ID: 31332
Comment by: dondop at gmail dot com
Reported By: marekm at apnet dot pl
Status: Verified
Bug Type: Performance problem
Operating System: *
PHP Version: 4CVS, 5CVS (2005-01-04)
New Comment:
It has been quite some time now and this is really an important bug to
fix.
I understand that open source means that development is done when
someone feels like it, but as this is crumbling big shared hosting
solutions where sites run on this PHP which use unserialize() I really
a fix is developed soon.
Comon devs, wake up and smell some coffee :)
Previous Comments:
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[2005-01-14 14:40:52] john at jelsoft dot com
I would agree with what Gik just said.
To quote from the PHP manual:
"serialize -- Generates a storable representation of a value"
Or later:
"serialize() returns a string containing a byte-stream representation
of value that can be stored anywhere.
This is useful for storing or passing PHP values around without losing
their type and structure."
I tried some comparisons a while back on different ways to store PHP
array data in a DB. I tried storing it in a form where I could run
eval($data) and it turned out to be a lot slower than
unserialize($data). (Perhaps this would be different given this bug).
serialize() seems to be ideal for this situation where large array or
object data is to be stored in a DB or shm.
So I was surprised that the usages outlined above are 'abuses', as they
seem to be using serialize() for exactly what it was intended for.
Perhaps the manual needs clarifying if this isn't the case?
------------------------------------------------------------------------
[2005-01-14 13:52:06] gik at zap dot cl
As far as I know, objects stored in shared memory using shm_put_var()
are stored serialized. I haven't looked at the sources yet, but the
problem affecting unserialize() should also degrade the performance of
shm_put_var() which is vastly used to store arrays or other objects in
shared memory for _quick_ access. I don't know if there are other
functions which use this method internally.
I wouldn't call it an abuse to serialize and store an array with 1000
elements in shm, as this is a very efficient way to do data caching.
The performance degradation is large enough to make a web server
collapse, because of the extra time required to process each request.
------------------------------------------------------------------------
[2005-01-14 09:05:51] [EMAIL PROTECTED]
Sorry to say... but abusing serialize for this is not a good idea in
the first place. It's not meant for storing data in this way in the
first place. But of course the slowdown shouldn't have been this much.
------------------------------------------------------------------------
[2005-01-13 21:11:06] gik at zap dot cl
The excessively high load average of a server recently updated to php
4.3.10 was driving me nuts. This bug is critical for many php based
systems as drupal, vBulletin and others.
Gik.
------------------------------------------------------------------------
[2005-01-10 13:43:52] kier at vbulletin dot com
I can confirm this problem from my experience with 4.3.10 and 5.0.3.
Unserialize() under the latest versions appears to be massively slower
than was previously so.
We have had wide reports of vBulletin installations running
significantly slower since we recommended that customers upgrade to
4.3.10 / 5.0.3.
Hoping for a quick resolution to this problem, as it affects so many
people so drastically.
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the rest of the comments, please view the bug report online at
http://bugs.php.net/31332
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