Linux Format forums

Bazza · Posted: Wed Nov 21, 2012 6:14 pm Post subject: Just had a thought...

Does deleting all the spammers from the database cause memory leaks and/or memory fragmentation and would this be a method of attempting to cause a system crash?

Just a thought...
_________________
73...

Bazza, G0LCU...

Team AMIGA...

bobthebob1234 · Posted: Wed Nov 21, 2012 6:59 pm Post subject:

Why would deleting things cause cause memory leaks and/or memory fragmentation?? Shocked

PHPBB usually runs on PHP&MySQL, last time I checked deleting things from MySQL doesn't cause memory leaks...

Updating and deleting lots can cause a little overhead on the MySQL tables, but that is very quick and easy to get rid of...
_________________
For certain you have to be lost to find the places that can't be found. Elseways, everyone would know where it was

nelz · Posted: Wed Nov 21, 2012 7:21 pm Post subject:

Also, this is a very small number of transactions, each one has to be done manually.
_________________
"Insanity: doing the same thing over and over again and expecting different results." (Albert Einstein)

Bazza · Posted: Fri Nov 23, 2012 6:47 pm Post subject:

Is the database not stored in RAM then for sheer speed?

It was only a passing thought, I am not a database man
but a HW oriented man instead.
_________________
73...

Bazza, G0LCU...

Team AMIGA...

guy · Posted: Fri Nov 23, 2012 8:14 pm Post subject:

It may all be loaded into RAM if it is small enough and there is enough RAM. But even so, every change (commit) must be saved to a non-volatile medium such as a hard disc, so that the system can recover it following an outage.

But you are right that deleting direct from the database can cause a crash. When say a user account is deleted directly, any post by that user will still link back to the account. and if someone views the post & clicks through, the software will probably assume that the account is still there to be linked to. If it isn't, expect the unexpected, such as a crash. Safer to delete posts & other fingerprints first, then the account. GUI tool designers tend to think of these sorts of things, so mandraulic GUIs tend to be more robust than direct database queries (e.g. allowing admins to lock the account but leaving out a "delete" button). And usually mandraulics is the only way to drive the GUI.
_________________
Cheers,
Guy
The eternal help vampire

Bazza · Posted: Fri Nov 23, 2012 9:50 pm Post subject:

Thanks Guy...

I am purely a hobbyist computer user and......

The only reason why I asked the question in the first place was
because of the recent attack of spammers. As I wrote earlier I
am no expert on database related stuff but I can see events
that might occur on large sized database files loaded into
memory.

By adding new spammers, then, them being deleted just
increases memory load which eventually overruns into a disk
based swapfile and/or causes system lock up or crash due to
out of memory error. Much akin to a buffer overrun, but on
a much larger scale...

Thanks a lot, you answered my question admirably.

CYA...
_________________
73...

Bazza, G0LCU...

Team AMIGA...

nelz · Posted: Fri Nov 23, 2012 11:11 pm Post subject:

1slipperyfish · Posted: Sat Nov 24, 2012 5:30 pm Post subject:

nelz · Posted: Sat Nov 24, 2012 9:23 pm Post subject:

1slipperyfish · Posted: Sun Nov 25, 2012 12:51 pm Post subject:

heiowge · Posted: Sun Nov 25, 2012 2:17 pm Post subject:

1slipperyfish · Posted: Mon Nov 26, 2012 5:12 pm Post subject:

Dutch_Master · LXF regular Joined: Tue Mar 27, 2007 2:49 am Posts: 2359

Gee, I wonder why.... Rolling Eyes

It was so nice and quiet here with you absent fishy one, what have we done wrong to get you back? Or rather: what went wrong elsewhere that made you come back, gotten your ar*e kicked around in that place? Twisted Evil

Rhakios · Posted: Mon Nov 26, 2012 7:34 pm Post subject:

1slipperyfish · Posted: Mon Nov 26, 2012 7:46 pm Post subject:

yo dm always a pleasure Razz

i haven't been anywhere else but here Confused

where i belong Very Happy