[asterisk-bugs] [Asterisk 0017564]: Asterisk "locks up" the system when an external process is called from the 'h' extension with a lower priority than Asterisk.

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=17564 
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Reported By:                ramonpeek
Assigned To:                
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Project:                    Asterisk
Issue ID:                   17564
Category:                   Resources/General
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     feedback
Asterisk Version:           1.4.33 
JIRA:                        
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2010-06-29 05:47 CDT
Last Modified:              2010-06-30 03:03 CDT
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Summary:                    Asterisk "locks up" the system when an external
process is called from the 'h' extension with a lower priority than Asterisk.
Description: 
We noticed that Asterisk "locks up" the system when an external process is
called from the 'h' extension with a lower priority than Asterisk.
This issue is a follow up on issue:
https://issues.asterisk.org/view.php?id=16349

See Additional Information Field for more info....
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 (0124071) ramonpeek (reporter) - 2010-06-30 03:03
 https://issues.asterisk.org/view.php?id=17564#c124071 
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@tilghman: 
In the tests used for these traces I'm using the res_odbc resource to
write or read data from my PostgreSQL database. In my dialplan I execute
many SQL queries with no problems, but when executing them from the 'h'
extension the execution is very slow or even "locks up" the system.
Please note that this behavior was introduced somewhere in Asterisk 1.4.22
and that the DONT_OPTIMIZE option reduces the problem tremendously. 

In other tests I've also tried calling other external processes using the
System() command, which showed exactly the same behavior. Which is why I
don't think this problem is related to the ODBC driver. 

PS: Hardware should also not be the problem, since we run similar images
of this system on multiple systems at our customers with 4 different types
of hardware; single core processors and dual core, they all show the same
problem.

@davidw: 
The "ht" option in cpuinfo indeed stands for the capability of the
processor to support HyperThreading, however hyperthreading support had
been turned of in the kernel and BIOS of this system. So there is only 1
CPU available in this test-system. Please note that other systems running
similar setups and multiple cores show the same behavior. 

Issue History 
Date Modified    Username       Field                    Change               
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2010-06-30 03:03 ramonpeek      Note Added: 0124071                          
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