Re: Apache keeping open deleted files

[Marat Khalili <mkh@xxxxxx>]

Well, apparently they are used as locks (mutexes) so that multiple Apache processes could safely access common resources. You can guess specific resources by file names. (Disclaimer: I'm not an Apache developer, probably one of them reading this will give better answer.)

The process shouldn't need to end for the file to disappear - just the file descriptor to be closed.

Yes, that's correct. What I wanted to say (but didn't) is such files disappear by themselves even if process that uses them ends abnormally and doesn't have chance to execute clean up.

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With Best Regards,
Marat Khalili

On 18/04/16 12:49, David Cunningham wrote:

Hi Marat,

Thanks for the reply. Do you know why Apache keeps them open? The process shouldn't need to end for the file to disappear - just the file descriptor to be closed.

On 18 April 2016 at 16:54, Marat Khalili <mkh@xxxxxx> wrote:

Hello David,

It is a normal practice in Linux to delete temporary files immediately after creating them. These files will still work for the process that keeps them open, and will automatically disappear as soon as the process ends.

I typed lsof /run/lock on a couple of my Ubuntu machines with Apache installed, and the output was similar to yours.

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With Best Regards,
Marat Khalili

On 18/04/16 08:25, David Cunningham wrote:

Hi,

While reviewing filesystem usage we noticed lots of deleted files still open by Apache, as reported by lsof. Some example lines are below.

Can anyone advise why Apache is keeping these files open, and if there's anything we can do about it? I have verified that the process numbers listed are still existing processes.

The server is running Apache 2.4.7-1ubuntu4.8 on Ubuntu 14.04 server, 64bit. Thank you in advance.

/usr/sbin 13262             root   23w      REG               0,19           0  110619773 /run/lock/apache2/rewrite-map.13262 (deleted)
/usr/sbin 13262             root   24w      REG               0,19           0  105844737 /run/lock/apache2/ssl-cache.13261 (deleted)
/usr/sbin 22669         apacheuser   23w      REG               0,19           0  110619773 /run/lock/apache2/rewrite-map.13262 (deleted)
/usr/sbin 22669         apacheuser   24w      REG               0,19           0  105844737 /run/lock/apache2/ssl-cache.13261 (deleted)
/usr/sbin 22669 22671   apacheuser   23w      REG               0,19           0  110619773 /run/lock/apache2/rewrite-map.13262 (deleted)
/usr/sbin 22669 22671   apacheuser   24w      REG               0,19           0  105844737 /run/lock/apache2/ssl-cache.13261 (deleted)
/usr/sbin 22669 22672   apacheuser   23w      REG               0,19           0  110619773 /run/lock/apache2/rewrite-map.13262 (deleted)
/usr/sbin 22669 22672   apacheuser   24w      REG               0,19           0  105844737 /run/lock/apache2/ssl-cache.13261 (deleted)
/usr/sbin 22669 22673   apacheuser   23w      REG               0,19           0  110619773 /run/lock/apache2/rewrite-map.13262 (deleted)
/usr/sbin 22669 22673   apacheuser   24w      REG               0,19           0  105844737 /run/lock/apache2/ssl-cache.13261 (deleted)
/usr/sbin 22669 22674   apacheuser   23w      REG               0,19           0  110619773 /run/lock/apache2/rewrite-map.13262 (deleted)
/usr/sbin 22669 22674   apacheuser   24w      REG               0,19           0  105844737 /run/lock/apache2/ssl-cache.13261 (deleted)


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David Cunningham, Voisonics
http://voisonics.com/
USA: +1 213 221 1092
UK: +44 (0) 20 3298 1642
Australia: +61 (0) 2 8063 9019

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David Cunningham, Voisonics
http://voisonics.com/
USA: +1 213 221 1092
UK: +44 (0) 20 3298 1642
Australia: +61 (0) 2 8063 9019