Re: [Zope] Counting threads

2008-01-23 Thread Peter Bengtsson




GDB can help you determine where the hanging condition originates. 
Here's some links:


http://plone.org/documentation/how-to/use-gdb-to-get-backtraces-of-hung-spinning-sites 



http://zopelabs.com/cookbook/1073504990

This is great! I haven't used it yet but it definitely appears to me the 
right tool for me.



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Peter Bengtsson,
work www.fry-it.com
home www.peterbe.com
hobby www.issuetrackerproduct.com
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Re: [Zope] Counting threads

2008-01-23 Thread Dieter Maurer
Peter Bengtsson wrote at 2008-1-22 22:33 +:
 ...
By dying I don't mean crashing and stopping but instead staying up and
running but not responding to anything. Like a coma.

Use the DeadlockDebugger to find out what your Zope is doing.



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Dieter
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[Zope] Counting threads

2008-01-22 Thread Peter Bengtsson
Perhaps I'm wrong but I suspect that a Zope I'm running is dying because 
of running out of threads. They probably die when being designated to 
open an external relational database connection or something dodgy.


What are my options for monitoring and debugging what zope's threads are 
doing?
Is there a simple tool to just get a simple readout of how many threads 
are busy?


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Peter Bengtsson,
work www.fry-it.com
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hobby www.issuetrackerproduct.com
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Re: [Zope] Counting threads

2008-01-22 Thread Jens Vagelpohl


On Jan 22, 2008, at 16:23 , Peter Bengtsson wrote:

Perhaps I'm wrong but I suspect that a Zope I'm running is dying  
because of running out of threads. They probably die when being  
designated to open an external relational database connection or  
something dodgy.


What are my options for monitoring and debugging what zope's threads  
are doing?
Is there a simple tool to just get a simple readout of how many  
threads are busy?


One simple option is the ZMI Control_Panel Debug screen. Go to / 
Control_Panel/DebugInfo/manage_main on your instance and scroll to the  
bottom. It shows current connections to the Zope server from the  
outside, and how long the connection has been around. You will always  
at least see one entry, which is the request to fetch that debug  
screen. If you have connections beyond a few seconds of age they may  
be stuck.


jens


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Re: [Zope] Counting threads

2008-01-22 Thread Dieter Maurer
Peter Bengtsson wrote at 2008-1-22 15:23 +:
Perhaps I'm wrong but I suspect that a Zope I'm running is dying because 
of running out of threads.

This is very unlikely. It may no longer respond when all its threads
are working -- but it will not die for this reason.

Zope uses a worker thread pool (of size 4, by default),
allocated quite early.
It does not create further threads. It is therefore very unlikely
that it hits a thread limit.


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Dieter
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Re: [Zope] Counting threads

2008-01-22 Thread Peter Bengtsson
On 22/01/2008, Dieter Maurer [EMAIL PROTECTED] wrote:
 Peter Bengtsson wrote at 2008-1-22 15:23 +:
 Perhaps I'm wrong but I suspect that a Zope I'm running is dying because
 of running out of threads.

 This is very unlikely. It may no longer respond when all its threads
 are working -- but it will not die for this reason.

By dying I don't mean crashing and stopping but instead staying up and
running but not responding to anything. Like a coma.

 Zope uses a worker thread pool (of size 4, by default),
 allocated quite early.
 It does not create further threads. It is therefore very unlikely
 that it hits a thread limit.

I'm just not certain if it's this. It seems highly related to MS SQL
connections but I could be wrong. The strange thing is, restarting the
MS SQL server might be (we're not certain) a solution to get Zope
responding again.

My theory was that the threads get too attached to a network service
that doesn't time out or raise an error.

Sadly I can't reproduce it but the next time it happens I'll look at
both DeadlockDebugger and the Control_Panel Debug info if there are
any clues there.


-- 
Peter Bengtsson,
work www.fry-it.com
home www.peterbe.com
hobby www.issuetrackerproduct.com
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Re: [Zope] Counting threads

2008-01-22 Thread Jens Vagelpohl


On Jan 22, 2008, at 23:33 , Peter Bengtsson wrote:


On 22/01/2008, Dieter Maurer [EMAIL PROTECTED] wrote:

Peter Bengtsson wrote at 2008-1-22 15:23 +:
Perhaps I'm wrong but I suspect that a Zope I'm running is dying  
because

of running out of threads.


This is very unlikely. It may no longer respond when all its threads
are working -- but it will not die for this reason.


By dying I don't mean crashing and stopping but instead staying up and
running but not responding to anything. Like a coma.


This symptom, especially when these hanging threads cause no load at  
all on the system, certainly point to connections to outside systems  
that do not respond for some reason. I have seen this issue with Zope  
instances that make HTTP calls to other systems, or even with a  
hanging LDAP server which accepted connections from Zope but never  
returned. Any software that makes outgoing network connections from  
Zope is a potential suspect.


GDB can help you determine where the hanging condition originates.  
Here's some links:


http://plone.org/documentation/how-to/use-gdb-to-get-backtraces-of-hung-spinning-sites

http://zopelabs.com/cookbook/1073504990

jens

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Re: [Zope] Counting threads

2008-01-22 Thread Jonathan


- Original Message - 
From: Peter Bengtsson [EMAIL PROTECTED]

To: Dieter Maurer [EMAIL PROTECTED]
Cc: zope user list zope@zope.org
Sent: Tuesday, January 22, 2008 5:33 PM
Subject: Re: [Zope] Counting threads



On 22/01/2008, Dieter Maurer [EMAIL PROTECTED] wrote:

Peter Bengtsson wrote at 2008-1-22 15:23 +:
Perhaps I'm wrong but I suspect that a Zope I'm running is dying because
of running out of threads.

This is very unlikely. It may no longer respond when all its threads
are working -- but it will not die for this reason.


By dying I don't mean crashing and stopping but instead staying up and
running but not responding to anything. Like a coma.

Sadly I can't reproduce it but the next time it happens I'll look at
both DeadlockDebugger and the Control_Panel Debug info if there are
any clues there.


You could also try this: http://www.zopelabs.com/cookbook/1073504990


Jonathan 


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Re: [Zope] Counting threads

2008-01-22 Thread Jaroslav Lukesh


- Original Message - 
From: Peter Bengtsson [EMAIL PROTECTED]




On 22/01/2008, Dieter Maurer [EMAIL PROTECTED] wrote:

Peter Bengtsson wrote at 2008-1-22 15:23 +:
Perhaps I'm wrong but I suspect that a Zope I'm running is dying because
of running out of threads.




I'm just not certain if it's this. It seems highly related to MS SQL
connections but I could be wrong. The strange thing is, restarting the
MS SQL server might be (we're not certain) a solution to get Zope
responding again.

My theory was that the threads get too attached to a network service
that doesn't time out or raise an error.


You have absolutelly true!

I was the same problems in past. I was make up to 150 threads in some rare 
cases, but 50..100 in general if I use MSSQL. It was with Zope 2.5.1, with 
modern zope, see attachment about pool_size.


Now I use 80 threads and 60 pool_size and my Zope+MSSQL is fine. MSSQL hits 
in day peaks 100% CPU load (about hour, two) , but it is not my business. 
But my business is functional zope webs which eats a lot of RAM due caching 
policy - about 5..10 times more than before... So you have been pointed and 
warned ;-)


Best Regards, JL.


pool_size.txt 
Description: Binary data
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