some budget
funds to do so.

> Why do you think that the I/O will become a problem? Could you give
> me some reasoning? I guess that the size of the sessions will not be
> so big as it is in the DB. At current its extreme size is mostly due
> to the corrupted data.

The last time (February or March of this year) that I looked into switching
to session4.inc, I started reading the PHP manual comments on PHP 4 native
sessions. Several people mentioned that they sped up their busy sites and
reduced server disk I/O by using a database handler for PHP 4 sessions
instead of the default file handler. After reading that, I abandoned
implementing PHP 4 native sessions and kept using classic PHPLib sessions.

I took a chance and trusted the manual comments so I don't have any persona=
l
experience to back up the assertion.

--=20

Layne Weathers