Re: balancer-manager docs

[Luca Toscano]

I like the how-to a lot!

Would it be useful to add a "logging" section explaining best practices
about how to enable logging of the various modules?
A lot of people ask for instruction about how to track what mod_proxy does
in the background, plus I think it would be really useful to have a history
of the status of each BalancerMember over time (for example to correlate
when a backend server was put out of the Balancer set due to health check
failures with access/error/etc.. logs after an outage - a balancer-manager
history written down somewhere).

Hope that this make sense!

Luca

2016-02-12 10:04 GMT+01:00 Daniel :

> Looks very nice indeed! For being a "rough" version looks quite complete.
> Also the diagram is a cool addition to help people understand how reverse
> proxying works.
>
> I think the examples may need some adjusting with the matching slashes:
>
> ProxyPass "/" "http://www.example.com;
> should be:
> ProxyPass / http://www.example.com/
> (I removed the quotes because they are not necessary)
>
> and
> ProxyPass "/images" "http://www.example.com;
> should be:
> ProxyPass /images/ http://www.example.com/
>
>
> Cheers!
>
>
>
>
> El vie., 12 feb. 2016 a las 9:48, Stefan Eissing (<
> stefan.eiss...@greenbytes.de>) escribió:
>
>> Very nice!
>>
>> > Am 11.02.2016 um 18:46 schrieb Jim Jagielski :
>> >
>> > A rough and very brief framework of such a guide is now available...
>> >
>> >http://httpd.apache.org/docs/trunk/howto/reverse_proxy.html
>> >
>> > On 2016-02-10 06:21, Luca Toscano  wrote:
>> >> 2016-02-10 10:33 GMT+01:00 Stefan Eissing <
>> stefan.eiss...@greenbytes.de>:
>> >>
>> >>> If you write one, I write one for http2! :-)
>> >>>
>> >>>
>> >> +1+1+1+1 :)
>> >>
>> > --
>> > Sent via Pony Mail for dev@httpd.apache.org.
>> > View this email online at:
>> > https://pony-poc.apache.org/list.html?dev@httpd.apache.org
>>
>>

Re: balancer-manager docs

[Stefan Eissing]

Very nice!

> Am 11.02.2016 um 18:46 schrieb Jim Jagielski :
> 
> A rough and very brief framework of such a guide is now available...
> 
>http://httpd.apache.org/docs/trunk/howto/reverse_proxy.html
> 
> On 2016-02-10 06:21, Luca Toscano  wrote: 
>> 2016-02-10 10:33 GMT+01:00 Stefan Eissing :
>> 
>>> If you write one, I write one for http2! :-)
>>> 
>>> 
>> +1+1+1+1 :)
>> 
> --
> Sent via Pony Mail for dev@httpd.apache.org. 
> View this email online at:
> https://pony-poc.apache.org/list.html?dev@httpd.apache.org

Re: balancer-manager docs

[Daniel]

Looks very nice indeed! For being a "rough" version looks quite complete.
Also the diagram is a cool addition to help people understand how reverse
proxying works.

I think the examples may need some adjusting with the matching slashes:

ProxyPass "/" "http://www.example.com;
should be:
ProxyPass / http://www.example.com/
(I removed the quotes because they are not necessary)

and
ProxyPass "/images" "http://www.example.com;
should be:
ProxyPass /images/ http://www.example.com/


Cheers!



El vie., 12 feb. 2016 a las 9:48, Stefan Eissing (<
stefan.eiss...@greenbytes.de>) escribió:

> Very nice!
>
> > Am 11.02.2016 um 18:46 schrieb Jim Jagielski :
> >
> > A rough and very brief framework of such a guide is now available...
> >
> >http://httpd.apache.org/docs/trunk/howto/reverse_proxy.html
> >
> > On 2016-02-10 06:21, Luca Toscano  wrote:
> >> 2016-02-10 10:33 GMT+01:00 Stefan Eissing  >:
> >>
> >>> If you write one, I write one for http2! :-)
> >>>
> >>>
> >> +1+1+1+1 :)
> >>
> > --
> > Sent via Pony Mail for dev@httpd.apache.org.
> > View this email online at:
> > https://pony-poc.apache.org/list.html?dev@httpd.apache.org
>
>

Re: balancer-manager docs

[Jim Jagielski]

A rough and very brief framework of such a guide is now available...

http://httpd.apache.org/docs/trunk/howto/reverse_proxy.html

On 2016-02-10 06:21, Luca Toscano  wrote: 
> 2016-02-10 10:33 GMT+01:00 Stefan Eissing :
> 
> > If you write one, I write one for http2! :-)
> >
> >
> +1+1+1+1 :)
> 
--
Sent via Pony Mail for dev@httpd.apache.org. 
View this email online at:
https://pony-poc.apache.org/list.html?dev@httpd.apache.org

Re: balancer-manager docs

[Jim Jagielski]

Work in progress in:

docs/manual/howto/reverse_proxy.xml

cheers!

