apache 2 reloads needed?

[Tomáš Bažant]

Greetings from cloudy Prague!


I am developing web application with mod_perl/apache/mysql. I am using
several own perl modules (*.pm), and after changing the contents of a
particular module, i usually have to reload/restart apache for these
changes to take effect. it is quite annoying. Is there any way how to
bypass this process and make apache aware of the changes automatically?

thanks


--
Tomáš Bažant <tbazant@...>
Novell, SUSE Linux s.r.o.

[Jie Gao]

* Tom??? Ba??ant <tbazant@...> wrote:

> Greetings from cloudy Prague!
>
>
> I am developing web application with mod_perl/apache/mysql. I am using
> several own perl modules (*.pm), and after changing the contents of a
> particular module, i usually have to reload/restart apache for these
> changes to take effect. it is quite annoying. Is there any way how to
> bypass this process and make apache aware of the changes automatically?
 
Install Apache::Reload from CPAN.

Regards,



Jie

[awarnier]

Jie Gao wrote:

> * Tom??? Ba??ant <tbazant@...> wrote:
>
>> Greetings from cloudy Prague!
>>
>>
>> I am developing web application with mod_perl/apache/mysql. I am using
>> several own perl modules (*.pm), and after changing the contents of a
>> particular module, i usually have to reload/restart apache for these
>> changes to take effect. it is quite annoying. Is there any way how to
>> bypass this process and make apache aware of the changes automatically?
>  
> Install Apache::Reload from CPAN.
>

Greetings from sunny (right now anyway) Southern Germany.

I see that you mention mysql.  This probably means DBI.
I think you need to be a bit careful with DBI and Apache::Reload.  I
seem to recall that there are some particularities there
(Probably in relation to permanent cached database connections).

In any case, I believe Apache::Reload is OK for a development server,
but on a production server this is probably not very efficient.
There is no free lunch : if you ask the server to monitor certain things
and do something in case of change, then that has a cost.

[Michiel Beijen-5]

On Tue, 2009-11-03 at 10:27 +0100, André Warnier wrote:

Greetings from sunny (right now anyway) Southern Germany.

Greetings from the cloudy Netherlands... BTW my colleagues from Straubing (Bavaria, Germany) were complaining that it's raining cats and dogs today there.

I see that you mention mysql.  This probably means DBI.
I think you need to be a bit careful with DBI and Apache::Reload.  I 
seem to recall that there are some particularities there
(Probably in relation to permanent cached database connections).

The project I work on uses mod_perl, Apache::Reload, and Apache::DBI. AFAIK Apache::Reload does not influence the database connection at all, it just would monitor the modules on disk and if they change, they are reloaded in memory. We use Apache::DBI to cache the database connection, which basically means that the Apache child does not need to set up a new connection any time it tries to open one. This has a performance benefit.

In any case, I believe Apache::Reload is OK for a development server, 
but on a production server this is probably not very efficient.
There is no free lunch : if you ask the server to monitor certain things 
and do something in case of change, then that has a cost.

We use it (and even recommend it) on a production server! We have measured a performance degradation of about 7% when running with Apache::Reload. In most setups, this would not be an issue and it is better than having to restart apache.... but of course in a high-load environment it will be something to consider.
--
Michiel

[Jonathan Vanasco-3]

On Nov 3, 2009, at 4:27 AM, André Warnier wrote:

I see that you mention mysql.  This probably means DBI.
I think you need to be a bit careful with DBI and Apache::Reload.  I seem to recall that there are some particularities there
(Probably in relation to permanent cached database connections).

In any case, I believe Apache::Reload is OK for a development server, but on a production server this is probably not very efficient.
There is no free lunch : if you ask the server to monitor certain things and do something in case of change, then that has a cost.

re: databases-- you should be fine as long as you use Apache::DBI.  if you're not, then I don't recall.  

Apache::Reload and Apache::DBI for mod_perl handler applications work perfect during development.  I've never made a registry app, so can't comment on that.

Apache::Reload shouldn't be used on production; however its indispensable during development.