Re: balancer-manager docs

[Daniel]

Sorry for the intrusion.

Since you guys are on it, a brief description telling that mod_slotmem_XXX
is REQUIRED if you choose to load any type of mod_lbmethod would also be a
good tip to add in the docs.

Cheers!

El mié., 10 feb. 2016 a las 22:08, Jim Jagielski ()
escribió:

> Work in progress in:
>
> docs/manual/howto/reverse_proxy.xml
>
> cheers!
>

Re: balancer-manager docs

[Stefan Eissing]

If you write one, I write one for http2! :-)

> Am 09.02.2016 um 21:36 schrieb Luca Toscano :
> 
> Hi Jim,
> 
> 2016-02-09 21:25 GMT+01:00 Jim Jagielski :
> The more I think of it, a HowTo guide, like the ones we have
> for public_html, Authn, etc regarding reverse proxy
> makes the most sense...
> 
> > On Feb 9, 2016, at 12:55 PM, Tim Bannister  wrote:
> >
> > On 9 Feb 2016, at 16:02, Rainer Jung  wrote:
> > The module pages can document the module; I think that's appropriate for 
> > reference documentation.
> >
> > What's missing is more of a “how do I set up X” guide. I think the topics 
> > could be:
> >
> > • forward proxy (and access control) with or without cacheing
> > • reverse proxy with or without cacheing
> > • balancing and high availability for reverse proxies
> >
> > I think this is me volunteering to at least draft some text, if people 
> > agree this approach makes sense.
> 
> +1 for the howto guides suggested by Tim and separate pages for each module 
> for whoever is interested to dive deep into options.
> 
> Ideally the howto summary page (https://httpd.apache.org/docs/trunk/howto/) 
> could be linked to https://httpd.apache.org/download.cgi as "suggested list" 
> of things to bookmark for whoever is interested in httpd.
> 
> Also I volunteer for helping writing/reviewing the new docs if needed :)
> 
> Luca 
> 
> 
> 
> 

Re: balancer-manager docs

[Luca Toscano]

2016-02-10 10:33 GMT+01:00 Stefan Eissing :

> If you write one, I write one for http2! :-)
>
>
+1+1+1+1 :)

Re: balancer-manager docs

[Luca Toscano]

Hi Jim,

2016-02-09 21:25 GMT+01:00 Jim Jagielski :

> The more I think of it, a HowTo guide, like the ones we have
> for public_html, Authn, etc regarding reverse proxy
> makes the most sense...
>
> > On Feb 9, 2016, at 12:55 PM, Tim Bannister 
> wrote:
> >
> > On 9 Feb 2016, at 16:02, Rainer Jung  wrote:
> > The module pages can document the module; I think that's appropriate for
> reference documentation.
> >
> > What's missing is more of a “how do I set up X” guide. I think the
> topics could be:
> >
> > • forward proxy (and access control) with or without cacheing
> > • reverse proxy with or without cacheing
> > • balancing and high availability for reverse proxies
> >
> > I think this is me volunteering to at least draft some text, if people
> agree this approach makes sense.
>

+1 for the howto guides suggested by Tim and separate pages for each module
for whoever is interested to dive deep into options.

Ideally the howto summary page (https://httpd.apache.org/docs/trunk/howto/)
could be linked to https://httpd.apache.org/download.cgi as "suggested
list" of things to bookmark for whoever is interested in httpd.

Also I volunteer for helping writing/reviewing the new docs if needed :)

Luca

Re: balancer-manager docs

[Jim Jagielski]

The more I think of it, a HowTo guide, like the ones we have
for public_html, Authn, etc regarding reverse proxy
makes the most sense...

> On Feb 9, 2016, at 12:55 PM, Tim Bannister  wrote:
> 
> On 9 Feb 2016, at 16:02, Rainer Jung  wrote:
>> Am 09.02.2016 um 13:25 schrieb Jim Jagielski:
>>> We currently have really really little info about the balancer-manager in 
>>> our docs, just a short little blurb on how to enable it and a brief 
>>> description of what it does [1]. I'd like to extend that, but does it make 
>>> sense to add it to the mod_proxy_balancer module page, or have a separate 
>>> page dedicated to it which we can link to?
>>> 
>>> 1. https://httpd.apache.org/docs/trunk/mod/mod_proxy_balancer.html
>> 
>> Adding even more questions:
>> 
>> I always think it is confusing for newbies, that all configuration 
>> directives for any mod_proxy_* are documented on the mod_proxy page. 
>> Although this reflects the code, config is done by mod_proxy, it is not what 
>> a user would expect. If e.g. He is working with a balancer, he would expect 
>> more info about how to configure a balancer in the mod_proxy_balancer page.
> 
> Cc: to docs@
> 
> The module pages can document the module; I think that's appropriate for 
> reference documentation.
> 
> What's missing is more of a “how do I set up X” guide. I think the topics 
> could be:
> 
> • forward proxy (and access control) with or without cacheing
> • reverse proxy with or without cacheing
> • balancing and high availability for reverse proxies
> 
> I think this is me volunteering to at least draft some text, if people agree 
> this approach makes sense.
> 
> -- 
> Tim Bannister – is...@c8h10n4o2.org.uk
> 

Re: balancer-manager docs

[Rainer Jung]

Am 09.02.2016 um 13:25 schrieb Jim Jagielski:

We currently have really really little info about the balancer-
manager in our docs, just a short little blurb on how to enable
it and a brief description of what it does [1]. I'd like to extend
that, but does it make sense to add it to the mod_proxy_balancer
module page, or have a separate page dedicated to it which we can
link to?


1. https://httpd.apache.org/docs/trunk/mod/mod_proxy_balancer.html


Adding even more questions:

I always think it is confusing for newbies, that all configuration 
directives for any mod_proxy_* are documented on the mod_proxy page. 
Although this reflects the code, config is done by mod_proxy, it is not 
what a user would expect. If e.g. He is working with a balancer, he 
would expect more info about how to configure a balancer in the 
mod_proxy_balancer page.


So I wonder whether proxy is an example, where the config reference 
should move to the docs page, for the module that is actually being 
configured, not the module that handles the configuration. I guess 
that's not possible without some redundancy and it's not an easy call to 
decide, what should go to the central mod_proxy page, and what to 
individual mod_proxy_xyz pages.


There are other cases as well (ajp, fcgi, ...).

Regards,

Rainer

Re: balancer-manager docs

[Tim Bannister]

On 9 Feb 2016, at 16:02, Rainer Jung  wrote:
> Am 09.02.2016 um 13:25 schrieb Jim Jagielski:
>> We currently have really really little info about the balancer-manager in 
>> our docs, just a short little blurb on how to enable it and a brief 
>> description of what it does [1]. I'd like to extend that, but does it make 
>> sense to add it to the mod_proxy_balancer module page, or have a separate 
>> page dedicated to it which we can link to?
>> 
>> 1. https://httpd.apache.org/docs/trunk/mod/mod_proxy_balancer.html
> 
> Adding even more questions:
> 
> I always think it is confusing for newbies, that all configuration directives 
> for any mod_proxy_* are documented on the mod_proxy page. Although this 
> reflects the code, config is done by mod_proxy, it is not what a user would 
> expect. If e.g. He is working with a balancer, he would expect more info 
> about how to configure a balancer in the mod_proxy_balancer page.

Cc: to docs@

The module pages can document the module; I think that's appropriate for 
reference documentation.

What's missing is more of a “how do I set up X” guide. I think the topics could 
be:

• forward proxy (and access control) with or without cacheing
• reverse proxy with or without cacheing
• balancing and high availability for reverse proxies

I think this is me volunteering to at least draft some text, if people agree 
this approach makes sense.

-- 
Tim Bannister – is...@c8h10n4o2.org.uk

Re: Balancer manager

[Jim Jagielski]

Obviously, one would only be able to remove a stopped/disabled
worker.

 On Apr 29, 2015, at 4:34 PM, William A Rowe Jr wr...@rowe-clan.net wrote:
 
 On Fri, Apr 24, 2015 at 8:52 AM, Jim Jagielski j...@jagunet.com wrote:
 Right now, the balancer manager allows for a member to be
 disabled/stopped, but it cannot *remove* that member...
 Seems to me that that would be good, especially since
 we could always re-use that slot.
 
 That means you must fully implement locking against the backends table
 in any use context, determine that there are no workers using that specific
 backend, and then 'remove' it ('repurpose' it, really, since it's just another
 slot.)  If there are any requests in-flight for that member, this will result
 in potentially bad collisions of misinformation.
 
 We usually ignore these mis-attributions, but I'm not sure that's feasible
 given all of the lb logic involved?
 

Re: Balancer manager

[Daniel Ruggeri]

(oops - saw this sitting int he outbox for the past week - sorry for
slow reply)

These were the notes I took. I was going to start biting them off after
I wrapped up splitting/editing the recordings from the ACNA talks:
*Ensuring all stats showed up on the page (I don't recall if any stuck
out that were missing)
*Add ability to reset the stats captured
*Set or adjust min/max for the connection pooling
*Send what httpd thinks the worker status is (useful for backends that
would like to know about drain, etc) to the backend in a header

-- 
Daniel Ruggeri

On 4/27/2015 9:43 AM, Jim Jagielski wrote:
 Can you list 'em here? I'd like to help w/ adding them :)

 On Apr 25, 2015, at 12:28 PM, Daniel Ruggeri drugg...@primary.net wrote:

 +1

 There are also some neat-o features I added in my notes during ACNA to
 stick into the balancer manager, too... I plan to get around to them in
 vague, noncommittal reference to free time as it permits days.

 -- 
 Daniel Ruggeri

 On 4/24/2015 7:52 AM, Jim Jagielski wrote:
 Right now, the balancer manager allows for a member to be
 disabled/stopped, but it cannot *remove* that member...
 Seems to me that that would be good, especially since
 we could always re-use that slot.

 Comments?

Re: Balancer manager

[William A Rowe Jr]

On Fri, Apr 24, 2015 at 8:52 AM, Jim Jagielski j...@jagunet.com wrote:

 Right now, the balancer manager allows for a member to be
 disabled/stopped, but it cannot *remove* that member...
 Seems to me that that would be good, especially since
 we could always re-use that slot.


That means you must fully implement locking against the backends table
in any use context, determine that there are no workers using that specific
backend, and then 'remove' it ('repurpose' it, really, since it's just
another
slot.)  If there are any requests in-flight for that member, this will
result
in potentially bad collisions of misinformation.

We usually ignore these mis-attributions, but I'm not sure that's feasible
given all of the lb logic involved?

Re: Balancer manager

[Jim Jagielski]

Can you list 'em here? I'd like to help w/ adding them :)

 On Apr 25, 2015, at 12:28 PM, Daniel Ruggeri drugg...@primary.net wrote:
 
 +1
 
 There are also some neat-o features I added in my notes during ACNA to
 stick into the balancer manager, too... I plan to get around to them in
 vague, noncommittal reference to free time as it permits days.
 
 -- 
 Daniel Ruggeri
 
 On 4/24/2015 7:52 AM, Jim Jagielski wrote:
 Right now, the balancer manager allows for a member to be
 disabled/stopped, but it cannot *remove* that member...
 Seems to me that that would be good, especially since
 we could always re-use that slot.
 
 Comments?
 

Re: Balancer manager

[Daniel Ruggeri]

+1

There are also some neat-o features I added in my notes during ACNA to
stick into the balancer manager, too... I plan to get around to them in
vague, noncommittal reference to free time as it permits days.

-- 
Daniel Ruggeri

On 4/24/2015 7:52 AM, Jim Jagielski wrote:
 Right now, the balancer manager allows for a member to be
 disabled/stopped, but it cannot *remove* that member...
 Seems to me that that would be good, especially since
 we could always re-use that slot.

 Comments?

Re: balancer-manager and XML

[Jim Riggs]

On Nov 30, 2011, at 9:16 AM, Jim Jagielski wrote:

 The XML interface for the balancer manager has, admittedly, lagged
 behind...
 
 Anyone have cycles and/or talent to bring it up to snuff? If not,
 I'll try to muddle thru it ;)

As I mentioned to Jim at ApacheCon, I have a 2.2 patch for this that I have 
been using in production for a couple of years so that we can monitor our 
balancers. I am in the process of updating this patch for 2.4 right now. I plan 
to submit the updated patch for discussion/input today. I am just doing some 
final testing and debugging.

Re: balancer-manager and XML

[Jim Riggs]

On Nov 30, 2011, at 10:26 AM, Jim Riggs wrote:

 On Nov 30, 2011, at 9:16 AM, Jim Jagielski wrote:
 
 The XML interface for the balancer manager has, admittedly, lagged
 behind...
 
 Anyone have cycles and/or talent to bring it up to snuff? If not,
 I'll try to muddle thru it ;)
 
 As I mentioned to Jim at ApacheCon, I have a 2.2 patch for this that I have 
 been using in production for a couple of years so that we can monitor our 
 balancers. I am in the process of updating this patch for 2.4 right now. I 
 plan to submit the updated patch for discussion/input today. I am just doing 
 some final testing and debugging.

https://issues.apache.org/bugzilla/show_bug.cgi?id=52264

Re: balancer-manager and server-status feature request.

[Mladen Turk]

On 16/11/09 11:33, Mark Watts wrote:


The statistics one gets from both /balancer-manager and mod_status are
useful but of course only exist until httpd is restarted.

It would be nice if they could be configured to periodically write some
lines to the error log (at LogLevel info or so) with these statistics so
the data can be preserved.


This could be done using watchdog module that would fire some
balancer log module.
Regarding xml data, it is my long standing wish to create
log output filter sub module system where the log lines would
go trough a VFS filter capable of writing to xml, database, etc
(depending on the VFS implementation).


If you came up with such a module I'd be happy to review it :)

Regards
--
^TM

Re: balancer-manager and server-status feature request.

[Jim Jagielski]

On Nov 16, 2009, at 5:52 AM, Mladen Turk wrote:
 Regarding xml data, it is my long standing wish to create
 log output filter sub module system where the log lines would
 go trough a VFS filter capable of writing to xml, database, etc
 (depending on the VFS implementation).
 


*grin*

I'd been mulling over the same idea... a data-set filter that
can take data and output it as XML, HTML, etc... 

Re: Balancer-manager, nonce, and xml

[Ruediger Pluem]

On 08/12/2009 08:11 PM, Akins, Brian wrote:
 I found something in proxy and was wondering if it was intentional:
 
 In proxy_balancer, we check the nonce param and clear the params if
 incorrect or missing, however, then you can't view it in xml unless you
 include the nonce, because the xml param is no longer available.
 
 I was trying to get one of our monitoring tools to read the xml when I
 noticed it.
 
 I also am working on a simple thing to mark balancer members
 enable/disabled, but have to first scrap the HTML to get the value of nonce.
 This is rather a pain as well.
 
 Basically, I gave up on having a real HTTP health check mechanism within
 apache and was going to use the balancer manager stuff to enable/disable
 origins. 
 

The xml output did not receive the love recently it might have needed as it 
wasn't
seen as being used. I remember vaguely that there are other issues with the xml 
output
as well. Propose a patch to fix this and lets see where this ends :-).

Regards

Rüdiger

Re: Balancer manager: bug and feature request

[Jean-frederic Clere]

Andrew Stribblehill wrote:


That is, bug and feature request, not bug and feature request.

As I reported in
http://issues.apache.org/bugzilla/show_bug.cgi?id=39907
I'm finding that with the worker MPM and a pristine httpd 2.2.2 on an
i386 Debian platform, changes I make to the configuration within
balancer-manager will periodically reset -- and it's faster under
load.

I can see the code where the config is being set, but I don't quite
know whether this is process-local or not. If so, this would explain
the symptoms.
 


The problem is that the information you entered is ONLY process-local.


If someone could point me in the right direction, I'll have a bash at
fixing this bug.


The feature request: sometimes we need to take down an origin server
on a planned basis. The app is session-based so we can't just
disable it completely. Is there any reason I shouldn't be able to set
the load factor for an origin server to 0? At present it's
constrained to the range 1..100 inclusive. If I had some form of
session replication, I could use route-redirect and then just disable
it, but this is not possible for me.
 


That won't work anyway due to the problem you describe above ;-(


Thanks